KR20000015951A - Connector for micro-electron device - Google Patents

Abstract

PURPOSE: A connecting assembly for connecting a micro-electron device having a bump lead array is provided to polarize a seat-typed body toward a substrate by opposing a lead on the device to an opposite contactor. CONSTITUTION: The assembly comprises a substrate having an electric conductive lead, an elastic seat-typed body having a first and a second main surfaces opposite to the substrate, a supporting structure having a cap and a solid section therein, and an array of a thin film contacting point fixed to be overlapped with the bump lead and aligned to the cap on the first main surface of the seat-typed body. The contacting point is surrounded by a connector of the body supported by the solid section in a circumferential surface thereof.

Description

Connector for microelectronic device

Modern electronic devices use semiconductor chips and are often referred to as "hybrid circuits" incorporating several types of electronic devices. These chips are mounted on a substrate that physically supports the chip and electrically interconnects the chip with other elements in the circuit. This substrate is used to hold a single chip and forms part of a discrete chip package with terminals for interconnecting with external circuitry. Alternatively, in so-called "hybrid circuits" one or more chips are mounted directly to a substrate which forms a circuit panel aligned to interconnect the chip with other circuit elements mounted on the substrate. In either case, the chip must be securely held on the substrate and reliable electrical interconnection with the substrate must be made. The interconnection of the chip itself and the substrate supporting the chip is often referred to as a "first level" assembly or chip interconnection, and interconnection of the substrate with large circuit elements, often referred to as "second level" interconnection. Is distinguished from.

The structure used for the first level interconnection between the chip and the substrate facilitates electrical interconnection with the required chip. Many connections with external circuit elements, often referred to as "input-output" or "I / O" connections, are determined by the structure and function of the chip. Highly capable chips that can perform many functions usually require multiple I / O connections.

The size of the chip and substrate assembly is a major concern. The size of each such assembly affects the size of the entire electronic device. A more compact assembly with shorter chip-to-chip distances results in smaller signal transmission delays, allowing faster device operation. The first level interconnect structure that connects the chip to the substrate is susceptible to substantial strain caused by thermal cycles as the temperature in the device changes in operation. Since the power dissipated in the chip is likely to cause heat to the chip and the substrate, the temperature of the chip and the substrate rises each time the device is turned on and falls each time the device is turned off. As the temperature changes, the chip and substrate expand and contract in different amounts. This causes electrical contact on the chip to move relative to the electrical contact pads on the substrate. This relative movement deforms the electrical interconnection between the chip and the substrate, resulting in mechanical stress. This stress can be applied repeatedly with repeated operation of the device, causing breakage of the electrical interconnect.

In addition, in spite of much effort in the manufacture of chips, bonding occurs in some chips. Such a defect may not be detected until the chip is often operated under power supply in an actual assembly or in a test facility. A single bad chip can be useless for large assemblies and many other useful components made up of many chips, or may require a difficult procedure to screen bad chips from the assembly. Therefore, the mounting elements used in the chip and any chip assembly system are subjected to chip testing to replace the defective chip before the chip is melted onto the substrate. The price of chip and substrate assemblies is also a major concern.

When you put all the different concerns together, it presents a daunting technical challenge. Many attempts have been made to provide first level interconnection and ways to meet these concerns. Currently, most widely used main interconnection methods are wire bonding, tape automatic bonding, or "TAB" and flip-flop bonding.

In wire bonding, the top surface of the substrate has a plurality of electrically conductive contact pads or lands arranged in a ring pattern. The chip is stuck to the top surface of the substrate at the center of the ring-shaped pattern, enclosing the chip with contact pads on the substrate. The chips are mounted in a face up arrangement with the back side of the chip facing the top surface of the substrate and the front side facing upwards slightly away from the substrate, exposing the electrical contacts on the front side. The thin wire is connected between the contact on the front side of the chip and the contact pad on the top surface of the substrate. These wires extend outwardly from the chip to the peripheral contact pads on the substrate. In a wire bonded assembly, the area on the substrate occupied by the chip, wire and contact pads on the substrate is much wider than the surface area of the chip itself. In addition, since the wire bonding process does not provide any pre-testing on the chip, the chip must be tested using standalone equipment. Therefore, the chip itself must be tested using standalone equipment prior to the wire bonding process. There are many practical difficulties in testing the chip itself. Therefore, it is difficult to make electrical connection at the same time with low inductance with all the contacts on the chip reliably. U. S. Patent No. 5,123, 850 to Elder et al. And U. S. Patent No. 4,783, 719 to Jameson et al. Disclose a chip test facility for pressing a conductive element on a flexible device against electrical contact of the chip. Doing.

In the TAB process, the polymer tape includes a thin layer of metallic material that forms a conductor on the first surface of the tape. These conductors are usually aligned in a fanout pattern and extend radially away from the center of the pattern. The chip is disposed on the tape in an underside alignment and has a contact located on the front side of the chip facing the conductor on the first surface of the tape. The contacts of the chip are bonded to the conductor on the tape. The assembly is much larger than the chip itself, because the leads used for tape autobonding extend radially outward from the chip into the fanout pattern. U.S. Patent No. 4,597,617 to Enochs and U.S. Patent No. 5,053,922 to Metta et al. Disclose changes in the TAB process. The outer ends of the leads of the tape are in contact with the substrate by mechanical pressure rather than by metal bonding.

In flip-flop bonding, the contact on the front side of the chip has bump leads, such as solder balls, projecting from the front surface of the chip. The substrate has contact pads aligned with the array corresponding to the contact array on the chip. By flipping the chip with solder bumps, the front side of the chip faces towards the top surface of the substrate, and each contact on the chip and the solder bumps are located on the appropriate contact pads of the substrate. The assembly then melts and heats the solder to bond each contact on the chip to an opposing contact pad of the substrate. The flip-chip configuration does not require leads arranged in a fanout pattern, thus providing a compact assembly. The substrate area occupied by the contact pad is almost the same as the chip. Furthermore, in flip-chip bonding, the contacts of the chip may be aligned in a so-called "area array" that almost covers the entire front surface of the chip. Flip-chip bonding is therefore suitable for use in chips with multiple I / O contacts. However, assemblies made by flip-chip bonding are susceptible to heat. Since solder joints are relatively inflexible, they may be subject to high stresses due to different expansion of the chip and substrate. These problems are especially noticeable on relatively large chips. In addition, it is well known that it is difficult to test a chip with an array of regions of contacts before attaching the chip to a substrate.

One known solution is to use socket or spring type contacts to connect the bump leads to the substrate. As the size of the microelectronic chip is reduced, the pitch of the solder bump connections is also becoming finer, and finer pitches are required when joining the sockets. Simultaneously with the demand for fine pitch, the mating socket must compensate for pitch and height errors in the solder bumps on the chip. Adjustments to solder bump positioning tolerances are becoming increasingly difficult as the socket is tightly packed into the connector.

