JP4683993B2 - IC socket contact device - Google Patents

Description

  The present invention relates to a contact device which is built in an IC socket for electrical connection between an IC package and an external circuit and obtains electrical conduction by elastic contact with an external contact of the IC package, and more specifically, for example, a BGA (ball grid) The present invention relates to an IC socket contact device that can be suitably used for a continuity test of an IC package in which a large number of substantially spherical or pad-like external contacts are arranged at a fine pitch, such as an array) type or an LGA (land grid array) type .

  With the recent reduction in size and performance of IC packages, the number of external contacts of IC packages has increased and the density has increased, and as a result, the pitch between external contacts has become a fine pitch of, for example, 0.4 mm or less. . With such a fine pitch of the external contacts of the IC package, an IC socket contact device that electrically connects the external contacts of the IC package and the external circuit of the test board is also required to have a high density.

  As an IC socket for responding to such a demand, between the first terminal (upper terminal) that contacts the external contact of the IC package and the second terminal (lower terminal) that contacts the external circuit. It is known that when an IC package is mounted and pressed downward by interposing a coil spring, the external contact of the IC package and the first terminal come into contact at a predetermined pressure by the elastic force of the coil spring. (For example, see Patent Document 1).

JP-A-8-213088

However, the conventional IC package incorporates a coil spring inside the first terminal, and when the terminal diameter is reduced in order to cope with the fine pitch described above, the coil spring also becomes smaller in diameter and its elastic restoring force. Therefore, it becomes difficult to obtain an elastic force larger than the sliding friction between the first terminal and the second terminal, and the contact between the external contact of the IC package and the first terminal becomes unstable. There is a fear.
If a large-diameter coil spring is used to obtain a predetermined elastic force, the inner diameter of the first terminal must be increased, and the above-mentioned fine pitch cannot be accommodated.
In order to ensure contact between the external contact of the IC package and the first terminal using a small-diameter coil spring, the sliding friction between the first terminal and the second terminal is reduced (the first terminal and It is conceivable that the second terminal is not slidably contacted), but in this case, electrical continuity is ensured by the coil spring, and the current path becomes longer and the resistance to the passing current becomes larger. May adversely affect performance characteristics and continuity test accuracy.
On the other hand, since the external contacts themselves of the IC package have become finer pitches, the external contacts themselves have become finer, and the external contacts may be deformed by contact with the first terminal. It is required to reduce the contact pressure with one terminal.

  The present invention has been made in view of such a conventional situation. The purpose of the present invention is to reduce the contact pressure with respect to the external contact of the IC package in a continuity test of the IC package in which a large number of external contacts are arranged at a fine pitch. An object of the present invention is to provide a novel IC socket contact device capable of performing stable contact with a simple structure while being as small as possible.

In order to achieve the above object, an IC socket contact device according to the first invention of the present application is built in an IC socket for electrical connection between an IC package and an external circuit, and is elastically contacted with an external contact of the IC package. A contact device for obtaining electrical continuity,
A lower contact terminal in which left and right elastic pieces are continuously provided on a lower terminal portion connected to the external circuit;
An upper contact terminal that is inserted between the left and right elastic pieces and is connected to a tapered contact piece that is in sliding contact with the left and right elastic pieces, below the upper terminal portion that is in contact with the external contact of the IC package;
The upper contact terminal is loaded outside the tapered upper contact piece and between the lower contact terminal and the upper contact terminal. The lower contact terminal and the upper contact terminal are supported so as to be vertically movable, and the lower contact terminal is lowered. A coil spring for urging in the moving direction and urging the upper contact terminal in the upward moving direction;
When the IC package is mounted on the IC socket and pressed downward, the external contact of the IC package comes into contact with the upper terminal portion of the upper contact terminal, and the taper shape as the upper contact terminal moves downward. The left and right elastic pieces are expanded by the contact piece,
When the downward pressing force of the IC package is released, the left and right elastic pieces are contracted and closed as the upper contact terminal moves upward.

