JP3804974B2 - Autoclave bonding of sputtering target assemblies - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to techniques used in the manufacture of internally cooled sputtering target assemblies used in planar magnetron sputtering, and more particularly to manufacturing techniques that improve and guarantee the parallel relationship between the surface of the target material and the sputter deposited substrate. .
Background of the Invention
Sputtering includes, for example, various metal thin films such as aluminum, aluminum alloys, refractory metal silicides, gold, copper, titanium-tungsten, tungsten, molybdenum, tantalum, indium-tin oxide (ITO), and items (substrates). A number of physical techniques commonly used in the semiconductor industry for depositing silicon dioxide and silicon on top, as well as wafers or glass plates to be processed are shown. Generally, this technique uses an electric field in the exhaust chamber to create a gas plasma of ionized inert gas “particles” (atoms or molecules). The ionized particles are directed towards the “target” and collide with it. As a result of the collision, free atoms are released from the target surface as atomic sized projectiles, inevitably converting the target material into its gas phase. Many free atoms emerging from the target surface become solid (atomic size projectiles collide and stay on the surface of the substrate), and the surface of the object to be processed (eg, wafer, substrate) that is relatively close to the target A thin film is formed (deposited) thereon.
One common sputtering technique is magnetron sputtering. When processing a wafer using magnetron sputtering, a magnetic field is utilized to concentrate the sputtering operating area, resulting in sputtering occurring at a faster rate and at a lower process pressure. The target itself is electrically biased with respect to the wafer and chamber and functions as a cathode. The effect of the magnetic field on the ions is proportional to the distance from the front of the target. Optimally, the target assembly (target and backing plate) is thin so that the magnetic field has a significant effect.
Considerable energy is used in generating a gas plasma and creating an ion stream that impinges on the cathode. This energy must be dissipated so that the structure and contained components are not melted or close to melting. The technique used to cool the sputtering target assembly is to pass water or another cooling liquid through certain internal paths of the sputtering target assembly.
As an example, a simplified perspective view of a sputtering system designed for a large rectangular substrate, including a relatively thin sputtering target assembly having an internal cooling passage, is shown in FIG. (Details of the chamber and its operation can be found in US patent application Ser. No. 08 / 157,763 filed Nov. 24, 1993, filed Apr. 29, 1993, US Ser. No. 08 / 236,715 filed Apr. 29, 1994. These are incorporated herein by reference.) A processing / sputtering chamber 30 surrounds a dark ring 31 around a substrate 32 to be sputter deposited. The upper flange of the sputtering chamber 30 supports the lower part of the insulating ring that supports the sputtering target assembly 40. The target material of the sputtering target assembly faces the substrate 32 to be sputtered. The target assembly is negatively biased with respect to the substrate and performs sputtering. An inlet cooling line 36 and an outlet cooling line 37 are connected to the cooling passages of the sputtering target assembly 40 to cool the assembly during sputtering. The top of the sputtering target assembly 40 is surrounded by a top chamber 35 that is supported on the back of the sputtering target assembly by an upper insulating ring 34. As fully described in the aforementioned documents, the top chamber 35 can be arranged with a moveable magnetron within the exhaust top chamber. The top chamber can be evacuated so that its pressure approaches that of the process chamber. The force applied to the target assembly area by the pressure difference between the processing chamber and the top chamber is minimal and is easily suppressed by the thin sputtering target assembly.
The multilayer sputtering target assembly 40 shown in FIGS. 2 and 3 is typically assembled according to the above-mentioned patent application using a two-step process. In one step, the target material 48 is soldered to the backing plate 50. In another step, a finned (or grooved) cover plate 52 is bonded to the back of the backing plate 50 using a structural epoxy-based adhesive. The structural epoxy-based adhesive is cured by placing it in place, raising the temperature of the parts to bond, and simultaneously pressing to maintain intimate contact of the parts throughout the heating cycle. The order in which the two steps are performed depends on the melting temperature of the solder and the curing temperature of the structural epoxy. The higher temperature bonding process takes place first and the adhesion of the first formed bond is not adversely affected by the next process.
The materials used to create this process and structural epoxy bond generally form a good bond, but cooling fluid may leak due to incomplete bonding, and such sputtering target assemblies are unacceptable. Factors that adversely affect the bondability of structural epoxy bonding are 1) surface treatment of the parts to be joined, 2) epoxy selection and curing procedures, and 3) surface mechanical bonding prior to adhesive curing. Fitting or meshing.
Surface treatment eliminates mechanically weak or non-adhesive surface films on the metal. For example, the surface treatment simply consists of mechanically polishing the surfaces to be bonded, resulting in a “clean” metal surface. Or, to obtain excellent results, this procedure can be: a) degreasing, b) acid etching to remove visible oxide or scale, and c) removing all traces of acid. Rinse), d) carefully form a corrosion-resistant film of controlled chemical composition and thickness, make surface conditioning to promote primer adhesion, e) dry, f) surface from atmospheric oxygen and moisture In order to seal, a step of priming within 1 hour may be included.
The choice of epoxy includes the type of substrate, the strength of the adhesive, adhesion to the primed surface, curing temperature and pressure procedures, and the ability of the adhesive to flow to create a leak-free joint. It's based on various factors.
Surface treatment, epoxy selection, and curing procedures are:Due to the strictness of the structureThe element to be controlled. However, a good mechanical fit or engagement with the surfaces to be joined is also necessary to achieve a leak-free joint. Deformations and voids are used to join large areas of a) different metals and / or b) non-uniformly heated or cooled similar metals (eg, 643 mm x 550 mm target material dimensions). Guided by a two-step soldering process. This process involves soldering the two surfaces to be bonded togetherwetIncludes steps. The target material is then heated and a pool of solder is created at the soldering location. The backing plate is also slid into the solder pool to avoid trapping the solder oxide that normally heats and floats over the molten solder, and the weight and light pressure of the components are soldered to the pool solder The two materials are in intimate contact as a whole. The parts are kept in alignment with each other until the solder is cooled below its melting temperature and the two parts are bonded.
For example, when soldering indium-tin oxide (ITO) to a commercially pure titanium backing plate, while cooling from soldering temperature (eg, 156 ° C. for pure indium solder) to ambient temperature, Differences in heat shrinkage at the solder joints tend to bend the part. The edge of the target material is first cooled, forming a stronger bend than at the higher temperature in the center of the target. As a result, when the target material and backing plate continue to shrink at different rates, the strong connection between the outer edges of the target material buckles the center of the target material and 0.125 ”(3.175mm from the backing plate at the center of the target). In subsequent structural epoxy bonding steps (finned cover 52 is bonded to this highly distorted target / backing plate assembly), it is difficult to mechanically fit or engage the surfaces to be joined. Bad engagement results in an uneven bonding thickness that causes the cooling fluid to leak, and such a sputtering target assembly is unacceptable.
