JP4954663B2 - Bonding device - Google Patents

Description

  The present invention relates to a laminating apparatus for laminating two substrates using a hot-melt adhesive.

  In recent years, for example, in the manufacturing process of semiconductor devices and MEMS (Micro Electro Mechanical Systems), the diameter of a semiconductor wafer (hereinafter referred to as “wafer”) has been increased, and in a specific process such as mounting, Thinning is required. For example, if a thin wafer with a large diameter is transported or polished as it is, the wafer may be warped or cracked. For this reason, for example, in order to reinforce the wafer, the wafer is attached to a reinforcing substrate, for example. Further, in order to reduce the thickness of the wafer, it is necessary to grind the wafer, and in this case, it is necessary to attach the wafer to a support substrate.

  For example, the above-described bonding of the wafer and the reinforcing substrate is usually performed using a bonding apparatus. In this bonding apparatus, for example, a wafer and a reinforcing substrate are held so as to be opposed to each other by upper and lower chucks, and, for example, liquid crystal wax as a hot-melt adhesive is melted on the wafer by heat. Then, by moving the chuck, the wafer and the reinforcing substrate are pressed against each other, the liquid crystal wax is spread over the entire surface, and then the liquid crystal wax is cooled and solidified to bond the wafer and the reinforcing substrate (Patent Literature). 1).

JP 2005-51055 A

  However, as described above, when the upper and lower chucks are moved and the opposing wafer and the reinforcing substrate are pressed, the liquid crystal wax between them is biased, and the wafer and the reinforcing substrate are not adhered exactly in parallel and stuck. In some cases, the thickness of the bonded body after the alignment varies within the wafer surface. For this reason, subsequent polishing or heat treatment of the wafer is not performed uniformly in the wafer surface, and as a result, for example, the quality of the device may vary in the wafer surface. If the wafer and the reinforcing substrate are not bonded in parallel, bubbles may enter the liquid crystal wax between the wafer and the reinforcing substrate. In this case, not only the adhesive force between the wafer and the reinforcing substrate is weakened, but also the wafer may be damaged due to expansion and contraction of the bubbles during the heat treatment of the wafer, for example.

  The present invention has been made in view of this point, and an object thereof is to bond two wafers such as a wafer and a reinforcing substrate in parallel.

In order to achieve the above object, the present invention provides a bonding apparatus for bonding two substrates using a hot-melt adhesive, wherein one substrate is bonded with the bonding surface facing upward. A first holding member to hold, and a second holding member to hold another substrate with the bonding surface facing downward so as to face the one substrate held by the first holding member A temperature raising / lowering mechanism capable of increasing the temperature until the adhesive supplied to the bonding surface of at least one of the one substrate and the other substrate is melted and further decreasing the temperature until solidified, and the first holding member Or a holding member driving mechanism for vertically moving at least one of the second holding members and pressing the bonding surfaces of the substrates with the adhesive interposed therebetween, and the first The holding surfaces of the holding member and the second holding member are It is formed larger than the one substrate and the other substrate, and is a holding surface of at least one of the first holding member or the second holding member, and is pressed at a position outside the held substrate. A spacer for making the gap between the first holding member and the second holding member constant is provided apart from the substrate, and the spacer is formed as a protrusion on the holding surface. A discharge passage for discharging the adhesive inside the spacer to the outside of the spacer is formed between the spacer and the holding surface of the first holding member. At least one of the holding surface of the first holding member and the holding surface of the second holding member is formed with a blowing port for blowing out gas, and the blowing port is formed on the substrate held on each holding surface. characterized in that it is formed at a position of the end portion To.

  According to the present invention, since the gap between the first holding member and the second holding member at the time of pressing is constant, the two substrates are bonded in parallel, and the thickness of the two substrates after bonding is It becomes uniform within the substrate surface. As a result, the substrate processing such as grinding performed after the bonding is performed uniformly within the substrate surface. In addition, bubbles that enter the adhesive are reduced, and the substrate can be appropriately heat-treated.

  The spacer may be formed with a ventilation portion communicating from the inside of the spacer to the outside of the spacer when pressed.

The spacer is formed by a plurality of linearly formed ridges, and the plurality of ridges are arranged so as to surround a substrate held on the holding surface in a square frame shape, The ventilation part may be formed between the protrusions.

  A groove from the inner side to the outer side of the spacer may be formed on the lower surface of the spacer, and the discharge passage may be formed by the groove and the holding surface of the first holding member.

  The discharge passages may be formed at equal intervals at a plurality of locations in the circumferential direction of the spacer.

  The holding surface of the first holding member may be formed with an inclined surface whose outer side is lowered, and the inclined surface may be formed outside a position where the substrate of the holding surface is held.

  The outlet may be formed in a slit shape along the outer periphery of the substrate.

  An air passage that communicates from the inside of the spacer to the outside of the spacer when pressed may be formed between the spacer and the holding surface of the second holding member.

  A groove from the inner side to the outer side of the spacer may be formed on the upper surface of the spacer, and the ventilation path may be formed by the groove and the holding surface of the second holding member.

  The air passages may be formed at equal intervals at a plurality of locations in the circumferential direction of the spacer.

  The holding surface of the second holding member may be formed with an inclined surface whose outer side is lowered, and the inclined surface may be formed outside a position where the substrate of the holding surface is held.

