JP3194708B2 - Socket for IC - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a socket used for connecting an IC (integrated circuit) to an evaluation device such as a burn-in test handler or mounting the IC on a wiring board. The present invention relates to a socket integrated with a wiring board.

[0002]

2. Description of the Related Art As IC wiring board mounting density increases, IC chips are reduced in size, and packages such as BGA (ball grid array) or CSP (chip size package) are becoming mainstream. In this case, since the BGA and CSP use solder balls on the bottom surface as contacts, soldering is generally used for mounting on the wiring board, and it is difficult to remove them after mounting. The emergence of sockets that do this was desired.

[0003]

However, this type of IC originally intended for mounting by soldering has a contact shape,
Since the tolerances of dimensions and arrangement are large, and the contacts themselves are arranged at very fine intervals, it is possible to secure the contact (contact) of the contact with ordinary sockets using hard metal contacts There was a problem that was difficult and could not be dealt with sufficiently. Therefore, a certain degree of mobility is required for the contacts on the socket side. For this purpose, there is a conventional technique for connecting the socket and the IC with an anisotropic conductive connector using an elastomer.

However, since this kind of anisotropic conductive connector essentially consists of forming a conduction path in the thickness direction by traversing the connector, the conduction path is inevitably lengthened, which affects the electrical characteristics. In particular, when the IC is used as a socket for connecting to an evaluation device, there is a problem that the measurement at a high frequency is adversely affected. Further, since this type of connector is used as a contact by embedding a conductive member in an elastomer or the like, each contact is separately provided as a separate member, and there is also a problem that the number of manufacturing steps is not reduced.

The present invention has been made in view of the above problems, and in order to surely make contact with an IC solder ball, the contact area can be increased, the IC can be moved up and down, and high frequency operation can be performed. It is an object of the present invention to provide an IC socket that can secure a transmission path that can withstand measurement and that can make an IC detachable.

[0006]

That is, the IC socket of the first invention is provided with a conductive plating layer from the upper end to the base.
A plurality of columnar bodies with the upper end of the columnar body as a contact
At least the movable contact member protruding from the upper surface of the base body.
The columnar part is made of elastomer, and the columnar body on the top
Is inserted into the plated through hole of the wiring board.
The top of the columnar body
Exposed through the plated through hole
And plated through-holes around the pillars connected to the contacts
It is characterized by being electrically conductive by an electroplating layer.
The IC socket of the second invention is made of an elastomer.
A part or all of the upper part of the formed column is made of conductive elastomer.
It is composed of a tomer and has a metal or conductive
By providing balls made of conductive plastic,
Of multiple pillars with the contacts as contacts
The movable contact member, and the columnar body on the top
-With the base part inserted into the hole,
By overlapping, the contact at the upper end of the pillar is plated through
Exposed, and furthermore, this contact and plated through hole
Electrically conductive through the conductive elastomer part of the columnar body
It is characterized by having made it.

Therefore, according to the present invention, since the columnar body is made of an elastomer, the contact provided at the upper end thereof has a function of being deformed and moved up and down with a repulsive force by the pressing force from the IC. Next, a plurality of the columnar bodies projecting from the base of the movable contact member are inserted into plated through holes of the wiring board, and the upper end thereof is used as a contact, so that the contact point can be made as large as possible. ,or,
Manufacturing and assembling will produce an easy action. Further, since the contact and the plated through-hole are electrically connected to the circuit of the wiring board, an effect of keeping the transmission path as short as possible is produced.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 8 are views showing an example in which the socket of the present invention is configured as a socket for mounting an IC. The most characteristic feature of this socket is that it is integrated with a wiring board. That is, a movable contact member S is prepared by projecting a plurality of columnar members 2 having contacts P at the upper end from the upper surface of the base 1, and the columnar members 2 on the upper surface of the movable contact member S are plated through the wiring board 10. Hall 11
The movable contact member S and the wiring board 10 combine to form a socket by superposing the base portion 1 on the back surface of the wiring board 10 in a state of being inserted into the socket.