Sockets or contacts for connecting microelectronic devices to the substrate are typically added to the chip package with a significant height. Since the space for packing is premium in all directions, low profile sockets or contact connectors are required.

U.S. Patent No. 3,795,037 to Lutmer discloses a number of separate and flexible gold wires that extend through the elastic medium to the connection surface. The gold wire is electrically connected to the lead of the substrate with respect to the opposing face of the elastic layer. When the bump lead array comes in contact with the contact surface, the gold wire contacts each bump lead and provides a conductor through the elastic layer. The elastic material and the gold wire are bent and contacted by bump leads that provide flexibility.

US patent application Ser. No. 08 / 511,131, assigned to the same assignee as a patent application and referenced herein, discloses a socket having a metal protrusion arranged around a circle of holes for receiving bump leads. This metal protrusion is deflected into the hole as a bump lead.

US Pat. No. 5,199,879 to Kohn et al. Discloses a pin socket having a plurality of deflectable tabs protruding at least partially across an opening. U.S. Patent No. 4,893,172 to Matsumoto et al. And U.S. Patent No. 5,086,337 to Noro et al. Disclose various flip-chip methods using flexible spring-type elements connected between the chip and the substrate.

U.S. Patent No. 5,196,726 to Nishiguchi et al. Discloses a variety of flip-chip methods in which nonmetallic bump leads on the surface of the chip are bonded by a low melting point material and housed in a cup-shaped socket of the substrate. have. US Pat. No. 4,975,079 to Beaman discloses a test socket for a chip in which a domed contact of a test substrate is disposed in a conical guide. The chip is forced against the substrate so that the solder ball enters the conical guide and engages the dome pin on the substrate. When sufficient force is applied, the domed pins will actually deform the solder balls of the chip.

US Patent No. 4,818,728 to Rai et al. Discloses a first substrate, such as a chip having studs or bump leads protruding outward, and a recess having soldered recesses for joining the bump leads. Two substrates are disclosed. U. S. Patent No. 5,006, 792 to Malhi et al. Discloses a test socket in which the substrate has an outer ring-shaped structure and a number of cantilever beams protruding inward from the ring-shaped structure. Contacts are disposed on these cantilever beams to enable elastic coupling with the contacts of the chip when the chip is placed in the socket. "A Tab Tape-Based Bare Chip Test and Burn Carrier" by Nolan et al., 1994, "ITAP And Flip Chip Proceedings", pp. 173-179 discloses another socket having a cantilevered contact finger for joining a contact to a chip. In this case, the contact fingers are formed on the flexible tab tape and reinforced by the silicon material, providing enhanced bonding force and wiping action with the chip contacts.

"Mechanical Interconnection System For Solder Bump Dice" by Hill et al., 1994, "ITAP And Flip Chip Proceedings", pp. 82-86 discloses test sockets for flip chip devices with solder bumps. This socket has a coarse dendritic structure on the contact pad. In addition, a chip with solder bumps is forced to engage with the dendritic structure to make temporary contact for testing.

References to "MCM to Printed Wiring Board (Second Level) Connection Technology Options" by Alan D. Knight ("Multichip Module Technologies and" by Daryl Ann Doane and Paul D. Franzon, Van Nostrand) Alternatives, 1993, pp. 504-509 and pp. 521-523, include deformable contacts with corresponding US Pat. No. 4,655,519 by Evans et al. And US Pat. No. 5,228,861 by Grabbe. However, in spite of this effort, improved components for the connection of semiconductor chips and other microelectronic devices, interconnecting these chips and components, and connecting the connected chips and components are disclosed. There is still a need for an improved system that includes.

Summary of the Invention

SUMMARY OF THE INVENTION The present invention solves these problems, and a first object of the present invention is to connect a microelectronic device having a sheet-like elastic body having first and second major surfaces and a bump lead array having a substrate with electrically conductive leads. It is to provide a connection assembly for the purpose. The second major surface faces the substrate and is constantly spaced apart from the substrate. A support structure having a gap and a solid portion extends between the substrate and the second major surface of the sheet-like body. The array of thin contacts can be secured to the first major surface of the body to achieve registration with the bump lead array on the microelectronic element to be mounted and alignment with the gaps in the support structure. Each contact is surrounded by an associated portion of the sheet-like body, the associated portion of the sheet-like body being supported by the solid portion of the support structure around it. The lead on the microelectronic element can be opposed to the corresponding contact to deflect the sheet-like body towards the substrate.

The elasticity of the sheet-like body reduces its need for deflection of the metal contact itself. Since the sheet-like material is more flexible than free-standing metal contacts, the contacts of the present invention can be made smaller than all metal contacts with similar elastic forces. This allows the array of contacts to have a fine pitch, allowing a fine pitch of the bump leads on the microelectronic device.

In addition, the resilient sheet-like body is less prone to flexing than all metallic contacts. This allows the connection device of the present invention to be used again as a test facility to form a repeatable and reliable connection with a microelectronic element.

The support structure can be an array of posts. In this embodiment, the post array can be electrically connected to the leads of the substrate, and the contacts of the array can be electrically connected to this post. In one embodiment, each deflectable portion of the body is supported by four posts. The array of contacts and the array of posts can be straight arrays with row and column directions, with the posts being diagonally offset relative to the rows and columns from the contacts. The post may be an unfolded core solder ball or conductive via.

At least one post from the post group can electrically connect each contact to a lead on the substrate. The sheet-like body portion associated with each contact deflects in response to the downward force exerted by each bump lead on the microelectronic element. The sheet-like body may have relief openings in portions engaged with the contacts to increase the flexibility of the sheet-like body.

The contacts may be coated with solder for easier bonding with the solder bumps on the microelectronic device. The connection assembly may further comprise a conductive layer on the second major surface of the sheet-like body to control the impedance. This layer can include conductive traces that interconnect the contacts, which can be used only on the second major surface of the sheet-like body.

In applications where it is desirable to not bond between the contacts and the bump leads on the microelectronic device, an anti-wetting agent may be deposited on the contacts.

The support structure may optionally be a support layer in which the gap is a hole, the edge of the hole defining the perimeter of the sheet-like body portion associated with the corresponding contact.

The sheet-like body may have a plurality of holes arranged in an array corresponding to the array of contacts, which contacts extend inwardly through the holes. The contacts may have asperities that project upwardly to contact the microelectronic device.

The connection assembly may have a frame that fits the microelectronic element to the sheetlike body and a biasing structure that presses the microelectronic element against the sheetlike body.

In another aspect of the invention, a method of connecting to a microelectronic device having an array of bump leads is provided. The connector is configured to have a sheet-like body, a substrate, an array of contacts on the first major surface of the sheet-like body, and an array of posts on the second major surface of the sheet-like body. The post positions the sheetlike body away from the substrate. Each contact is disposed in a sheet-like body portion having two or more posts around it.