  A vertical groove may be formed on the inner peripheral surface of the spacer.

  The bonding apparatus may include a parallelism adjusting mechanism that adjusts the parallelism between the first holding member and the second holding member.

  The parallelism adjusting mechanism may include a push-down member that pushes down the second holding member with a center portion of the second holding member as a fulcrum, and a lifting member that pulls up the second holding member.

  The push-down member and the pull-up member are respectively provided at a plurality of locations of the second holding member, and the push-down member and the pull-up member are the same with the center portion of the second holding member as a center when viewed from the plane. You may arrange | position at equal intervals on the circumference.

  The holding surfaces of the first holding member and the second holding member may be subjected to a surface treatment for flattening.

  The adhesive includes a plurality of spherical particles that define a gap between one substrate and another substrate at the time of bonding, and the plurality of particles may have a certain diameter. .

  According to the present invention, since the two substrates are attached in parallel, the treatment of the attached substrates is performed uniformly within the substrate surface.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is an explanatory view of a longitudinal section showing an outline of a configuration of a bonding apparatus 1 according to the present embodiment.

  The laminating apparatus 1 has a processing container 10 that can be hermetically closed, for example. In the center of the processing container 10, for example, a lower chuck 11 is provided as a first holding member for mounting and holding the reinforcing substrate S. Further, an upper chuck 12 as a second holding member for holding the wafer W, for example, is provided above the lower chuck 11 at a position facing the lower chuck 11. In the present embodiment, the wafer W is a substrate on which a device is formed. A substrate having the same diameter as the wafer W is used as the reinforcing substrate S.

  The lower chuck 11 has, for example, a thick and substantially disk shape. On the upper surface of the lower chuck 11, a horizontal holding surface 11a larger than the diameter of the reinforcing substrate S is formed. The holding surface 11a is subjected to a surface treatment for flattening, and has a center line average roughness of 5 μm or less, for example. A suction port (not shown) is formed in the holding surface 11a of the lower chuck 11, and the reinforcing substrate S can be adsorbed to the holding surface 11a by suction by the suction port. Accordingly, the lower chuck 11 can hold the reinforcing substrate S on the holding surface 11a with the bonding surface facing upward.

  A heater 21, which is a heating member that generates heat when power is supplied from the power supply 20, is built in the lower chuck 11. The heater 21 can heat the reinforcing substrate S on the lower chuck 11 and the adhesive on the reinforcing substrate S.

  Further, inside the lower chuck 11, for example, a refrigerant flow path 23 that is a cooling member that allows a refrigerant supplied from the refrigerant supply device 22 to flow therethrough is formed. Thereby, the reinforcing substrate S on the lower chuck 11 and the adhesive on the reinforcing substrate S can be cooled. In the present embodiment, for example, the temperature raising and lowering mechanism is configured by the power source 20, the heater 21, the refrigerant supply device 22, and the refrigerant flow path 23.

  The lower chuck 11 is supported by the rod 32 via, for example, a heat insulating plate 30 and a support plate 31. The rod 32 moves up and down by a cylinder 33, for example. Thus, the lower chuck 11 can be raised to the upper chuck 12 side, and the reinforcing substrate S held by the lower chuck 11 can be pressed against the wafer W held by the upper chuck 12. In the present embodiment, the rod 32 and the cylinder 33 constitute a holding member drive mechanism.

  The upper chuck 12 has, for example, a thick and substantially disk shape. On the lower surface of the upper chuck 12, a horizontal holding surface 12a larger than the diameter of the wafer W is formed. The holding surface 12a is subjected to a surface treatment for flattening, and has a center line average roughness of 5 μm or less, for example. A suction port (not shown) is formed in the holding surface 12a, and the upper surface of the wafer W can be attracted to the holding surface 12a by suction by the suction port. The upper chuck 12 can hold the wafer W so as to face the reinforcing substrate S of the lower chuck 11 with the bonding surface of the wafer W facing downward.

  Inside the upper chuck 12, a heater 41, which is a heating member that generates heat by power supply from the power supply 40, is built in. For example, the wafer W on the lower surface of the upper chuck 12 can be heated by the heater 41. Further, the reinforcing substrate S and the adhesive of the lower chuck 11 can be heated by the radiant heat from the upper chuck 12.

  For example, a disk-shaped heat insulating plate 50 is attached to the upper surface of the upper chuck 12. A support plate 51 is attached to the upper surface of the heat insulating plate 50. The central portion of the support plate 51 is supported by a ball plunger 52 attached to the ceiling surface of the processing container 10. The overall height of the upper chuck 12 can be adjusted by turning the ball plunger 52.

  On the support plate 51, there is provided a pulling screw 60 as a lifting member having an upper end attached to the ceiling surface of the processing container 10 and a lower end attached to the support plate 51. By turning the pulling screw 60, the upper chuck 12 can be lifted upward with the central portion of the support plate 51 having the ball plunger 52 (the central portion of the upper chuck 12) as a fulcrum. Further, on the support plate 51, a push screw 61 is provided as a push-down member whose upper end is attached to the ceiling surface of the processing container 10 and whose lower end is in contact with the upper surface of the support plate 51. By turning the push screw 61, the upper chuck 12 can be pushed downward with the central portion of the support plate 51 as a fulcrum.