The IC socket contact device according to the second aspect of the present invention is a contact device that is built in an IC socket for electrical connection between an IC package and an external circuit, and obtains electrical continuity by elastically contacting the external contact of the IC package. Because
An upper contact terminal in which left and right elastic pieces are continuously provided below an upper terminal part that contacts an external contact of the IC package;
On the lower terminal connected to the external circuit, a lower contact terminal that is inserted between the left and right elastic pieces and is continuously provided with a tapered contact piece that is in sliding contact with the left and right elastic pieces;
The lower contact terminal is mounted outside the tapered upper contact piece and between the lower contact terminal and the upper contact terminal. The lower contact terminal and the upper contact terminal are supported so as to be vertically movable, and the lower contact terminal is lowered. A coil spring for urging in the moving direction and urging the upper contact terminal in the upward moving direction;
When the IC package is mounted on the IC socket and pressed downward, the external contact of the IC package comes into contact with the upper terminal portion of the upper contact terminal, and the taper shape as the upper contact terminal moves downward. The left and right elastic pieces are expanded by the contact piece,
When the downward pressing force of the IC package is released, the left and right elastic pieces are contracted and closed as the upper contact terminal moves upward.

  According to such a configuration, when the IC package is mounted on the IC socket and pressed downward, the external contact of the IC package contacts the upper terminal portion of the upper contact terminal and resists the elastic force of the coil spring. Accordingly, the upper contact terminal moves downward, and accordingly, the right and left elastic pieces expand against the elastic force by the tapered contact pieces. At this time, the elastic pieces on the left and right firmly hold the tapered contact piece by its elastic restoring force, so that conduction between the upper contact terminal and the lower contact terminal is ensured reliably. When the force that presses the IC package downward is released from this state, the upper contact terminal is surely moved upward by the contraction due to the elastic restoring force of the coil spring and the elastic restoring force of the left and right elastic pieces, and the initial position Return to. Accordingly, stable contact can be performed while using a coil spring having a small elasticity to reduce the contact pressure of the upper terminal portion with respect to the external contact of the IC package as much as possible.

  In the first invention, the left and right elastic pieces can be formed, for example, by a substantially U-shaped or substantially V-shaped spring portion continuously provided on the upper portion of the lower terminal portion. In the second invention, for example, It can be formed by a substantially inverted U-shaped or substantially inverted V-shaped spring portion provided continuously to the lower portion of the upper terminal portion.

  In the first invention, for example, the tapered contact piece may have a shape having a tapered side surface so as to be gradually tapered downward from the upper terminal portion. It can be set as the shape provided with the taper-shaped side surface so that it may taper up gradually from the side terminal part upwards.

  In order to smoothly expand and contract the left and right elastic pieces accompanying the vertical movement of the upper contact terminal, it is preferable that the sliding contact friction between the tapered contact pieces and the left and right elastic pieces is small. Preferably, the left and right elastic pieces are provided with contact ends protruding inwardly so that the tapered contact pieces are slidably contacted with the left and right elastic pieces at the contact ends.

  For example, the coil spring can be disposed between the base of the left and right elastic pieces and the tip of the tapered contact piece between the left and right elastic pieces, but in this case, the contraction of the left and right elastic pieces may be hindered. Therefore, it is necessary to use a coil spring with a fine diameter, and it becomes difficult to obtain a predetermined resilience. Therefore, it is preferable that the coil spring is disposed outside the tapered contact piece. In this case, there is no possibility of hindering the expansion / contraction of the left and right elastic pieces, and a predetermined resilient force can be obtained by a coil spring having a predetermined diameter, thereby making it possible to perform more stable contact.

In order to make the contact between the upper terminal portion and the external contact of the IC package more stable, it is preferable that the upper terminal portion includes a plurality of contact points that contact the external contact.
In order to provide a plurality of contact points, for example, it is possible to exemplify forming at least two or more contact points on the upper end of the upper terminal portion. In terms of contact stability, it is more preferable to form three or more contact points.

