GB2092837A - No-load engaging socket for IC package - Google Patents

Abstract

A socket for an IC package 6 includes a base plate 1 accommodating two rows of contacts 3 and a movable plate 4 supporting the IC package with its lead wires passing through rows of through openings 5. The movable plate is only movable in directions which are perpendicular to the direction of the rows of contacts between a lead wire release position and a contact engaging position. All the contacts are open to one of the movement directions. Guide means limit the movement of the movable plate. The through openings of the movable plate are wide enough to accommodate production variables of the IC package. <IMAGE>

Description

SPECIFICATION Socket having means of no-load engaging with and releasing from IC package The present invention relates to a socket having means of no-load engaging with and releasing from IC package, and more especially to a socket including a base plate having at least one row of contact receiving vertical openings each accommodating a contact engageable with a lead wire, a movable plate having at least one row of through openings each corresponding to the vertical opening and passing said lead wire of the IC package which is placed on the movable plate and means to move the movable plate between lead wires release position and contact engage position.

Such socket is known from Japanese Utility Model Application Publication No. 49978/1977. The movable plate of the socket supports all wire leads of IC package by lead wire receiving through holes, and when the movable plate is moved from release position to contact engage position, lateral urging force is applied directly to the side surfaces of the lead wires and the movable plate is moved parallel with the direction of the row of the vertical opening, i.e. to the direction of rows of contacts.

Japanese Laid-Open Patent Publication No.

8898711978 (U.S. Patent Application S. No. 755759, Mark Auriana) also describes a socket of generally similar construction with the above described publication.

As the movable plate moves to the direction of rows of contacts, there must be a space to allow movement of corresponding lead wire between release position and contact engage position in each vertical opening of the base plate. As well known, the lead wires of such IC package has many lead wires in a row with very narrow space each other.

Thus, distance between adjacent vertical openings is also very small to receive the lead wires. As distance wall between the vertical openings is also very thin so that there is no sufficient space to allow move mentofthe movable plate between release position and positive contact engage position. Thus, there are serious problems as to design of contact, positive release and positive engagement and bending of lead wire to adjacent lead wire. These problems affect to design of IC package and LSI package both of which tend to have more lead wires and desire to decrease distance between adjacent lead wires.

In the above-mentioned Japanese Utility Model Publication, the movable plate has very small through openings to pass the lead wires and urges the side surface of the lead wire. Thus, the lead wire tends to bend to adjacent lead wire by the side pressure. When one or more lead wires are bent, the IC package is difficult to reinsert, as all the lead wires must align with the through openings of the movable plate.

Accordingly, the object of the present invention is to eliminate or at least mitigate the abovementioned problems, and to provide a socket of the above-mentioned type having means to move the movable plate to horizontal lateral directions which are perpendicular to the direction of the row of contacts. Another object of the present invention is to provide the socket having means to urge the body of the IC package when the movable plate moves to the horizontal lateral directions between the release and contact engage positions.

To attain the above-mentioned object, a socket of the above-mentioned type, according to the present invention, comprises means to limit the movement of the movable plate relative to the base plate onlyto horizontal lateral directions which are perpendicular to the direction of the row of vertical openings, and said each contact in the vertical opening opened to at least one of the horizontal lateral directions, whereby the movable plate and IC package with the lead wires integrally move to the lateral directions to effect horizontal lateral movement of the lead wires in the vertical openings of the base plate between lead wires release position and contacts engage position.

As there is no disturbance to the lateral directions, desired long range of movable plate can be adopted, and design problems of contacts will not occur whether the distance between the lead wires of the IC package is further decreased.

Preferably, the movable plate has means to engage with and urge a body portion of the IC package on the upper surface of the movable plate when the movable plate moves to at least one of the lateral directions.

Thus, the through openings of the movable plate can be wide enough to accommodate production variables of IC package. Also, insertion and removal of the IC package is easy even when one or more lead wires are bent.