In this case, the wiring substrate 10 is a known substrate having a plurality of plated through holes 11 in which a plating layer 11A such as electroless plating is provided on the hole wall surface on a substrate made of an insulating material. The plating through hole 11 at a portion constituting the socket in combination with the movable contact member S described below has a diameter capable of inserting a plurality of pillars 2 of the movable contact member S.
They are arranged at a pitch that matches the pitch (see FIG. 3).

On the other hand, the movable contact member S is made of an elastomer excellent in heat resistance, cold resistance and flexibility (for example, fluorine rubber, silicone rubber, fluorosilicone rubber, etc.). A plurality of protruding shapes are configured (see FIG. 4). The pillars 2 are arranged at a pitch corresponding to the pitch of the contacts of the IC to be connected (the details will be described later). Further, in the material, at least a portion of the base 1 needs to be insulative (in this embodiment, an elastomer is used). However, the portion of the column 2 is made to be insulative as described below. There are several choices of whether to be conductive or conductive.

FIGS. 5 and 6 are views showing details of the columnar body 2 in this embodiment. In this case, the columnar body 2 is formed of an insulating elastomer molded integrally with the base 1. In this case, by setting the length to be longer than the thickness of the wiring board 10, the upper end thereof is plated with the plated through hole 1.
Exposed from 1 and the upper end is the contact point of the IC (solder ball)
It is configured in a dome shape in order to improve the contact with the dome. A conductive plating layer 2A (here, gold is electrolessly plated) is applied from the upper end to the base of the columnar body 2 to form a diaphragm-like conductive surface, and as a result, the upper end is a contact point of IC ( It acts as a contact point P for contact with the solder ball, and the base portion acts as a conductive portion with the wiring board by conducting with the plated through hole 11. In this case, since the columnar body 2 is made of an elastomer having elasticity, the contact P is compressed and deformed in the vertical direction by the pressing of the contact of the IC, thereby causing an operation to move up and down. A gap may be provided between the plating through hole 11 and the columnar body 2 to allow its diameter to expand when the columnar body 2 is compressed in the vertical direction. As described above, the contact P of the columnar body 2 can be expected to come into contact with the dimensional deviation and position error of the contact (solder ball) of the IC while deforming.

Next, FIG. 7 is a view showing a different embodiment of the columnar body 2. Here, in order to improve the reliability of the contact point P, the columnar body 2 is made of a conductive elastomer. The other configuration and operation are the same as those of the embodiment shown in FIG.

FIG. 8 is a view showing another embodiment of the columnar body 2. Here, in order to improve the reliability of the contact point P, FIG.
A portion 2B above the middle of the columnar body 2 is made of a conductive elastomer, and a ball 2C made of metal or conductive plastic is insert-molded at the upper end thereof.
In this embodiment, the ball 2C is electrically connected to the plated through hole 11 together with the contact point P for contact with the contact point of the IC, thereby acting as a conductive portion with the wiring board. The upper portion 2B also functions as a conductive portion with the wiring board by conducting with the plated through hole 11. In this embodiment and the above-described embodiment shown in FIG. 7, it goes without saying that the molding die is used in common with the embodiment shown in FIG. 6 and can be integrally molded. Needless to say, metal plating, conductive plastic balls, and conductive elastomers can be electroplated.

As described above, the movable contact member S having the above configuration is combined with the back surface of the wiring board 10 to form a socket as described above. However, the movable contact member S is movable by the pressing force from the IC mounted on the socket. Here, the movable contact member S is fixed to the back surface of the wiring board 10 by applying the bottom plate 3 to the back surface of the movable contact member S so that the contact member S is not pushed out in the direction away from the wiring board 10. (See FIG. 1).