When the upper contact terminal is formed by processing a plate material, press the left and right (two) contact points on the upper end of the upper terminal portion by pressing the upper end of the plate material into a substantially V shape or U shape. Can be easily formed.
When the upper contact terminal is formed by processing a bar material, the header has a concave shape at the center of the upper end of the bar material, and the annular wall surrounding the recess has a substantially crown shape in which peaks and valleys are alternately connected. Three or more contact points can be easily formed on the upper end of the upper terminal portion by processing or the like.

In the first invention, since the lower contact terminal has left and right elastic pieces, the lower contact terminal is preferably formed by pressing a plate material. Moreover, since the upper contact terminal has a tapered contact piece, it is preferable to form the upper contact terminal by processing a bar material as a header.
Therefore, in the first invention, the upper terminal portion having three or more contact points can be easily formed.

  In the second invention, since the upper contact terminal has left and right elastic pieces, the upper contact terminal is preferably formed by pressing a plate material. Moreover, since the lower contact terminal has a tapered contact piece, it is preferable to form the lower contact terminal by processing a bar material as a header.

In the first invention or the second invention, when the lower contact terminal is also movable up and down, an IC socket is mounted on a test board, and the lower contact terminal is brought into pressure contact with the external circuit on the surface of the test board, Only the lower contact terminal rises by a predetermined stroke against the elastic force of the coil spring, and the left and right elastic pieces are expanded by the tapered contact piece as the lower contact terminal moves upward. May be.
In this case, in the non-soldering type IC socket in which the lower contact terminal is pressed against the external circuit, in addition to the advantage of using the coil spring having a small elasticity, the external circuit of the lower contact terminal due to the elasticity of the coil spring It is possible to reduce the load (bounce contact force) against the test board and to prevent warping or cracking of the test board.

As described above, the contact device and the IC socket incorporating the same according to the present invention stably move the upper contact terminal up and down by the cooperation of the elastic force of the coil spring and the elastic force of the left and right elastic pieces. Thus, contact with the external contact of the IC package is obtained, and the elastic contact pieces on both sides sandwich the tapered contact piece with its elastic force, so that the upper contact terminal and the lower contact terminal can be reliably conducted. Further, since the upper contact terminal is returned to the initial position by the cooperation of the coil spring and the left and right elastic pieces, the above-described operation can be obtained while using the coil spring having a smaller elastic force than the conventional one.
Therefore, the contact pressure with respect to the external contact of the IC package can be reduced as much as possible, and stable contact and conduction can be realized with a simple structure. In addition, since the current path is shortened without going through the coil spring, the electrical characteristics are excellent. Therefore, it can be suitably used for a continuity test of an IC package in which many external contacts are arranged at a fine pitch.
Furthermore, the load of the lower contact terminal (elastic contact force) on the test board with an external circuit can be reduced as much as the elastic force of the coil spring can be reduced, and the test board can be prevented from warping or cracking. There are many effects.

Hereinafter, an example of an embodiment of a contact device according to the present invention and an IC socket incorporating the contact device will be described with reference to the drawings.
FIG. 1 is a plan view of the IC socket a of this example, FIG. 2 is a front view thereof, FIG. 3 is an enlarged sectional view of a main part showing a contact device b built in the IC socket a, and FIG. FIG. 2 is an enlarged cross-sectional view showing a main part of the IC socket a. The IC socket a can be moved up and down on a lift plate 3 on which an IC package c is mounted above a socket body in which the plate 2 is fixed above the socket substrate 1. In the socket body, a number of contact devices b equal to or greater than the number of external contacts c1 of the IC package c to be mounted are built into the socket body, and fixed pins projecting from the bottom surface of the socket substrate 1 4 is detachably mounted on a test board d having an external circuit.
The elevating plate 3 is supported by a coil spring (not shown) built in the socket body so as to be movable up and down and is urged in the upward movement direction.
A space s is provided between the socket substrate 1 and the plate 2 so that a lower contact terminal 10 described later can be moved up and down.

  The IC package c is a BGA type IC package in which a large number of substantially spherical external contacts c1 are arranged with a fine pitch of about 0.4 mm, for example, and is electrically connected to an external circuit of the test board d via the IC socket a. A continuity test (operation reliability test) is performed by performing a general connection.