The invention will be described in more detail hereinafter with reference to the accompanying drawing which is given solely by way of example, in which: Figure 1 is a plan view of a socket for IC package according to the present invention; Figure 2 is a side view of Fig. 1; Figure 3 is a left end view of Fig. 1; Figure 4 is a plan view of the base plate with contacts of the socket shown in Fig. 1; Figure 5 is a left end view of Fig. 4; Figure 6 is a sectional view along line X-X of Fig. 4 in enlarged scale; Figure 7 is an enlarged sectional view of a portion of Fig. 4 along line Y-Y of Fig. 4; Figure 8 is an enlarged sectional view of a portion of Fig. 4 along line Z-Z of Fig. 4; Figure 9 is an enlarged sectional view along line W-W of Fig. 4; Figure 10 is plan view of the movable plate of the socket shown in Fig. 1;; Figure 11 is a left end view of Fig. 10; Figure 12 is an enlarged sectional view along line X-X of Fig. 10; Figure 13 is an enlarged sectional view of a portion of Fig. 10 along line Y-Y of Fig. 10; Figure 14 is an enlarged sectional view of a portion of Fig. 10 along line Z-Z of Fig. 10; Figure 15 is an enlarged sectional view of a portion of Fig. 10 along line W-W of Fig. 10; Figure 16 is an enlarged sectional view of the soc ket shown in Fig. 1 showing open or lead wire release position; Figure 17 is an enlarged sectional view of the socket shown in Fig. 1 showing contact engage position; Figures 18 and 19 are enlarged perspective views of the lead wire and the contact showing open or release ##s-tic#i and contact engage position respectively;; Figure 20 is an enlarged side view of the contact shown in Figs. 18 and 19; Figure 21 is a right end view of Fig. 20; Figure 22 is a plan view of Fig. 20; and Figure 23 is a side view of the lever of the socket shown in Fig. 1.

Referring now to the drawings an electric connector socket, according to the present invention comprises a contact mounting base plate 1 of suitable insulating material having two rows of contact receiving vertical openings 2 each of which receives a contact 3. A leg 3a of each contact 3 projects under the base plate 1 through the opening 2. A movable plate 4 is placed on the base plate 1 and has two rows of through openings 5 each of which aligns with one of the openings 2 of the base plate 1. The movable plate 4 is movable to lateral direction to the direction of the rows of the contacts 3, as will be described more fully afterwards.At least one circuit element constitution, e.g., so-called IC package or LSI package 6 having a plurality of IC lead wires 7 which projec. from both sides of the package and project downwards, is placed on the movable plate 4 and each of the lead wires 7 passes through the opening 5 of the movable plate 5 into the opening 2 of the base plate 1. Each lead wire 7 is engaged with the contact 3 in the opening 2.

On the upper surface of the movable plate 4, along both side edges of the plate 4 parallel with the lon- gitudinal direction of the rows of the openings 5, upwardly projected walls 4a and 4a are formed.

Between the projected walls 4a and 4a, a plane space 4b is formed, as shown in Figs. 10-12. As shown in Figs. 16 and 17, a body 6a of the IC package 6 is placed on the space 4b, and when the movable plate 4 is moved to the lateral direction P, shown in Fig.

16, the shoulder portion between the projected wall 4a and the space 4b engages with a side edge 6b of the body 6a of the package 6 and urges the same to the lateral direction P,. Thus, the projected wall 4a acts as IC package engage wall. The wall 4a is formed as a generally continuous wall forming a plurality of recesses by the openings 5 in the illustrated embodiment, however the wall 4a may be formed as suitable spaced projections to urge the side edges 6b of the body 6a of the IC pack age 6.

On the lower surface of the movable plate 4, at leasttwo slide and retainer 8 shown in Fig. 14 are projected downwards and engage with retainer grooves 9 formed in the base plate 1 as shown in Fig.

1. Claws of the slide and retainer 8 engage with downward facing shoulders of the groove 9 and retain the movable plate 4 on the base plate 1. The width of the groove 9 is larger than the width of the slide and retainer 8 so that the movable plate 4 is slidable to the lateral direction P, and cannot move loigitudinally relative to the base plate 1. The lateral movement of the movable plate 4 may be deiur- mined by the width of the groove 9 and the width of the slide and retainer 8.Preferably, the width of the groove 9 is larger than the lateral movement of the movable plate 4 relative to the slide and retainer 8, by a plurality of slide elements 11 which are formed on lower surface of the movable plate 4 and corresponding grooves 10 formed on the upper surface of the base plate 1. By determining accurate dimentions of the slide element 11 and the groove 10 in the lateral direction Pt, desired contact engage position and release position of the lead wires 7 of the IC package 6 can be determined.

To displace the movable plate 4 manually to the lateral direction P, between the contact engage position and the release position relative to the base plate 1, the socket according to the present invention includes a lever 12. The lever 12 is shown in Fig. 23 and extends in the longitudinal direction P2 shown in Fig. 4 between the movable plate 4 and the base plate 1. As shown in Fig. 4, the lever 12 is rotatably supported in bearing grooves 13 formed on the upper surface of the base plate 1 and has eccentric operating rods 12a which are received in lever operating spaces 14 formed also on the upper sur sace of the base plate 1. Lever engage elements 15 shown in Figs. 10 and 15 engage with the eccentric operating rods 12a of the lever 12 in the leveroperat- ing space 14.The lever engage elements 15 are formed on lower surface of the movable plate 4. One end of the lever 12 is bent perpendicular outside of the socket to form a operating handle 12b. Thus, by rotating the bandle 12b manually, the eccentric operating rods 12a displace laterally in plan view shown in Figs. 4 and 10, with the lever engage elements 15 so that the movable plate 4 which is integral with the element 15 is also displaced relative to the base plate 1 in the lateral direction Pt between contact engage position and release position. Stoppers 16 and 17 may be formed on corresponding end surface of the base plate 1 to limit the rotation of the lever 12.