In addition, if such a sputtering target assembly is not flattened, the target material and the substrate to be sputtered are not parallel, thereby forming a non-uniform film on the substrate. The raised area at the center of the target material may generate voids on the back side of the raised area, and the target material may break. Such voids change the thermal conductivity between the target and the backing plate and the heat distribution across its surface. The distribution of the sputtered material and the sputtering rate of the target depend on the distance of the target material from the substrate and its temperature, respectively, the change in the gap (distance) between the target and the substrate, and the temperature change of the target material Varying the uniformity of the target material sputter deposited.
Since the purpose of the chamber to sputter a large area is a uniform film thickness over the entire area of the substrate to be sputter deposited as described above, the film thickness due to the variable characteristics of the target surface of the sputtering target assembly The change improves processing efficiency and is a major obstacle to sputter depositing a uniform thickness film across the surface.
Summary of the Invention
The method according to the invention eliminates deformations and imperfections introduced by the sputtering target assembly manufacturing technique described above.OvercomeProvide target properties that are generally uniform across the surface of the target. In particular, improved manufacturing techniques can be used when bonding layers of materials comprising a sputtering target assembly using solder and / or structural adhesives.Pressure assistedPerforming bonding; surrounding the cooling passage in the target backing plate by laser welding or electron beam welding one or more cover plates above the voids in the backing plate forming the cooling passage. Both technical changes are described.
These techniques according to the present invention reduce the number of steps in the manufacturing process andCoefficient of thermal expansionDue to differencesEven if the distortion cannot be removed, it can be reduced. These techniques virtually eliminate the possibility of cooling fluid leakage due to structural bonding failures based on cured adhesives.
In one method (technology), a sputtering target assembly (mainly consisting of a backing plate, a finned cover (plate), an insulating sheet and a target material layer) is machined and ground prior to assembly if necessary. , Overlaid, chemically cleaned, primed and polished. The final step of bonding the layers under pressure is performed in a gas bag (preferably in an oxygen-free environment) that does not leak gas in the autoclave. A pressurized autoclave applies a uniform force to the bag surface and maintains a leak-free contact of the layers through the thermal cycle of bond formation and / or curing. During the cooling cycle, the applied pressure causes the solder layer to plastically flow and prevent the assembly from distorting. Spacers located between the target material and the backing plate and interspersed with the solder layer control the thickness, uniformity, and bondability of the joint made by the solder layer.
In the bonding step, the solder can be used to bond the target to the backing plate with pressure (preferably given in the autoclave) and the structural plate can be used to bond the backing plate to the finned (grooved) cover plate. This is done in one step. An electrically insulating layer is bonded to the back of the target assembly using a structural adhesive during the same step. In order to perform this bonding step, the target assembly is partially double vacuum bagged to separate the solder bonding process from the structural bonding process. One (lower) vacuum bag configuration (system) is attached to the backing plate and surrounds only the target material that is solder bonded to the backing plate. A second (upper) vacuum bag configuration (system) generally surrounds the lower bag system, backing plate, finned cover and electrical insulation sheet and provides a gas communication path to the lower vacuum bag. A laminate of epoxy-based structural adhesive between the backing plate and the finned cover plate and between the finned cover plate and the electrically insulating sheet bonds these layers.
The vacuum bag is first evacuated and the autoclave pressure is increased to approximately 15 psi above atmospheric pressure. The vacuum bag is refilled to approximately 1 atm with inert or oxygen-absorbing gas without moisture, eliminating the risk that the vacuum system evacuating the bag will suddenly receive high pressure gas from the autoclave environment (bag failure event). The autoclave pressure is then increased to provide the desired pressure on the unbonded target assembly layer. The assembly is then heated and cooled according to a predetermined procedure.
This method change involves first bonding the target to the backing plate with solder, then enclosing the entire assembly in a vacuum bag system, curing the bonded parts with structural adhesive, while simultaneously removing the stress, and the target backing Flatten plate subassemblies.
Yet another modification of this method is that the target is first solder bonded in the autoclave and the cover holding the cooling fluid is attached by a fastener sealed with a gasket-type (preferably O-ring) seal.
A second method according to the present invention includes a void structure and closure that forms a cooling fluid passage in the backing plate and cover assembly. A backing plate receives a cover that includes a recess and is configured to fit into the recess. The cover and backing plate are laser welded around the edge between the recess and the cover and regularly spaced as a whole corresponding to the ends of the fins (or walls between the grooves) in the finned backing plate. Joined by spot or seam welding across the field of the cover in place. As a modification, it is also possible to use electron beam welding (low heat input is desirable to avoid material distortion due to welding). The target material is a)singleUse vacuum bag autoclave procedure to target,Solder bonded to welded backing plate, or b) First bond target to welded backing plate with solder, surround entire assembly with vacuum bag, relieve stress, flatten target assembly in autoclave By doing so, it can be bonded to the welded assembly with solder.
[Brief description of the drawings]
FIG. 1 is a simplified perspective view of a sputtering chamber system using a sputtering target assembly 40 manufactured in accordance with the present invention.
FIG. 2 is a plan view of the target side of the sputtering target assembly according to the present invention.
FIG. 3 is a cross-sectional side view of FIG. 2 taken along 3-3.
FIG. 4 is an exploded side cross-sectional view illustrating one embodiment of a layer of material included in assembling the single target assembly shown in FIG.
FIG. 5 is a cross-sectional exploded view showing a second embodiment of a layer of material used in assembling the single target assembly shown in FIG.
FIG. 6 is a detailed view of the assembled target assembly shown in FIG.
FIG. 7 shows a panel of target material consisting of three tiles for use in a sputtering target assembly according to the present invention.
FIG. 8 shows tape a) wrapped around tiles to cover the junction between tiles of the target panel, and b) covering the target side of the tile of FIG.
8A and 8B are a perspective view of the pre-assembly of the joint between adjacent tiles as shown in FIGS. 8, 9 and 10, and a cross-sectional view of the final configuration.
FIG. 9 shows the assembly of the target panel of FIG. 8 on a base plate according to the present invention.
10 shows a perspective view of the assembled sputtering target assembly of FIG.
FIG. 11 is a view partially removing the exterior of the bottom surface of the target backing plate using two welded cover panels covering the cooling passage voids of the backing plate.
12 is a cross-sectional view of FIG. 11 taken along 12-12.
FIG. 13 shows a target backing plate having cooling passage voids covered with a single cover plate.
14 is a cross-sectional detail of an exemplary weld along the top of the fin of the finned backing plate assembly having the welded cover plate shown in FIGS. 11, 12, 13 and 15 at the edge of the cover plate. FIG.
FIG. 15 is another example of a target backing plate having two separate cover plates.
FIG. 16 shows an overall cross-sectional view of the material layer used to surround and make a bag around a target assembly that is processed in an autoclave.
FIG. 17 is a simplified perspective view of the layers of FIG. 16, but does not show a gas coupling joint.
FIG. 18 is a plan view of a polyamide tape layer on a backing plate surrounding a target material used when processing a target assembly according to the present invention.
19 is a cross-sectional side view of FIG. 16 in the processing position.
