JP4006199B2 - IC package socket - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides an IC package socket having a pressing mechanism that presses and holds a semiconductor integrated circuit package (hereinafter referred to as an IC package) against a socket body while maintaining a predetermined contact pressure state between its terminals and contacts. About.
[0002]
[Prior art]
In general, in order to test an IC package (for example, a heat resistance test), a so-called burn-in test is performed in which the IC package is placed in a heating furnace in a state where the IC package is mounted on an IC package socket and the quality is determined.
[0003]
In such a burn-in test, generally, an IC package is loaded into each of a plurality of IC package sockets arranged in a grid pattern on the burn-in board, and the IC package is attached to the socket body by a pressing mechanism using a normal spring restoring force. The burn-in board is inserted into the burn-in test tank while maintaining a predetermined contact pressure state between the terminal and the contact. When loading the IC package, the socket cover is pressed against the spring force of the normal spring or the like by a robot arm or the like to open the contact and position the IC package terminal at a predetermined position. By releasing the pressure on the cover, the IC package is pressed against the socket body by the above-mentioned pressing mechanism, and is held while maintaining a predetermined contact pressure state between the terminal and the contact.
[0004]
[Problems to be solved by the invention]
However, in such a conventional pressing mechanism that uses the restoring force of a normal spring, the pressing force is almost constant regardless of the temperature change, so that the pressing force required in the high-temperature burn-in test chamber is A spring having an obtained spring constant must be used, and an excessive operating force is required when an IC package is loaded that is operated at room temperature against the spring force of the spring.
[0005]
This is because the burn-in test chamber uses a blower for blowing heated air and a compressor for adjusting the temperature, and the vibration of the machine is transmitted to the entire burn-in test chamber. If the spring force due to the is weak, the IC package will dance in the socket, and in the worst case, the contact may be momentarily left between the contact and the terminal of the IC package, which may be misjudged as poor conduction. It is.
[0006]
In such a socket having a large spring force, a large operating force is required when the IC package is loaded at room temperature. Then, the strength of the burn-in board itself in which a plurality of IC package sockets are arranged in a grid shape is also necessary, and if the strength is not sufficient, the amount of deflection differs between the central portion and the peripheral portion of the burn-in board. As a result, the positional accuracy of the socket is deteriorated or the socket cannot be completely operated, and it becomes difficult to load the IC package into the socket. Therefore, the number of IC packages arranged on the burn-in board is limited, and the productivity of the burn-in test is limited.
[0007]
Considering this, it is expected that a sufficient pressing force is obtained at the time of burn-in, and an IC package socket that can be operated with a small operating force when an IC package is loaded is expected.
[0008]
An object of the present invention is to provide a socket for an IC package that can meet such a demand.
[0009]
[Means for Solving the Problems]
An IC package socket of the present invention that achieves the above object includes a socket body that has a slide substrate that is slidably disposed on a base substrate on which contacts are arranged and on which an IC package having ball-shaped lead terminals is mounted. In a socket for an IC package, a pressing mechanism including a pair of latch members configured to press the main body of the mounted IC package against the slide substrate and hold the IC package, which is rotatably supported by the base substrate, A cover member that is arranged to be movable up and down on the socket body, and that performs an operation of pressing and holding the pair of latch members in the pressing mechanism according to the attaching and detaching operation of the IC package ; and a pivot shaft of the latch member; Between the spring seat portion of the latch member and the spring seat of the base substrate formed in the orthogonal direction, respectively. A shape memory spring and a coil spring disposed adjacent to each other, wherein the shape memory spring is disposed at a position separated from the rotation shaft of the latch member as compared with the coil spring; The spring seat portion is urged so that the pressing force is increased at the time of burn-in as compared with that at normal temperature .
[0010]
Further, the IC package socket of the present invention is an IC package socket comprising a socket body having a slide substrate on which the IC package is mounted, and is slidably arranged with respect to the base substrate on which the contacts are arranged. And a pressing mechanism including a pair of latch members that press the body of the mounted IC package against the slide substrate and hold the IC package, and the socket body is vertically movable. A cover member that performs a pressing and holding operation on a pair of latch members in the pressing mechanism in accordance with an attaching / detaching operation of the IC package, and the latch formed in a direction orthogonal to a rotation axis of the latch member The pressing force of the latch member between the spring seat portion of the member and the spring seat of the base substrate is compared with that at normal temperature. A shape memory spring that biases the spring seat so as to increase at the time of turn-in, and a pressing force changing means including a coil spring disposed adjacent to the shape memory spring, the shape memory spring comprising: It is arranged at a position spaced apart from the rotation axis of the latch member as compared with the coil spring .
