JPH1126128A - Chip scale carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent tangential force by which a terminal ball comes out or bends by arranging a mutual connection band arranged on the surface of a first layer and having a plurality of conducting traces for connecting a connecting pad and a mutual connecting pad. SOLUTION: When a BGA device 16 is moved in the direction of a rubber supporting pad 50, a terminal ball 15 comes in contact with a connecting pad 42a exposed through a window and a top pad 41a for being bonded. Since the connecting pad 42a and the top pad 41a are flexible and the supporting pad 50 is elastic, pressure is uniformly applied to the whole terminal ball 15, and vertically acts to the surface of the device 16. By the strong contact of the terminal ball 15, the top pad 41a and the connecting pad 42a are deformed along the surface of the terminal ball 15, contact pressure is uniformly dispersed, and the terminal ball 15 is electrically connected to the connecting pad 42a and a conducting trace 41b. Conducting traces 41, 42 are insulated each other by insulating a top layer 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present application relates to
US Provisional Application No. 60 / 041,736, filed on date
Claim the priority of the issue.

[0002] The present invention relates to a current test for small electronic packages and semiconductor chips. More specifically, the present invention relates to a method and an instrument for handling a small electronic device and a device package such as a chip scale package during an electric conduction test, and to an input / output terminal having a close space on the small scale package. With respect to achieving and maintaining positive electrical contact,
This is done without damaging the chip, its package, its interconnect terminals or the test carrier.

[0003]

2. Description of the Related Art Advances in microelectronics technology tend to develop electronic device chips and packages that perform more functions while taking up less space. As a result, the physical size of each interconnect must be reduced, as the number of electrical interconnects between the chip and the external electronics required for circuits in the chip to communicate with the outside world increases. No. In order to make an electrical connection between the chip and external electronic circuits, the circuit chip is usually housed in a housing or package,
The housing or package supports interconnects such as leads, pads, lands, etc. on one or more external surfaces thereof. In order to reduce the overall lead length from the chip to the external electronics and to provide adequate spacing between the input / output terminals on the package, high pin count devices are usually provided on the package, In it, input /
The output terminals are arranged in a grid pattern on one side of the package. The terminals may be in the form of pins extending from the package (usually described as a pin grid array or PGA), and in the form of contact pads or contact lands on the package surface (usually a land grid array or LGA).
Is called). Device to physically attach the chip to the substrate and electrically connect between its terminal lands and similar interconnect lands or interconnect pads on the surface of the substrate, such as the circuit board on which the package is to be mounted Small drops or ball-shaped solder is fixed to each terminal land on the package. The device is commonly referred to as a ball grid array (BGA) device because the solder drops form ball-like protrusions extending from the terminal lands.

[0004] The term "ball grid array device" is generally used for a device package having a substantially spherical contact portion extending from one side of the device package.
This term is also used for other structures. For example, in order to attach a bare (unencapsulated) chip to a package, the chip may be provided with a grid array of ball-shaped contacts. However, at a certain point in time, a bare chip with ball-shaped contacts is often referred to as a ball grid array device.
Similarly, terminal pads may be provided on one side of the finished chip with ball-like solder deposits forming interconnects. Next, the chip is turned over and attached directly to the corresponding pattern of interconnect pads on the substrate. The solder balls reflow upon heating, forming electrical and physical contacts. Obviously, this process (sometimes called "flip chip" technology) uses a device called a ball grid array device. More recently, small device packages have been devised that have input / output terminals at very close spacing on one side of the chip. Such devices are called chip-scale packaged chips or micro-BGAs and are the most difficult to handle without damage because of their extremely small size, configuration and physical structure, but nonetheless still have all the inputs / outputs It is essential to make electrical contact with the terminals. When using such small packages and such closely spaced terminals, it is not practical to probe each terminal with a separate wire probe. The probe is liable to bend (and thus not be aligned), overlap two or more terminals, apply sufficient pressure to the terminal ball to destroy or damage it, distort the terminal ball, and / or Or, it is combined with a terminal ball. Therefore, it is possible to devise an apparatus which can easily mount a small package such as a ball grid array device, particularly a chip scale package (preferably by automatic operation), and can perform inspection and / or stress inspection by an electric current test or the like. desirable. For the purposes of the present invention, the term "ball grid array" refers to all ball grid array configurations described above. The term "chip-scale package" is used to specifically denote a small ball grid array package, but does not exclude other ball grid array devices.