FIG. 20 is a detailed view of the layers of material of FIG. 19 around the gas fitting 92.
FIG. 21 is a detailed view of the outer bag edge seal shown in close proximity to the gas fitting 90.
FIG. 22 shows an arrangement for providing thermocouple wires to a vacuum bag enclosure that monitors the temperature of the target material and / or backing plate.
FIG. 23 shows a side view of an exemplary gas coupling connection through the barrier film of the vacuum bag.
FIG. 24 is an exploded view of a cross section of a single vacuum bag bonding system in accordance with the present invention.
FIG. 25 is a cross-sectional view of a layer of the material of FIG. 24 bonded in accordance with the present invention.
FIG. 26 is a plan view of the sputtering target assembly shown in FIG. 9 and clearly shows an example of possible positions for gas connection to the gas barrier layer of the vacuum bag.
FIG. 27 shows an exemplary configuration for gas coupling through the outer (upper) bag barrier to the inner (lower) bag barrier of the dual bag configuration shown in FIGS. 16, 19, 20 and 26. It is a perspective view.
Detailed description
FIG. 1 illustrates a sputtering process system using a sputtering target assembly 40 manufactured in accordance with the present invention as described above.
The overall configuration of the embodiment according to the present invention is shown in FIG. The integrated sputtering target assembly 40 is shown in plan view with its target side viewed from above. The sputtering target material 48 is bonded to the backing plate 50. Bonding is done by soldering, diffusion bonding, or another technique that can provide and maintain a satisfactory bond between different metals at process temperatures. In another example, the target 48 and backing plate 50 (eg, aluminum or titanium) are a single piece of material that does not require bonding.AlsoGood. In general, prior to bonding the target material 48, a highly polished vacuum seal surface 77 is formed on the backing plate boundary 78 surrounding the target area (preferably 8 μin (0.20 μm) Ra, surface finish, mirror finish). To machine) and grind the target side of the backing plateLapping andIt is preferable to polish. This surface 77 provides a particularly leak-proof seal when the O-ring is placed against it. The backing plate 50 has water inlet fitting ports 67 and 68, water outlet fitting ports 69 and 71, and a low vacuum port 75 that is preferably machined into the backing plate 50 prior to bonding in accordance with the present invention.
FIG. 3 is a cross-sectional view of the target material 48 of FIG. 2 taken along 3-3. The target material 48 is attached to the backing plate 50, and the backing plate 50 is attached to the finned cover plate 52 in order, The outer surface of the plate 52 is covered with an electrical insulating sheet 54.
FIG. 4 is an exploded view of one embodiment of the configuration typically shown in FIG. 3 showing a first structural adhesive laminate 60 disposed between the electrical insulation sheet 54 and the finned cover plate 52. . The first adhesive laminate 60 is trimmed to fit the outer shape of the finned cover plate 52 in order to bond the insulating sheet 54 to the cover plate 52. A second layer 58 of structural adhesive laminate is located between the top surface of the finned cover plate 52 and the back surface of the backing plate 50. The second stack 58 is trimmed (typically a support screen or mesh not shown).FromOnly the surfaces that are intended to contact each other are bonded (ie, at the top of the fin 59 and the fin side boundary of the cover plate 52). is there). The solder layer 56 comprises a strip of solder material having a thickness of 0.010 ″ -0.020 ″ (0.25 mm-0.51 mm) and is disposed between the target material 48 and the front surface of the backing plate 50. The solder layer 56 is formed on the front surface of the target material 48 and the backing plate 50 in advance.wetA) a hot plate that immerses the surface to be bonded in a pool of solder, b) brushing over the solder on the surface to be bonded, and c) a surface to be bonded with the solder layer. Means such as sputter coating are used.
FIG. 5 is an exploded view of another configuration, typically illustrated by FIG. 3, illustrating another embodiment in accordance with the present invention. In some instances, surface bonding or prior to solder bondingWet (also called wet)The surface to be solder bonded can be cleaned by sputter etching (impacted by ions), and one or more layers of sputter coating material 65 can be applied to the target material 48 and backing plate. Sputter-coated (deposited) on the 50 bonded sides and pre-coated their surfaces for solderingWet, ieTin plating. Another unreliable procedure pre-defines the surface to be solder bonded as before.WetBefore bondingWetScrap the solder to remove surface oxide. Once the surface to be bonded isWhen tinned (pre-wetted)For example, a solder material strip 56, which is pure indium, a spacer 63 (eg, a pre-wet 0.001 ″ -0.010 ″ (0.025 mm-0.25 mm) diameter copper wire) is applied to the target material 48 and backing plate 50 for solder bonding. It is arranged between.
6 shows details of the cross section of FIG. 3 near its edge including the layers shown in the embodiment of the invention shown in FIG. The backing plate 50 is a rectangular single body having a target top surface and a back surface as described above. The target top surface can be wetted by sputtering pure indium onto a backing plate 50 made of titanium, for example, after being sputter coated with an adhesive layer. For example, indium-tin oxide (ITO)Made fromBy coating the target material 48 with an adhesive layer and coating it on the back (eg pure indium)Get wetbe able to. Solder 56 (eg, a pure indium 0.010 ″ -0.020 ″ (0.25 mm-0.51 mml) thick strip)WetA series of alternating strips of spacers 63 (which are 0.005 ″ -0.010 ″ (0.13 mm-0.25 mm) diameter copper wire) are disposed between the target material 48 and the backing plate 50. Although a series of spacers 63 and solder regions 56 alternating at high density is shown in FIG. 6, it is not necessary for the spacers 63 to be present at such a high frequency. The spacer 63 provides a vertical spacing (preferably approximately 0.010 ″ (0.25 mm)), and after bonding the target plate 48 to the backing plate 50, the spacerofThick solder joints are maintained. This extra thickness of the solder joint easily plastically generates solder material when subjected to the clamping pressure during the solder cooling cycle. The resulting solder avoids excessive distortion of the surface of the target material 48 due to thermal expansion differences. With the exception of spacer 63, the solder joint is significantly reduced in thickness, for example, to be thinner than 0.005 ″ (0.13 mm), and thickness uniformity cannot be controlled. Also, excess solder from thicker solder strips. However, the surface oxide floating on the melted solder is applied to the outside of the joint, and as a result, excellent solder bonding coverage is obtained.
The finned cover plate 52 is covered with a layer of structural adhesive laminate 58 trimmed, for example, with a safety razor blade, and fits the top of the exposed surface that contacts the back of the backing plate 50. When the structural adhesive laminate 58 is cured, good bonding creates a leak-free seal between the cooling passages of the finned cover plate 52 and the backing plate 50. The complete bonding of the fin ends of the cover plate 52 and the backing plate 50 is such that the cooling passage ballooning occurs when the cooling fluid is directed into the cooling passage under pressure.(ballooning)Can be avoided. An electrical insulation sheet 54 is bonded to the back of the finned cover plate 52 by a structural adhesive stack 60 similar to the structural adhesive stack 58 used for bonding between the finned cover plate 52 and the backing plate 50.
