JPH09213440A - Contact pin for ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent coming off unreasonably after press fitting to a socket main unit, by specifying a relation between a distance to a hook tip end part from a lower edge in a base part of a hook press fit part and a distance to the lower edge of the press fit part from the base part lower edge. SOLUTION: A contact part 2a, base part 2b, spring part 2c formed between the contact part 2a and the base part 2b, simple hook-shaped press fit parts 2d, 2d having a sharp hook tip end extended downward from the base part 2b and an external connection terminal 2e extended downward from the press fit part 2d or the base part 2b are provided, in a contact pin 2 for an IC socket implanted in an IC socket main unit by press fitting the press fit part 2d to an opening or a through hole 1e drilled in the IC socket main unit, when assuming (a) for distance to a hook tip end from a lower edge of the base part 2b and (b) for distance to a lower edge of the press fit part 2d from the lower edge of the base part 2b, the press fit part 2d is formed in such a manner that (a) is nearly equal to (b)/3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the shape of a contact pin incorporated in an IC socket used for inspection and mounting of electronic parts such as IC packages.

[0002]

2. Description of the Related Art A contact pin for an IC socket of this type includes a contact portion that comes into contact with a lead of an IC package loaded in the socket, a base portion, a spring portion formed between the contact portion and the base portion, and a base portion. One or a plurality of hook-shaped press-fitting portions which have a sharp or flat hook tip and which are extended downward and are press-fitted into a slit-shaped opening or through hole formed in the socket body, and one of the press-fitting portions. And an external connection terminal portion extending downward.

[0003]

By the way, such an IC
The contact pin for socket has a thickness of, for example, 0.1 to 0.1.
It is manufactured by pressing a beryllium copper plate of about 0.4 mm, and the width of the hook-shaped press-fitting portion is, for example, 1.4 mm, and the length thereof is, for example, about 0.9 mm. Corresponding to these dimensions, at least the width or diameter is slightly smaller than the width of the above-mentioned press-fitting portion, and is planted in the socket main body by being press-fitted into, for example, a slit-shaped opening or through hole formed in the socket main body. Was there.
Therefore, when the socket is mounted by inserting the external connection terminal portion into a predetermined position of the test circuit board, a force is applied to the contact pin in a direction of coming out of the socket, or the socket body of the IC package. There is a possibility that the contact pin may come out of the slit-shaped opening or the through hole due to vibration or shock caused by loading into the socket or removal from the socket body.

The present invention has been made in view of the above problems of the prior art, and its purpose is to once press-fit the press-fitting portion into the slit-shaped opening or through hole. An object of the present invention is to provide an IC socket contact pin having a press-fitting portion having a shape and dimension that does not slip out.

[0005]

In order to achieve the above object, an IC socket contact pin according to the present invention comprises a contact portion, a base portion, a spring portion formed between the contact portion and the base portion, and a base portion. An IC including a single or a plurality of hook-shaped press-fitting portions which extend downward and have sharp or flat hook tips, and an external connection terminal portion which extends downward from one of the press-fitting portions or the base. In an IC socket contact pin that is implanted in the IC socket body by press-fitting the press-fitting portion into the opening or through hole formed in the socket body, the distance from the lower edge of the base portion to the tip of the hook is a, and the bottom of the base portion is a. If the distance from the edge to the lower edge of the press-fitting part is b and the length of the flat part of the hook tip is at least 0.1 mm, then if the hook tip is sharp, the formula a≈b / 3 should be satisfied. Flat tip If it is characterized by the formation of the press-fit portion so as to satisfy the formula a = b / 2 to a = b / 4.

According to the present invention, preferably, the press-fitting portions are formed in a pair with a space therebetween, and at least one notch is formed in the flat portion of the hook tip.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the illustrated embodiments.

FIG. 1 is a plan view of an IC socket equipped with an embodiment of a contact pin according to the present invention, and FIG.
A sectional view taken along line II, FIG. 3 is a bottom view of FIG. 1 in which the external connection terminal portion of the contact pin is omitted, and FIG. 4 is an enlarged view of a main part of the contact pin shown in FIG.

In the figure, reference numeral 1 designates a plurality of ribs 1b for forming a plurality of slits 1a for respectively receiving a plurality of contact pins 2 in an insulating manner, and a pair of press-fitting portions 2d of the contact pins 2.
Socket body 2 having a rectangular planar shape having a pair of through holes 1c formed in the bottom portion of the slit 1a for press-fitting and a guide groove 1d extending in the vertical direction, a contact portion 2a, a base portion 2b, the contact portion and a base portion. And a hook-shaped press-fitting portion 2d, 2d extending downward from the base portion and having a sharp hook end, and an external connection terminal portion extending downward from one of the press-fitting portion 2d. 2e and the contact pin. In this case, depending on the number and arrangement of the through holes 1c, the external connection terminal portions 2e may be formed so as to extend directly below the base portion 2b, and the press-fitting portions 2d may be provided corresponding to the other through holes 1c. .

