RU2498449C1 - Contacting device - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: contacting device is made as a frame with a flexible printed circuit stretched on it and protrusion with external connector; at the flexible printed circuit there are oriented fixed patterns with reach-through windows for placement of controlled electronic components; at surface of the flexible printed circuit conductors with their peaks form lamellae with contact areas in compliance with topology of contact areas for the controlled components. At that total gap between the pattern window and electronic component should not exceed the distance between adjoining lamellae; between the base of contacting device and flexible printed circuit there is an elastic gasket made of material having properties of elastic strain; electronic components placed in the pattern windows at the other side have a thermal contact with heat sink which serves at the same time as a mechanical holdback; at the surface of heat sink and frame contacting with flexible printed circuit there is an applied electric insulating coating.

EFFECT: invention provides low costs for operations of functional check and electrical training of electronic components.

6 cl, 8 dwg

Description

FIELD OF THE INVENTION

This invention relates to the field of designing devices that provide group functional control and electrothermotherapy (ETT) of semiconductor crystals after they are removed from the plate and microplates for three-dimensional electronic modules.

State of the art

The known method and apparatus for the production of a guaranteed suitable crystal according to US patent 5,640,762, IPC Н05К 3/30 dated June 24, 1997.

The method includes the steps: testing the suitability of the crystal on the plate, cutting the plate into single crystals; and then testing the crystal by assembling a carrier having interconnects adapted to create an electrical connection between the contact pads on the chip and external testing devices. Interconnects for a carrier can be formed using various technologies, including: thick-film contact structural members on a rigid substrate; self-limiting contact structural elements on a silicon substrate or micro-column elements with a texture surface. During carrier assembly, the crystal and interconnects are optically aligned and come into contact with a specific contact force. This establishes an electrical connection between the contact structural members and the contact pads of the crystal. In the assembled carrier, the crystal and the interconnect are joined together using a force distribution mechanism, which includes a curved bracket, a pressure plate and a spring clip. Testing of the crystal follows, the carrier is disassembled, and the tested crystal is removed.

This solution has several fundamental drawbacks: the design does not provide for the possibility of aligning each contact element with the contact area of the crystal; the contact element has a protrusion height of not more than a fraction of a micrometer, which is practically impossible; simultaneous group contacting of several crystals is not provided. All this makes this solution only theoretically feasible.

There is also known a method and apparatus for implementation at the level of the wafer of testing crystals of integrated circuits according to US patent No. 5,399,505, IPC H01L 21/66 of 03/21/95.

Semiconductor wafers include integrated circuit crystals, conductors on the wafer, and wafer pads formed thereon. The conductors on the wafer are used to transmit electrical signals to and from the crystals of integrated circuits so that testing of ETT crystals of integrated circuits can be carried out at the wafer level. According to one embodiment, each conductor on the plate is electrically connected to the same pad on each chip of the integrated circuits. Each conductor on the plate includes at least a portion of the conductor that extends from above the surface of the at least one integrated circuit chip.

The advantages of this solution include the attempt at group control and ETT crystals in the plate. The disadvantages are the parallel connection of the same contact pads of all crystals, which makes it very difficult to identify a failed crystal; the solution is practically limited only to memory circuits, since other circuits will require very complex wiring along the surface of the plate and a huge number of external contact pads on the plate; the proposed design of the contacting device provides for rigid fastening of each contact relative to the external contact area of the plate, which does not allow the secondary use of such a contacting device.

There is also known a technical solution according to patent EP 0287451, IPC H01L 21/66 of 04/12/08, "Method and device for connecting and mounting an electronic component during testing."

The method involves connecting a component to a frame located on the periphery of the component using wire conductors. Testing of the component is carried out by connecting test equipment to said frame. After testing, the component is mounted on a substrate, and the connection of the component with the substrate is carried out by conductors connecting the component to the frame. After connection, the conductors are cut along the line between the contact pads on the substrate and the frame, after which the frame is removed. This method is practically applicable only for subsequent use of the component by welding and is not applicable for other uses, for example, in three-dimensional modules.