The microelectronic device is fitted with a connector so that the array of contacts is matched with the array of bump leads. The microelectronic device is pressed toward the sheet-like body such that the array of bump leads is in contact with the array of contacts, and each portion of the sheet-like body is elastically deflected between two or more posts and the bump leads.

Each contact is electrically connected to each post, and the post is electrically connected to a lead of the substrate, and an electrical connection is formed between the bump lead and the lead of the substrate by pressing the microelectronic element toward the sheet-like body.

After electrically connecting the leads to the substrate, the microelectronic device can be electrically tested through this electrical connection to determine whether the microelectronic device can be tolerated. If this device is acceptable, the contacts can be permanently bonded to the bump leads.

In another embodiment of the present invention, a connector is provided for mounting a microelectronic device on a substrate. The connector consists of an elastic sheet-like body having first and second major surfaces and a number of thin contacts fixed to the first major surface of the body. The contacts are arranged in an array corresponding to the array of bump leads on the microelectronic device to be mounted. Each contact is adapted to mate with a corresponding bump lead. The connector further includes an array of terminal posts on the second major surface of the sheetlike element. The terminal post is electrically connected to the contact. Thus, the terminal posts can be adhered to the substrate to electrically connect the contacts to the substrate and support the body in a stand-off space between the body and the substrate. When the microelectronic device is pressed against the body, the bump leads on the device are coupled to the contacts on the body, and the body portion surrounding the contacts is elastically deflected into the standoff space.

The sheet-like body may have a plurality of holes arranged in an array corresponding to the array of bump leads on the microelement, and each contact may extend inwardly through each hole from the first major surface. Each contact may include at least one protrusion that extends through a hole associated with the contact. The contact may further comprise a plurality of protrusions extending inwardly from a position spaced about the periphery of the hole.

The connector may further include a protective layer formed on the lead. The terminal post may be an unfolded core solder ball.

The sheet-like body may have a plurality of holes corresponding to the terminal posts, the terminal posts being electrically connected to the contacts through the holes. The electrical connection can be formed by a plurality of thin contact tabs on the first major surface of the sheet-like body.

The array of contacts and the array of terminal posts can be straight arrays with row and column directions, and the terminal posts can be offset from the contact in a diagonal direction that is inclined with respect to the row and column directions.

The connector may further have a support post that does not electrically connect to all the contacts that further support the body.

In a further embodiment of the invention, a socket is provided to mate the bump leads on the microelectronic device. The socket has an elastic dielectric sheet having first and second major surfaces and electrically conductive contacts secured to the first major surface of the sheet. The contact has an active contact. The socket further includes a support substrate for the first surface, the first surface of the substrate being juxtaposed with the second major surface of the dielectric sheet. The substrate first surface has a conductive terminal. Many posts are spaced around the active contact. The post mechanically supports the sheet portion surrounding the contact associated with the substrate such that a gap exists between the sheet and the substrate. One post electrically connects the terminals and the contacts. The sheet deflects when the cushioning lead is engaged with the active contact of the contact.

The opening extends between the first major surface and the second major surface of the sheet. The active contact of the contact lines up with the opening and partially extends over the opening.

The post may be a solid core solder ball or be a via. Spacers are disposed between each post and the first surface of the substrate, electrically connecting the posts to the substrate and providing a greater vertical height for deflection of the sheet. The spacer may comprise a thin substrate having an opening arranged in line with the active contact of the contact.

The socket includes a second contact and a plurality of second posts that mechanically support the second seat portion surrounding the active second contact of the contact. In this case, the plurality of first posts and the plurality of second posts usually have at least one post. The flexible sheet in this case includes a conductive layer deposited on the second major surface and interconnecting the first contact portion and the second contact portion.

The features and advantages of the invention will be apparent from and elucidated in more detail with reference to the following preferred embodiments and figures.

The present invention relates to components used to mount semiconductor chips and associated electronic components, assemblies made using such components, and methods of making such components and assemblies.

1 is a schematic diagram of a connection assembly with a connector according to one embodiment of the invention.

2A is a fragmentary plan view of a portion of a connector used in the connection assembly of FIG.

2B is a fragmentary plan view of a portion of another embodiment of the connector for use in the connection assembly of FIG.

3 is a partial cross-sectional view cut along line 3-3 of the connection assembly of FIG. 1 with the microelectronic element to be mounted thereon;

4 is a partial cross-sectional view cut along the line 4-4 of the connection assembly of FIG. 1 with the microelectronic element to be mounted.

5 is a schematic diagram of a connector according to another embodiment of the present invention;

6 is a schematic view of a connection assembly according to the invention.

FIG. 7 is a schematic exploded view of the connection assembly of FIG. 6. FIG.

8 is a schematic exploded view of a connection assembly according to another embodiment of the present invention.

9 is a schematic perspective view of a substrate including a portion of a connection assembly according to one embodiment of the invention.

10 is a schematic cross-sectional view of a connection assembly according to another embodiment of the invention, with the microelectronic element to be mounted.

11 is a schematic view of a connection assembly using a connector according to another embodiment of the present invention.

12 is a perspective and schematic partial sectional view of a connecting assembly according to an embodiment of the present invention.

13 is a perspective and schematic partial sectional view of a connecting assembly according to another embodiment of the present invention.

14 is a schematic partial cross-sectional view of a connecting assembly according to another embodiment of the present invention.

15 is a schematic view of a connecting assembly according to another embodiment of the present invention.

16 is a schematic cross-sectional view of a connection assembly according to another embodiment of the invention, with the microelectronic element to be mounted.

17 is a schematic cross-sectional view of a connection assembly according to another embodiment of the invention, with the microelectronic element to be mounted.

The connection assembly 5 (FIG. 3) according to an embodiment of the present invention is a connector or insert 10, a substrate 41, and an unfolding structural element or post supporting the connector 10 on the substrate 41. And a support structure having a portion in the solid state, such as (23). The substrate 41 (FIG. 9) in this arrangement is a multilayer thin-film circuit panel with a number of electrical leads 50, of which only a few of the leads are schematically shown. The leads 50 extend perpendicular to each other and are parallel to the top and bottom surfaces of the substrate. According to the conventional semiconductor industry, the horizontal directions are indicated in the "x" and "y" directions. In addition, the "upward" direction as used herein refers to the direction from the substrate toward the mounted microelectronic device, which becomes the "top" or "normal" of the substrate.