[0005]

SUMMARY OF THE INVENTION In accordance with the present invention, positive electrical contact with each terminal ball of a BGA package is obtained by using a flexible interconnect band at various depths of the band. Include conductive strips or patterns separated by a thin insulating layer, wherein the insulating layer is provided with openings or windows, and the surfaces of the interconnecting bands and / or conductive strips exposed through the windows in the insulating layer. Above, the input / output terminals of the ball grid arrangement are allowed to make electrical contact with the conductive strip. By pressing the surface of the terminal ball against the flat surface of the conductive strip or pad, any force applied to the terminal ball will be normal to the plane of the package. In this way, it is possible to prevent a tangential force or other force that may cause the terminal ball to come off or bend. By pressing the terminal ball against the flat surface of the conductive strip or pad, the conductive strip or pad is encouraged to match the shape of the terminal ball, thereby maximizing the physical contact area. In addition, the flat surface of the contact strip can scratch the terminal ball,
Do not carve or deform. Because there is no point contact,
Undesirable moving coupling between terminal ball and contact pad
The possibility of (migration bonding) occurring can be prevented or greatly reduced. Most importantly,
The physical distance (lead length) between the terminal ball and an external electronic circuit to which the terminal ball is connected by the conductive strip is greatly reduced. In this manner, the interconnect configuration of the present invention can be used for energization testing of very high frequency devices. Other features and advantages of the present invention will be more readily understood by reference to the following detailed description, taken in conjunction with the appended claims and drawings.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS It is contemplated that the principles of the present invention may be utilized or embodied in various forms. To illustrate these principles, the invention will be described by reference to particularly preferred embodiments.

The embodiment shown in the drawing includes a hinged swash or a body 10 supporting a door 20 supporting a carrier pad 21. The carrier pad 21 is located at the same position as the window hole 11 in the body 10.
The bottom plate 30 carries a plurality of output terminal pins 31 in the pattern holes 32. Interconnecting band 40
Are arranged on the support pad 50 such that one side faces the terminal pin 31 and the other side faces the window hole 11. Conductive traces or strips 41 are disposed on the surface of the interconnecting band 40 and the interconnecting band 40 contains at least one conductive trace or strip 42. Each conductive trace or strip 42 and the surface conductive trace or strip 41 are insulated from each other by insulating the top layer 43.

[0008] By utilizing multi-layer interconnect bands, it is possible to create interconnect bands that are insulated from one another, such that the distance between the terminal ball arrangement and the external circuit components is very small. FIG. 7 shows the interconnection between the output terminal pins 31 and the terminal balls 15. FIG. 14 shows a combination of a ball grid array socket and a carrier on a large scale.

The electrical connection between the terminal balls 15 of the ball grid array package 16 and the conductive traces or strips of the interconnect band in the present invention is shown in FIGS. A component part 16 consisting of a BGA with terminal balls 15 protruding from one surface is drawn suspended above a component part 40 consisting of an interconnecting band 40 arranged on a support pad 50. 5 and 6 are interconnected bands 40 (such as Mylar).
It includes two upper layers 43 of electrically insulating material. The conductive traces 42 are sandwiched between the insulating layer 43 and the conductive traces 41 and are disposed on the top layer 43 of the interconnect band 40. In this embodiment, conductive traces 42 are formed by depositing a layer of conductive metal (such as copper) on the surface of lower layer 43;
The pattern of the conductive traces 42 is formed by photomasking, etching, or the like. Other means such as formation through a mask or the like may be used. For the purposes of the present invention, any process that forms conductive traces in a desired pattern between two layers of insulating material can be used. Second layer, conductive trace 41
Is formed on the surface of the insulating layer 43. The windows 44 are made at appropriate locations on the insulating layer 43 and make electrical interconnections with the resulting exposed conductive pads 42a.
In a pattern having a plurality of extended connection pads (such as conductive pads 42a) connected to thin conductive strips that are electrically connected to interconnect pads 52a at other locations within interconnect band 40. That the conductive traces 42 can be formed deserve evaluation. By properly arranging the conductive traces 42 and the windows 44, the pattern of the connection pads 42 a exposed through the windows 44
Will be formed in contact with the selected pattern. A similar pattern of the connection pads 41a is formed on the surface of the upper surface layer 43 (each connection pad 41a is
1) and will be placed in contact with the selected pattern of terminal balls 15. The conductive ring 41b may be formed so as to be close to the window 44. In this arrangement, the terminal balls 15 are electrically connected to the connection pads 42a and the electric traces 41b.