Known technical solution according to patent EP 0554622, IPC G01R 31/26 from 12/21/92, "Equipment and control method of bare crystals."

This method consists in combining a bare crystal, isolated from a semiconductor wafer, using a flip-chip optical alignment system with solder protrusions deposited on a multilayer printed circuit board made on a silicon or aluminum base. An external force is applied to the crystal, which is necessary for plastic deformation of the protrusions and for ensuring that all the contact pads of the crystal are in contact with the protrusions on the printed circuit board. The disadvantages of this method are the inability to reuse a printed circuit board for contacting another crystal, and group control of crystals is also not provided.

A known method of attaching a semiconductor device using flat leads to a test substrate and using a wedge-shaped electrode application PCT / US 90/06583, IPC H01L 21/66 from 12.26.90,

The electronic component is temporarily mounted on a temporary test substrate. The pads of this component are connected to the pads of the test substrate using wire or flat leads. A wedge-shaped electrode is used to connect the leads, with the help of which in the central part of the lead a “gull wing” -type section is formed. The component installed on the test site is tested by applying the given signals to its contacts. After that, the contact leads are cut in the area of their connection with the contact pads of the test substrate and the device is removed with the remaining leads. The contact pins are made of hard material and are attached to the edges of the device with glue, which allows you to maintain your shape after removal from a temporary test substrate. Then the component is installed on a permanent substrate of the device and attach its conclusions to the corresponding contact pads of this substrate. The disadvantage of this method is the presence of wire or flat leads welded to the component, which then need to be cut, as well as the high complexity of testing the components.

A known method of mounting on a tape for dynamic ETT crystals according to US patent No. 4,981,817, IPC H01L 23/528 from 01/01/91.

The method consists in the fact that the crystals mounted on the tape are attached to the conductors formed on the tape by standard methods. The tape provides through-windows to which the conductors necessary for dynamic ETT crystals are suitable. An additional tape is attached to the back of the tape having conductors for connection to an external test device. The wiring on the main tape is connected in the windows with the wiring on the additional tape using jumpers or volume contacts. The disadvantage of this method is the need to use the crystal after conducting ETT only with the portion of the tape to which it is attached, the secondary use of carriers is excluded.

A known design of the contacting device according to the article "Bum-in test sockets beneficial for high volume CSP applications" in the journal "Advanced Packaging" July / August 1998, p.32 ÷ 37.

The contacting device is designed to test both ETT crystals and packaged integrated circuits with ball terminals. Each ball pin is captured by a split socket such as a tweezers with pointed ends. In this case, the ball lead made of soft solder is somewhat deformed from the side. A spacing of ball terminals of at least 0.75 mm is allowed. This technical solution is limited to the use of devices with ball terminals with a significant spacing and is very difficult to manufacture, especially with a large number of conclusions.

There is also known a method of manufacturing and control of electronic components ”according to Russian patent 2133522, IPC H01L 21/66 of 03/03/97.

This method consists in the fact that many crystals are placed in the mold, focusing on the contact pads of the crystals and the basic elements of the mold, isolate all unprotected surfaces of the crystals, except for the contact pads. The difference of the method lies in the fact that, when placed in the mold, the crystals are fixed together with the formation of a group carrier, while ensuring that the front surfaces of the crystals are in the same plane with one of the surfaces of the group carrier, while all the conductors necessary are applied to this plane at the same time. for ETT and control as well as connector. A variant of the method is that simultaneously with crystals, a group metal frame is placed in the mold, which is fixed simultaneously with the crystals. The advantage of this method is the implementation of group monitoring and ETT, as well as a highly reliable connection between components and with an external connector. The disadvantages include the one-time use of a group microplate and the inability to control and ETT bare crystals.

The closest analogue to the claimed invention (prototype) is a technical solution according to US patent No. 5,831,445, IPC: G01R 1/06 from 11/03/98.