  For example, as shown in FIG. 2, the pull screw 60 and the push screw 61 are sequentially arranged from the center side along the radial direction of the support plate 51 (upper chuck 12) as viewed from above. Further, the pull screw 60 and the push screw 61 are provided at a plurality of locations, for example, at three locations. The pull screw 60 and the push screw 61 are arranged at equal intervals (120 ° intervals) on the same circumference. With these pull screw 60 and push screw 61, the height of the upper chuck 12 can be adjusted, and the parallelism of the upper chuck 12 and the lower chuck 11 can be adjusted. In the present embodiment, for example, the parallelism adjusting mechanism is configured by the ball plunger 52, the pull screw 60, and the push screw 61.

  A leaf spring 70 is provided on the outer peripheral portion of the support plate 51 as shown in FIG. The support plate 51 is pressed from the upper surface side by the leaf spring 70. The leaf spring 70 is supported by a support pillar 71 attached to the ceiling surface of the processing container 10, for example. For example, as shown in FIG. 2, the leaf springs 70 are arranged at three positions every 120 °. A pair of pulling screws 60 and pressing screws 61 and leaf springs 70 are alternately arranged at equal intervals.

  A spacer 80 is provided on the outer peripheral portion of the holding surface 11a of the lower chuck 11 as shown in FIG. For example, as shown in FIG. 3, the spacer 80 is formed so as to surround the reinforcing substrate S held on the holding surface 11a. The spacer 80 is formed from, for example, four protrusions 81. For example, the four protrusions 81 are linearly formed with the same height and the same length, and are arranged so as to surround the reinforcing substrate S in a square frame shape. For example, as shown in FIG. 4, the height of each protrusion 81 defines a gap when the lower chuck 11 and the upper chuck 12 approach and the spacer 80 contacts the upper chuck 12. The bonded body B, which is a combination of the wafer W and the adhesive A, is set to have a desired thickness. The spacer 80 keeps the gap between the lower chuck 11 and the upper chuck 12 during bonding constant within the holding surface, so that the reinforcing substrate S and the wafer W are bonded in parallel.

  Further, as shown in FIG. 3, a ventilation portion 82 is formed between the protrusions 81 of the spacer 80. As a result, as shown in FIG. 4, even when the spacer 80 of the lower chuck 11 contacts the upper chuck 12, the region where the joined body B is located and the region outside the spacer 80 communicate with each other. The degassed gas can be discharged to the outside of the spacer 80.

  As shown in FIG. 1, an exhaust pipe 90 is connected to the side wall surface of the processing container 10. The exhaust pipe 90 is connected to a negative pressure generator 91 such as a vacuum pump. Thereby, the inside of the processing container 10 can be depressurized to a predetermined pressure. In the present embodiment, for example, the exhaust pipe 90 and the negative pressure generator 91 constitute a decompression mechanism that decompresses the ambient atmosphere of the liquid crystal wax A.

  For example, the control of the operation of the cylinder 33, the heaters 21, 41, the refrigerant supply device 22, the negative pressure generation device 91, and the like described above is performed by the control unit 100, for example. The control unit 100 is, for example, a computer, and can execute a stored program, drive each member or device, and control the bonding process.

  Next, a bonding process between the reinforcing substrate S and the wafer W performed by the bonding apparatus 1 configured as described above will be described. FIG. 5 is a time chart regarding the temperature of the reinforcing substrate S, the pressure of the processing container 10, and the position of the lower chuck 11 in the bonding process. Moreover, FIG. 6 is explanatory drawing which shows the mode in the processing container 10 at the time of each process of a bonding process.

  First, as shown in FIG. 1, the reinforcing substrate S and the wafer W are sucked and held by the lower chuck 11 and the upper chuck 12 in the processing container 10 so as to face each other. At this time, as shown in FIG. 5, the reinforcing substrate S is maintained at a normal temperature T1 (for example, 23 ° C.), for example. The pressure in the processing container 10 is maintained at normal pressure P1, for example. Further, the lower chuck 11 is disposed at a standby position K1 that is separated from the upper chuck 12. At this time, the distance between the lower chuck 11 and the upper chuck 12 is set to about 5 to 30 mm, more preferably 10 mm or less.

  When the reinforcing substrate S and the wafer W are held by the lower chuck 11 and the upper chuck 12, a solid liquid crystal wax A, which is a hot-melt adhesive, is placed at the center of the reinforcing substrate S ((( a)). Thereafter, for example, the heater 21 generates heat, and the temperature of the reinforcing substrate S is increased to a bonding temperature T3 (for example, 170 ° C.) exceeding the melting point temperature T2 (for example, 148 ° C.) of the liquid crystal wax A as shown in FIG. The The bonding temperature T3 is set to a temperature higher by about 5 ° C. to 30 ° C. than the melting point temperature T2, for example. Further, due to the heat generated by the heater 41, the wafer W is also heated to a temperature that is, for example, equal to or higher than the melting temperature T2 and that has a difference from the bonding temperature T3 within 10 ° C., for example, about 5 ° C. higher than the bonding temperature T3. . By heating the reinforcing substrate S and the wafer W, the liquid crystal wax A melts exceeding the melting point temperature T2 ((b) of FIG. 6). The melting of the liquid crystal wax A is performed by heat transfer from the reinforcing substrate S and radiant heat from the wafer W, for example. Thereafter, the temperature of the reinforcing substrate S is maintained at the bonding temperature T3 as shown in FIG.