The substrate also includes z-direction leads 52 that interconnect the vertical or various horizontal leads 50. If possible, some z-direction leads as well as some horizontal leads 50 are exposed to the upper surface 43 of the substrate 41. This exposed lead is connected to a terminal 42 (Fig. 3) arranged in a straight grid of uniform pitch in the x and y directions. For example, terminal 42 includes a flowable conductive material, such as solder, eutectic bonding alloy, polymeric material with metal filler, and the like, and may also include structures such as vertically extending vias. The substrate is formed of a dielectric material that supports and insulates the leads. The substrate 41 may include other elements conventionally used in a multilayer circuit, for example, a ground power supply potential plane or the like.

The connector 10 according to the invention connecting the substrate 41 to the microelectronic device has a first surface 32 facing away from the substrate 41 and a second surface 33 facing downward toward the substrate. And a sheet-shaped dielectric connector body portion 24 (FIGS. 1 and 3). Thus, the second surface 33 of this sheet-shaped body portion 24 opposes the top surface of the substrate 41. According to the presently described embodiment, the sheetlike element 24 has a plurality of holes 27 extending from the first surface 32 to the second surface 33. The connector body portion 24 preferably has a thickness of about 100 mu or less, more preferably 50 mu or less. In a preferred embodiment, the sheet-like element is approximately 25 to 40 microns thick. In order to force the center as described below, the diameter of the hole 27 should be slightly smaller than the diameter of the bump lead of the microelectronic element to be connected.

As shown in FIGS. 1-3, the elongated metallic contact tabs 21 are coupled to each hole 27. Each contact tab is disposed above the first surface 32 of the connector body 24. Each contact tab comprises an active contact 22 having a ring-like structure surrounding the opening of each hole 27 at one end of the tab 21 and a plurality of protrusions 28 extending inwardly from the ring-shaped structure. . The protruding portion 28 protrudes from the upper portion of the opening of the hole 27 (FIG. 3). The protrusions are spaced apart from each other by the slot 31. The protrusions 28 of each contact tab 21 are defined together with an active contact 22 placed jointly over the hole 27.

The holes 27 and their contact tabs 21 are arranged in a straight grid array on the top surface 32 of the sheet-like body 24, as shown in FIG. 1. The grid array of active contacts 22 corresponds to the contacts of the grid array, such as solder bumps 46 (FIG. 3) in contact with the microelectronic elements 45 to be connected.

Each contact tab 21 extends through the sheet-shaped body 24 toward the unfolded element or post 23 connected to the contact tab 21. In the preferred embodiment, the hole 40 (FIG. 3) is provided within the sheet-like body 24, exposing the bottom surface of the contact tab 21. The post 23 is bonded directly to the contact tab 21 through the hole 40.

As shown in FIG. 1, the active contacts 22 and the holes 27 are arranged in rows extending in the x and y directions. Each contact tab 21 is aligned at an inclination angle of 45 ° with respect to the x direction (and hence tilted at 45 ° with respect to the y direction) and each post 23 is 45 ° from the active contact 22 and the hole 27. Is offset in the inclined direction. Thus, the posts 23 are also arranged in a horizontal and vertical straight array extending in the x and y directions, but this array is offset from the array of holes 27 and active contacts 22.

The distance or spacing of the posts 23 on the connector 10 corresponds to the spacing of the terminals 42 on the top surface 43 of the substrate 41. The post 23 is bonded to the z-lead 52 (FIG. 3) and forms an electrical and mechanical connection between the contact tab 21 in the connector 10 and the leads 50, 52 in the substrate 41. have.

Straight arrays may necessarily have any pitch or space between adjacent elements. However, the pitch of each array is preferably a pitch corresponding to a standard pitch for contacting the surface of a microelectronic element such as a semiconductor chip having "array region" contacts. Microelectronic devices are well known with contacts having a pitch of about 0.5 mm or less measured along the width or length between adjacent devices.

The contact tab 21 and the protrusions 28 formed in the contact tab are generally thin layers. "Thin layer" described below means sheet or plate shape. That is, the thin layer structure has two opposing major surfaces and edges, and the major surface has a surface area considerably larger than the surface area of the edge. The thin layer structure does not necessarily have to be flat. For example, the thin layer structure may have bumpy or raised sites that project upwardly from its top surface. The contact tab 21 can be formed of a metallic material and preferably has good electrical conductivity and good processing properties in the conventional etching and plating processes used in microelectronic components. Materials that can be used include copper and copper containing alloys such as copper beryllium and bronze phosphorus. The metal of the contact tab and the protrusions is preferably between about 10 microns and 25 microns thick, and more preferably between about 10 microns and 25 microns thick. Standard lithography process techniques can be used to fabricate contact tabs. The size of the component may vary somewhat depending on the selected pitch and the nature of the microelectronic component to be coupled with the connector. However, for a system with a pitch of about 0.75 mm, the width w of each contact tab (FIG. 2A) is about 0.45 mm, while the length between the center of the active contact area 22 and the center of the post 23 " May be about 0.53 mm. The diameter of the hole in the sheet-like element 24 below the active contact area 22 is about 0.35 mm, and the protrusions 28 extend about 50 microns per side above the hole 27.

The contact tab 21 is covered by a solder mask or coating layer 37 (FIG. 3) to protect the underlying copper tab so that solder from the connection during the bonding process to the microelectronic element 45 is removed from the tab 21. It is advisable not to penetrate by and to prevent adjacent tabs from joining together. The coating layer 37 also protects the copper tabs underneath during the test treatment of the microelectronic device in which the solder in the microelectronic device is melted. The coating layer 37 has a hole 38 in the active contact area 22 to expose the protrusion 28 overlying the metallic contact tab 21.

The contact tab 21 with the overlying protrusions 28 may be further coated with an anti-wetting agent. For example, osmium, rhodium, rhenium, graphite, or other suitable material may be electroplated on contact area 22 (or only on protrusions 28) to prevent solder from invading the contact. The desiccant enables the connector assembly to be used as a socket for burn-in and test processing of high temperature microelectronic devices that can range from 150 ° C. or higher. Under these conditions, the solder of the bump leads can be melted or softened and joined with the contact without desiccant.

On the other hand, in the case of one embodiment of the present invention where permanent solder bonds are formed between the bump lead 46 and the connector 10 of the microelectronic element 45, it is desirable to encourage solder invasion of the contact tab 21. In this case, the projections 28 of the contact tabs 21 are tinned or soldered to facilitate solder bonding to the mating bump leads 46. The mechanical and electrical connection between the microelectronic element 45 and the contact tab 21 is made permanent by cycling the assembly including the microelectronic element and the connector through a solder temperature cycle. During the soldering process, the solder initially on the protrusions 28 melts and flows into the bump leads 46 of the microelectronic device. The solder invades the protrusions 28 of the contacts and couples the contacts to their respective bump leads, causing the protrusions to penetrate the bump leads 46 with flowable solder balls, such as eutectic Sn-Pb solder.