On the other hand, the plated through hole 1 of the wiring board 10
In order for the terminal P of the movable contact member S exposed from 1 to function as a terminal of the socket, the IC must be arranged at a predetermined position on the wiring board 10, but here, there is a window 4A into which the package of the IC fits. This effect is achieved by fixing the guide frame 4 to the surface of the wiring board 10 (see FIGS. 1 and 2). In this case, the movable contact member S
In addition, there is an effect that it becomes possible to support ICs of various standards (number of pins) by simply exchanging the guide frame 4 while leaving the through holes 11 of the wiring board 10 corresponding thereto. For example, in this embodiment, an example in which a socket corresponding to a 13 × 13-pin IC is configured is illustrated in FIGS. 1 and 2, but is illustrated in, for example, FIGS. 7 × 7 pin IC
It is also possible to configure a socket corresponding to an IC and a socket corresponding to an IC having a different number of pins.

In this embodiment assuming a socket for mounting an IC, the mounted IC is connected to the wiring board 1.
The fixing frame 5 for fixing the IC chip on the guide frame 4 is overlapped with the above-mentioned guide frame 4 so that an IC
(See FIGS. 1 and 2).

Next, FIGS. 11 and 12 show examples in which the socket of the present invention is configured as a socket for an IC evaluation device. In this embodiment, since it is not necessary to fix the mounted IC on the wiring board 10, the fixing frame as in the above embodiment is not necessary. As shown, the upper part of the guide frame 4 from the upper edge of the window 4A is tapered so as to expand toward the opening.

By the way, in the socket of the present invention,
The contact P can be made as large as possible. In the embodiment, since the contact P is formed in a dome shape, the contact with the contact of the IC can be made good. The contact P is expected to come into contact with the contact of the IC while being deformed. As described above, the socket according to the present invention has an action capable of sufficiently coping with a dimensional deviation and a position error of an IC contact (solder ball).

FIGS. 13 to 15 show an example of this operation by using a BGA having a package size of 12 mm square and 13 × 13 pins.
(Ball grid array) This is shown by taking a socket for an evaluation device of the IC 20 as an example.
Indicates a contact (solder ball) of this IC. Here, the standard value of the solder ball diameter of the IC 20 is 0.40 mm,
Similarly, the standard value of the pin (contact) pitch is set to 0.80 mm, and the pitch of the contact points P of the socket matches this standard value. FIG. 13 shows a mounting example of the IC 20 which maintains the standard value.
FIG. 14 shows a mounting example of the C20, and FIG. 15 shows a mounting example of the IC 20 having the minimum values of the solder ball diameter and the pin pitch. Table 1 below lists the dimensions assumed in each figure.

[0020]

[Table 1]

As described above, here, the solder ball diameter ±
An error of 0.10 mm and a pin pitch of ± 0.05 mm is illustrated as a general example. In this case, the error of the total pitch is ± 0.10 mm, but the total pitch from the 3rd pin to the 11th pin is kept within the range of 6.30 mm to 6.50 mm, so the maximum and minimum pitch Does not apply to all. The maximum pin pitch is 0.85
mm, which is within a minimum of 0.75 mm. Therefore, if the contact point P of the socket is made large enough not to contact the contact points 20P adjacent to the IC 20 at the same time, it can be handled.

[0022]

The present invention having the above configuration has the following specific effects. It is possible to realize a socket having a movable contact that can be deformed and moved up and down by utilizing the elasticity of the elastomer without using a conventional anisotropic conductive connector.

Since a plurality of pillars projecting from the base of the movable contact member are inserted into the plated through holes of the wiring board and the upper end thereof is used as a contact, the contact point can be made as large as possible. It is possible to cope with the dimensional deviation and position error of the contact point of the IC in combination with the deformation and the movability that can move up and down freely.
An optimal socket for P (chip size package) is realized.

For the same reason, the contacts can be integrally molded and integrated, so that each contact can be individually embedded as a separate member in an elastomer or the like, and the number of steps can be significantly reduced as compared with the prior art. Become, production,
Assembly becomes easy, and a high-performance socket can be realized at low cost.

For the same reason, it is possible to easily replace only the contacts that are liable to deteriorate with time without damaging the circuit board, so that a user-friendly and economical socket can be realized.