  Subsequently, the pressure in the processing container 10 is reduced from the normal pressure P1 to the low pressure P2 of, for example, 20 kPa or less by the exhaust from the exhaust pipe 90. By this decompression, bubbles in the liquid crystal wax A are removed ((c) in FIG. 6).

  Thereafter, in a state where the inside of the processing container 10 is maintained in a reduced pressure atmosphere, the lower chuck 11 is raised to the bonding position K2, the reinforcing substrate S is pressed against the wafer W, and the reinforcing substrate S and the wafer W are aligned (FIG. 6 (d)). As the lower chuck 11 is raised at this time, the spacer 80 comes into contact with the upper chuck 12, the gap between the upper chuck 12 and the lower chuck 11 is kept constant within the holding surface, and the reinforcing substrate S and the wafer W are parallel to each other. Maintained. Thereby, the thickness of the joined body B composed of the reinforcing substrate S, the liquid crystal wax A, and the wafer W becomes uniform in the wafer surface.

  After the reinforcing substrate S and the wafer W are pressurized with each other, the pressure in the processing container 10 is returned from the low pressure P2 to the normal pressure P1 and maintained as shown in FIG. As a result, the liquid crystal wax A is prevented from leaking and scattering from between the reinforcing substrate S and the wafer W due to the pressure difference. Further, for example, by flowing a coolant through the cooling flow path 23, the reinforcing substrate S is cooled, and the temperature of the reinforcing substrate S is lower than the solidification temperature T4 (for example, 113 ° C.) of the liquid crystal wax A, for example, the final temperature T5 (for example, 103). ℃) gradually. The liquid crystal wax A solidifies when the solidification temperature T4 is reached, and bonds the reinforcing substrate S and the wafer W together. The temperature fluctuation rate at the time of cooling is set to be smaller than the temperature fluctuation rate at the time of heating, for example, 5 ° C./min or less.

  When the reinforcing substrate S is cooled to the final temperature T5, the suction of the wafer W on the upper chuck 12 is released. Thereafter, as shown in FIG. 5, the lower chuck 11 is lowered to the standby position K1, and the lower chuck 11 and the upper chuck 12 are separated ((e) of FIG. 6). Thus, the bonding process between the reinforcing substrate S and the wafer W is completed. The series of bonding processes is performed by the control unit 100 controlling the operations of the cylinder 33, the heaters 21, 41, the refrigerant supply device 22, the negative pressure generation device 91, and the like.

  By the way, for example, when the parallelism between the lower chuck 11 and the upper chuck 12 in the processing container 10 is not sufficient before the bonding process is started, the push screw 60 and the pull screw 61 that act on the upper chuck 12. Is used to adjust the parallelism. The tilt of the upper chuck 12 is adjusted by pushing down the upper chuck 12 with the center portion of the upper chuck 12 as a fulcrum by a push screw 60 at a predetermined position, or pulling up the upper chuck 12 with a pull screw 61. Thus, the parallelism between the upper chuck 12 and the lower chuck 11 is adjusted.

  According to the above embodiment, since the spacer 80 is provided on the holding surface 11a of the lower chuck 11 so as to surround the reinforcing substrate S, the gap between the upper chuck 11 and the lower chuck 12 becomes constant, The reinforcing substrate S and the wafer W are maintained in parallel. Thereby, the thickness of the bonded body B in a bonded state becomes uniform in the wafer surface.

  Since the spacer 80 is provided with the ventilation portion 82 that communicates the inside and outside of the joined body B, the gas that escapes from the liquid crystal wax A can be discharged to the outside of the spacer 80. Thereby, it is possible to suppress the bubbles from remaining in the bonded body B.

  Since the mechanism for adjusting the parallelism between the upper chuck 12 and the lower chuck 11 is attached to the upper chuck 12, the holding surface 12a of the upper chuck 12 and the holding surface 11a of the lower chuck 11 can be maintained in parallel. Thereby, the parallelism between the wafer W and the reinforcing substrate S at the time of bonding is further increased, and the uniformity of the thickness of the bonded body B can be further improved.

  Since the push screw 60 and the pull screw 61 are provided at three positions in the surface of the upper chuck 12 and are arranged at equal intervals on the same circumference, the parallelism of the upper chuck 12 can be adjusted easily and accurately. be able to.

  Since the holding surfaces of the lower chuck 11 and the upper chuck 12 are flattened, the parallelism between the reinforcing substrate S and the wafer W at the time of bonding can be further increased.

  In the above embodiment, the spacer 80 of the lower chuck 11 is formed in a square four-sided frame shape, but may be in a ring shape as shown in FIG. 7, for example. The ring-shaped spacer 80 may be divided into a plurality of pieces in consideration of thermal expansion and contraction.