7, 8, 9 and 10 are taken to place multiple tile target materials (eg ITO) to be bonded on a backing plate 50 of a quality material (eg titanium) compatible with the sputtering target material. It is a simple visual representation of the steps. As shown in FIG. 7, since indium-tin oxide is difficult to produce in large plates, when large ITO plates are required for sputtering, multiple tiles 49a, 49b, 49c Adjacent to complete sputtering coverage. The tiles are held adjacent to each other by an assembly frame (not shown). In FIG. 8, the edge of the tile and the target side of the tile are covered with high temperature polyamide flash breaker tape 43 and the solder is applied to these surfaces.wetTo prevent. Also, the flash braking tape 43 can easily remove the solder material from the spacing between the panels, thereby avoiding contamination of the solder when sputtering the final target assembly 40.
FIG. 8A shows the peripheral edge of each tile wrapped with polyamide tape 43a, 43b having a width equal to the thickness of the tile. Tiles (eg 49a, 49b) are shims that maintain the spacing between tiles (Spacing adjustment plate)45 adjacent to each other. Bonded portion forming flash breaker tape 43z, edges are polyamide tapes 43a, 43bsoIt is placed over two adjacent tiles 49a, 49b that are rolled.
FIG. 8B shows tiles 49a, 49b arranged in a plane prepared to be mounted on backing plate 50. FIG. When the joint-forming flash breaker tape 43z is bent around the joint shim 47 in a position where the tiles are adjacent to each other in the plane, the joint shim 47 disposed between the tiles 49a, 49b provides a uniform spacing between the tiles. maintain. The typical thickness of tapes 43a, 43b, 43z is 0.003 "(0.076mm). The four layers of this tape have an assembled thickness of 0.012" (0.30mm) as shown in FIG. 8B. Bring. When all the tape and shim are removed, the final spacing between tiles is preferably 0.015 "-0.020" (0.38-0.51mm), so the thickness of shim 47 is 0.003 "(0.076mm) And between 0.008 ″ (0.020mm). The shim 47 is held until the soldering is complete and the uniformity of the spacing between the tiles is guaranteed. The height of the shim 47 is typically 0.003 ″ (0.076 mm) lower than the tile thickness. Once the soldering is complete, the shim 47 and all tape layers (43z, 43a, 43b) are removed. This leaves a gap of 0.015 "-0.020" (0.38-0.51 mm). Sputtering does not occur in this gap, and this gap acts as a dark part shielded from the effects of sputtering.
Behind the tiles 49a, 49b and 49cWetAlternatively, tin plating is performed at this time if necessary. Frames around the tiles are used to align and handle them before soldering.
As shown in FIG. 9, when the panels 49a, 49b, 49c are placed over the solder panels (strips) 56a and spacers 63 and heated, the solder strips 56a melt and the solder flows easily. The target backing plate is provided by placing a series of solder panels 56 and spacers 63 adjacent to each other so as to bond the backing plate 50 to the target panel material 48 including tiles 49a, 49b and 49c.
FIG. 10 shows three tiles of ITO target material 48 located on the backing plate 50. The same process is performed for a single target material without joints. The number of spacers 63 and solder material strips 56 shown in FIG. 9 is necessary to maintain an overall uniform top surface without excessive deflection of the target material in terms of the uniform clamping pressure exerted by the autoclave. Represents the type of interval. In each of the depicted ITO tiles (49a, b, c), the outer two spacers 63 act as bridges, for example the tile 49aBends at both ends and bends. Excessive deflection is not acceptable. For this purpose, an intermediate spacer is provided. Further, the configuration is adjusted based on empirical means if necessary.
A structural configuration for a finned backing plate 50a without epoxy cured bonding is shown in FIG. Finned backing plates 50a, 50b, 50c are shown in FIGS. 11, 12, 13, 14 and 15 and include cover receiving recesses extending downwardly from the top surface in the finned region, as shown, for example, in FIG. . The cover plates 53a, b, c, d or e are adapted to the size and thickness of the recesses, cover the cooling passages and fins 51, and divide and direct the cooling fluid flow from the inlet cooling passage port to the outlet cooling passage port. FIG. 11 shows two-part covers 53a and 53b, each panel being symmetrical with the other along a common edge. Two separate cooling passagesofA depression is provided. Each cooling passageofThe indentation and cover plate are separated separately by edge welds (eg 78), seam welds or a series of intermediate plug (ie spot) welds 80 regularly arranged along the top of the fin 51, and intermediate barriers 55 between adjacent indentations. It is possible to weld only a few fins. Typically, seam welding is performed on the top of each fin 51.
The finned plate 50 a also includes a low vacuum port 75, a power interlock port 74, and a power adjustment device 76.
FIG. 12 shows a cross section of FIG. 11 taken along 12-12.
FIG. 13 provides another configuration of a finned backing plate using a one-piece cover plate 53c. The welded finned backing plate 50b and the cover 53c form a collection of cooling fluid passages. A recess is created on the backing plate 50b and receives a thin cover 53c to hold the cooling fluid and all seams are welded and closed. A one-part cover plate 53c is welded around its periphery by welding 72 and welded from end to end at the top of each fin by seam welding 70.
FIG. 14 is a cross-sectional detail of FIGS. 11, 13 and 15 showing typical welding locations and configurations.
FIG. 15 shows another configuration of the finned backing plate 50c, in which the cooling passages are separated by a thicker intermediate wall than in the previous embodiment and covered by separate cover plates 53d and 53e. The surrounding weld 61 passes below the central axis of the finned backing plate 50c. A seam weld 62 is provided at the top of each cooling passage fin. Seam welding is done over the fins to prevent the cover 53c from ballooning under pressure.
When using a weldable aluminum (eg, aluminum alloy 6061) backing plate (ie, 50a, 50b, or 50c), the recommended material for a thin cover (ie, 53a, 53b, 53c, 53d, or 53e) is: Aluminum alloy (9% -13% Si) rich in silicon (for example, aluminum alloy 4047 containing 11% -13% Si, aluminum alloy used in the hybrid package industry). Silicon-rich aluminum is used to avoid breaking the thin cover along the heat affected part of the weld. A commercially pure titanium backing plate is welded to a thin cover of the same alloy.
The method for bonding the sputtering target assembly is preferably vacuum autoclave pressure bonding using two bags. FIG. 16 is an exploded view showing the different layers included in the configuration of the two vacuum (flexible) bag systems for bonding the target assembly. FIG. 17 is a perspective view of the molded article of FIG. 16 without showing a gas connector. A vacuum bag sealant 98, such as a bead of General Sealants, Inc., product number 213, high temperature (350 ° F. or 177 ° C.) synthetic rubber tape, is attached to the tool (support) plate 79. A sheet of release film 100 with no holes is located within the area surrounded by sealant 98 and is used to prevent the molded article (sputtering target assembly 40) from bonding to tool plate 79. Release film 100 is, for example, Airtech International, Inc. product number Wrightlease 5900, where high temperature PTFE release film is used up to 650 ° F. or 340 ° C., or Wrightlon 5200 Blue. (Blue), a fluorocarbon release film is used up to 450 ° F. or 230 ° C.