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same parts to avoid redundant description.
[0016]
1 to 9 show a first embodiment of an IC package socket according to the present invention. In this embodiment, the present invention is applied to a so-called socket for a BGA type IC package in which contact is made with the contact at two positions on the left and right sides with respect to the ball-like lead terminal BLT of the BGA type IC package ICP. .
[0017]
1 is a plan view showing the entire rectangular IC package socket 10, FIG. 2 is a sectional view taken along line II-II in FIG. 1 along its diagonal line X, and FIG. 3 is a view along a center line parallel to the side. 3 is a half sectional view taken along line III-III in FIG. The socket 10 basically includes a base body 20 made of glass fiber-containing resin and a slide base 30 made of the same resin, which is slidable with respect to the base board 20, and a vertical movement with respect to the socket body. And a cover member 40 that can be arranged.
[0018]
A large number of contacts 50 are attached to the base substrate 20 in a lattice pattern parallel to each side at the same pitch. Each of the contacts 50 is a pair of elastic contacts that elastically hold the ball-shaped lead terminals BLT. It has the piece 50a, 50b (refer FIG.5, 8).
[0019]
The slide substrate 30 is provided so as to be movable toward a corner on one diagonal line X of the base substrate 20, and acts to elastically displace one elastic contact piece 50a during this movement. More specifically, the slide substrate 30 has contact receiving holes 32 corresponding to the grid-like arrangement of the ball-like lead terminals BLT and the contacts 50 of the IC package, and receives the elastic contact pieces 50a and 50b. A partition wall 34 is provided between the elastic contact pieces 50a and 50b so as to cross the contact receiving hole 32. A guide frame member 31 for guiding the IC package ICP to a predetermined mounting position is provided on the upper surface of the slide substrate 30.
[0020]
The slide substrate 30 is moved by a moving mechanism 60 described below. Since this moving mechanism 60 can be of a type provided with known levers 61 and 62 according to Japanese Patent Laid-Open No. 10-302925, etc., only a brief description will be given. That is, as shown in FIG. 2, the moving mechanism 60 includes levers 61 and 62 pivotally supported by shafts 61 </ b> A and 62 </ b> A on the base substrate 20, and drive shafts 61 </ b> B provided on the levers 61 and 62. 62B, engagement grooves 35 and 36 formed on the slide substrate 30 and engaged with the drive shafts 61B and 62B, and a spring 38 that biases the slide substrate 30 to the initial position. Although not shown, the levers 61 and 62 extend from the shafts 61A and 62A along the sides of the cover member 40, respectively. The axes of the shafts 61A and 62A, the drive shafts 61B and 62B, and the engagement grooves 35 and 36 are all orthogonal to one diagonal line X of the base substrate 20.
[0021]
A return spring 22 that biases the cover member 40 upward is provided between the base substrate 20 of the socket 10 and the cover member 40.
[0022]
Next, referring to FIGS. 1, 3, and 6, as a part of the pressing mechanism of the present invention, as a pressing member that is rotatable with respect to the base substrate 20 on the center line of two opposite sides of the socket 10. A pair of latch members 70 is provided. The latch member 70 contacts and presses the upper surface of the IC package ICP, a pressed piece portion 70A, a pressed portion 70B pressed when the cover member 40 is lowered, and a spring seat portion formed below the pressed portion 70B. 70C and a protrusion 70D that is in contact with the base substrate 20 and serves as a rotation center of the latch member 70.
[0023]
In the present embodiment, two spring seat portions 70C are juxtaposed in parallel with the side of the socket 10 (see FIG. 9). The two spring seats 70C arranged side by side have a normal coil spring 82 made of a normal spring material or the like as a pressing force changing means for changing the pressing force of the pressing mechanism between normal temperature and burn-in. A shape memory coil spring 84 made of a shape memory material is combined with a pair and provided between a spring seat 90 provided on the base substrate 20. The number of the shape memory coil springs 84 combined with the normal coil spring 82 is not limited to one. However, it is necessary to provide at least one normal coil spring. This is because, if both are made shape memory coil springs, the yield strength at room temperature is insufficient, and the springs remain deformed, making it impossible to press the IC package.