The plates are connected to a printed circuit board that is electrically in contact with the pads on each chip using small conductive contact posts. Exact alignment of the whole plate inside the device allows you to test all the crystals on the plate at the same time, eliminating the need to study each crystal separately. The device is equipped with thermal elements and cooling channels to obtain the required plate temperature during ETT and testing. The method eliminates the use of defective crystals after ETT and testing, thereby increasing assembly efficiency. The advantage of this technical solution is an attempt to conduct a group ETT and control in the composition of the plate, as well as the presence of a heat sink. The disadvantages include contacting the plate with the contact columns by plastic deformation, which necessitates great efforts when articulating the circuit board with the plate and makes it impossible to reuse this design of the contacting device.

The main objective of this invention is to create a design of a group contacting device that provides a low cost of functional control and ETT electronic components.

Disclosure of invention

The problem is solved in that a group contacting device (hereinafter referred to as KU) having a contact field, a mechanical clamp providing contact of components with a KU, having a rigid base and heat sink, has a contact field made in the form of a flexible printed circuit board forming contact zones, lamellas which are located in accordance with the topology of the pads of the controlled components, and also has lamellas of the external connector. Lamellas of contact fields of a flexible printed circuit board having contact with the contact pads of the components, as well as the lamellas forming the external connector, have a wear-resistant conductive coating, and the contact pads of the components must be previously cleaned of dirt and oxide films. A flexible printed circuit board can have a multilayer wiring and is made of thin insulating material that allows you to compensate for the non-flatness in the location of the contact zone lamellas.

The flexible printed circuit board is fixed in a stretched form on the frame and partially covers the frame along the external contour, forming an external connector. It is advisable to fix it by gluing. Templates are installed on a flexible printed circuit board, having through windows for placement of controlled components. Places for fixing templates are at the maximum possible distance from the window. Templates can be made of both insulating material and metal, but in this case all surfaces of the templates must have an insulating coating. The material of the templates should allow precision processing in the manufacture of through windows.

The size of the total gap between the template window and the component in the plan should ensure that the lamellas of the contact area of the KU are combined only with the corresponding contact pads of the component. An increased gap can lead to the absence of contact between the lamella and the contact pad of the component or to the lamella shorting adjacent contact pads of the component. Each template is installed with the orientation of each of its windows with the location of the slats of the corresponding contact zone of the flexible printed circuit board.

Between the base of KU and a flexible printed circuit board there is an elastic gasket made mainly of a rubber plate of small thickness (usually not more than 1 mm) and having good elastic properties. At the base there are depressions for filling the gasket material with the application of compressive force on the KU. The role of the elastic strip is also performed by an elastic layer deposited on the surface of the base adjacent to the flexible printed circuit board.

The components located in the template windows, on their reverse side, have thermal contact with the heat sink, which simultaneously serves as an external clamp. The thermal contact of the component with the heat sink is provided by applying a metered layer of heat-conducting material to the contact points, for example, heat-conducting paste. The surface of the heat sink in contact with the component, as well as the surface of the frame in contact with a flexible printed circuit board, have an electrical insulation coating or must be made of electrical insulation material.

The external size of each template in plan, the place of its attachment to a flexible printed circuit board, the amount of compressive force, as well as the thickness and material of the elastic strip are chosen so as to ensure elastic deformation of the elastic strip and flexible printed circuit board in order to obtain reliable electrical contact of each lamella of the contact field a flexible printed circuit board with the appropriate pad for the component being monitored.

The device is also described in which a flexible printed circuit board with templates fixed on it, in which the controlled components are placed, has a wavy (zigzag) shape, while elastic pads are placed in the hollows of the printed circuit board. The components in pairs with their return surfaces have thermal contact with the heat sink plates, while the heat sink plates protruding beyond the dimensions of the flexible printed circuit board form an external radiator of the contacting device. At least one of the heat sink plates has a protrusion for forming, together with a flexible printed circuit board, an external connector of the described device.