  An accommodation space 5 for the IC package c is recessed in the center of the elevating plate 3 in the IC socket a, and a recess 6 for accommodating each external contact c1 of the IC package c is provided at the bottom of the accommodation space 5. A plurality of through-holes 7 are formed corresponding to the respective external contacts c1 and into which the upper terminal portions 21 of the upper contact terminals 20 described later are slidably inserted at the bottoms of the recesses 6.

  Each contact device b built in the IC socket a is composed of a lower contact terminal 10, an upper contact terminal 20, and a coil spring 30, and a large number of fine contact pitches corresponding to a matrix arrangement pattern of external contacts c1 in the IC package c. It is arranged.

  The lower contact terminal 10 is formed into a shape integrally including the lower terminal portion 11 and the left and right elastic pieces 12, 12 by pressing from a thin metal plate, and is coaxial with the concave portions 6. In order to be positioned, the socket substrate 1 is inserted into a large number of through-holes 8 so as to be vertically movable.

  The lower terminal portion 11 protrudes from the bottom surface of the socket substrate 1, and when the IC socket a is mounted on the test board d, it is pressed against an external circuit on the surface thereof and is electrically connected to the external circuit. At that time, only the lower contact terminal 10 is raised by being immersed in the socket substrate 1.

  The left and right elastic pieces 12, 12 are connected to the lower terminal portion 11 so as to form a spring portion that rises in a substantially U shape from the upper end of the lower terminal portion 11, and are expanded and contracted by their own elasticity. It can be closed.

  Contact ends 13, 13 projecting inward are formed at the tips of the left and right elastic pieces 12, 12, and these contact ends 13, 13 are in sliding contact with a tapered contact piece 22 described later, The expansion / contraction described above is performed.

The upper contact terminal 20 is formed from a metal bar by header processing into a shape integrally including the upper terminal portion 21 and the tapered contact piece 22, and corresponds to each of the recesses 6 and the through holes 8. In order to be positioned coaxially, the plate 2 is inserted in a large number of through holes 9 provided so as to be vertically movable.
Further, the upper contact terminal 20 is moved upward when the small-width end portion 25 of the tapered contact piece 22 is held between the contact ends 13 and 13 of the left and right elastic pieces 12 and 12 and the left and right elastic pieces 12 and 12 are in a contracted state. The position (see FIG. 3) and the middle part of the large width of the tapered contact piece 22 (the middle part of the tapered side surface 26) are sandwiched between the contact ends 13 and 13, and the left and right elastic pieces 12 and 12 are expanded. It moves up and down between the moving positions (see FIG. 4).

  The upper terminal portion 21 is formed so that it can be slidably inserted into the through-hole 7. The upper end of the upper terminal portion 21 has a concave portion at the center, and the annular walls surrounding the concave portion are alternately peak portions and trough portions. Four contact points 23 that come into contact with the external contact c1 are provided, for example, by processing into a continuous crown shape.

  The tapered contact piece 22 is formed so as to be slidably inserted into the through hole 9 coaxially with the upper terminal portion 21 from the flange portion 24 formed at the lower end of the upper terminal portion 21 downward. At the same time, a tapered side surface 26 and a small-width distal end portion 25 are continuously provided so as to be gradually tapered from the proximal end (upper end) to the distal end (lower end), thereby forming a space between the left and right elastic pieces 12 and 12. The left and right elastic pieces 12 and 12 are expanded by the downward movement of the upper contact terminal 20 and the left and right elastic pieces 12 and 12 are contracted by the upward movement. Yes.

The coil spring 30 is loaded over the upper end (left and right contact ends 13, 13) of the lower contact terminal 10 and the middle part (the flange 24) of the upper contact terminal 20, and supports the upper contact terminal 20 so as to be movable up and down. And urging in the upward movement direction.
In addition, the coil spring 30 returns the upper contact terminal 20 to the upward movement position in cooperation with the left and right elastic pieces 12 and 12, so that the coil spring 30 has a small elasticity.