The sputtering target assembly 40 is assembled as an unbonded sandwich according to FIG. 16, with the side edges of the insulating sheet 54 wrapped with flash breaker tape 49 and the edges of the finned cover plate 52 wrapped with flash breaker tape 44. Rarely, the edge of the backing plate 50 is wrapped with flash breaker tape 42 and the backing plate boundary 78 leading to the edge of the target material 48 is masked with a polyamide high temperature tape coating 46. A top view of the boundary coating 46 is shown in FIG.
An example of a flash breaker tape utilized is a fully cured silicone adhesive high tensile polyester film, traded by Airtech International as Flashbreaker 1,2,5, Refers to film thickness (1,2,5 mils (0.025,0.051,0.127 mm, respectively)) and has a service limit up to 400 ° F. (205 ° C.). Polyamide tapes that mask the target material are, for example, manufactured by 3M under the names of Scotch® brands 5413 and 5419 (low static) and have a service limit of 500 ° F. (260 ° C.). The assembled sputtering target assembly 40 is then placed on top of the release film 100 on the tool plate 79.
beneathofTo form a vacuum bag system, a bead of vacuum bag sealant 102 is placed on a tape coating 46 that covers the boundary (target side) of the backing plate 50. Although General Sealant's serial number 213 may be used, General Sealant manufactures a variety of vacuum bag sealants that are evaluated for adhesiveness, which is the ability to cleanly remove after bonding, and the service temperature being investigated.
Within the area surrounded by the sealant 102, a release film 104, a bleeder film 106 and a vent mat 108 are placed above the target material 48.
The release film 104 used is, for example, an aluminum foil without oil leakage according to ASTM B479 and an uncoated polyamide film. These release films are used to protect the target surface from contaminants and avoid bonding another film.
The bleeder film 106 is, for example, Release Ply A and B, traded by Airtech International, which are heat-set, scoured, uncoated nylon fabrics that can absorb excess bonding material. Their equivalents, Bleeder Lease A and B, are not used here to prevent contamination from the release agent used in these films.
Degassing mat 108 is, for example, Airweave N7 (7 oz polyester degasser and resin absorbent) and Ultraweave 715 (nylon 6-6 non-woven gas that does not seal 350 ° F / 177 ° C cure) (Excluded) is traded by Airtech International. The degassing material is required to facilitate evacuation almost completely from the vacuum bag.
A vacuum fitting base 120 is placed on top of the vent mat 108 near the boundary of the backing plate 50 (see plan view 26 for gas connection locations). A nylon bag film 110 extends a) around the periphery of the peel and bleeder films 104 and 106 and b) around the mat 108 and is placed above the assembly,ofPress against vacuum sealant 102 to complete the vacuum bag system. A hole is formed in the nylon bag film 110 and connects the vacuum fittings 92 and 94 to the base 120.
Nylon bag film 110 is, for example, KM 1300 and Wrightlon 7400 with usage limits of 390 ° F / 199 ° C, and is traded by Airtech International. These nylon films exhibit 300% elongation at break, causing the film to conform to the shape of the molded product without bridging, and the bag breaks and breaks the required differential pressure. Alternatively, reusable silicon sheeting bags, such as those traded by Zip-Vac, may be substituted for the vacuum bag film.
A typical vacuum fitting is shown, for example, as 90 in FIGS. 16, 21 and 23, with a base 120, a seal 136 attached to the pressure plate 138, a male quick-cut fitting 140, and a downwardly extending central portion. It is constituted by an upper assembly consisting of T-shaped pins 144 positioned. The top assembly pin 144 extends through the hole in the base and when the top assembly is twisted to seal the fitting 90 against the bag film 110, the pin arm is in an opposing circular shape at the base bottom. Engage with the ramp.
beneathofThe vacuum bag system is mainly composed of a release film 112, a bleeder film 114, a degassing mat 116 and a vacuum bag film 118.ofSurrounded by a vacuum bag system. The peel and bleeder films 112 and 114 and the venting mat 116 extend beyond the periphery of the target assembly 40 and are placed within an area surrounded by the bag sealant 98.
Available release films 112 are, for example, traded by Airtech International in the name of Release Ease 234 TFP and, according to the manufacturer, porous release coated glass that releases from all commercially available resin systems. A fiber film with a working limit of 550 ° F / 285 ° C.
For example, the bleeder film 114 is the aforementioned release plies A and B or bleeder leases A and B.
For example, the degassing mat 116 is the aforementioned air weave and ultra weave 715.
For example, the nylon bag film 118 is the aforementioned KM 1300 and Lightlon 7400, or a reusable silicone sheeting bag.
TopofDuring assembly of the vacuum bag system, the base 120 for the fittings 90 and 96 is placed over the vent mat 116 away from the sputtering target assembly 40 side (see position in FIG. 26) and the nylon bag film 118. Is placed above the assembly and pressed against the vacuum bag sealant 98,ofComplete the vacuum bag system. Holes are created in the nylon bag film 118 and connect the fittings 90 and 96 to the base 120.
Hall is at the topofThe gas connection from the lower bag system is given to the bag system, the upper and lowerofAllows the upper bag system to pass through while separating between the bag systems. Beads 119 and 121 (shown as 146 in FIG. 27) of vacuum bag sealant (eg, moldings 98 and 102 described above) are provided inside the perimeter of each opening to seal the openings and gas fittings 92, 94. Around the bottomofThe bag system is exposed to autoclave 88 pressure.
The tool plate 79 and the element to be attached are placed in the container of the autoclave 88, to which vacuum and gas supply fittings 81, 83, 85, 87 are connected. For example, a vacuum cut fitting 87 connects to the male fitting 96 and pulls the vacuum on the upper bag. When the vacuum female pipe 81 is connected to the male pipe 90 and the autoclave pressure reaches approximately 1 atm, the upper partofThe vacuum bag system is filled with clean, dry nitrogen.
FIG. 19 is a cross-sectional view of a double bag processing laminate (sandwich) after evacuating the interior of the bag. All layers are completely compressed against the contour of the sputtering target assembly (ie the part to be bonded) and there is no bridging. The sputtering target assembly 40 is placed between a “Blanchard” ground tool plate 79 (to maintain flatness) and a double bag processing vacuum system. Magnify in detail.
The autoclave 88 consists of a pressure vessel provided with an internal heater and a fan (not shown). The fan helps to maintain a nearly constant fluid temperature inside the autoclave. A thermocouple 142 is attached to the molded article 40 and tool plate 79 to monitor the temperature inside the autoclave and provide input to a temperature controller (not shown) located outside the autoclave. This controller cycles the heater on and off to reach the desired temperature. The autoclave is pressurized by pumping nitrogen using a compressor (not shown) located outside the autoclave. A vacuum line is attached to the vacuum pump and enters the autoclave wall through a sealed port to provide vacuum to the bag system. Similarly, a gas line attached to the gas bottle at one end enters the autoclave wall through a sealed port and is used to fill the vacuum bag system.