As shown in FIG. 5, each terminal ball 15 is
It comes into contact with either the inner pad 42a or the upper surface pad 41a exposed through the window 44. The interconnecting band 40 is a support pad 5 made of an elastic material such as rubber.
It is desirable to be supported above zero. Therefore, when the BGA device 16 moves in the direction of the rubber support pad 50,
The terminal ball 15 is connected to the connection pad 41a and the connection pad 4
2a. However, since the connection pads 41a and the connection pads 42a are flexible and the support pads 50 are resilient, the pressure is evenly applied to all the terminal balls 15, and the BG in which the terminal balls 15 hang
It works only in the direction perpendicular to the surface of A16. Furthermore, if the tip or edge of the pin is not sharp, the probe or the like will engage with the terminal ball 15. Otherwise, each terminal ball 1
5 makes strong contact with the large surface of the connection pad. Since the ball makes strong contact with the connection pad, the connection pad 41a and the connection pad 42a are deformed along the surface of the terminal ball, and the contact pressure is evenly distributed to the terminal ball to be purchased.

The conductive traces 41 and 42 can be insulated from each other by deforming the connection pads 41a and 42a in the parallel plate insulated from each other by the upper surface insulating layer 43.
Single layer traces (such as conductive traces 41) can be placed in appropriate locations to prevent electrical shorts and crosstalk. In this way, the connection pads 41a and the connection pads 42a are staggered so as to form insulated contact with the terminal balls in close proximity.

In this embodiment, the interconnect band 40
Is formed using a Mylar film 43 having a thickness of about 0.001 inch. The connection pads 41a, the connection pads 42a, and the conductive traces 41 are formed of copper having exactly the same thickness as the connection band. The interconnect band 40 is flexible and is adapted to contact the connection pad 41a within 0.5 mm from the center of each pad in the grid pattern. Also, the combined trace is
It is electrically isolated from other traces.

Although the interconnect band 40 shown in FIGS. 5 and 6 consists of two insulating layers and two conductive pattern layers, it will be readily understood that there is no limitation in the present invention. In order to similarly set the interconnecting band 40 comprising three or more layers of conductive traces, the terminal balls must be arranged more closely or it is desired to improve the separation between the traces. I do.

Each connection pad 41a and each connection pad 42
In order to make an electrical connection between a and an external electronic circuit,
The conductive trace 41 and the conductive trace 42 must be connected to an external circuit. In the illustrated embodiment, the connection pads 41a and 42a
0.50mm interval (interval from center to center is 0.50m
m), and the opposite ends (interconnect pads) of the conductive traces are arranged in a pattern spaced 1.27 mm apart. As shown in FIGS. 3, 4, and 7, the interconnect band 40 covers the support pad 50 and includes an interconnect pad 51a and an interconnect pad 52a.
(The conductive trace 41 and the conductive trace 42, respectively.
Are connected to the connection pad 41a and the connection pad 42a via the connection pad 42a).