  The procedure of the continuity test of the IC package c using the IC socket a of this example configured as described above will be described. In the state shown in FIG. 3, the lower contact terminal 10 is in the downward movement position, the upper contact terminal 20 is in the upward movement position, and the small-width front end portion 25 of the tapered contact piece 22 is Since it is pinched by the contact ends 13, 13, the left and right elastic pieces 12, 12 are in a contracted state.

From this state, as shown in FIG. 4 (i), when the IC socket a is mounted on the test board d, only the lower contact terminal 10 moves upward, and the tapered side surface 26 of the tapered contact piece 22 is elastic to the left and right. Since it enters between the pieces 12, 12, the left and right elastic pieces 12, 12 are slightly expanded. At this time, the coil spring 30 is slightly contracted and its elastic restoring force is applied to the test board d via the lower contact terminal 10, but the elastic force of the coil spring 30 depends on the cooperation with the left and right elastic pieces 12, 12. Since the force is reduced, the load on the test board d is reduced, and warping or cracking of the test board d can be prevented.
In this state, when the IC package c is mounted in the accommodation space 5, each external contact c <b> 1 is accommodated in the recess 6.

  Further, as shown in FIG. 4 (ii), when the IC package c is pressed downward to move the elevating plate 3 downward, each external contact c1 comes into contact with each contact point 23 of the upper terminal portion 21, and upper contact is made. The terminal 20 and the lower contact terminal 10 are connected to the external circuit of the test board d and each external contact c1, and a continuity test can be performed. At this time, since the tapered side surface 26 of the tapered contact piece 22 further enters between the left and right elastic pieces 12, 12, the left and right elastic pieces 12, 12 are further expanded. At this time, since the elastic pieces 12 and 12 on the left and right firmly hold the tapered contact piece 22 by its elastic restoring force, conduction between the upper contact terminal 20 and the lower contact terminal 10 is ensured reliably, and reliability is ensured. High continuity test can be performed. Further, since the elastic force of the coil spring 30 is small, the contact pressure with respect to the external contact c1 of the upper terminal portion 21 is reduced, and deformation or damage of the external contact c1 can be prevented.

  After the test, when the force that presses the IC package c downward is released, the elastic restoring force of the coil spring 30 and the elastic elastic members 12, 12 are contracted and closed by the elastic elastic members 12, 12 by the elastic elastic members 12, 12. The upper contact terminal 20 is reliably moved up and returned to the initial position.

Next, a modification of the contact device b described above is shown in FIG. The contact device b ′ in this example is roughly the reverse of the upper contact terminal 10 and the lower contact terminal 20 described above.
That is, the upper contact terminal 20 ′ of this example is an upper terminal that contacts the external contact c1 of the IC package c, in which the same shape as the lower contact terminal 10 described above is arranged so that the vertical relationship is reversed. The left and right elastic pieces 12, 12 are connected below the portion 11 ′. Further, the lower contact terminal 10 ′ is formed by arranging the same shape as the upper contact terminal 20 described above so that the vertical relationship is reversed, and the lower terminal portion 21 connected to the external circuit of the test board d. A tapered contact piece 22 that is inserted between the left and right elastic pieces 12, 12 and that is in sliding contact with the left and right elastic pieces 12, 12 is provided on the upper side of “. Further, the upper end of the upper terminal portion 11 ′ is punched into a substantially V shape, and contact points 23 ′ and 23 ′ are formed at two left and right positions.

  Since the other components and the operation thereof are the same as the relative relationship between the upper contact terminal 10 and the lower contact terminal 20 described above, description and illustration are omitted.

  Although the embodiments of the contact device according to the present invention and the IC package incorporating the contact device have been described with reference to the drawings, the present invention is not limited to the illustrated examples, and the scope of the technical idea described in each claim. Needless to say, various modifications are possible.

The top view of the IC socket which concerns on an example of embodiment of this invention. The front view of the IC socket shown in FIG. The contact device built in IC socket is shown, (i) is a principal part expanded sectional view in alignment with XX, (ii) is a principal part expanded sectional view in alignment with YY. The state where the IC package is mounted on the IC socket mounted on the test board is shown, (i) shows a state before the IC package is pressed downward, and (ii) shows the state where the IC package is pressed downward. The perspective view of an upper contact terminal, a lower contact terminal, and a coil spring. The perspective view of the upper contact terminal which concerns on the other example of embodiment of this invention, a lower contact terminal, and a coil spring.