  By the way, when the reinforcing substrate S and the wafer W are pressed against each other during the bonding process described above, the liquid liquid crystal wax A may flow out from between the reinforcing substrate S and the wafer W to the outside. When the liquid crystal wax A remains inside the spacer 80, the liquid crystal wax A adheres to the inner peripheral surface of the spacer 80, the holding surface 11a of the lower chuck 11, and the like, which may cause particles. Further, the liquid crystal wax A that has flowed out enters between the reinforcing substrate S and the holding surface 11a or between the wafer W and the holding surface 12a, and adsorbs the reinforcing substrate S and the wafer W of the lower chuck 11 and the upper chuck 12. There is a risk of contaminating the suction line and the holding surfaces 11a and 12a. For example, when the holding surfaces 11a and 12a are contaminated, the reinforcing substrate S and the wafer W are not held horizontally on the holding surfaces 11a and 12a, so it is difficult to bond the reinforcing substrate S and the wafer W in parallel. become.

  Therefore, a discharge passage for discharging the liquid crystal wax A inside the spacer 80 to the outside of the spacer 80 may be formed between the spacer 80 and the holding surface 11 a of the lower chuck 11. FIG. 8 shows such an example. A groove 110 is formed on the lower surface of the spacer 80 along the radial direction from the inner side to the outer side of the spacer 80, and a discharge passage 111 is formed by the groove 110 and the holding surface 11a. Has been. For example, as shown in FIG. 9, the discharge passages 111 are formed at a plurality of intervals in the circumferential direction of the ring-shaped spacer 80. When the reinforcing substrate S and the wafer W are brought into pressure contact during the bonding process, for example, the pressure inside the spacer 80 is the pressure outside the spacer 80 due to gas compression or the heat of the holding surfaces 11a and 12a. As shown in FIG. 8, the liquid crystal wax A that has flowed out between the reinforcing substrate S and the wafer W is pushed out of the spacer 80 through the discharge passage 111 of the spacer 80 and discharged. By doing so, the holding surfaces 11a, 12a and the like are prevented from being contaminated by the liquid crystal wax A.

  Note that when the reinforcing substrate S and the wafer W are brought into pressure contact with each other, the inside of the processing container 10 may be depressurized, and the pressure outside the spacer 80 may be positively negative to facilitate the discharge of the liquid crystal wax A. Further, the groove 110 forming the discharge passage 111 may be formed on the holding surface 11 a side of the lower chuck 11, or may be formed on both the lower surface of the spacer 80 and the holding surface 11 a of the lower chuck 11.

  In the above example, as shown in FIG. 10, the holding surface 11a of the lower chuck 11 is formed with a lower surface outlet 120 for blowing a gas such as air, and the upper surface outlet 121 is formed on the holding surface 12a of the upper chuck 12. May be. For example, the lower surface outlet 120 is formed at the position of the end of the reinforcing substrate S held on the holding surface 11a. The lower surface outlet 120 is formed in a slit shape in a ring shape along the outer periphery of the reinforcing substrate S, for example. The lower surface outlet 120 is connected to a gas supply source 131 outside the processing container 10 by, for example, an air supply pipe 130 passing through the inside of the lower chuck 11. For example, the gas supply source 131 has a temperature adjustment function of the supply gas.

  A buffer 130 a for equalizing the pressure of the gas supplied from the gas supply source 131 is formed in the supply pipe 130 near the opening of the lower surface outlet 120. The buffer portion 130 a is formed in a ring shape corresponding to the lower surface outlet 120. For example, a ring-shaped rectifying plate 130b is formed in the buffer unit 130a. By this rectifying plate 130b, the gas supplied from the gas supply source 131 is once flowed to the center side of the reinforcing substrate S in the buffer portion 130a, and then the gas is directly below the back surface of the reinforcing substrate S at the center of the reinforcing substrate S. It can flow from the side toward the outside and blow out from the lower surface outlet 120. As a result, gas can be blown out from the lower face outlet 120 obliquely upward.

  Further, the upper surface outlet 121 is formed at the position of the end of the wafer W held by the holding surface 12a, for example, similarly to the lower surface outlet 120. The upper surface outlet 121 is formed in a ring shape along the outer periphery of the wafer W in a slit shape, and is connected to the gas supply source 141 by, for example, an air supply pipe 140 passing through the inside of the upper chuck 12. For example, the gas supply source 141 has a temperature adjustment function of the supply gas. A ring-shaped buffer portion 140a corresponding to the upper surface outlet 121 is formed in the air supply pipe 140 near the upper surface outlet 121, and a ring-shaped rectifying plate 140b is formed in the buffer portion 140a. By this rectifying plate 140b, the gas supplied from the gas supply source 141 is once flowed to the center side of the wafer W in the buffer unit 140a, and then the gas is directed from the center side of the wafer W to the outside right above the upper surface of the wafer W. And can be blown out from the upper surface outlet 121. Thereby, gas can be blown out from the upper face blowing port 121 in a diagonally downward direction.

  Further, for example, a ventilation path 150 that leads from the inside to the outside of the spacer 80 is formed between the upper surface of the spacer 80 and the holding surface 12 a of the upper chuck 12. For example, as shown in FIG. 11, a groove 151 is formed on the upper surface of the spacer 80 along the radial direction from the inner side to the outer side of the spacer 80, and the holding surface 12 a of the upper chuck 12 comes into contact with the groove 151. 150 is formed. For example, the air passage 150 is formed at a plurality of positions in the circumferential direction of the spacer 80 at equal intervals. For example, the discharge passages 111 and the air passages 150 are formed in a staggered pattern at alternate positions along the circumferential direction of the spacer 80.