The principle of the “press” of the autoclave is to maintain a differential pressure between the molded product 40 that is evacuated and the outside air that is the autoclave pressure during heating or cooling. The molded product 40 supported on one side of the tool plate 79 receives a uniform autoclave pressure that presses against the vacuum bag. When the autoclave pressure reaches approximately 15 psi above atmospheric pressure, a sufficient pressure differential exists across the vacuum bag, vacuum pumping is stopped, the vacuum bag is filled with, for example, clean, dry nitrogen, moist air or contamination Prevent material from entering the bag. Instead, reducing oxygen absorbing gas (ie carbon monoxide) is used to eliminate the risk of oxidizing parts at elevated temperatures. The autoclave pressure continues to increase the bonding pressure recommended by the instructions for use with the structural adhesive. The outer portion of the vacuum bag is pressurized at, for example, 60 psi or the recommended autoclave pressure while the interior of the bag is maintained at atmospheric pressure (˜15 psi). This pressure differential creates the pressure necessary to maintain the parts to be bonded in intimate contact while the adhesive is cured.
Normally, when the recommended curing pressure is reached, the autoclave is heated to the recommended curing temperature of the adhesive. For example,
1) Cytec Engineered Materials, Inc. manufactures Cybond EF-9500, 250 ° F ± 5 ° F (120 ° F) from ambient temperature with a gradient of 6 ° F (3.3 ° C) per minute. Curing is held at 250 ° F. ± 5 ° F. (120 ° C. ± 3 ° C.) for 90 minutes while maintaining the pressure at 60 psi ± 5 psi (0.28 MPa ± 0.03 MPa). Recommend cycle.
2) 3M Aerospace Materials manufactures AF-191, an improved epoxy structural adhesive film, 4 ° per minute up to 350 ° F ± 5 ° F (177 ° C ± 3 ° C) curing temperature Increase temperature from F by 5 ° F (2 ° C to 3 ° C) and then maintain temperature at 350 ° F ± 5 ° F (177 ° C ± 3 ° C) for 60 minutes while maintaining pressure at 45 psi ± 5 psi .
Preferably, the part should be cooled to temperatures below 160 ° F. (71 ° C.) before being removed from the autoclave 88 or vented to the atmosphere.
The structural adhesive film and the double bag processing vacuum system are selected to withstand the melting point of the solder. For example, when indium solder is used (melting point 156 ° C.), the adhesive system is selected to withstand a curing temperature of 350 ° F./177° C. The vacuum bag element is also selected to withstand a high temperature of 350 ° F./177° C. that ensures melting of the solder material.
Using a dual bag processing vacuum system, the target assembly 40 is manufactured by solder bonding and structural epoxy bonding in a single autoclave operation. The manufacturer's curing procedure for the adhesive film is modified to adjust the soldering process. For example, when using indium solder and the Cybond EF-9500 structural adhesive described above, the autoclave is at a rate of 6 ° F. (3.3 ° C.) per minute from ambient temperature to 350 ° F. ± 5 ° F. (177 ° C. ± 3 ° C). This temperature is maintained for approximately 1 minute to ensure that the indium solder strip 56 melts (see FIG. 9). The autoclave is then cooled to 250 ° F ± 5 ° F (120 ° C ± 3 ° C) at a rate of 9 ° F (5 ° C) per minute to solidify the solder and fully cure the structural adhesive. For 60 minutes at 250 ° F. ± 5 ° F. (120 ° C. ± 3 ° C.).
During the complete heating and cooling cycle, the pressure is maintained at 60 psi ± 5 psi (0.28 MPa ± 0.03 MPa). Lower part surrounding the solderofA vacuum bag system is purged with a reducing gas (ie, carbon monoxide) to help reduce or remove the oxygen present and improve the solder joint compatibility (ie, indium oxide in the molten solder). To prevent formation). In order to minimize solder oxidation, the solder strip 56, spacer 63, target material 48 and backing plate 50 (only the sides are bonded) strip off the surface oxide and an inert gas atmosphere during the deposition process. Maintained in. Other techniques are also used, such as ion bombardment (removing surface oxides) by sputtering a thin film of carbon (one or two monolayers). The carbon layer reacts with oxygen to form a gas that is pumped by a vacuum system attached to the lower vacuum bag.
(beneathofA vacuum male fitting 94 (attached to the vacuum bag system) and a line that separates into two valved lines (one going to the vacuum pump and the other going to the vent) exiting the autoclave 88 and the male fitting 94. A vacuum female fitting 85 (attached to the hose leading to the bottom) surrounds the target material 48, a portion of the backing plate 50, and the solder material (see FIG. 5) disposed therebetween.ofConnect to vacuum bag system. Similarly, mating pipe joints 92 and 83 connect to a valved gas supply outside the autoclave 88. Although not shown, one or more sets of vacuum lines are attached to each vacuum bag system to facilitate vacuum pumping or purging of the bag.
(TopofA vacuum male fitting 96 (attached to the vacuum bag system) and a line that separates into a male fitting 96 and a line with two valves (one goes to the vacuum pump and the other goes to the vent) leaving the autoclave. The vacuum female pipe fitting 87 attached to the connecting hose is a) (lower part)ofSurrounding the vacuum bag) enclosing the target backing plate assembly, the finned cover 52 and the adhesive 58 therebetween, and b) enclosing the finned cover 52, the electrically insulating sheet 54 and the adhesive 60 therebetween. Upper partofConnect to vacuum bag system.
When the pressure in the autoclave 88 reaches 15 psi (for the reasons described above), the valve to the vacuum pump is closed and the valve to the gas line is opened to allow approximately inert or oxygen absorbing (getter) gas in the vacuum bag. A pressure of approximately 15 psi or 1 atmosphere of suitable gas is drawn. When the pressure in the vacuum bag reaches approximately 1 atmosphere, the vacuum pump hose vent valve is opened once and then closed to purge the vent line and saturate the vacuum bag with vent / purge gas.
For example, carbon monoxide gas is lowered through a hose attached to a female pipe joint 83 connected to a male pipe joint 92.ofGuided to vacuum bag system. As mentioned above, carbon monoxide is used here to absorb free oxygen and maintain the cleanest environment possible for solder bonding. Clean and dry nitrogen is passed through the hose attached to the female pipe fitting 81 that mates with the male pipe fitting 90ofGuided to a vacuum bag system to prevent ingress of moist air or contaminants while the structural adhesive laminate is cured.
FIG. 22 shows an example of the path of the thermocouple wire 142 through the bag seal 98 of the vacuum bag system barrier film 118. Typically, at least two thermocouples are provided to each target assembly in the autoclave 88, and the temperature of the target material 48 serves as an input to a temperature controller that cycles the autoclave heater on and off.