The ground or power plane layer 61 may be provided on the bottom surface 33 of the flexible sheet 24, as shown in FIG. 3. This layer comprises a solid layer covering all or substantially part of the bottom surface 33 of the flexible layer 24. Depending on the requirements of the individual connectors, layer 61 may comprise a ground layer in some areas of the connector and a power plane layer in other areas of the connector, the areas being electrically insulated by a gap in layer 61. do. Layer 61 may be used to control the impedance within microelectronic device 45, connector 10, and substrate 41.

Alternatively, layer 61 may include a plurality of conductive traces that electrically interconnect selected contacts in the test pattern, or provide additional interconnects that add to the substrate. In one of these embodiments, conductive traces in the layer can be used to connect two or more posts 23 with a single solder bump 46 to the microelectronic device. This can be done by directly interconnecting the posts 23 using the conductive traces of the layer 61. Alternatively, the leads 21 can be interconnected to the conductive traces by a path (not shown) through the flexible layer. In some cases, a significant amount of test circuitry can be included in the layer 61 to test the microelectronic device 45. Eventually, the layer 61 will include a coupling that interconnects conductive traces within a region when such traces are required, and a ground or power plane region within another region when interconnecting conductive traces are not needed. It may include.

Preferably, the post 23 is a solid core having a conductive solid core 35, which is a relatively high melting point material such as copper or nickel, surrounded by a conductive layer with a thermally active bonding material 36 such as solder. And solder balls. By connecting the connector 10 and the substrate 41 using the array of solid core solder balls, standard ball grid array methods and apparatus can be used to assemble the components.

Thus, when the post 23 is bonded to the contact tab 21 and the lead wire 52 of the substrate 41, the solid core 35 is formed of the upper surface 43 of the substrate 41 and the sheet-like element 24. The standoff space 57 (see FIG. 3) is held in between. The standoff space 57 has a predetermined thickness 58 which is set by the size of the unfolded portion of the post 23, for example the diameter of the core 35.

In another embodiment of the present invention shown in FIG. 16, a via 366 is used instead of a solid core solder ball to form a post. The via 366 includes an opening that is a cylindrical or hourglass shaped post formed substantially of copper, gold, another conductive material, or an alloy thereof. Alternatively, the path can be formed with other surfaces of the revolution, such as conical or cylindrical members. The via 366 extends through the opening 365 of the contact tab 321 and the opening 340 of the flexible sheet 324. The path terminates over the contact tab 321 in contact with the tab to have a flange 368. The tab and the via are electrically connected. The via extends downwardly of the flexible sheet 324 by a fixed distance 358 that sets the standoff distance between the connector 310 and the substrate 341. The via 366 terminates in the lower wall 369 to form a cup shaped member. In use, the connector 310 is connected to the substrate 341 by soldering an array of paths 366 to a corresponding array of terminals 342 on the substrate 341.

The vias 366 may be formed using a sacrificial layer (not shown) of resist or other suitable material. The sacrificial layer has an opening in the opening 340 of the flexible layer 324 and the opening 365 of the contact tab 321. The three openings are typically formed to be straight. After forming the opening, an additional sacrificial layer (not shown) is deposited on top of the first lean layer to form the bottom wall 369 in the via 366. After appropriately forming the top surface of the contact tabs 321, the via is formed in a conventional manner by plating the side and bottom surfaces of the opening so that it has a small area surrounding the opening on the contact tab 321. The sacrificial layer is then removed and only the remaining vias 366 remain. Solder mask layer 377 may be formed over contact tab 321 and top flange 368 of path 366.

In another form of connector shown in FIG. 17, via 370 is inverted as compared to the embodiment of FIG. 16. In this embodiment, the opening is not necessary in the contact tab 372 but only a single sacrificial layer (not shown) is needed to form the via 370. The via 370 is formed by plating an opening in the sacrificial side from the opposite side of the contact tab 372.

In the case of the embodiments of FIGS. 16 and 17 where the post incorporates the vias to have good structural preservation, additional resistance to being crushed in the z direction can be provided by filling the vias with lead or any other suitable material. In the embodiment shown in FIG. 17, the solder 371 is also provided as a bonding material for bonding the substrate terminal 342. Alternatively, a more flexible material can be used in the via to prevent the via wall from being crushed or bucked at the same time that some elasticity occurs to absorb heat cycling and other forces. For example, polymers, high durometer elastomers, conductive elastomers or other suitable materials may be provided in the vias.

Each contact tab 21 is connected to the lead wire 52 in the substrate 41 through one of the posts 23 as described above. In addition, additional non-folding structural elements 25, 26 (see FIG. 1), which are not provided as conductors, may be provided to further support the connector 10 over the upper surface 43 of the substrate 41. For example, some contact tabs may be omitted at the location if the microelectronic package is missing a bump lead. In a position in the regular grid pattern of the connector 10, the non-folding structural element 26 may be provided only for the purpose of supporting the connector 10. Furthermore, additional non-folding structural elements 25 may be provided around the periphery of the grid array of contact tabs 21 to provide a support for the connector 10 at the periphery. An additional metal element 30 formed of the same thin metal as the contact tab is installed on the connector located above each additional non-folding structural element 25 to provide a bonding surface for the post. The additional metal element 30 may be formed of one or more large linear elements or buses.

Each active contact (or " contact ") 22 of the grid array of FIG. 1 is alternately connected to the periphery 60 of the elastic connector 10 supported by four posts (see FIGS. 1 and 4). It is located in the center. In the case of the corner socket 53 shown in the lower left corner of FIG. 1, it is arranged as an array of three peripheral posts 25 and the posts associated with the corner sockets 53. In addition, other grid array systems may be used, each active junction 22 supported by two, three, four, five or more posts 23. Thus, a single post typically provides electrical connections for the socket and mechanical support for multiple adjacent sockets.

In the connection method according to the invention, microelectronic elements, such as element 45, are coupled to the connector assembly 5 (see FIGS. 3 and 4). The microelectronic element 45 has a plurality of bump lead wires 46 each protruding from the bottom surface 49 of the element 45. The bump lead wire is disposed in a straight grid having the same pitch as the grid of the active contact portion 22 (see FIG. 1). In this regard, although the bump leads are scattered only in locations defined by such a grid, the bump leads need not all be present at that location. That is, the grid of bump lead wires has an effective pitch where the bump lead wire positions occupied are two, three, or some other integer multiple of the pitch of the holes in the connector.

Each bump lead 46 has a spherical ball shape similar to the configuration of the post 23 that is electrically connected to the internal circuit of the element 45, and an internal sphere formed of a relatively rigid metal such as copper or nickel which is electrically conductive or It may comprise a core. Each sphere is in turn covered with a layer of electrically conductive thermally activated bonding material such as solder.