  When the reinforcing substrate S and the wafer W are pressed against each other during the bonding process, for example, gas is blown out from the lower surface outlet 120 and the upper surface outlet 121 as shown in FIG. The temperature of this gas is adjusted to, for example, the solidification temperature T4 or higher of the liquid crystal wax A. The gas blown out from the lower face blowing port 120 is blown out from the end portion of the reinforcing substrate S in an obliquely upward direction (the arrow direction in FIG. 10) in the outer direction. The liquid crystal wax A protruding from between the reinforcing substrate S and the wafer W is pushed outward by the gas and discharged from the discharge passage 111 of the spacer 80. Further, the gas blown out from the lower surface blowing port 120 prevents the liquid crystal wax A from being pushed up and drooping to the side surface of the end portion of the reinforcing substrate S.

  The gas blown out from the upper surface blowing port 121 is blown out from the end portion of the wafer W obliquely downward (in the direction of the arrow in FIG. 10) in the outer direction. The liquid crystal wax A that protrudes from between the reinforcing substrate S and the wafer W is also pushed outward by this gas and is discharged from the discharge passage 111 of the spacer 80. Further, the gas blown out from the upper surface blowing port 121 prevents the liquid crystal wax A from entering the side surface of the end portion of the wafer W. A part of the gas blown out from the lower face outlet 120 and the upper face outlet 121 is exhausted to the outside of the spacer 80 through the air passage 150 on the upper face of the spacer 80.

  According to this example, discharge of the liquid crystal wax A to the outside of the spacer 80 is promoted by the gas blown from the lower face outlet 120 and the upper face outlet 121. Further, the liquid crystal wax A is reliably prevented from entering between the reinforcing substrate S and the holding surface 11a or between the wafer W and the holding surface 12a, and contamination of the holding surfaces 11a and 12a is prevented. Thereby, high parallelism between the reinforcing substrate S and the wafer W is ensured.

  In the above example, since the lower surface blowing port 120 and the upper surface blowing port 121 are formed in a ring-shaped slit shape, the liquid crystal wax A that has flowed out over the entire circumference of the reinforcing substrate S and the wafer W is appropriately washed away without deviation. be able to.

  In the above example, since the air passage 150 is formed on the upper surface side of the spacer 80, the gas blown from the upper surface outlet 120 and the lower surface outlet 121 can be exhausted to the outside of the spacer 80 through the air passage 150. By so doing, for example, the atmosphere inside the spacer 80 does not become unnecessarily high, and gas is prevented from being mixed into the liquid crystal wax A. Further, the pressure difference between the inner side and the outer side of the spacer 80 becomes larger than necessary, and the flow rate of the liquid crystal wax A passing through the discharge passage 111 is increased, so that the liquid crystal wax A is prevented from scattering to the outside of the spacer 80. Further, since the air passage 150 is formed at a plurality of positions in the circumferential direction of the spacer 80 at equal intervals, the liquid crystal wax A that has flowed out of the wafer W can be discharged to the outside of the spacer 80 evenly.

  Further, according to the above example, since the discharge passages 111 and the air passages 150 are alternately provided at alternate positions in the spacer 80, the thickness of the spacer 80 is made uniform over the entire circumference, thereby the heat capacity of the spacer 80. Is also made uniform. As a result, the temperature of the spacer 80 during the pasting process is made uniform over the entire circumference, and the thermal expansion of the spacer 80 is also made uniform, so that the gap between the reinforcing substrate S and the wafer W is constant over the whole circumference. Can be maintained. Further, it is possible to prevent the liquid crystal wax A passing through the discharge passage 111 in the vicinity of only a part of the spacer 80 from being cooled to be cooled and solidified.

  In such an example, the groove 151 for forming the ventilation path 150 may be formed on the holding surface 12a side of the upper chuck 12, or formed on both the upper surface of the spacer 80 and the holding surface 12a of the upper chuck 12. May be.

  The outer peripheral portions of the holding surface 11a of the lower chuck 11 and the holding surface 12a of the upper chuck 12 described in the above embodiments are horizontal, but may be inclined so that the outer side becomes lower. For example, as shown in FIG. 12, an inclined surface 11b is formed on the outer peripheral surface of the holding surface 11a of the lower chuck 11 on the outer side of the reinforcing substrate S so that the outer side becomes lower. An inclined surface 12b is formed on the outer peripheral surface of the holding surface 12a of the upper chuck 12 on the outer side of the wafer W so that the outer side is lowered. In this case, since the liquid crystal wax A that has flowed out between the reinforcing substrate S and the wafer W flows outward along the inclined surface 11b of the lower chuck 11, the discharge of the liquid crystal wax A is further promoted. Even when the liquid crystal wax A that has flowed out adheres to the holding surface 12a of the upper chuck 12, the liquid crystal wax A is discharged to the outside of the spacer 80 along the inclined surface 12b. Contamination of the holding surface 12a is prevented.

  Although the outlets 120 and 121 described in the above embodiment are formed on both the holding surface 11a of the lower chuck 11 and the holding surface 12a of the upper chuck 12, any one of them may be used.