FIG. 23 shows a side view of the connection of representative male fittings (ie, 90, 92, 94 and 96) through the barrier film (ie, 110 or 118) of the vacuum bag. For example, using a safety razor blade, a hole is created on the vacuum bag and the pin 144 extends downward to engage the base 120. The seal is created by a rubber seal 136, but leaking connections are often repaired by sealing the connections using vacuum sealants (98, 102).
FIG. 24 is an exploded view showing the various layers including a single vacuum bag system. The vacuum bag sealant 98 is pressed against the tool plate 79 (which later forms a vacuum seal for the nylon bag film 118). The assembled sputtering target assembly 40 is surrounded by a sealant 98 and placed on a release film 100 that is on a tool plate 79. The release film 112, the bleeder film 114 and the degassing mat 116 are positioned above the sputtering target assembly 40. The vacuum fitting base 120 is positioned on the vent mat 116 away from the sputtering target assembly 40 and a nylon bag film 118 is placed over the assembly and against the vacuum sealant 98 to complete the vacuum bag system. Pressed. Holes are created in the nylon bag film 118, fitting the fittings 90 and 96 to the base 120 and all the same to fit the two bag system described above.
25 is a cross-sectional view of the single bag vacuum system stack shown in FIG. 24 after a vacuum has been drawn into the bag. While the dual bag processing system is useful for solder and epoxy bonding during single autoclave operation, the single bag processing system is: (a) a sub-assembly of the target / backing plate that has been stressed and previously soldered The entire assembly is sealed in a vacuum bag system while flattening, the adhesive bonded surface is cured in the autoclave 88, and (b) the target / backing plate subassembly is first solder bonded in the autoclave; The cover for holding the cooling fluid is attached by a fastener that is later sealed by an O-ring seal, (c) after the finned backing plate and the cover holding the cooling fluid are welded (laser or electron beam welding) , Target in autoclave Bonding solder subassembly of the backing plate, or (d) bonding solder a new target material 48, again honing target assembly 40 that is processed by the above method ( "backing plate" recycling method).
FIG. 26 shows the position of the sputtering target assembly 40 on the tool plate 79 as described in FIG. 16, showing the paths of the sealants 98 and 102 on the tool plate 79, and the boundary of the backing plate 50, respectively. Shown are hoses that connect to gas passage fittings 81, 83, 85 and 87.
FIG. 27 shows a representative opening in the upper bag barrier film 118 sealed with a bead of sealant 146 as described in FIG. 16, exposing the gas connection fitting 92 to the lower bag film barrier 110.
The autoclave method is a well-known and economical technique. Nevertheless, the autoclave process described above is a unique, reliable and effective method for producing sputtering target assemblies. Of course, it is possible to achieve the desired temperature and pressure by means other than autoclaving.
Although the present invention has been described in accordance with specific embodiments, those skilled in the art will recognize that various modifications can be made without departing from the spirit and scope of the invention.

Claims (42)

A method of manufacturing a sputtering target assembly, comprising:
Providing components of a sputtering target assembly that are assembled into an unbonded sandwich, wherein at least two layers of the unbonded sandwich are separated by a bonding layer;
Pressing the unbonded sandwich layer with a pressure source that provides a substantially uniform pressure distribution from the top surface to the bottom surface of the unbonded sandwich;
Increasing the temperature of the unbonded sandwich above the bonding temperature of the bonding layer while maintaining pressure on the unbonded sandwich layer;
Maintaining a temperature above the bonding temperature, above the unbonded sandwich layer and maintaining a pressure during a period of time during which bonding is completed;
Maintaining the pressure on the unbonded sandwich while the temperature of the unbonded sandwich is lowered to a process completion temperature at which bond cure is complete;
Having a method. Enclosing the unbonded sandwich in a flexible vacuum tight enclosure;
Generating a vacuum pressure in the flexible vacuum tight enclosure to form a vacuum sealed unbonded sandwich assembly;
Have
Pressing comprises pressing a flexible vacuum tight enclosure and a vacuum-encapsulated unbonded sandwich assembly in a pressure chamber; and
The method of claim 1, wherein the steps of raising the temperature, maintaining the temperature, and maintaining the pressure are all performed in a pressure chamber. The enclosing step includes supporting the unbonded sandwich on a support plate, and covering and sealing the unbonded sandwich with a flexible vacuum tight cover sealed to the support plate. 3. The method of claim 2, comprising steps. The enclosing step comprises: a target backing plate supporting the unbonded sandwich target member on the target backing plate and covering the unbonded sandwich target member against the target backing plate The method of claim 2 including the step of sealing the flexible vacuum tight cover. A method of manufacturing a sputtering target assembly, comprising:
Stacking components of an unbonded sandwich sputtering target assembly on a support plate, wherein at least two layers of the unbonded sandwich are separated by a bonding layer;
Covering the unbonded sandwich on the support plate with an upper flexible vacuum tight seal sealed to the support plate to form a vacuum-encapsulated unbonded sandwich assembly;
Generating a vacuum pressure in the unbonded sandwich and the upper flexible vacuum tight cover over the support plate;
Pressurizing the support plate and the vacuum-encapsulated unbonded sandwich assembly in a pressure chamber;
Raising the temperature of the vacuum-encapsulated unbonded sandwich assembly in the pressure chamber to a temperature higher than the bonding temperature of the bonding layer;
Maintaining the temperature of the vacuum-sealed unbonded sandwich assembly in the pressure chamber above the bonding temperature and maintaining the pressure for a period of time during which bonding is completed;
While the temperature of the vacuum-encapsulated unbonded sandwich assembly is lowered to the process completion temperature at which bond curing is complete, the pressure applied to the support plate and the vacuum-encapsulated unbonded sandwich assembly is reduced. Maintaining steps;
Having a method. The step of covering the unbonded sandwich further comprises covering the target material with a lower flexible vacuum tight cover, and the lower flexible vacuum tight cover with the upper flexible vacuum tight cover. Sealing against the unbonded sandwich target backing plate inside the cover; and generating the vacuum pressure includes the target material and the lower flexibility on the target backing plate. Generating a vacuum pressure in a permeable vacuum tight cover;
6. The method of claim 5, comprising: 6. The method of claim 5, wherein the laminating step comprises disposing a first release film between the unbonded sandwich and the support plate. The laminating step includes placing the solder material in an interval between spacer members arranged to maintain a predetermined gap between the sputtering target material and the backing plate when the solder melts. The method according to claim 5. The laminating step includes placing the solder material in an interval between spacer members arranged to maintain a predetermined gap between the sputtering target material and the backing plate when the solder melts. The method according to claim 6. The step prior to the laminating step includes sputter depositing a backside of the target material with a solder material, wherein a bonding temperature is achieved in a subsequent step of raising the temperature of the vacuum-encapsulated unbonded sandwich assembly 6. The method of claim 5, wherein said method acts as wetting in preparation for subsequent solder bonding of said target to a backing plate. The step prior to the laminating step includes sputter depositing a backside of the target material with a solder material, wherein the bonding temperature raises the temperature of the vacuum-encapsulated unbonded sandwich assembly. 7. The method of claim 6, wherein once achieved, the method acts as wetting in preparation for solder bonding the target to a backing plate. The method of claim 10, wherein the back surface is sputter etched prior to sputter depositing the back surface of the target material with a solder material. 12. The method of claim 11, wherein the back surface is sputter etched prior to sputter depositing the back surface of the target material with a solder material. The step of providing a component of the sputtering target assembly comprises degassing mat film over the unbonded sandwich provided between the unbonded sandwich and the upper flexible vacuum tight cover. 8. The method of claim 7, comprising the step of providing. The step of providing a component of the sputtering target assembly includes a second release film above the unbonded sandwich provided between the unbonded sandwich and the upper flexible vacuum tight cover. The method according to claim 7, further comprising: sequentially providing a bleeder film and a degassing mat film. Providing the component includes a target backing plate as a component of the unbonded sandwich;