Reference numeral 3 designates a mounting surface 3a for mounting the IC package P and a plurality of slits for receiving a part of the contact portion 2a of the contact pin 2 which are integrally attached to the socket body 1. Having a large number of ribs 3b
The package mounting table 4 includes a columnar portion 4a (which is provided at each of four corners in FIG. 1) slidably fitted in the guide groove 1d, and a large number of cam portions slidably contacting the operation portion 2a 'of the contact pin 2. A frame-shaped cover 5 having the same outer shape as the planar shape of the socket body 1 provided with 4b is a spring for giving the cover 4 a rising habit. Although not shown, the cover 4 is designed so that its ascending movement is restricted to the position shown in FIG.

Since the present embodiment is constructed as described above, when the IC package P is loaded, if the cover 4 is pushed down against its habit, the operating portion 2a 'of the contact pin 2 will move to the cover 4. It is pushed by the cam portion 4b and is displaced leftward to the position of the chain line in FIG. Therefore, the contact part 2
a is also displaced to the left to the chain line position, and the IC package can be mounted on the mounting table 3. Thus, if the pressing of the cover 4 is released after the IC package P is placed at the predetermined position on the mounting table 3, the contact pin 2 returns to the position shown by the solid line in FIG.
The lead R of the C package is pressed onto the mounting table 3, and the two are electrically connected with a predetermined pressure contact force. As is clear from this description, the cover 4 may be pushed down even when the loaded IC package P is taken out.

As described above, the contact pin 2 has the hook-shaped press-fitting portion 2d in the through hole 1c formed in the socket body 1.
According to an experiment conducted by the applicant of the present application, a socket having a thickness of 0.25 mm and a contact pin having a single press-fitting portion is planted in a row as shown in FIG. When the hook tip of the press-fitting portion 2d is sharp as in the present embodiment, when the distance a (see FIG. 4) from the lower edge of the base portion 2b to the hook tip is changed in the range of 0.3 mm to 1 mm, the press-fitting portion is pressed. It was found that the subsequent withdrawal force (gf) changed as shown by the solid line in FIG. Then, it was confirmed that when the length of the press-fitting portion 2d, that is, the distance from the lower edge of the base portion 2b to the lower edge of the press-fitting portion 2d is b, the extraction force becomes maximum near a = b / 3.

FIG. 6 is an enlarged view of a main part of another embodiment of the contact pin according to the present invention. According to this embodiment, the tip of the hook of the press-fitting portion 2d is formed flat, and this flat portion is formed. If at least one notch 2d 'is formed in the groove or the edge is formed in a sawtooth shape, and the length is c, the contact pin has a thickness of 0.25 mm, the press-fitting portion is one, and a is 0. .3 mm to 1 mm and c = 0.
It was found that when 1 mm, the withdrawal force after press fitting changes as shown by the chain line in FIG. 5, and when c = 0.3 mm, the withdrawal force changes as shown by the broken line in the figure. It was experimentally confirmed that the removal force is maximum in the range of a = b / 2 to a = b / 4.

Although the through hole 1c is shown as a circular hole in the embodiment, it may be a rectangular hole, that is, a slit-shaped opening.
Although the case where two press-fitting portions 2d of each contact pin 2 are formed has been described, at least one external connection terminal portion 2e may be formed. In this case, another fitting portion is formed, It may not form a hook.
Further, when two press-fitting portions 2d of each contact pin 2 are formed, the width dimension of the press-fitting portion 2d provided with the external connection terminal portion 2e and the portion having only the press-fitting portion 2d are mutually changed. If the pair of hole sizes are opened in a corresponding size, even if the terminal portions 2e are alternately arranged in a staggered pattern, they will not be erroneously assembled. Further, when using only the press-fitting portion 2d having one external connection terminal portion 2e for each contact pin, in order to arrange the external connection terminal portions 2e alternately in a zigzag pattern, The press-fitting holes may be formed in a zigzag pattern correspondingly, but in order to prevent sagging of the piece for the contact pin fitting part of the molding die, face the zigzag arrangement hole for the press-fitting part having the above terminal part. It is preferable to provide an inverted zigzag array of holes. However, in this case, there is a problem that a contact pin which is not proper is inserted into the discard hole by mistake. Therefore, when forming this discard hole, the press-fitting portion 2 of the regular contact pin is used.
In order to prevent d from entering, it is sufficient to make the hole small, to make it irregularly shaped, or to make a bag hole.

