JPH0135431Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a no insertion/extraction force (hereinafter abbreviated as ZIF) type IC socket.

(Prior Art) ICs including LSIs are originally designed to be used by directly soldering connection leads to a printed wiring board. However, on the other hand, it is often the case that an IC socket is soldered to a printed wiring board, and a desired IC is inserted into the socket so that it can be replaced. IC sockets are also used to connect ICs under test during the burn-in process, in which ICs are operated normally or at their limits in a high-temperature atmosphere, and ICs that are defective or at the limits of their specifications are removed in a short period of time.

These conventionally used IC sockets have contacts pre-tensioned in the numerous lead insertion holes in the housing, and when inserting an IC, the contacts must be pulled against the pretension of the contacts. A connection lead is inserted into each lead insertion hole, and this pretension presses the contact and the connection lead of the IC to establish an electrical connection between the two.

(Problem that the invention aims to solve) However, as mentioned above, the IC connection leads are designed to be directly attached to the printed wiring board, and the dimensional accuracy as a connector plug is not maintained. Since no particularly hard material is used, when using such conventional IC sockets, the pre-applied tension on the contacts often causes the connection leads to bend when inserted into or removed from the IC socket. In extreme cases, there was a risk that unnecessary stress would be applied to the IC package, causing it to break. Furthermore, in order to prevent such accidents, if the contact spring pressure of the IC socket is lowered, there is a problem in that the reliability of the connection is significantly reduced.

In addition, several ZIF-type IC sockets have been proposed to eliminate these problems, but their mechanisms are extremely complex, and none of them can be provided at low cost. It was also inconvenient to handle, such as requiring a jig.

The present invention has been developed with these points in mind; it has a simple structure, is easy to handle, does not require special force to attach and remove ICs, and improves reliability and extends lifespan. The aim is to provide an IC socket with a new design.

(Means for Solving the Problems) Therefore, in the present invention, the IC socket includes a housing made of a hard insulating material and equipped with a large number of lead insertion holes corresponding to the connection leads of the IC.
It consists of a contact placed in each lead insertion hole of this housing, a slider placed in each lead insertion hole so as to be able to move in and out approximately at right angles to the insertion direction of the connecting lead of the IC, and a shape memory alloy. The spring has a memorized shape that presses the slider and presses the connection lead of the IC inserted into the lead insertion hole against the contact when the contact is crossed.

(Function) In the IC socket of the present invention configured as described above, the spring made of the shape memory alloy contracts at a temperature lower than the transformation temperature, so that when the IC is mounted, the connection lead is not subjected to any resistance. I C
It can be inserted into the lead insertion hole of the socket. When the temperature exceeds the transformation temperature, the spring assumes its memorized shape, so it presses the slider that can move in and out of the lead insertion hole and pushes it into the lead insertion hole. Press the inserted IC connection lead to the contact. This provides a highly reliable connection. When removing the IC, if the temperature of the spring made of the shape memory alloy is lowered below the transformation temperature, the pressure of the slider is removed and the IC can be removed from the IC socket without experiencing any resistance. .

This has resulted in an IC socket that has a simple structure, is easy to handle, does not require special force to attach or remove an IC, and has improved reliability and extended life.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings. The drawing is a longitudinal cross-sectional view of the main part of one embodiment of the IC socket according to the present invention, and
The figure shows a non-connected state, and FIG. 2 shows a connected state. In the drawing, 11 is an IC, and 13 is its connection lead.

15 is a housing made of a hard insulating plastic molded product; 17 is this housing 15;
A large number of lead insertion holes are drilled from the upper surface of the IC 11 in correspondence with the connection leads 13 of the IC 11. Reference numeral 19 denotes a contact disposed within each lead insertion hole 17, and is made of a highly elastic metal strip. This contact 19 includes a first contact piece 23 disposed along the inner side wall 21 of each lead insertion hole 17 and a second contact piece disposed along the outer side wall 25.
contact pieces 27 are provided facing each other, and the first
The contact piece 23 is given a pretension toward the inner side wall 21.

Reference numeral 29 denotes a slider made of insulating hard plastic, and the IC 11
The connecting lead 13 is disposed in a through hole 31 that is formed substantially perpendicularly to the direction in which the connecting lead 13 is inserted. 33 is a spring arranged behind the slider 31 inside the housing 15. This spring 33 is made of a shape memory alloy, and when the transformation temperature is exceeded, it presses the slider 29 from behind and inserts the lead between the first contact piece 23 and the second contact piece 27 of the contact 19. The shape of the connection lead 13 of the IC 11 inserted into the hole 17 is memorized.

In the IC socket configured in this way, when a shape memory alloy with a transformation temperature of 40°C is used for the spring 33, the spring 33 contracts at a temperature lower than 40°C, and the first contact 19
Since there is an open space between the first contact piece 23 and the second contact piece 27, when the IC 11 is installed, the connection lead 13 will not receive any resistance as shown in FIG.
It can be inserted into the lead insertion hole 17 of the IC socket.