By providing the microelectronic element 45 adjacent the connection assembly, the microelectronic element 45 is coupled with the connection assembly 5 such that the contact support surface of the element 45 is juxtaposed with the top surface of the sheet-like element 24. . The microelectronic element 45 is arranged such that the array of bump leads 46 is roughly inserted with the array of active contacts 22 of the contact tab 21 (FIG. 3). The microelectronic element 45 is downwardly forced such that the bump lead 46 contacts the protrusion 28 of the contact tab 21. The metal corners of the projections 28 contact and solder to the solder bump leads 46. Scrap or solder contacts between the protrusions 28 and the solder bump leads 46 may be unnecessary to electrically connect the two components, but such contacts may form any oxide layer that may be formed on the connection surface. Penetration increases the reliability of the connection.

When the downward movement of the microelectronic element 45 relative to the connection assembly 5 continues, the connector 10 is deflected between the solder bump lead 46 and the unfolded element 23 (FIG. 4). The sheet-like element 24 is burnt with each solder bump lead 46 which elastically deflects the periphery 60 of the sheet-like element 24 downward into the isolation space 57 between the sheet-like element and the substrate 41. Sexually Deformed

Each peripheral portion 60 surrounding the active contact area 22 of the connector 10 encloses a group of at least two, preferably three support posts 23. In the presently most preferred embodiment shown in FIG. 1, the perimeter of the peripheral portion 60 comprises four groups of posts 23. When the peripheral portion 60 of the sheetlike element 24 is deflected into the standoff space 57, the sheetlike element 24 extends. The post forces upward on the sheet-like element 24 and the bump leads 46 exert downward force on the sheet-like element. The elasticity of the sheetlike element 24 maintains contact between the bump lead 46 and the protrusion 28 of the contact tab 21.

The elasticity of the sheet-like element provides a tolerance for misalignment and position errors of the array of active contacts 22 and the array of bump leads 46. For example, as shown in FIG. 3, the centerline 47 of the bump lead 46 may not be properly aligned with the centerline 29 of the active contact 22. The misalignment portion 48 is controlled by the asymmetrical deflection of the enclosing portion 60 of the sheetlike element 24. The elasticity of the sheetlike element also compensates for the non-uniformity of the height of the individual bump leads 46 on the microelectronic element 45.

Moreover, some magnetic center force is exerted on the bump lead 46 as a result of the socket-like nature of the active contact 22. Thus, the slightly misaligned microelectronic device is forced into a position where the bump lead is well aligned with the active contact 22 when the microelectronic device is forced down on the connector 10.

Since the elasticity of the connector 10 is due to the elasticity of the sheet-like element 34 in addition to the elastic deformation of the metallic contact tab 21, the connector 10 is more difficult to artificially deform in use than the prior art connector. For this reason, the connector 10 and the connection assembly 5 are particularly suitable as reusable test fixtures for testing microelectronic devices. The connector assembly 5 may be used as a permanent mount for the microelectronic device by activating the bonding component of the bump lead 46 and permanently bonding the microelectronic device to the connector assembly 5.

The connectors of the present invention are particularly suitable for testing and selectively bonding microelectronic devices during the assembly process. In this application, the microelectronic device is first exerted toward the connector of the present invention using a first force F ₁ sufficient to create a contact between each bump lead and the corresponding socket. The microelectronic device is then tested. If the microelectronic device is defective, remove it from the connector and replace it with another microelectronic device. When the microelectronic device passes the test, a force is applied toward the connector using a second force F _{2 that} is greater than the first force F ₁ that actually inserts each bump lead into each socket. The bump leads can then be coupled to the connector without disturbing the contact between the connector and the microelectronic element. A connector with a rather large opening 27 in the dielectric layer is provided to allow the bump lead to penetrate into the socket in this application. The connector assembly of the present invention is particularly suitable for this application where the fabric is suitable as a permanent connector for microelectronic assemblies due to its low profile compared to typical test fixtures.

In another embodiment of the present invention shown in FIG. 15, the connector 210 has a flexible layer 224 with a grid array of holes 227 and a corresponding array of contact tabs inserting into the holes 227. In the active contact 222 of each contact tab 221, a plurality of protrusions 228 extend inwardly and protrude beyond the passageway of the hole 227. The contact tab further has an elongate connection 230 extending over the hole 240 of the flexible sheet 224 as a whole. The hole 240 exposes a connection 230 that connects the contact tab 221 to a post (not shown) as described above.

The flexible sheet 224 is provided with a number of arcuate slots or relief apertures 263 surrounding the active contact 222. The arcuate slots define a bridge of flexible layers 224 between slots that provide support in the area surrounding the active contact 222. Arched slots 263 provide additional stretch and elasticity to the flexible layer 224 in the immediate vicinity of the active contact 222. Such additional stretch allows the individual contacts 222 to move relatively during bonding with the solder bump leads on the microelectronic device and during thermal cycling of the substrate and the microelectronic device.

The contact tab 221 further includes a necked-down portion 262 between the active contact 222 and the contact 230 of the contact tab 221. The recessed portion allows the surrounding arched slots 263 to be placed closer together and reduces the cross sectional area of the rigid contact tab 221. These two effects increase the elasticity of the area of the connector 210 directly surrounding the active contact 222.

The contact tab can have a different configuration than that shown in FIG. 2A. For example, the contact tab 21a (FIG. 2B) can have a circular overlapping protrusion 28a separated by a circular slot 31a. The gradually curved feature of this embodiment has increased hardenability due to the inherent properties of the etching process and photolithography to fabricate circular corners.

In another example, the contact tab 70 (FIG. 5) has a larger relatively small width in contact with the post 23, which surrounds the hole of the flexible sheet-like element 24. The protrusion 71 includes a curved arm configured to scrape the bump lead when the bump lead is forced down toward the sheet-like element 28. Other contact protrusion configurations and contact tab shapes can be used as known in the art.

The contact tab will have a shape added to or in place of the contact protrusion to enhance contact between the solder bumps of the microelectronic device and the contact tab. For example, the contact tab 90 (FIG. 10) has a rugged portion 91 facing away from the sheet-like body 24. Such irregularities are disclosed in US Pat. No. 5,632,631, which is incorporated herein by reference and jointly assigned to the applicant. The rugged portion 91 will have a sharp edge or corner on its upper surface. When the microelectronic device 25 is pressed into the connector, the rugged portion 91 penetrates the oxide coating that will be present on the solder bumps 46 to provide a reliable electrical connection. The elasticity of the sheet-like layer 24 makes contact with the solder bumps 46 and the associated bumps on the connector. In certain application devices, such as the embodiment shown in FIG. 10, holes in the active contact area through the sheet-like element 24 will be eliminated. The rugged portion may be used in connection with the protruding portion of the contact extending over the hole of the sheet-like body 24.