[0015] As shown in FIGS.
Are located in the pattern holes 32 in the bottom plate 30 (see FIG. 6), are arranged so as to be connected to the interconnect pads 51a and the interconnect pads 52a, and make an electrical connection with an external electric circuit. doing. As shown in FIG. 8, in the chip scale carrier of the present invention, the BGA terminal balls provide an electrical connection of 0.5 mm between centers, and the output leads to the output terminal pins have a center of 1.27 mm.
The output terminal pins 31 can be connected to a conventional external circuit through a circuit board, a current test board, or the like. Also, as shown in FIG. 14, the interconnection output terminal pins 31 protruding from the bottom plate 30 can be attached to a larger test socket or an energized test socket.

In this embodiment, the chip scale carrier is capable of receiving four BGA devices at the same time for a test or a power-on test.
The carrier has a bottom plate 30 including four pattern holes 32.
(See FIGS. 8 and 9). Window hole 1
The output terminal pin 31 in 1 makes an electrical connection with the external circuit described above.

As shown, the interconnecting band 40 covers the resilient support pad 50 (see FIGS. 7 and 8) and the output terminal pins 31 are oriented in the first direction in the intended pattern. Are mounted so as to mesh with the interconnect pads 51a and 52a. The connection pads 41a and the connection pads 42a are arranged on a grid arrangement pattern facing in the opposite direction.

The carrier body 10 has four windows, each window aligned with each of the four connection pads such that each pattern of the robust connection pads of the interconnect band 40 passes through the window. (See FIGS. 12 and 13). The body 10, the interconnecting band 40 (covering the support pad 50), and the bottom plate 30 are all securely fixed by rivets 60, screws, bolts, and the like.
The window 61 in the body 10 is preferably adjusted to the same position as the BGA so that the terminal balls on the BGA match the positions of the connection pads 41a and the connection pads 42a.
Various alignment means, such as keyways, ramps, and asymmetrically shaped objects, may be used in accordance with the appropriate direction and position of the BGA in the window. The splash or door 20 is mounted on the body 10 and includes four holes 63 in which the carrier pad 21 is mounted.
The carrier pad 21 is desirably made of a flexible and resilient material such as rubber, and is desirably aligned with the window 61 in the body 10. Door 2
In the case of the pivoting with the 0 closed (see FIGS. 1 and 3), the carrier pad 21 remains on the surface of the BGA package 16.

It should be noted that when the door 20 is closed, the carrier pad 21 merely remains on the device package 16 without firm pressure (while the pressure is in a certain direction). While facing, the terminal balls hanging from all four packages are connected to the connection pads 41a and 42.
a). The door 20 also has two ridges 7 extending in the direction from the hinge to the free end of the door 20.
There is 0. Each bump has two steps, the highest surface being surface 71 and the second parallel surface being surface 72.
Surface 72 (on the free end side of door 20) and surface 71 are identical except that surface 72 is farther from the bottom of the door than surface 71 when the door is closed. The closure 80 is mounted in a groove 81 formed at a joint between the body 10 and the bottom plate 30 (see FIGS. 1 and 3). A bump or non-slip 82 is formed on the top cover of the closure 80 and contacts and slides over the surface 72. At the same time, the guiding edge 83 is also in contact with the surface 72 and slides thereon. Therefore, when the door 20 is closed when the chip scale package 16 is present in each window 11, the carrier pad 21 is left on the surface of the package 16. When the closure 80 is closed, the guide edge 83 and the non-slip 82 come into contact with the slope 72a and the slope 71a at the same time. When the closure moves in the closing direction, the guide edge 83 and the non-slip 82 move to the slope 72 a and the slope 7.
Beyond 1a, rise on surface 72 and surface 71. By this movement, the door 20 (and the connection pad 21) is pressed in the direction of the bottom plate 30. In this manner, when the closure 80 is closed, a uniform downward pressure is automatically applied to all the terminal balls 15.

It will be appreciated that all components of the chip scale carrier of the present invention can be constructed using readily available materials and conventional techniques. Of course, when the carrier is used as a current-carrying test socket, a material that can withstand not only repeated use but also heat must be used. Also, the incorporation and removal of the device package 16 are as follows.
It can also be seen that it can be easily automated using conventional techniques.