  In the above example, the liquid crystal wax A may be recovered by forming a ring-shaped groove 160 outside the spacer 80 of the inclined surface 11b of the lower chuck 11 as shown in FIG. Further, a discharge pipe 162 communicating with the collection container 161 may be connected to the groove 160, and the liquid crystal wax A accommodated in the groove 160 may be discharged to the collection container 161 through the discharge pipe 162 and collected. Furthermore, a temperature adjustment function may be provided in the discharge pipe 162 so that the inside of the discharge pipe 162 is maintained at a high temperature so that the liquid crystal wax A passing through the discharge pipe 162 does not solidify. According to this example, the liquid crystal wax A discharged to the outside of the spacer 80 can be suitably collected.

  In the above example, the inclined surfaces 11 b and 12 b are formed on both the holding surface 11 a of the lower chuck 11 and the holding surface 12 a of the upper chuck 12, but either one may be used.

  Further, a large number of vertical grooves 170 may be formed on the inner peripheral surface of the spacer 80 described in the above embodiments as shown in FIG. By doing so, the liquid crystal wax A that contacts the inner peripheral surface of the spacer 80 is separated and dropped by the groove 170, so that the liquid crystal wax A does not stay on the inner peripheral surface of the spacer 80, but from the discharge passage 111 of the spacer 80. It is discharged properly. Note that the shape of the groove 170 may be uneven, V-shaped or U-shaped.

  The liquid crystal wax A described in the above embodiment may contain a plurality of spherical particles. These particles P have a constant diameter, and are sandwiched between the reinforcing substrate S and the wafer W during bonding, as shown in FIG. As the material of the particles P, a resin, metal, glass, or the like that does not chemically react with the liquid crystal wax A and has heat resistance with respect to the melting temperature of the liquid crystal wax A is used. Further, as the particles P, for example, particles having the same diameter as the gap between the reinforcing substrate S and the wafer W determined by the spacer 80 at the time of pressing are used. By doing so, the gap is kept constant even on the bonding surface between the reinforcing substrate S and the wafer W, so that higher parallelism between the reinforcing substrate S and the wafer W can be secured.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, in the above embodiment, the spacer 80 is attached to the lower chuck 11 side, but may be attached to the holding surface 12 a of the upper chuck 12. The spacers 80 may be provided on both sides of the holding surface 11 a of the lower chuck 11 and the holding surface 12 a of the upper chuck 12. In the above embodiment, the lower chuck 11 moves up and down to bond the reinforcing substrate S and the wafer W, but the upper chuck 12 may move up and down. Further, both the upper chuck 12 and the lower chuck 11 may move up and down. In the above embodiment, the reinforcing substrate S is held on the lower chuck 11 side and the wafer W is held on the upper chuck 12 side. Furthermore, the present invention can also be applied when holding the wafer W on both sides of the lower chuck 11 and the upper chuck 12 and bonding the wafers together. Further, in the above embodiment, the adhesive is supplied onto the substrate on the lower chuck 11 side, but the adhesive may be supplied to the substrate on the upper chuck 12 side. In this case, an adhesive may be fixed to the substrate held by the upper chuck 12 in advance, and then the substrate and the substrate on the lower chuck 11 side may be bonded together. The present invention can also be applied to bonding of substrates other than the wafer W and the reinforcing substrate S. The present invention can also be applied to the case of using a hot melt type adhesive other than liquid crystal wax.

  For the bonding apparatus 1 having the spacer 80, an experiment of bonding accuracy was performed. In FIG. 16, the wafer W and the reinforcing substrate S are bonded a plurality of times using the bonding apparatus 1 having the spacer 80, and the in-plane variation of the thickness of the bonded body B after each bonding is measured. The results are shown.

  As shown in FIG. 16, as a result of a plurality of experiments, when the thickness after bonding is the largest, it is about +5.5 μm from the target thickness (0), and from the target thickness when the bonding thickness is the smallest − It is about 6 μm. That is, according to the bonding apparatus 1 having the spacer 80, the thickness variation after bonding is suppressed to 12 μm or less. Compared to the conventional bonding apparatus without the spacer 80 in which the variation in thickness after bonding is about 40 μm, the bonding apparatus 1 with the spacer 80 significantly reduces the variation in the thickness of the bonded body B after bonding. The wafer W and the reinforcing substrate S can be bonded in parallel.

  The present invention is useful when two substrates are bonded in parallel so as to have a uniform thickness.

It is explanatory drawing of the longitudinal cross-section which shows the outline of a structure of the bonding apparatus. It is a top view of an upper chuck | zipper. It is a top view of a lower chuck. It is sectional drawing of the upper chuck | zipper and lower chuck | zipper explaining the state at the time of bonding. It is a time chart which shows control of the temperature of the board | substrate for a reinforcement | strengthening in a bonding process, the pressure in a processing container, and the position of a lower chuck | zipper. (A) is explanatory drawing which shows the state which put the liquid crystal wax on the board | substrate for reinforcement. (B) is explanatory drawing which shows the state which liquid crystal wax melt | dissolved. (C) is explanatory drawing which shows a mode that it defoams from liquid crystal wax. (D) is explanatory drawing which shows the state which bonded the board | substrate for reinforcement and the wafer. (E) is explanatory drawing which shows the state which separated the wafer from the upper chuck | zipper. It is a top view of the lower chuck | zipper provided with the ring-shaped spacer. It is a longitudinal cross-sectional view of the outer peripheral part of an upper chuck | zipper and a lower chuck | zipper at the time of forming a discharge path in a spacer. It is sectional drawing of the spacer which has a groove | channel on the lower surface. It is a longitudinal cross-sectional view of the outer peripheral part of the upper chuck | zipper and lower chuck | zipper which have a blower outlet. It is sectional drawing of the spacer which has a groove | channel on the upper and lower surfaces. It is a longitudinal cross-sectional view of the outer peripheral part of the upper chuck | zipper and lower chuck | zipper which have an inclined surface. It is a longitudinal cross-sectional view of the outer peripheral part of the upper chuck | zipper which has a groove | channel on an inclined surface, and a lower chuck | zipper. It is sectional drawing of the spacer which has a groove | channel on an internal peripheral surface. It is a longitudinal cross-sectional view of an upper chuck and a lower chuck when spherical particles are contained in liquid crystal wax. It is a graph which shows the dispersion | variation in the thickness after bonding at the time of bonding a wafer and a reinforcement board | substrate using the bonding apparatus which has a spacer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bonding apparatus 10 Processing container 11 Lower chuck 11a Holding surface 12 Upper chuck 21 Heater 33 Cylinder 80 Spacer S Reinforcing substrate W Wafer A Liquid crystal wax