The contact 3 which is mounted in each of the contact receiving vertical openings 2 formed in the base plate 1 is shown in Figs. 18-22. The contact 3 is formed from a metal plate and includes a leg 3a and a a pair of bent and forked contact elements 3c which are extended horizontally when the leg 3a is extended vertically. Between the contact elements 3c, a contact clearance 3b is formed, and the open end portion of the clearance 3b is enlarged to form enlarged end portion 3e. Between the horizontal contact elements 3c and the leg 3a, bent portions 3d are formed and the forked portion extends from the horizontal contact elements through the bent por tions 3d sufficiently downwards to obtain desired elasticity of the contact elements. As shown in Figs.

16 and 17, all the contacts 3 are mounted in the open ings 2 such that the enlarged end portions 3e bet ween the contact elements 3c are directed to one direction so that the enlarged end portions 3e are aligned on two lines which are parallel with the lon- gitudinal direction P2.

To assemble the socket, all the contacts 3 are inserted in the openings 2 to project the legs 3a downwards through the openings 2 and the contact elements 3c are directed to the lateral direction P1, as shown in Figs. 16 and 17. Then the lever 12 is placed on the base plate 1 such that the lever 12 is in the bearing grooves 13. Then the movable plate 4 is placed on the base plate 1 to engage the slide elements 11 with the groove 10, the slide and retainers 8 with the groove 9, and the lever engage elements 15 with the eccentric operating rods 1 2a. By pressing the movable plate 4 downwardly, the claws of the slide and retainers 8 engage under the shoulders of the grooves 9 and permanently retain the movable plate 4 from disassembly. Thus, the movable plate 4 can be moved relative to the base plate 1 by rotating the handle 12 only in the lateral direction P,.

To mount the IC package 6, the movable plate 4 is moved to the lateral direction P, by operating the handle 12b of the operating lever 12 to open position so that the openings 5 of the movable plate 4 aligns vertically with the enlarged end portions 3e between the contact elements 3c of the contacts 3 which are in the openings 2 of the base plate 1. Then the IC package 6 is placed on the space 4b between the upwardly projected walls 4a of the movable plate 4.

The lead wires 7 of the IC package 6 are inserted through the openings 5 of the movable plate 4 into the openings 2 of the base plate 1. As shown in Figs.

16 and 18, the lead wires 7 pass freely between the contact elements 3c at the enlarged end portions 3e so that the IC package 6 can be placed on the movable plate 4 without any force until the bottom surface of the body 6a of the IC package 6 contacts with the upper surface of the space 4b of the movable plate 4. Then, the handle 1 2b of the lever 12 is rotated to contact engage position to move the movable plate 4 to the lateral direction. The side surface of one of the upwardly projected walls 4a engages with the side surface 6b of the body 6a of the IC package 6 and urges the same to the lateral direction P1. Thus the lead wires 7 are urged laterally and are moved sidewise in the clearances 3b between the contact elements 3c, as shown in Figs. 17 and 19, against elasticity of the contact elements 3c.Consequently all the lead wires 7 of the IC package 6 are elastically gripped by the contacts 3 and superior electrical connections between the lead wires 7 and the contacts 3 are obtained. The IC package 6 is firmly retained on the movable plate 4 and no other retainer is necessary.

To remove the IC package 6 from the socket, the handle 12b is rotated to the open position. The movable plate 4 is moved laterally and the side wall of the other upwardly projected wall 4a urges the opposite side surface of the body 6a of the IC package 6. Thus the lead wires 7 of the IC package 6 move sidewise in the contact clearance 3b of the contact elements 3c until the lead wires 7 are free from the contact elements 3c in the enlarged end portions 3e.

Thus, as the lead wires 7 are not gripped by the contact elements 3c, the IC package 6 can be removed without any force from the socket.

The lever 12 which acts as operating mechanism to move the movable plate 4 between the engaging and open positions is known in itself. The operating mechanism may be realized as various desired means. For example, the movable plate 4 may be urged directly by fingers or may be urged by a driver as shown in the Japanese Patent Laid-open Publication No. 53-88987.