The chip scale carrier shown here as an embodiment can be incorporated into a circuit board or the like by connecting the lower end of the output terminal pin 31 to a surface or a hole on the circuit board. Further, the exposed side of the output terminal pin 31 can be temporarily installed in a BGA test socket 100 incorporated in a current-carrying test board or the like (see FIG. 14). In the arrangement shown in FIG.
The A-power test socket 100 is disclosed in US Pat.
The socket shown in No. 5 or other suitable mounting device may be used. For the purposes of this specification, US Pat.
Issue 05 is cited here.

From the foregoing, it is apparent that using the principles of the present invention, the mounting and temporary electrical connection of almost any BGA package or device without the risk of damaging the terminal ball. Obviously, It should be understood, however, that while numerous features and advantages of the present invention are set forth in the foregoing description, including structural details and features of the present invention, this description is by way of example only. Various small changes and modifications may be made without departing from the spirit and scope of the present invention, as defined by the appended claims, particularly in shape, size, and arrangement of components.

[Brief description of the drawings]

FIG. 1 is a top perspective view of a preferred embodiment of a chip scale carrier using the principles of the present invention.

FIG. 2 is an exploded view of the chip scale carrier of FIG. 1 in an opened position, showing a position of a chip scale package therein.

FIG. 3 shows the chip scale carrier of FIG.
It is sectional drawing cut | disconnected along the line.

FIG. 4 shows the chip scale carrier of FIG. 2 as 2b-2b.
It is sectional drawing cut | disconnected along the line.

FIG. 5 is a partial cross-sectional view showing terminal balls arranged on a chip scale package contacting a conductive strip pattern in an interconnect band of the present invention.

FIG. 6 is a partial cross-sectional view showing terminal balls arranged on a chip scale package contacting a conductive strip pattern in an interconnect band of the present invention.

FIG. 7 is an enlarged partial cross-sectional view showing contact between an output pin of a chip scale carrier and an interconnect pad of an interconnect band.

FIG. 8 is an exploded view of the chip scale carrier assembly shown in the preferred embodiment of FIG. 1;

FIG. 9 is a top perspective view of a base plate of the chip scale carrier of FIG. 1;

FIG. 10 is a top perspective view of a flap door of the chip scale carrier of FIG. 1;

FIG. 11 is a bottom perspective view of a flap door of the chip scale carrier of FIG. 1;

FIG. 12 is a top perspective view of the chip scale carrier body of FIG. 1;

FIG. 13 is a bottom perspective view of the chip scale carrier body of FIG. 1;

FIG. 14 is an exploded perspective view of the chip scale package carrier of the present invention and the ball grid array mounting socket disclosed in US Pat. No. 5,611,705.

[Explanation of symbols]

 (21) Carrier pad (10) Body (11) Window hole (15) Terminal ball (30) Bottom plate (31) Output terminal pin (40) Interconnection band (50) Support pad (16) Ball grid array package (41) (42) Conductive trace (43) Insulated wire (44) Window

Claims (17)

