JPH06333654A - Socket for ic - Google Patents

Abstract

PURPOSE:To reduce height dimension when being mounted on a circuit board, cope with the difference in a length dimension between IC pins, and narrow the pitch of a contact terminal. CONSTITUTION:A forcibly inserting hole 5 in which a forcibly inserting piece 3b of a contact terminal 3, is arranged in the peripheral vicinity of a base 1 formed in a plate shape. A projection shape contact point 3c is arranged by two pieces continuously in the end part of the contact terminal 3. The forcibly inserting piece 3b is inserted forcibly in the forcibly inserting hole 5 from the reverse side of the base 1, and the contact terminal 3 is installed on the base 1. A QFPIC4 is loaded on the obverse of the base 1. A pin 4a of the QFPIC 4 comes into contact with the contact point 3c of the contact terminal 3. A frame 2 is fitted to the base 1 from the obverse side of the base 1 on which the QFPIC4 is loaded. The pin 4a is brought into pressure contact with the contact point 3c by the frame 2, and electrical continuity between the pin 4a and the contact terminal 3 is obtained. Here, since the contact point 3c is arranged by two pieces continuously in a projection shape, at least a single contact point 3c comes into contact with the pin 4a regardless of the length dimension of the pin 4a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC socket used when mounting an IC on a circuit board.

[0002]

2. Description of the Related Art An example of a conventional IC socket is shown in FIGS.
It shows in FIG. This socket is for a QFPIC4 in which pins 4a formed in a substantially S shape on each side of a quadrilateral flat package (abbreviated as QFP below) are arranged outward at a constant pitch. And includes a base 8 shown in FIG. 11 and a frame 9 shown in FIG.

As shown in FIG. 11, the base 8 is formed in a substantially square flat plate shape, and the back surface is a circuit board (not shown).
Then, the QFPIC 4 is mounted on the surface. On each side of the base 8, contact terminals 10 are provided at positions corresponding to the pins 4a of the QFPIC 4 mounted on the surface of the base 8. As shown in FIG. 13, the contact terminal 10 is formed in a substantially U-shape, and one end thereof has a QFP.
A contact point 10a that is in contact with the pin 4a of the IC 4 is formed by bending the tip end upward. The contact terminal 10 is press-fitted into a press-fitting groove (not shown) provided on the side surface of each side of the base 8 to dispose the contact terminal 10 on the base 8. Further, as shown in FIG. 12, the frame 9 is formed in a substantially square shape and fits with the base 8.

When the QFPIC 4 is placed on the base 8, the pins 4a of the QFPIC 4 come into contact with the contacts 10a of the contact terminals 10 arranged on the sides of the base 8. Here, as shown in FIG. 14, the frame 9 is fitted from the front surface side of the base 8 on which the QFPIC 4 is mounted, and the pin 4 a of the QFPIC 4 is connected to the contact terminal 10 of the base 8 at the rear end portion of the frame 9.
The contact point 10a of the QFPIC 4 is pressed to obtain conduction with the pin 4a of the QFPIC 4.

[0005]

In the configuration of the conventional example as described above, the contact terminal 10 needs to have an elastic force because it is pressed against the pin 4a of the QFPIC 4, and for that purpose, the contact terminal 10 has The length of the arm portion 10b must be increased. However, if the length of the arm portion 10b is increased, the height of the contact 10a from the lower piece of the contact terminal 10 is also increased. As a result, the height of the base 8 is increased and the QFPIC 4 is connected to the circuit board (see FIG. There is a problem that the height dimension when mounted on (not shown) also becomes high.

Further, since the contact 10a provided at the tip of the arm 10b of the contact terminal 10 is in contact with the pin 4a of the QFPIC 4 at one point of the tip of the contact 10a, the length of the pin 4a of the QFPIC is short. In some cases, there is a problem of poor contact. Further, in the above-mentioned conventional example, since the contact terminals 10 are press-fitted into the press-fitting grooves (not shown) provided on the side surfaces of the sides of the base 8, the pitch of the contact terminals 10 is increased in order to obtain the holding strength of the contact terminals 10. A press fit in the direction is required. Therefore, there is a problem that the pitch of the contact terminals 10 cannot be narrowed corresponding to the QFPIC in which the pitch of the pins 4a is narrow.