The contact receiving vertical opening 2 of the base plate 1 is extended to the lateral direction P, to allow lateral sidewise displacement of the lead wire 7 of the IC package 6. The through opening 5 of the movable plate 4 is substantially largerthan the diameter of the lead wire 7 of the IC package 6 in the illustrated preferred embodiment of the present invention. Thus, the lead wire 7 freely pOses through the opening 5 into the vertical opening 2 of the base plate 1. Conventionally, such opening of the movable plate has generally similar diameter with that of the lead wire to support and urge the side surface of the lead wire to engage the lead wire with contact of the base plate.By urging the side surface 6b of the body 6a of the IC package 6 by engaging with projected wall 4a of the movable plate 4, according to the present invention, the lead wires 7 are not urged directly by the movable plate 4. As the dimention of the opening 5 is sufficiently largerthan that of the lead wire 7, the lead wire can be freely inserted and removed without disturbance. Further, even when the position and alignment, and dimention of the lead wires 7 are different each other as to IC packages, such package can be mounted on the socket as long as the lead wires pass into the enlarged end portions 3e of the contacts 3. Thus, interchangeability is greatly improved.

It will be appreciated that the socket according to the present invention allows no load mounting and removing of IC package. As the movable plate 4 and the lead wires 7 of the IC package 6 moves to the lateral direction P1, i.e., perpendiculartothe direction of rows of contacts, other remarkable advantages are attained. To obtain contact engage position and open or release position by sidewise displacement of the lead wires 7 and the IC package, sufficient dimention of the vertical openings 2 is necessary to allow such displacement of the lead wires. As to the longitudinal direction along the rows of contacts, which is common direction of displacement of conventional socket, such dimention is limited by thickness of division walls between the vertical openings.As the movable plate 4 and the lead wires moves laterally to the direction of the rows of contacts, desired dimention of the vertical openings 2 to allow desired sidewise displacement of the lead wires 7 can be obtained. As the limitation of the sidewise displacement is not necessary, the contact 3 can be very easily designed as to the dimention, contact area and strength thereof. As the lead wires 7 of the IC package 6 are loaded uniformly, no sidewise deflection of the lead wire by lateral over load is not occurred so that distances between the lead wires are constant.

The movable plate 4 urges the body of the IC package 6 to the lateral direction to engage and disengage the lead wire with the contact, according to the present invention. As the lead wires do not receive sidewise urging force in the longitudinal direction of the rows of contacts, inclination and deformation of the lead wire to adjacent lead wire are not occurred.

Further, as the through openings 5 of the movable plate 4 do not act as sidewise urging elements for the lead wires 7, the openings 5 can be made as sufficiently large to allow free pass of the lead wires.

Thus, insertion and removal of the IC package are easy and strict accuracy of the formation of the openings 5 is not necessary so that the socket can be made cheap. Also the socket can be accommodated tc production variables of IC packages as to dimention and shape of the lead wires.

One preferred embodiment of the present invention is described in detail. Many variables can be made without departing from the scope of the present invention. For example, the contact may be a straight bent plate having lateral open ends or a pair of straight or formed metal plates having one or both lateral enlarged end portions therebetween to receive laterally moving lead wire. Also the projected walls to urge the body of the IC package may be desired number of pins or lugs projected from the movable plate.

Claims (7)

1. A socket for IC package and including a base plate having at least one row of contact receiving vertical openings each accommodating a contact engageable with a lead wire, a movable plate having at least one row of through openings each corresponding to the vertical opening and passing said lead wire of the IC package which is placed on the movable plate and means to move the movable plate between lead wires release position and contacts engage position.

means to limit the movement of the movable plate relative to the base plate only to horizontal lateral directions which are perpendicular to the direction of said row of vertical openings; and said each contact in the vertical opening opened to at least one of said horizontal lateral directions, whereby said movable plate and IC package with said lead wires integrally move to said lateral directions to effect horizontal lateral movement of the lead wires in the vertical openings of the base plate between lead wires release position and contacts engage position.

2. A socket set forth in claim 1,furthercompris- ing said movable plate having means to engage with and urge a body portion of said IC package on the upper surface of the movable plate when the movable plate moves to at least one of said lateral directions.

3. A socket set forth in claim 2, in which said movable plate includes a pair of projected walls on the upper surface, said walls extending parallel with the direction of now of the vertical openings at side edge portions, said body of the IC package is placed between the projected walls so as to be urged by the walls when the movable plate is moved relative to the base plate.

4. Asocketsetforth in claim 1, in which said means to limit the movement of the movable plate includes at least one slide element projected from lower surface of the movable plate and groove means formed on upper surface of the base plate to guide each slide element to slide to said lateral directions.

5. A socket set forth in claim 1, in which said means to move the movable plate includes an operating lever extending parallel to the direction of the row of vertical openings, rotatably suppoed to the base plate, and having means to engage with and displace the movable plate.

6. A socket set forth in claim 1, in which said contact having a pair of forked contact elements forming contact clearance therebetween and extending in a lateral direction from a leg, and said contact clearance adapted to receive said lead wire which moves laterally.

7. A socket for an IC package, substantially as described herein with reference to the accompanying drawings.