The electrical connection between the contact tab and the substrate need not be made through one of the posts 23 near its active contact. Instead, a circuit trace 96 (FIG. 11) on the sheetlike element 24 is directed to the contact 97 on the circumference of the sheetlike element 24, thereby making electrical connection between the substrate and the contact 95. FIG.

In another embodiment of the invention, the support structure is a support layer 101 (FIG. 12) between the sheet-like body 110 and the substrate 41. The support layer may be a dielectric such as polyimide or other suitable material. The support layer 101 has a gap such as the hole 103 and the solid portion 111. The active contact 105 of the contact tab 107 is located directly above the hole 103 of the support layer 101. The perimeter of the hole 103 forms part 120 of the sheet-like body 110 associated with the active contact 105. Upon contact with the solder bumps (not shown), the active contact 105 moves into the hole 103 when the relevant portion 120 of the sheetlike element 110 is bent down.

Electrical contact between the terminal 41 and the active contact 105 in the substrate 41 is made by contacting the contact tab 107 with the via 109 in the sheet-like body 110. The via 109 has electrical conductors extending therethrough which are in electrical contact with the ring-shaped electrical conductors 102 which can be formed by plating the interior of the holes 103 of the support structure 101. The ring-shaped structure 102 electrically connects the terminals 42 and the vias 109 of the substrate 41.

The holes 115 of the flexible sheet 110 provide wiping / scraping of the solder bumps as the contacts bend down with the protrusions 106 of the active contact region 105.

In another embodiment of the invention (FIG. 13), the support layer 101 has a ring-shaped conductor 102 of metal connected to the terminal 42 of the substrate 41 as described above. However, the electrical connection between the contact tab 130 and the conductor 102 is made through the hole 115 to connect to the sheet-like element 110. Conductor 131 is formed in hole 115 by, for example, plating to connect lead 132 and contact tab 130 on the second surface of sheet-like element 110 opposite contact tab 130. do. Accordingly, electrical contact is made between the contact tab 130 and the terminal 42 via the conductor 131, the lead 132, and the conductor 102.

Additional travel for bending sheet-like element 24 by separating the support structure, such as post 23, from substrate 41 using glue lam or other spacer layer 150 (FIG. 14). Will be provided. The spacing layer 150 has a hole 152 associated with the active contact 22 of the contact tab 21. As the solder bumps (not shown) bend the sheet-like layer 24 towards the substrate 41, the holes 152 provide additional spacing for additional downward travel. Similar results may be obtained by forming the holes 152 directly in the substrate. This configuration further reduces the height of the entire assembly.

The connector of the present invention can be used with a biasing facility 80 according to another embodiment of the present invention (FIGS. 6 and 7). The connector 10 is aligned and bonded to the array of terminals 42 and the substrate. In the present embodiment, the frame 70 presses the outer circumference of the connector 10 against the substrate 41. The frame will be attached to the substrate 41 by pins 72 passing through the frame 70 and into a hole (not shown) provided in the substrate 41. The holes provided for the pins 72 are associated with the array of terminals in the substrate and thus also with the contacts 22 on the connector 10. Thus, the frame 70 is aligned with the contact.

A window 71 in the frame 70 is provided to align the microelectronic element 45 with the contacts of the connecting element 10. The microelectronic element 45 is pressed against the connecting element 10 by the leaf spring 73 having the arcuate portion 74. The leaf spring is held in the cover 76 by two pins 75. The cover 76 will be removably attached to the frame 70 by engaging the head of the pin 72 with the slotted hole 77 of the cover. With the cover 76 in place, the leaf spring 73 urges the microelectronic element 45 against the connector 10 to deflect the plate element 24 as described above. Thereby, the microelectronic device is electrically connected to the substrate 41 for burn-in test, adhesion or permanent use.

In another arrangement, as shown in FIG. 8, the frame 80 has a window 82 for positioning the microelectronic element 45 in relation to the conductor 10. Cover element 83 has a larger spacing window to provide access for inserting microelectronic element 45 into window 82 of frame 80. The frame and cover are attached to the substrate 41 by screws 81. The frame may also be precisely positioned by a dowel (not shown) extending through the substrate and the frame. After inserting the microelectronic element 45 into the window 82, a spring clip 84 is clipped onto the cover 83. The protruding portion 85 of the spring clip 84 presses the microelectronic element 45 onto the connector 10 to complete the electrical connection between the microelectronic element 45 and the substrate 41.

As can be readily understood, many modifications and combinations of the above-described features are possible without departing from the technical gist of the present invention. For example, the hole 27 in the sheet-like element 24 may be removed, and the active contact 22 contacts the continuous portion of the contact tab 21 in the region where the bump lead 46 contacts the connector 10. It may also include. Although this configuration does not provide the self-centering and scraping features of the preferred embodiment, fewer processing steps are used in manufacturing. Furthermore, the support structure between the sheet-like layer and the substrate may comprise a plurality of metal rings each centered around the active contact of the contact tab.

Although the present invention has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the present invention. For example, the post or spacer may be composed of a flexible conductive material, such as silver containing epoxy or other suitable material having a suitable structural strength, to provide further cosmetic matching between the socket and the underlying substrate. Accordingly, various modifications may be made to the illustrated embodiment, and other configurations are possible without departing from the spirit and spirit of the invention as defined by the appended claims.

The invention can be applied to microelectronic assemblies.

Claims (42)