Explanation of symbols

a: IC package b: contact device 10: lower contact terminal 11: lower terminal part 12: left and right elastic pieces 13: contact end 20: upper contact terminal 21: upper terminal part 22: tapered contact piece 23: contact point 25 : Small width front end portion 26: Tapered side surface 30: Coil spring b ': Contact device 10': Lower contact terminal 21 ': Lower terminal portion 20': Upper contact terminal 11 ': Upper terminal portion 23': Contact point c : IC package c1: External contact d: Test board

Claims (7)

A contact device built in an IC socket for electrical connection between an IC package and an external circuit, and obtaining an electrical continuity by elastically contacting an external contact of the IC package,
A lower contact terminal in which left and right elastic pieces are continuously provided on a lower terminal portion connected to the external circuit;
An upper contact terminal that is inserted between the left and right elastic pieces and is connected to a tapered contact piece that is in sliding contact with the left and right elastic pieces, below the upper terminal portion that is in contact with the external contact of the IC package;
The upper contact terminal is loaded outside the tapered upper contact piece and between the lower contact terminal and the upper contact terminal. The lower contact terminal and the upper contact terminal are supported so as to be vertically movable, and the lower contact terminal is lowered. A coil spring for urging in the moving direction and urging the upper contact terminal in the upward moving direction;
When the IC package is mounted on the IC socket and pressed downward, the external contact of the IC package comes into contact with the upper terminal portion of the upper contact terminal, and the taper shape as the upper contact terminal moves downward. The left and right elastic pieces are expanded by the contact piece,
The contact device for an IC socket, wherein the left and right elastic pieces are contracted with the upward movement of the upper contact terminal when the downward pressing force of the IC package is released. A contact device built in an IC socket for electrical connection between an IC package and an external circuit, and obtaining an electrical continuity by elastically contacting an external contact of the IC package,
An upper contact terminal in which left and right elastic pieces are continuously provided below an upper terminal part that contacts an external contact of the IC package;
On the lower terminal connected to the external circuit, a lower contact terminal that is inserted between the left and right elastic pieces and is continuously provided with a tapered contact piece that is in sliding contact with the left and right elastic pieces;
The lower contact terminal is mounted outside the tapered upper contact piece and between the lower contact terminal and the upper contact terminal. The lower contact terminal and the upper contact terminal are supported so as to be vertically movable, and the lower contact terminal is lowered. A coil spring for urging in the moving direction and urging the upper contact terminal in the upward moving direction;
When the IC package is mounted on the IC socket and pressed downward, the external contact of the IC package comes into contact with the upper terminal portion of the upper contact terminal, and the taper shape as the upper contact terminal moves downward. The left and right elastic pieces are expanded by the contact piece,
The contact device for an IC socket, wherein the left and right elastic pieces are contracted with the upward movement of the upper contact terminal when the downward pressing force of the IC package is released.   2. A contact end projecting inwardly at the tip of each of the left and right elastic pieces is formed so that the tapered contact piece is slidably contacted with the left and right elastic pieces. Or the contact device for IC sockets of 2.   The contact device for IC socket according to any one of claims 1 to 3, wherein the coil spring is disposed outside the tapered contact piece.   5. The contact device for an IC socket according to claim 1, wherein the upper terminal portion includes a plurality of contact points that come into contact with external contacts of the IC package.   When the IC socket is mounted on the test board and the lower contact terminal is brought into pressure contact with the external circuit on the surface of the test board, only the lower contact terminal has a predetermined stroke against the elastic force of the coil spring. 6. The IC socket according to claim 1, wherein the left and right elastic pieces are formed to expand by the tapered contact piece as the lower contact terminal moves upward. Contact device.   An IC socket for electrical connection between an IC package and an external circuit, comprising the contact device according to any one of claims 1 to 6.

Images