The present invention is intended to solve the above problems, and has a low height dimension when mounted on a circuit board, can cope with a difference in the length dimension of IC pins, and can reduce the pitch of contact terminals. The present invention aims to provide an IC socket that can be achieved.

[0008]

In order to achieve the above object, the present invention provides a base which is formed in a flat plate shape, is mounted on a circuit board with the back surface facing the circuit board, and has an IC mounted on the front surface. , IC with contacts that make contact with the pins of the IC
A plurality of contact terminals provided on the periphery of the base corresponding to the number of pins of the base, and a frame fitted to the base from the surface side of the base to press each pin of the IC into contact with the contact of the corresponding contact terminal, The contact terminal is formed in a substantially U shape, a plurality of protruding contacts are provided at one end in parallel with the longitudinal direction of the pin of the IC, and an inwardly bent press-fitting piece is formed at the other end. A press-fitting hole for press-fitting is provided near the peripheral edge of the base along a direction that penetrates the front and back surfaces of the base.

[0009]

In the structure of the present invention, the base of the flat plate is mounted on the circuit board with the back surface facing the circuit board and the IC is mounted on the front surface, and the contacts of the IC that are in contact with the pins of the IC are provided. It consists of a plurality of contact terminals provided on the periphery of the base corresponding to the number of pins, and a frame that fits into the base from the surface side of the base and presses each IC pin to the contact of the corresponding contact terminal. The terminal is formed in a substantially U shape, and a plurality of protruding contact points are provided at one end in parallel with the longitudinal direction of the IC pin, and at the other end, an inwardly bent press-fitting piece is formed. Since the press-fitting holes for press-fitting are provided near the periphery of the base along the direction that penetrates the front and back surfaces of the base, it is not necessary to take a press-fitting margin to press-fit and attach the contact terminals to the base. Can be narrowed. Further, even when the length of the IC pin is short, at least one of the protruding contact points provided at the end of the contact terminal in parallel with the longitudinal direction of the IC pin contacts the pin, resulting in poor contact. Can be prevented. Further, the substantially U-shaped contact terminal that is press-fitted into the press-fitting hole provided near the periphery of the base and attached to the base projects toward the outside of the base, so that the socket can be contacted without increasing the height dimension. By increasing the length of the terminal, the elastic force required for the contact terminal can be obtained.

[0010]

EXAMPLES The present invention will be described in detail below with reference to examples.
In this embodiment, a socket for a QFPIC will be described, but the technical idea of the present invention can be applied to an IC socket of another package form. The contact terminal 3 of this embodiment is shown in FIG. The contact terminal 3 is formed in a substantially U shape by punching a metal plate. The blanking process has an advantage that the shape can be freely formed to some extent. However, it may be formed by another method. One end of the bent arm portion 3a of the contact terminal 3 is bent inwardly at a substantially right angle, and the bent portion is press-fitted into a press-fitting hole 5 provided near a peripheral edge of a base 1 of an IC socket described later. It is the piece 3b. On the other hand, on the outer surface of the other end of the arm portion 3a of the contact terminal 3, two protruding contact points 3c are provided in series. However, the number of contacts is not limited to this, and may be three or more. Further, since the contact terminal 3 is formed in a substantially U shape, the bent arm portion 3a can be given an elastic force.

Further, as shown in FIGS. 3A and 3B, the base 1 is formed in a substantially square flat plate shape, and penetrates the front and back surfaces of the base 1 in the vicinity of the periphery of each side of the base 1. The press-fitting holes 5 having substantially rectangular openings as viewed from the front and back sides are provided at the same pitch along each side of the base 1. And
The number and pitch of the press-fitting holes 5 per side of the base 1 correspond to the number of terminals and the terminal pitch per side of the QFPIC 4 mounted on the base 1. The QFPIC 4 of this embodiment has 80 pins and a pitch of 0.65 mm, but it goes without saying that it is not limited to this. Further, guides 6 are provided upright on the surface sides of the four corners of the base 1.

