JPS63308940A - Ic socket for burn-in - Google Patents

Abstract

PURPOSE:To improve the working efficiency by facilitating the insertion and pulling-out of IC, and enable the sure burn-in operation by increasing the contact pressure, by constituting a contact provided with a contacting part coming into contact with the tip of an IC lead frame, of shape memory alloy. CONSTITUTION:A contact 3 is constituted of bi-directional shape memory alloy. At a normal temperature lower than or equal to 40 deg.C as a boundary, the contact 3 comes into contact with a lead frame at one upper point, and constitutes a contact part 4 with an IC lead frame, which is in the state of small contact pressure. At a temperature higher than the above, the contact 3 comes into contact linearly with the lead frame in the range of a specified length, and constitutes the contact part 4 with the IC lead frame, which is in the state of large contact pressure. As mentioned above, two forms are constituted. Thereby, as the insertion and pulling-out are enabled in the state while the contact is opened, these works are made smooth. During a burn-in operation, the IC lead frame and the contact are in the state of sure contact, which increases the reliability of the operation.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to a burn-in operation performed in a energized state for the purpose of eliminating defects in the initial stage of a semiconductor product prior to actual use. , burn-in I for mounting semiconductor products
This invention relates to C-sockets, and particularly relates to those aimed at improving the burn-in effect.

(Prior Art) The burn-in IC socket is generally composed of an insulator and a contact housed inside the insulator, and the contact contacts the IC lead frame with a constant pressure.

This burn-in IC socket must: ■ be able to withstand burn-in, a high-temperature atmosphere of about 125°C for a long period of time, and be able to make reliable contact with the IC lead frame; ■ be able to withstand the frequent insertion and removal of ICs. The function required is to be able to work efficiently and to maintain a certain level of contact pressure between the contacts and the IC lead frame.

Conventionally, the above-mentioned contacts were generally made of a material such as a beryllium copper plate or gold plating on a nickel base, and the shape of the contacts was always constant when an IC was mounted, that is, at room temperature and at high temperature.

(Problem to be Solved by the Invention) For this reason, for example, if the contacts are bent and formed into a shape that increases the contact pressure with the IC lead frame, physical strength is required to insert and remove the IC lead frame, which increases work efficiency. Not only will this lead to a decrease in performance, but the IC lead frame will also be bent.

In addition, if the contacts are bent to reduce the contact pressure so that the IC lead frame can be easily inserted and removed, the contact pressure will be reduced, and furthermore, under the high temperature condition of Bahrein, the IC lead frame and the contacts will be There was a problem in that it was not possible to tell whether contact was being made and there was a lack of certainty.

In view of -1-, it is an object of the present invention to provide an IC that facilitates the insertion and removal of ICs to improve work efficiency, and that can increase contact pressure to ensure burn-in operations. .

Structure of the Invention C] (Means for Solving the Problems) In order to achieve the above object, the present invention
In the burn-in 1c socket for implementing
A contact with a contact part that comes into contact with the tip of the IC lead frame is made of a shape memory alloy, so that the contact pressure of the contact is weak when the operating environment is at room temperature, and the contact pressure of the contact is low when the operating environment is high temperature. The contact pressure of the contact changes with changes in the temperature of the usage environment so that the contact pressure becomes stronger.

(Function) Therefore, when inserting and removing an IC in a normal temperature environment, the contact area of the contact with the IC lead frame is opened and the contact pressure is small to facilitate this operation. Under the high temperature environment during the burn-in operation, the contact portion of the contact with the IC lead frame is closed and a strong contact pressure is created to ensure that this operation is performed reliably.

(Embodiment) The drawing shows an embodiment of the present invention, and a burn-in IC socket 1 is composed of an insulator 2 and a contact 3 housed inside the insulator 2.

This contact 3 is connected to the IC socket 1 for burn-in.
This contact 3 is for contacting with this lead frame (not shown) with a constant pressure when C is mounted, and this contact 3 is made of a bidirectional shape memory alloy.

At normal temperatures below 40°C, the contact 3 has a shape in which the contact portion 4 is open as shown in FIG. , this becomes the contact part 4 with the IC lead frame, and the contact pressure is small, and at higher temperatures,
The shape of the contact portion 4 in a closed state as shown in FIG. It is configured to have two shapes so that the contact pressure is strong.

In this way, the transformation initiation temperature of two different shapes was set at 40°C.
The reason for this is that if burn-in is carried out at 125°C, contact 3 will be around 40°C to 140°C as shown in Fig.
This is to ensure that the contact portion 4 shown in b) is always in a closed shape. As a result, if the transformation start temperature is high, the IC lead frame and the contact 3 will separate at the transformation start temperature, the IC will be in the same state as if it had been baked, and initial defects that should be removed by burn-in may be recovered. However, this can be prevented.

Therefore, when inserting and removing the IC with the contact portion 4 of the contact 3 open at room temperature as shown in FIG. 1(a), and performing the barrein operation with the IC mounted,
The contact portion 4 of the contact 3 shown in b) is in a closed state to increase this contact pressure.

〔Effect of the invention〕

Since the present invention has the configuration as described in item 1, it is possible to insert and remove the IC with the contacts open, and therefore this work can be performed smoothly and with less bending of the IC lead frame. Can be done.

Also, during the burn-in operation, the contacts are in reliable contact with the IC lead frame, increasing the reliability of this operation, and even though the IC has not cooled down sufficiently,
This has the effect of eliminating the operator's mistake of removing C.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG.
Vertical cross-sectional view showing the contact in the open state, same figure (b)
FIG. 3 is a longitudinal cross-sectional view showing a state in which the high-temperature contacts are closed. 1... IC socket for burn-in, 2... Insulator,
3...Contact, 4...Contact part. Applicant's agent: Yu Sato (a) No. 1 (b) l Figure

Claims (1)

[Claims] 1. In a burn-in IC socket for mounting an IC during burn-in, a contact with a contact portion that comes into contact with the tip of an IC lead frame is formed of a shape memory alloy to prevent temperature changes in the usage environment. I for burn-in, characterized in that the contact pressure of the contact is changed by
C socket. 2. Claim 1 characterized in that the contact pressure of the contacts is weak when the usage environment is at room temperature, and changes so that the contact pressure of the contacts is strong when the usage environment is high temperature. Burn-in IC socket as described.