A connection assembly for connecting a microelectronic device having an array of bump leads, (a) a substrate having electrically conductive leads; (b) an elastic sheet-like body having first and second major surfaces facing the substrate; (c) a support structure extending between the second major surface of the sheet-like body and the substrate, wherein the sheet-like body is spaced apart from the substrate and has a gap and a solid portion therein; (d) an array of thin film contacts aligned and secured to the gap on the first major surface of the sheet-like body to be mounted overlapping with the array of bump leads on the microelectronic device, the contacts being the solid portion of the support structure. And the bump lead on the microelectronic element is deflectable towards the substrate when a force is applied against this contact, the enclosed portion of the sheet-like body supported by the outer circumferential surface thereof. The connection assembly of claim 1, wherein the support structure is an array of posts. The connection assembly of claim 2, wherein the post array is electrically connected to a lead of the substrate, and the contacts of the array are electrically connected to the post. A connecting assembly according to claim 2, wherein each engaging portion of the sheet-like body is supported by four posts. 3. The method of claim 2, wherein the array of contacts and the array of posts are straight arrays having a column direction and a row direction, and the posts are offset in the diagonal direction from the contact and inclined in the column direction and the row direction. Connecting assembly. 2. A connection assembly according to claim 1, wherein the support structure is a support layer, the gap is a hole, and the edge of the hole forms an outer circumferential surface of a portion of the sheet-like body engaged with a corresponding contact. The apparatus of claim 1, wherein the sheet-shaped body has a plurality of holes disposed in an array corresponding to the contact array, each contact extending inwardly from the first major surface through one of the plurality of holes. Connection assembly characterized in that. The connection assembly of claim 1, wherein the contact has an rugged ridge projecting inward to contact the microelectronic element. The connection assembly of claim 2, wherein the post is a solid core solder ball. The connection assembly of claim 2, wherein the post is a via. 3. The connection assembly of claim 2, wherein the group of three or more posts surround the contact. 12. The connection assembly of claim 11, wherein at least one post of the group of posts electrically connects each contact to a lead on the substrate. 12. A connection assembly according to claim 11, wherein the sheet-shaped body portion associated with each contact point is deflected in response to a downward force applied by each bump lead. 2. A connection assembly according to claim 1, wherein the sheet-shaped body further comprises a bump opening in the sheet-shaped body portion associated with the contact, wherein the sheet-shaped body has increased plasticity. A connection assembly according to claim 1, wherein said contact is covered with solder. The connection assembly of claim 1, further comprising a conductive layer on the second major surface of the sheet-like body to adjust impedance. 17. The connection assembly of claim 16, further comprising a conductive trace on the second major surface of the sheet-like body for interconnecting the contacts. The connection assembly of claim 1, further comprising a conductive trace on the second major surface of the sheet-like body for interconnecting the contacts. The connection assembly according to claim 1, wherein a desiccant is deposited on the contact point. The apparatus of claim 1, further comprising: (a) a frame for aligning the microelectronic element to the sheet-shaped body, (b) the microelectronic device further comprises a biasing structure in which a force is exerted on the sheet-like body. In the connection method for connecting a microelectronic element having an array of bump leads, (a) an array of posts in which the sheet-shaped body is spaced apart from the substrate by connecting a sheet-shaped body, a substrate, an array of contacts on the first major surface of the sheet-like body, and a second major surface of the sheet-shaped body to an upper surface of the substrate Providing a connector having a plurality of contacts, each contact disposed on the sheet-shaped body portion having two or a plurality of the posts on its outer circumferential surface; (b) aligning the microelectronic element with the connector such that the array of contacts substantially overlaps the array of bump leads; (c) said microelectronic element being said sheet-like such that said array of bump leads is in contact with said array of contacts, and each portion of said sheet-shaped body is elastically deflected between said two or more posts and bump leads. And applying a force towards the body. 22. The method of claim 21, wherein the angular contact is electrically connected to one of the plurality of posts, the post is electrically connected to a lead in the substrate, and applying the force comprises: the bump lead and the bump in the substrate. An electrical connection is made between the lead and the connecting method. 23. The method of claim 22, further comprising: (d) electrically testing the microelectronic device through the electrical connection to determine whether the microelectronic device is acceptable; (e) permanently coupling said contact to said bump lead, if said microelectronic element is acceptable. In the connector which mounts a microelectronic element to a board | substrate, (a) an elastic sheet-like body having first and second major surfaces; (b) a plurality of thin film contacts fixed to a first major surface of said sheet-shaped body to be disposed and mounted in an array corresponding to an array of bump leads on said microelectronic device, each contact being associated with a corresponding bump lead; Become; (c) an array of posts offset from the contact and electrically connected to the contact and disposed on a second major surface of the sheet-shaped body, the post electrically connecting the contact to a substrate, the post-shaped body and the substrate And the microelectronic device is coupled to the substrate to support the sheet-shaped body having a space separated therebetween, wherein the microelectronic device is configured such that the microelectronic device is coupled by the contact on the sheet-shaped body such that the bump lead on the device is coupled by the contact. And the sheet-shaped body portion surrounding the contact point is elastically deflected into the separated space by applying a force against the body. 25. The apparatus of claim 24, wherein the sheet-shaped body has a plurality of holes disposed in an array corresponding to the contact array, wherein each contact extends inwardly through the one of the plurality of holes from the first major surface. A connector, characterized in that. 26. The connector of claim 25, wherein each contact comprises at least one protrusion extending through a hole associated with the contact. 27. A connector as claimed in claim 26, wherein each contact comprises a plurality of protrusions extending inwardly from about a position spaced apart on the circumference of the hole. The connector according to claim 24, further comprising a conductive layer formed on each lead. 25. The connector of claim 24, wherein each post comprises a solid core solder ball. 25. The connector of claim 24, wherein the sheet-like body has an array of holes corresponding to the post array, and the terminal post is electrically connected to the contact through the hole. 31. A connector as claimed in claim 30, further comprising a plurality of thin film contact tabs on said first major surface of said sheet-shaped body for electrically connecting said contact and said post. 25. The method of claim 24, wherein the array of contacts and the array of terminal posts are straight arrays having column and row directions, wherein the terminal posts are diagonally offset from the contacts and tilted in the column and row directions. Featured connector. 25. The connector of claim 24, further comprising a support post further supporting the sheet-like body, wherein the support post is not electrically connected to any contact. A socket for coupling a bump lead onto a microelectronic device, An elastic dielectric sheet having first and second major surfaces; An electrically conductive contact fixed to said first major surface of said sheet and having an active contact; A support substrate having a first surface arranged in parallel with a second major surface of said sheet, and a conductive terminal thereon; A plurality of posts spaced around the active contact, the posts mechanically supporting the sheet portion surrounding the contact with respect to the substrate such that a gap is formed between the sheet and the substrate, one of the plurality of posts Is electrically connected with the terminal and the contact, and the sheet is deflected as a bump lead coupled with an active contact of the contact. 35. The method of claim 34, comprising an opening extending between the first and second major surfaces of the sheet, wherein the active contact of the contact is aligned with the opening and partially extends through the opening. socket. 35. The socket of claim 34 wherein said post is a solid core solder ball. 35. The socket of claim 34 wherein said post is empty. 35. The apparatus of claim 34, further comprising a spacer positioned between each post and the first surface of the substrate, the spacer electrically connecting the post to the terminal and providing a vertical height greater than the deflection height of the sheet. Characterized in that the socket. 39. The socket of claim 38 wherein said spacer comprises a thin film substrate having an opening that is aligned with an active contact of said contact. 35. The plurality of first posts of claim 34, further comprising a second contact and a plurality of second posts mechanically supporting a second portion of the sheet surrounding the second active contact of the second contact. And the second post has at least one common post. 41. The socket of claim 40 wherein said sheet further comprises conductive traces secured to said second major surface, said conductive traces electrically interconnecting said first and second contacts on said sheet. . In a connector for coupling a bump lead on a microelectronic device, An elastic dielectric sheet having first and second major surfaces and electrically conductive contacts secured to the first major surface and having active contacts; A hard substrate having a terminal thereon; A plurality of posts supporting the sheet against the substrate such that a gap is formed between the posts, the contacts disposed on the joining portions of the sheets supported by the group of joined posts, the joining with adjacent contacts Wherein the group of posts share at least one post.