After assembly, a compressive force is applied to the heat sink plates located at the ends of the contacting device, sufficient to ensure electrical contact between the component pads and the contact field lamellas of the flexible printed circuit board.

Brief Description of the Drawing

Where in figures 1-8 are specific examples of the invention, in which:

figure 1 depicts a planar variant of a group contacting device;

figure 2 depicts a frame mounted flexible printed circuit board with templates;

figure 3 depicts the combination of the contact pads of the component with the lamellas of the contact zone of a flexible printed circuit board;

figure 4 depicts the area of contacting the component with a flexible printed circuit board;

5 shows an embodiment of a bolt clamp of a group contacting device;

6 shows a variant of flat spring clamping of a group contacting device;

7 depicts a batch version of a group contacting device;

Fig.8 depicts a flexible printed circuit board with templates in a batch version of a group contacting device.

The implementation of the invention

Figure 1 shows a planar version of the contacting device, which consists of a heat sink 1, which simultaneously performs the clamping function, frame 2 with a flexible printed circuit board 3 stretched over it. Templates 4 are fixed on the flexible printed circuit board 3. The flexible printed circuit board 3 is in contact with the back side an elastic gasket 5, which is sandwiched between the flexible printed circuit board 3 and the base 6. The frame 2 has a protrusion 7, which surrounds the flexible printed circuit board 3, forming an external connector 8 of the control device. Figure 1 shows a variant of using as a test electronic components a bare crystal 9 and a crystal with ball terminals 10 placed in the windows 11 of the templates 4. A layer of heat-conducting material 12 is dosed between the heat sink 1 and the reverse sides of the components 9 and 10.

Figure 2 shows a frame 2 with a flexible printed circuit board 3 stretched over it, on the surface of which are conductors 13 that form lamellas 14 contact zones in accordance with the topology of the contact pads 15 of components 9 and 10. The templates 4 are oriented oriented on a flexible printed circuit board 3 with the orientation of the windows 11 on the slats 14 of the contact zones. The conductors 13 also form the lamellas 16 of the external connector 8.

Figure 3 schematically shows a variant of the possible combination of the contact pads 15 of the component 9 with the lamellas 14 of the contact zones. In this case, the size of the gap “a” between the window 11 in the template 4 and component 9 should be such that any contact area 15 of size “b × b” would be completely covered by the lamella 14 of the contact zone by a value of “c”, but would be maintained the necessary clearance “d” so that the contact pads 15 are not bridged by the lamella 14. The lamella 14 can be bifurcated, as shown below in FIG. 3, to facilitate monitoring the presence of electrical contact between the lamella 14 and the contact pad 15.

Figure 4 shows in large detail the contact area of the component 9 with the female conductor 17 applied to it with a flexible printed circuit board 3. The heat sink 1 presses through the heat-conducting material 12 on the component 9, which, through the flexible printed circuit board 3, deforms the elastic strip 5, ensuring reliable electrical contact of the lamella 14 of the contact zone with the conductor 17 of component 9. The depression in the base 6 is partially filled with the material of the elastic strip 5.

Figure 5 shows a variant of the bolt clamp of the control device, in which the clamp is carried out using a bolt 18 and nut 19. The clamping force is controlled by the length of the sleeve 20 and the parameters of the spring 21. Between the heat sink 1 and the frame 2, a spring washer 22 is placed, holding the frame 2 in a fixed position condition. FIG. 6 shows a variant of clamping the device using a flat spring 23 inserted in the window of the pin 24. In this case, the device is pre-compressed to the required force and then the pin 24 with the flat spring 23 is inserted from below (in FIG. 6), after which the compression take off. The shape of the flat spring 23 is such that it seizes the entire assembly in a compressed state. To disassemble the device, it is necessary to compress it again, put on all the pins 24 of the sleeve, compressing the flat springs 23, and then remove the pins 24 from the holes of the control device.