[0024]
Here, a normal spring has a constant spring constant regardless of temperature, and a shape memory spring changes its spring constant depending on the temperature due to a shape recovery action at a predetermined temperature. A typical shape memory spring is composed of a shape memory material of Ni-Ti alloy, and the shape recovery temperature varies depending on the amount of Ni, but the burn-in test is generally performed at 120 to 150 ° C. It is preferred to select a shape memory spring that recovers.
[0025]
In the present embodiment, the IC package ICP is attached to the socket 10 as follows.
[0026]
When the cover member 40 is pressed by a robot arm or the like in the non-mounted state of the IC package ICP shown in FIG. 2, the cover member 40 is lowered against the return spring 22 and the levers 61 and 62 are lowered on its lower surface. Press. The levers 61 and 62 rotate about the shafts 61A and 62A, and the slide substrate 30 is turned into the spring 38 by the drive shafts 61B and 62B engaged with the engagement grooves 35 and 36 formed in the slide substrate 30. Move against. When the slide substrate 30 moves, the elastic contact piece 50a of the contact 50 is elastically deformed by the partition wall 34 provided across the contact receiving hole 32, and the contact 50 is expanded.
[0027]
When the cover member 40 is lowered, at the same time, the cover member 40 presses the pressed portion 70B of the latch member 70 against the spring force of the normal coil spring 82 and the shape memory coil spring 84, and the latch member 70 is pressed. The latch member 70 is opened as shown in FIG. 3 by rotating around the projection 70D. Since the operation of mounting the IC package ICP in the socket 10 is performed at room temperature, the spring force of the shape memory coil spring 84 before the shape recovery is weak, and the pressing force on the robot arm or the like is a small force accordingly. It will be good. Therefore, even in a burn-in board in which a plurality of sockets 10 are arranged, the reaction force is small, and the amount of deflection is small.
[0028]
The IC package ICP is inserted through the opening of the cover member 40 in a state where the contact 50 is expanded and the latch member 70 is opened. The inserted IC package ICP is guided to a predetermined mounting position by the guide frame member 31.
[0029]
In this state, when the pressing force by the arm of the robot is released, the cover member 40 is raised by the return spring 22 and the slide substrate 30 is returned to the initial position by the spring 38 (see FIG. 7). Then, the lead terminal BLT of the IC package ICP is elastically sandwiched between the pair of elastic contact pieces 50a and 50b as shown in FIG. 8, while the IC package ICP is latched by the latch member 70 as shown in FIG. The pressing piece 70A is pressed against the slide substrate 30 as the socket body. The pressing force at this time depends on the spring force of the normal coil spring 82 and the shape memory coil spring 84 before shape recovery.
[0030]
When the mounting of the IC package ICP in the socket 10 on the burn-in board is completed, the burn-in board is inserted into the burn-in test tank and a test is performed at a predetermined high temperature. However, according to the present embodiment, when this high temperature state is reached, the shape of the shape memory coil spring 84 is restored, and the spring constant becomes large, and the IC package ICP is applied to the IC package ICP by the pressing piece portion 70A of the latch member 70 described above. Even if the pressing force increases and analogy occurs, such as vibration of the burn-in test chamber, the IC package ICP is prevented from dancing in the socket 10, and the instantaneous disconnection between the worst case contact and the IC package terminal is prevented. Is done.
[0031]
Furthermore, as a second embodiment of the present invention, as shown in FIG. 10, the spring seat 70 </ b> C may be juxtaposed in a direction perpendicular to the rotation axis of the latch member 70. Then, the shape memory coil spring 84 is disposed at a position farther than the normal coil spring 82 with respect to the protrusion 70 </ b> D forming the rotation axis. In this way, the moment by the shape memory coil spring 84 can be increased, so that the pressing force can be greatly different between normal temperature and burn-in. In other words, when each spring force is set so as to obtain a predetermined pressing force at the time of burn-in, it means that the operating force at normal temperature can be made smaller.