[Claims] (A) at least first and second layers of a sufficiently flexible insulator; (b) windows between the first and second layers, each within the first insulating layer. A plurality of conductive traces electrically connecting the connecting pads and the interconnecting pads exposed through the substrate; (c) a plurality of conductive traces disposed on the surface of the first layer, each connecting the connecting pads and the interconnecting pads. An interconnect band comprising: conductive traces; 2. A method according to claim 1, further comprising a third layer of an insulator proximate to a surface of the second layer, wherein a plurality of conductive traces are sandwiched between the second layer and the third layer, and each of the conductive traces includes 2. The interconnect band as defined in claim 1, wherein the interconnect band electrically connects the interconnect pad and the interconnect pad exposed through windows in the first insulating layer and the second layer. 3. An interconnect band as defined in claim 1, wherein said interconnect band covers an insulating support pad so as to expose a grid array pattern of connection pads in a first direction and to expose a pattern of interconnect pads in a reverse direction. 4. A connection pad on a grid pattern corresponding to a terminal ball pattern of a ball grid array to be attached, an interconnection pad spatially separated from the connection pad, and the connection pad and the interconnection pad. A stretched flexible interconnect band having conductive traces electrically connecting the interconnect pads to the first and second interconnect pads exposing the interconnect pads facing in the opposite direction. An insulating support pad for supporting a flexible interconnect band having a portion; (c) a bottom plate; (d) one end of each of which is electrically connected to the interconnect pad and an opposite end within the bottom plate protruding from the bottom plate. A plurality of terminal pins supported on: (e) securing the flexible interconnect band secured to the bottom plate and the support pad between the support body and the bottom plate; A support body having an aligned window through which the window is adjusted to expose the grid pattern of the connection pads; (f) connecting a ball grid array of terminal balls through the window; Apparatus for mounting a ball grid array device comprising means for pressing against a pad. 5. The pressing means comprises a door mounted on the support body for pivoting movement between a closed position and an open position, wherein when the door is in the closed position, the insulating pad is supported at the position of the window. 5. The mounting device as defined in claim 4, wherein: 6. The mounting device as defined in claim 5,
Means for uniformly pressing the door in the direction of the bottom plate are included. 7. The pressing means comprises a closure plate which can be moved between an open position and a closed position with respect to each other, wherein when the closure is in the closed position, the closure plate is parallel to the door, Has a first surface in contact with a first height portion of the door and a second surface in contact with the door, wherein the first and second surfaces are provided when the closure plate moves to a closed position. 7. The mounting device according to claim 6, wherein the door contacts the door so that the door is pressed toward the bottom plate. 8. The mounting device as defined in claim 7, wherein said first surface and said second surface simultaneously contact a slope on a door. 9. The mounting device as defined in claim 4, wherein said support body includes means for positioning a ball grid array device within said window. 10. (a) an interconnecting band having the following configuration: (i) a flexible first and second layer made of an insulator; and (ii) encapsulated between the first and second layers. A plurality of conductive traces, each conductive trace interconnecting an interconnect pad and a contact pad exposed through a window in the first layer, in a grid pattern corresponding to terminal balls depending from the ball grid array device. (B) a plurality of input / output terminal pins each of which connects to an interconnect pad and electrically connects the interconnect pad to an external electrical circuit; and (c) a terminal ball depending from the ball grid array device. Means for physically pressing the connection balls exposed through the window to the terminal pads of the ball directory arrangement device. Device that temporarily connected to. 11. The interconnect band includes a plurality of conductive traces disposed on the first layer, the conductive traces being coincident with internal connection pads and a grid pattern of terminal balls depending from the ball grid array device. 11. The apparatus as defined in claim 10, wherein the connection pads arranged in a corresponding grid pattern are electrically interconnected. 12. The interconnect band defined in claim 10, wherein the interconnect band covers an insulating support pad to expose a grid array pattern of the contact pads in the first direction and to expose a pattern of the interconnect pads in a reverse direction. Equipment 13. The apparatus defined in claim 12, wherein said plurality of input / output pins are arranged and held in pattern holes in a bottom plate. 14. A support body fixed to the bottom plate, the support body including an interconnect band between the bottom plate and the support body and the support pad, and the support body includes: 14. The apparatus defined in claim 13, wherein there is at least one window aligned to expose a grid pattern of the connection pads. 15. A door, further comprising a door mounted on the support body, the door pivoting between an open position and a closed position.
The door has the following parts: (i) a rotating end; (ii) a free end; (iii) an insulating pad attached to the position of the window in the support body when the door is in a closed position;
An apparatus as defined in claim 14. 16. A closure comprising a top plate mounted to be reciprocally movable over the door between an open position and a closed position, the closure having the following parts: (i) A first edge contacting the door at a first height; and (ii) a second edge contacting the door at a second height, wherein the first edge and the second edge are each a first edge on the door. 16. The apparatus defined in claim 15, wherein the device contacts the first and second surfaces and pushes the door toward the support body as the closure moves from the open position to the closed position. 17. The apparatus as defined in claim 16, wherein said first edge is a leading edge of said top plate.