The backing plate is
Providing a finned target backing plate with voids forming a collection of cooling fluid passages in the backing plate, the void comprising a series of fins, each fin having a top surface;
Placing a cover over the void;
Sealing the edge of the cover to the backing plate to seal the void;
2. The method of claim 1, wherein the method comprises: spot or seam welding the cover to the top surface of the fin. A method of manufacturing a sputtering target assembly, comprising:
Applying a bonding material to the surface of the first plurality of substantially flat panels, one of them having a sputtering target;
Arranging the plurality of panels together, wherein a surface of the first plurality of panels faces a second plurality of panels, and the first and second plurality of panels are panel firsts. Composing a pair;
Applying a first pressure across at least two of the plurality of panels including the first pair, the first pressure being directed toward the second panel; Pressing a panel of;
Heating at least the first and second panels to a first temperature at which the bonding material bonds the first pair of panels simultaneously with applying the first pressure;
Having a method. The method of claim 17, wherein the bonding material is solder. The method of claim 18, wherein the bonding material is an adhesive. 18. The plurality of panels includes at least three of the panels, and the first pressure applies pressure across at least two of the panels including the first pair. The method described. The bonding material comprises solder;
Further comprising applying an adhesive to a third surface of one of the second pair of panels, wherein the second panel and the third panel of the plurality of panels comprise the second pair; The third side faces the fourth side of the second pair of panels;
The first pressure exerts a first force that presses the first pair of panels;
further,
Applying a second pressure across at least two of the panels comprising the second pair;
At least the second panel of the plurality of panels at a second temperature lower than the first temperature at which the adhesive bonds the second pair of panels simultaneously with applying the second pressure. 21. The method of claim 20, further comprising heating the third panel. The method of claim 17, wherein the first pressure is a fluid pressure difference. At least one of the layers of the unbonded sandwich includes a collection of tiles having one or more joints therebetween, where the solder flows from a backing plate surface to the one or more joints. In order to prevent this, the flexible tape is sealed to the edge of each tile and is sealed during soldering by bridging the one or more joints. The method of claim 1. A method of manufacturing a sputtering target assembly, comprising:
Providing a component of a sputtering target assembly that is assembled into an unbonded sandwich, wherein at least two layers of the unbonded sandwich are separated by a solder layer ;
Pressing the layers of the unbonded sandwich together using a pressure source that provides a substantially uniform pressure distribution from the top surface to the bottom surface of the unbonded sandwich;
Raising the temperature of the unbonded sandwich to the melting temperature of the solder layer ;
Maintaining the temperature of the unbonded sandwich at the melting temperature for a melting time while pressing the unbonded sandwich layer;
Pressing the layers of the unbonded sandwich together while the temperature of the unbonded sandwich is lowered to the completion temperature of the solidification process;
Having a method. The component of claim 1, wherein the component is exposed to a substantially inert gas environment during the preparing, pressing, raising temperature, and maintaining temperature. the method of. The component is exposed to a substantially moisture-free and inert gas environment during the preparing step, pressing step, raising temperature step, and maintaining temperature step. Item 2. The method according to Item 1. The method of claim 1, wherein the component is exposed to a substantially oxygen-absorbing gas environment during the preparing, pressing, raising, and maintaining temperature steps. During the step of providing, pressing, raising temperature, maintaining temperature, and maintaining pressure, the component is surrounded by a gas-tight enclosure having a flexible wall, The method of claim 1, wherein the enclosure has a substantially inert gas environment. During the preparing step, pressing step, raising temperature step, maintaining temperature step, maintaining pressure step, the component is surrounded by a gas-tight enclosure having a flexible wall, and the enclosure The method of claim 1, wherein the method has an inert gas environment substantially free of moisture. During the step of providing, pressing, raising temperature, maintaining temperature, and maintaining pressure, the component is surrounded by a gas-tight enclosure having a flexible wall, The method of claim 1, wherein the enclosure has a substantially oxygen absorbing gas environment. The method of claim 30, wherein the substantially oxygen-absorbing gas environment is formed primarily of carbon monoxide. 29. The method of claim 28, wherein the enclosure is substantially evacuated prior to providing the substantially inert gas environment to a gas leak-free enclosure. 30. The method of claim 29, wherein the enclosure is substantially evacuated prior to providing the substantially inert gas environment to a gas leak-free enclosure. 31. The method of claim 30, wherein the enclosure is substantially evacuated prior to providing the substantially inert gas environment to a gas leak-free enclosure. Providing the component comprises providing at least one surface of the unbonded sandwich layer faced with each other and separated by a coated bonding layer by sputter depositing the layer of bonding material. The method according to claim 1. Providing the component comprises providing at least one surface of the unbonded sandwich layer faced with each other and separated by a coated bonding layer by sputter depositing the layer of bonding material. 26. The method of claim 25. Providing the component comprises providing at least one surface of the unbonded sandwich layer faced with each other and separated by a coated bonding layer by sputter depositing the layer of bonding material. 27. A method according to claim 26. Providing the component comprises providing at least one surface of the unbonded sandwich layer faced with each other and separated by a coated bonding layer by sputter depositing the layer of bonding material. 28. The method of claim 27. 18. The method of claim 17, wherein one of the first pair of panels includes a surface having a groove for forming a fluid cooling channel in the sputtering target assembly. The step of providing a component of the bonding layer includes soldering a gap between spacer members arranged to maintain a predetermined gap between at least two layers of the unbonded sandwich when the solder melts. The method of claim 1, comprising placing the material. Prior to the step of providing the component, the bonding side of the first layer of the at least two layers is sputter deposited with a solder material and a bonding temperature is achieved by raising the temperature of the unbonded sandwich. 2. The method of claim 1, wherein the method sometimes acts as wetting for solder bonding of the first layer of the at least two layers to a second layer of the at least two layers. 42. The method of claim 41, wherein the bonding side is sputter etched prior to the step of sputter depositing the bonding side of the first layer of the at least two layers with a solder material.

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