7 shows a batch version of the control device. Templates 4 are fixed on the flexible printed circuit board 3 and components are placed in their windows 11, for example, in the form of a crystal 9 with the covering conductors 17 applied on it and in the form of a microplate 25. A wave-shaped (zigzag) shape is first given to the flexible printed circuit board and then inserted into the resulting the grooves are elastic gaskets 5. Between the pairs of components 9 and 25 are placed the plate-heat sinks 26, which have elongated zones 27, forming an external radiator of the control device. The heat sink plates 26 are in thermal contact with the components 9 and 25 through the heat-conducting material 12. At least one of the heat sink plates 26 has a protrusion 28 for forming, together with the flexible printed circuit board 3, an external connector 8. To the heat sink plates 26 located on at the ends of the control device, an external force necessary for contacting is applied by the means shown in FIGS. 5 and 6. This embodiment is more compact than that shown in FIG. 1, but more difficult to assemble.

On Fig shows a flexible printed circuit board 3 for a batch version of the control device. A flexible printed circuit board 3 with deposited conductors 13, lamellas 14 of the contact zones and lamellas 16 of the external connector 8 is pre-stretched in the technological device and in this form, templates 4 are fixed on it with orientation to the lamellas 14 of the contact zones, after which the flexible printed circuit board is cut along contour. The batch version of the control device and the flexible printed circuit board 3 can be performed in a multi-row version, but this, accordingly, will entail an increase in the necessary compression force.

This invention can be successfully used in the manufacture of miniature electronic equipment using bare crystals, crystals with special conclusions, as well as for the manufacture of guaranteed suitable crystals and microplates for three-dimensional modules.

Claims (6)

1. The contacting device, designed primarily for monitoring and testing electronic components, containing a mechanical clamp to ensure contact of the electronic components with the contacting device, a rigid base and heat sink, characterized in that the contacting device is made in the form of a frame with a flexible printed circuit board stretched over it, having protrusion with an external connector, oriented on a flexible printed circuit board, templates having through windows for placement of controlled electronic components in them are fixed ponents, on the surface of a flexible printed circuit board, the conductors with their protrusions form lamellas with contact zones in accordance with the topology of the contact areas of the elements being monitored, while the total clearance between the template window and the electronic component should not exceed the distance between adjacent lamellas, between the base of the contacting device and the flexible printed circuit board an elastic gasket is located, the material of which has the property of elastic deformation, electronic components located in the windows of the templates, with its of inverse sides have thermal contact with the heat sink, which also serves as a mechanical holder, on the surface of the heat sink and the frame in contact with the flexible printed circuit board electrically insulating coating is applied. 2. The contacting device according to claim 1, characterized in that between the heat sink with the electronic component in the places of contact are layers of heat-conducting material, made, for example, in the form of heat-conducting paste. 3. The contacting device according to claim 1, characterized in that the lamellas of the contact fields of the flexible printed circuit board and the lamellas forming the external connector have a wear-resistant conductive coating. 4. The contacting device according to claim 1, characterized in that the elastic gasket is made of an elastic layer deposited on the surface of the base adjacent to a flexible printed circuit board. 5. The contacting device according to claim 1, characterized in that the heat sink material in contact with the electronic component, as well as the frame material in contact with the flexible printed circuit board, are made insulating. 6. The contacting device according to claims 1 to 4, characterized in that the flexible printed circuit board with the templates fixed on it, in which the controlled components are placed, has a wavy shape, while elastic pads are placed in the hollows of the printed circuit board, and the components are paired with their return surfaces have thermal contact with heat sinks; in this case, the heat sinks protruding beyond the dimensions of the printed circuit board form an external radiator of the contacting device, and at least one of the heat sinks has a protrusion for forming, together with the flexible printed circuit board, the external connector of the contacting device; in this case, the heat sink plates located at the ends of the contacting device are connected to the element to give a compressive force sufficient to ensure electrical contact of the component pads with the contact field lamellas of the flexible printed circuit board.

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