When the temperature rises in this state and exceeds the transformation temperature of 40° C., the spring 33 extends according to the memorized shape and presses the slider 29 from behind. Therefore, the slider 29 is pushed out into the lead insertion hole 17 and the first contact piece 2 of the contact 19 is pushed out.
3 and push it down toward the outer side wall 25. As a result, the IC inserted into the lead insertion hole 17
The eleven connection leads 13 are held under pressure between the first contact piece 23 and the second contact piece 27 of the contact 19, thereby realizing a highly reliable connection.

If the IC 11 is to be removed, it may be left at room temperature and cooled below the transformation temperature of 40° C., for example. That is, due to this temperature drop, the spring 11 contracts again according to its memorized shape, and the pressure of the spring 11 is removed, and the slider 29 is moved by the pretension applied to the first contact piece 23 of the contact 19. I get pushed back. Therefore, the connection lead 13 of IC11 is released from the pressure clamping, and IC11
1 can be removed from the IC socket without encountering any resistance.

Such an IC socket is effective as a burn-in socket. That is, at a room temperature below 40°C, the first contact piece 23 and the second contact piece 27 of the contact 19 are open, making it possible to insert and remove the IC 11 using ZIF, and during testing when the temperature is between 80°C and 150°C. Since the first contact piece 23 and the second contact piece 27 of the contact 19 close and tightly crimp the connection lead 13 of the IC 11, there is no need to consider the deterioration of the spring properties of the contact 19, which increases reliability. The first contact piece 23 and the second contact piece 27 of the contact 19 are improved when the IC 11 is attached and removed.
Since there is no pressurized sliding contact between the IC 11 and the connection lead 13, there is less peeling of the plating and the life is extended.

Furthermore, if a shape memory alloy having a transformation temperature of, for example, -30 DEG C. is used for the spring 33, a ZIF type IC socket mounted on a printed wiring board of equipment used at room temperature can also be realized. That is, if the spring 33 is cooled to -30°C or lower using cooling gas, the first contact piece 23 and the second contact piece 27 of the contact 19 will open, allowing insertion and removal of the IC 11 using the ZIF, and the temperature will rise to room temperature. If it is returned, the first contact piece 23 and the second contact piece 27 will close and tightly crimp the connection lead 13 to achieve a highly reliable connection.

Further, as the shape memory alloy used as the spring 33, not only the bidirectional shape memory alloy as described above but also the unidirectional shape memory alloy can be used. In other words, when a unidirectional shape memory alloy is used, it will not shrink to its original shape even if the temperature is lower than the transformation temperature, but it will not work as a spring when the temperature is higher or lower than the transformation temperature. Taking advantage of the fact that the power changes significantly, the first contact piece 23 of the contact 19 is forcibly contracted to its original shape by the spring pressure, thereby making it possible to repeat the ZIF operation.

Further, the contact 19 is not limited to the shape of the illustrated embodiment; for example, the contact 19 is
Even if the contact piece 27 is omitted, if the structure is such that the connecting lead 13 of the IC 11 is pressed and held between the first contact piece 23 and the outer side wall 25 of the lead insertion hole 17, a similar ZIF type IC socket can be used. In addition, if a bidirectional shape memory alloy is used as the spring 33, the first It is also possible to omit the contact piece 23.

(Effects of the invention) The invention is constructed as described above, and the spring made of shape memory alloy contracts at a temperature lower than the transformation temperature, so that when an IC is attached, its connection lead does not receive any resistance. The slider can be inserted into the lead insertion hole of the IC socket, and when the temperature exceeds the transformation temperature, the spring assumes the memorized shape and pushes the slider into the lead insertion hole, and the IC socket is inserted into the lead insertion hole.
If you make an electrical connection by pressing the connection lead to the contact and lowering the temperature below the transformation temperature,
The pressure on the slider due to the spring is removed, and the IC
Since the IC socket can be removed from the IC socket without experiencing any resistance, there is no need to consider the deterioration of the spring properties of the contact during installation, improving reliability. This eliminates the pressure-sliding contact between the contact and the IC connection lead, which reduces the chance of peeling of the plating, resulting in a longer life.Furthermore, it is possible to create a ZIF-type IC socket that has a simple structure and is easy to handle. It has excellent effects.

[Brief explanation of the drawing]

The drawings are longitudinal cross-sectional views showing essential parts of an embodiment of the IC socket according to the present invention, with FIG. 1 showing the unconnected state and FIG. 2 showing the connected state. 11...IC, 13...Connection lead, 15...
Housing, 17...Lead insertion hole, 19...Contact, 29...Slider, 33...Spring.

Claims (1)

[Scope of utility model registration request] A housing made of a hard insulating material and provided with a large number of lead insertion holes corresponding to the connection leads of the IC, a contact arranged in each lead insertion hole of this housing, and a housing in each lead insertion hole.
It consists of a slider that can be freely moved in and out approximately at right angles to the insertion direction of the IC connection lead, and a shape memory alloy.
An IC socket comprising: a spring that stores a shape that presses the slider and presses the connection lead of an IC inserted into the lead insertion hole to the contact when the transformation temperature is exceeded.