As shown in FIG. 5, the press-fitting piece 3 of the contact terminal 3
The contact terminal 3 is attached to the base 1 by press-fitting b into the press-fitting hole 5 of the base 1 from the back surface side of the base 1. Where base 1
Insulating pieces 1a for maintaining insulation between the adjacent contact terminals 3 are arranged between the contact terminals 3 on the side surface of the peripheral edge of the contact terminals 3. The insulating pieces 1b adjacent to both sides of each of the guides 6 standing on the four corners of the base 1 are higher than the other insulating pieces 1a.

As shown in FIGS. 4 (a) and 4 (b), the frame 2 is formed into a substantially square shape so as to be fitted to the base 1. Each side of the frame 2 is provided with a fitting groove 2a that fits with the insulating piece 1b having a height higher than that of the other insulating piece 1a when fitted with the base 1. In the above configuration,
As shown in FIG. 6, the QFPIC 4 is placed on the surface of the base 1, the four corners of the frame 2 are aligned with the guides 6 standing on the four corners of the base 1, and the frame 2 is fitted to the base 1 from the surface side of the base 1. When combined, as shown in FIGS. 7A and 7B, the pin 4 a of the QFPIC 4 comes into contact with the contact 3 c of the contact terminal 3 attached to the base 1 and the pin 4 a by the frame 2.
a is pressed against the contact 3c. Here, as shown in FIG. 1A or 1B, at least one of the two protruding contact points 3c, 3c contacts the pin 4a regardless of the length of the pin 4a of the QFPIC4. Since they are pressed together, Q
It is possible to prevent a conduction failure from occurring between the pin 4a of the FPIC 4 and the contact terminal 3. Further, in the valley portion formed between the two contacts 3c, 3c of the contact terminal 3, plating residue or the like that is peeled off from the pin 4a due to sliding friction between the contact 3c and the pin 4a is accumulated, and such plating residue or the like is generated in the contact 3
It is possible to prevent the adhesion failure to the c or the pin 4a and the poor conduction.

Fixing tools 7 are provided at the four corners of the base 1 to fix the fitted base 1 and frame 2 together. As shown in FIG. 10 (a), the conventional fixture 11 is formed by bending a flat plate member into a substantially L shape, fixing one side to the back surface of the base 8, and forming a cutout portion 11 a on the other side. It is provided. As shown in FIG. 10B, a locking projection 9a provided on the side surface of the frame 9 is locked to the notch 11a to fix the base 8 and the frame 9.

However, the fixture 1 generated from the QFPIC 4
In order to release the heat propagating to the frame 9 through 1, the contact area between the locking projection 9a and the fixture 11 needs to be increased. There is a problem that the locking projection 9a of the frame 9 made of resin is deformed. In view of this, in this embodiment, as shown in FIG. 5, a plate-shaped member is bent into a substantially J-shape to form a fixture 7, and the base 1 is inserted into the fixture press-fitting holes 1c provided at the four corners of the base 1. Press in from the back side of and attach. The tip of the long side is bent inward to form the locking piece 7a. On the other hand, as shown in FIG.
Notches are formed by inclining the four corners of the frame 2 from the front surface to the back surface, and rod-shaped locking portions 2b are provided on both side surfaces of the notched portions.
Has been installed. Therefore, as shown in FIGS. 8A and 8B, when the frame 2 is fitted to the base 1,
The locking piece 7a of the fixture 7 attached to the base 1 is attached to the frame 2
The base 1 and the frame 2 can be fixed by engaging with the respective engaging portions 2b provided at the four corners.

With the above structure, the contact area with the locking portion 2b of the frame 2 can be increased irrespective of the plate thickness of the fixture 7, and therefore the fixture 7 can be made thicker.
Does not reduce the resilience of. Further, as shown in FIG. 9, the locking piece 7a of the fixture 7 and the locking portion 2b of the frame 2 are provided.
If the angle formed with the side surface of the base plate is set to 75 degrees to 80 degrees, it is possible to reduce the amount by which the frame 2 is pushed into the base 1 side when the locking piece 7a is locked to the locking portion 2b.