The contact is made by directly contacting the plated through hole of the wiring board with the contact itself, so that the connection is made to the circuit of the wiring board. The transmission path is much shorter than the connector, the electrical characteristics are improved, and a socket that can withstand high-frequency measurement can be realized.

It is possible to cope with ICs of various standards simply by replacing the guide frame having a window into which the package of the IC fits, while keeping the combination of the wiring board and the movable contact member as it is. A wide range of sockets can be manufactured, and a high-performance socket can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of an embodiment of an IC socket of the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is a plan view of the wiring board;

FIG. 4 is a side view of the movable contact member.

FIG. 5 is an enlarged partial cutaway side view of a main part of the movable contact member.

FIG. 6 is an enlarged partial cutaway side view of a main part of the embodiment.

FIG. 7 is a partially cutaway side view of a main part of another embodiment of the IC socket of the present invention.

FIG. 8 is a partially cutaway side view of a main part of another embodiment of the IC socket of the present invention.

FIG. 9 is a perspective view of another embodiment of the IC socket of the present invention.

FIG. 10 is a partially cutaway side view of a different embodiment of the IC socket of the present invention.

FIG. 11 is a partially cutaway side view of another embodiment of the IC socket of the present invention.

FIG. 12 is a partially cutaway side view of a different embodiment of the IC socket of the present invention.

FIG. 13 is a partially cutaway side view showing an example of the operation of the IC socket of the present invention.

FIG. 14 is a partially cutaway side view showing an example of the operation of the IC socket of the present invention.

FIG. 15 is a partially cutaway side view showing an example of the operation of the IC socket of the present invention.

[Explanation of symbols]

 P contact S movable contact member 1 base (of movable contact member) 2 pillar (of movable contact member) 2A (plated) conductive plating layer 4 guide frame 4A (guide frame) window 10 wiring board 11 plated through hole

Claims (6)

(57) [Claims] The conductive plating layer (2 ) extends from the upper end to the base.
By applying A), the upper end of the columnar body (2) is contacted
The movable contact member (S) in which the plurality of columnar bodies (2) configured in (P) are protruded from the upper surface of the base (1), at least the columnar body (2) is formed of an elastomer, and the columnar body ( 2) The plated through hole (1) of the wiring board (10)
With the base (1) being inserted into the wiring board (1),
0), the contact (P) at the upper end of the columnar body (2) is exposed through the plated through hole (11),
Further contact of the contact (P) and plated through holes (11)
(P) and a conductive plating layer (2) around the columnar body (2).
IC characterized by being electrically conducted through A)
Socket. 2. A contact (P) at an upper end of a columnar body (2) of a movable contact member (S) exposed from a plating through hole (11).
2. The IC socket according to claim 1, wherein the socket is formed in a dome shape. 3. The IC socket according to claim 3, wherein a part or all of the columnar body (2) of the movable contact member (S) is made of a conductive elastomer. 4. A columnar body made of an elastomer.
Part or all of the upper side of (2) is made of conductive elastomer
And metal or conductive plus
By providing a ball (2C) made of tics,
(2C) as a contact (P)
The movable contact member (S) protruding from the upper surface of the base (1) is
The columnar body (2) on the upper surface is plated through the wiring board (10).
The base (1) portion is connected to the wiring base while being inserted into the base (11).
By stacking on the back surface of the plate (10),
The contact (P) at the upper end is exposed from the plated through hole (11)
Then, contact (P) and plated through hole (11)
Through the conductive elastomer portion of the columnar body (2)
Socket for IC to conduct electrically. 5. The diameter of the column (2) expanded between the column (2) of the movable contact member (S) and the plated through hole (11) into which the column is inserted when the column (2) is compressed in the vertical direction. 5. I according to claim 1, wherein a gap is provided to allow
Socket for C. 6. A guide frame (4) having a window (4A) into which a package of an IC fits is placed on the surface of a wiring board (10) in order to arrange an IC to be mounted on a socket at a predetermined position. The IC socket according to claim 1.