Claims (17)

A laminating apparatus for laminating two substrates using a hot-melt adhesive,
A first holding member that holds one substrate with the bonding surface facing upward;
A second holding member for holding another substrate with the bonding surface facing downward so as to face the one substrate held by the first holding member;
A temperature raising / lowering mechanism capable of increasing the temperature until the adhesive supplied to the bonding surface of at least one of the one substrate or the other substrate is melted and further lowering the temperature until solidified;
A holding member driving mechanism for vertically moving at least one of the first holding member and the second holding member and pressing the bonding surfaces of the substrates with the adhesive interposed therebetween. And
The holding surfaces of the first holding member and the second holding member are formed larger than the one substrate and the other substrate,
A holding surface of at least one of the first holding member and the second holding member, the first holding member and the second holding member at the time of pressing at a position outside the held substrate, A spacer for making the gap of the substrate constant is provided apart from the substrate ,
The spacer is formed as a protrusion on the holding surface, and is formed so as to surround a substrate held on the holding surface,
Between the spacer and the holding surface of the first holding member, a discharge passage for discharging the adhesive inside the spacer to the outside of the spacer is formed,
At least one of the holding surface of the first holding member and the holding surface of the second holding member is formed with a blow-out port for blowing out gas, and the blow-out port is an end of the substrate held on the holding surface. A bonding apparatus, wherein the bonding apparatus is formed at a position of a part . The bonding apparatus according to claim 1, wherein the spacer is formed with a ventilation portion that communicates from the inside of the spacer to the outside of the spacer when pressed. The spacer is formed by a plurality of protrusions formed linearly,
The plurality of protrusions are arranged so as to surround a substrate held on the holding surface in a square frame shape,
The bonding apparatus according to claim 2, wherein the ventilation portion is formed between the protrusions. The groove on the lower surface of the spacer is formed from the inner side to the outer side of the spacer, and the discharge passage is formed by the groove and the holding surface of the first holding member. The bonding apparatus as described. The bonding apparatus according to claim 4, wherein the discharge passages are formed at a plurality of intervals in a circumferential direction of the spacer. The holding surface of the first holding member is formed with an inclined surface whose outside is lowered, and the inclined surface is formed outside a position where the substrate of the holding surface is held, The bonding apparatus according to claim 1, 4 or 5. The bonding apparatus according to claim 6, wherein the outlet is formed in a slit shape along the outer periphery of the substrate. 8. Affixing according to claim 7, wherein an air passage is formed between the spacer and the holding surface of the second holding member so as to communicate from the inside of the spacer to the outside of the spacer when pressed. Alignment device. 9. A groove is formed on the upper surface of the spacer from the inner side to the outer side of the spacer, and the ventilation path is formed by the groove and a holding surface of the second holding member. The bonding apparatus as described in. 10. The bonding apparatus according to claim 8, wherein the air passages are formed at a plurality of locations in the circumferential direction of the spacer at equal intervals. The holding surface of the second holding member is formed with an inclined surface whose outside is lowered, and the inclined surface is formed outside a position where the substrate of the holding surface is held, The bonding apparatus according to any one of claims 8 to 10. The bonding apparatus according to any one of claims 1 to 11, wherein a vertical groove is formed on an inner peripheral surface of the spacer. The bonding apparatus according to claim 1, further comprising a parallelism adjustment mechanism that adjusts a parallelism between the first holding member and the second holding member. The parallelism adjusting mechanism includes a push-down member that pushes down the second holding member with a central portion of the second holding member as a fulcrum, and a lifting member that pulls up the second holding member. The bonding apparatus according to claim 13. The push-down member and the pull-up member are provided at a plurality of locations of the second holding member, respectively.
  The push-down member and the pull-up member are arranged at equal intervals on the same circumference with the center portion of the second holding member as a center when viewed from above. Bonding equipment. The bonding apparatus according to any one of claims 1 to 15, wherein the holding surfaces of the first holding member and the second holding member are subjected to a surface treatment for flattening. The adhesive contains a plurality of spherical particles that define a gap between one substrate and another substrate at the time of bonding,
  The bonding apparatus according to claim 1, wherein the plurality of particles have a constant diameter.

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