[0017]

As described above, the present invention forms a flat plate, mounts the circuit board on the front surface with the back surface facing the circuit board, and mounts the IC on the front surface, and the contacts that make contact with the pins of the IC. A plurality of contact terminals provided on the periphery of the base corresponding to the number of pins of the IC, and a frame fitted to the base from the surface side of the base and press-contacting each pin of the IC with the contact of the corresponding contact terminal. And the contact terminal is approximately U
A press-fitting hole into which a plurality of protrusion-shaped contacts are formed in parallel with each other in parallel with the longitudinal direction of the IC pin and a press-fitting piece bent inward is formed at the other end, and the press-fitting piece is press-fitted. Since it is provided near the periphery of the base along the direction of penetrating the front and back surfaces of the base, it is not necessary to press fit the contact terminal to press it into the base to attach it, thus reducing the pitch of the contact terminal. There is an effect that it can be applied to ICs with a narrow pitch. Further, in accordance with the length dimension of the IC pin, at least one of the protruding contact points provided at the end of the contact terminal in parallel with the longitudinal direction of the IC pin can be brought into contact with the pin. Therefore, there is an effect that it is possible to prevent the contact failure of the IC. Further, the U-shaped member is press-fitted into a press-fitting hole provided near the periphery of the base and attached to the base.
Since the V-shaped contact terminal projects toward the outside of the base,
There is an effect that the length of the contact terminal can be increased without increasing the height of the socket to obtain the elastic force required for the contact terminal. Moreover, fine particles such as plating dust produced by abrasion when the pins of the IC and the contacts of the contact terminals are slightly slid fall into the valleys formed between the protruding contacts, so that such fine particles adhere to the contacts. There is an effect that it is possible to prevent a contact failure that occurs.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention,
(A) is a figure when a pin is long, (b) is a figure when a pin is short.

FIG. 2 shows the same as above and is a side view of a contact terminal.

FIG. 3 shows the same as above, (a) is a front view of the base, and (b) is an A-B-C side view of the base obtained by partially cutting the same (a) at B-C.

FIG. 4 shows the same as above, (a) is a front view of the frame, and (b) is an A-B-C side view of the frame of FIG.

FIG. 5 shows the same as above and is a partially exploded perspective view of the base.

FIG. 6 is an exploded perspective view showing the same as above.

FIG. 7 shows the same as above, (a) is a front view of an IC socket to which a QFPIC is attached, and (b) is the same view (a).
It is an ABC side view of the socket for IC which partially broken in BC.

FIG. 8 shows the same as above, FIG. 8A is a front view of a corner of an IC socket, and FIG. 8B is a sectional view taken along line XX in FIG. 8A.

FIG. 9 is a sectional view of a corner portion of the IC socket showing the same as above.

10A and 10B show a conventional example, in which FIG. 10A is a front view of a corner of an IC socket, and FIG. 10B is a sectional view taken along line XX of FIG. 10A.

FIG. 11 shows the same as above, (a) is a front view of the base, and (b) is an A-B-C side view of the base in which FIG.

FIG. 12 shows the same as above, (a) is a front view of the frame, and (b) is an A-B-C side view of the frame of FIG.

13A and 13B show the contact terminal of the above, wherein FIG. 13A is a front view, FIG. 13B is a side view, and FIG. 13C is a top view.

FIG. 14 shows the same as above, (a) is a QFPIC.
The front view of the attached IC socket, (b) is the IC socket AB shown in FIG.
-C is a side view.

[Explanation of symbols]

 1 base 2 frame 3 contact terminal 3b press-fitting piece 3c contact 4 QFPIC 4a pin 5 press-fitting hole

Claims (1)

[Claims] 1. An IC having a base formed on a flat plate, mounted on the circuit board with the back surface facing the circuit board, and having the IC mounted on the front surface, and a contact for conducting contact with a pin of the IC.
A plurality of contact terminals provided on the periphery of the base corresponding to the number of pins of the base, and a frame fitted to the base from the surface side of the base to press each pin of the IC into contact with the contact of the corresponding contact terminal, The contact terminal is formed in a substantially U shape, a plurality of protruding contacts are provided at one end in parallel with the longitudinal direction of the pin of the IC, and an inwardly bent press-fitting piece is formed at the other end. An IC socket characterized in that a press-fitting hole for press-fitting is provided near a peripheral edge of the base along a direction penetrating the front and back surfaces of the base.