As described above, according to the present invention, it is possible to provide an IC socket which can very stably hold the contact pin in the socket body in a planted state and can withstand long-term use.

[Brief description of drawings]

FIG. 1 is a plan view of an IC socket provided with an embodiment of a contact pin according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a bottom view of FIG. 1 in which an external connection terminal portion of a contact pin is omitted.

FIG. 4 is an enlarged view of a main part of the contact pin shown in FIG.

FIG. 5 is a diagram showing the relationship between the distance from the lower edge of the base of the contact pin to the tip of the hook and the withdrawal force after press-fitting the contact pin.

FIG. 6 is an enlarged view of a main part of another embodiment of the contact pin according to the present invention.

[Explanation of symbols]

 1 Socket body 1a Slits 1b, 3b Rib 1c Through hole 1d Guide groove 2 Contact pin 2a Contact part 2a 'Operation part 2b Base part 2c Spring part 2d Hook-like press-fitting part 2e External connection terminal part 3 IC package mounting table 3a Mounting surface 4 Cover 4a Columnar part 4b Cam part 5 Spring PIC package R Lead

Claims (6)

[Claims] 1. A single hook shape having a contact portion, a base portion, a spring portion formed between the contact portion and the base portion, and a sharp hook tip extending downward from the base portion. It is composed of a press-fitting part and an external connection terminal part extending downward from the press-fitting part or the base part, and is planted in the IC socket body by press-fitting the press-fitting part into an opening or a through hole formed in the IC socket body. In the provided IC socket contact pin, when the distance from the lower edge of the base portion to the hook tip is a and the distance from the lower edge of the base portion to the lower edge of the press-fitting portion is b, the expression a≈b A contact pin for an IC socket, characterized in that the press-fitting portion is formed so as to satisfy ⅓. 2. A plurality of hook-shaped press-fittings each having a contact portion, a base portion, a spring portion formed between the contact portion and the base portion, and a sharp hook tip extending downward from the base portion. And an external connection terminal portion extending downward from any one of the plurality of press-fitting portions or the base portion, and the plurality of press-fitting portions are provided in a plurality of openings or through holes formed in the IC socket body. In the IC socket contact pins, which are planted in the IC socket body by press-fitting respectively,
When at least one of the plurality of press-fitting portions has a distance from the lower edge of the base portion to the hook tip as a and a distance from the lower edge of the base portion to the lower edge of the press-fitting portion as b, equation a≈
IC characterized by being formed so as to satisfy b / 3
Contact pin for socket. 3. A single hook shape having a contact portion, a base portion, a spring portion formed between the contact portion and the base portion, and a flat hook tip extending downward from the base portion. It is composed of a press-fitting part and an external connection terminal part extending downward from the press-fitting part or the base part, and is planted in the IC socket body by press-fitting the press-fitting part into an opening or a through hole formed in the IC socket body. In the provided IC socket contact pin, the distance from the lower edge of the base to the hook tip is a, the distance from the lower edge of the base to the lower edge of the press-fit section is b, and the flat portion of the hook tip is When the length is at least 0.1 mm, the formula a = b / 2 to a = b / 4
A contact pin for an IC socket, wherein the press-fitting portion is formed so as to satisfy the above condition. 4. A plurality of hooks each having a contact portion, a base portion, a spring portion formed between the contact portion and the base portion, and a flat hook tip extending downward from the base portion. The press-fitting portion and any one of the plurality of press-fitting portions or an external connection terminal portion extending downward from the base portion. The plurality of press-fitting portions are inserted into a plurality of openings or through holes formed in the IC socket body. In a contact pin for an IC socket which is planted in the IC socket body by press-fitting the respective parts, at least one of the plurality of press-fitting parts is a distance from the lower edge of the base part to the hook tip is a, When the distance from the lower edge of the base portion to the lower edge of the press-fitting portion is b, and the length of the flat portion of the hook tip is at least 0.1 mm, the equations a = b / 2 to a = b / 4 are satisfied. It is characterized in that Contact pin for C socket. 5. The contact pin for an IC socket according to claim 2, wherein a pair of the press-fitting portions are formed with a space therebetween. 6. The I according to claim 3, wherein at least one notch is formed in a flat portion of the hook tip.
Contact pin for C socket.