[0032]
In the above-described embodiment, an example in which the present invention is applied to a socket for a BGA type IC package has been described. However, the present invention is not limited to this type of socket, and other types may be used. Needless to say, the present invention is applicable to any type in which the package body or the lead terminal is pressed by a pressing mechanism using a spring force to hold it.
[0033]
【The invention's effect】
As is apparent from the above description, according to the present invention, a sufficient pressing force can be obtained at the time of burn-in, and an IC package socket that can be operated with a small operating force when an IC package is loaded can be obtained.
[0034]
Therefore, the operating force at the time of loading the IC package can be kept as it is, and the pressing force at the time of burn-in can be increased to prevent the dance of the IC package and the instantaneous disconnection of the contact.
[0035]
Further, by enabling operation with a small operating force, adverse effects on the burn-in board and the socket can be eliminated, and an IC package loading error can be prevented.
[0036]
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an IC package socket according to the present invention.
2 is a cross-sectional view taken along line II-II along the diagonal line X of the IC package socket of FIG. 1, showing a state in which no IC package is mounted.
3 is a half sectional view taken along line III-III along a center line parallel to the side of the IC package socket of FIG. 1; FIG.
4 is a cross-sectional view taken along line II-II along the diagonal line X of the IC package socket of FIG. 1, showing a state in which the cover member is lowered for mounting the IC package.
FIG. 5 is an enlarged view showing a relationship between a contact and a lead terminal, showing a state in which the contact is expanded.
6 is a half sectional view taken along line III-III along a center line parallel to the side of the IC package socket of FIG. 1, and shows a loaded state of the IC package.
7 is a cross-sectional view taken along line II-II along the diagonal line X of the IC package socket of FIG. 1, showing a loaded state of the IC package.
FIG. 8 is an enlarged view showing a relationship between the contact and the lead terminal, and shows a state in which the contact is closed.
9 is a view as viewed from the direction of the arrow in FIG. 6 showing the relationship between the latch member and the spring of the present invention.
FIG. 10 is a cross-sectional view showing another relationship between the latch member and the spring of the present invention.
[Explanation of symbols]
10 IC package socket 20 Base substrate 30 Slide substrate 40 Cover member 50 Contact 60 Moving mechanism 70 Latch member 82 Normal coil spring 84 Shape memory coil spring

Claims (2)

In an IC package socket comprising a socket body having a slide substrate on which an IC package having ball-shaped lead terminals is mounted, which is slidably arranged with respect to a base substrate on which contacts are arranged.
A pressing mechanism including a pair of latch members that are rotatably supported by the base substrate and press the body of the mounted IC package against the slide substrate to hold the IC package;
A cover member that is arranged to be movable up and down on the socket body, and that performs an operation of pressing and holding the pair of latch members in the pressing mechanism in accordance with the attaching and detaching operation of the IC package;
A shape memory spring disposed adjacent to each other between a spring seat portion of the latch member and a spring seat of the base substrate formed in a direction perpendicular to the rotation axis of the latch member; and a coil spring; With
The shape memory spring is disposed at a position separated from the rotating shaft of the latch member as compared to the coil spring, and the spring seat is configured to increase the pressing force of the latch member at the time of burn-in as compared with that at normal temperature. IC package socket characterized by energizing part . In an IC package socket comprising a socket body having a slide substrate on which an IC package is mounted, slidably arranged on a base substrate on which contacts are arranged,
A pressing mechanism including a pair of latch members that are rotatably supported by the base substrate and press the body of the mounted IC package against the slide substrate to hold the IC package;
A cover member arranged to be movable up and down on the socket body, and configured to perform an operation of pressing and holding a pair of latch members in the pressing mechanism in accordance with an attaching / detaching operation of the IC package; and a rotation shaft of the latch member The spring seat portion between the spring seat portion of the latch member and the spring seat of the base substrate, which is formed in a direction orthogonal to the base plate, so that the pressing force of the latch member is increased at the time of burn-in as compared with the normal temperature. And a pressing force changing means including a shape memory spring for biasing and a coil spring disposed adjacent to the shape memory spring,
The IC package socket according to claim 1, wherein the shape memory spring is disposed at a position separated from the rotation shaft of the latch member as compared with the coil spring .

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