FR2507831A1 - Integrated circuit socket for circuit boards - has doubly-curved female contact forming heart-shaped transversal cross=section - Google Patents

Abstract

The socket is made in a conventional insulating base which has chamfer-sided entrance holes at the conventional pitch in its upper and lower surfaces. Each contact unit is inserted into a rectangular cavity from the lower-side entrance hole. Protruding notches (111) in the rectangular shaft (101) are deformed elastically upon entry and catch in internal recesses (71) which prevents further movement. The female end of the contact consists of a doubly curved sheath presenting two lobes (46) convex inwards. An inserted pin is forced by the inward-acting elastic force against the outer curved wall (47) whilst the inner face of the pin is pressed against both ends of the lobe extremities. Contact along four lines in the pin surface is achieved.

Description

Connection device for integrated circuits.

The invention relates to a connection device for integrated circuits.

It is known that many commercially available integrated circuits are in the form of a parallelepipedal block from which depend the tabs provided for the connections.

These tabs were initially designed to allow the electrical connections of the components of the integrated circuit to conductive tracks of a card, in a specific way by introduction of said tabs into eyelets present on said tracks, and interposition of a weld between said tabs and the internal surface of the eyelets, the contribution of the solder being most often carried out by dipping the card in a solder bath.

 It has been found that such a connection had drawbacks when the integrated circuit had to be replaced by another integrated circuit, for example during a test of the apparatus comprising the integrated circuit and the card with conductive tracks (usually called printed circuits), or during the use of said equipment.

It has therefore been proposed to interpose, between the integrated circuit and the card, an intermediate device, usually called support, and which, while allowing the realization of electrical connections, allows the replacement of an integrated circuit by another integrated circuit. .

Such a support commonly comprises female organs, into which the tabs of the integrated circuit penetrate, and which are each connected each to male organs capable of cooperating with the eyelets of the printed circuits, in the same way as the usual legs of integrated circuits.

For the replacement of an integrated circuit, it suffices to disengage the legs of the latter relative to the female members of the support and to reinsert in said female organs the legs of a replacement integrated circuit.

These supports find an extended use, especially since they allow the connection of the integrated circuit not only to printed circuit boards, but also to other conductors, and this in particular by the technique known as miniwrapping according to which the outputs of the support, constituted by the male members, can receive the windings of wires constituting the ends of the conductors to be connected to the integrated circuit.

But all known supports have a certain number of drawbacks, the main one being perhaps that they reduce the quality of the electrical connection between the integrated circuit and the printed circuits of a card or the other conductors.

The present invention overcomes these drawbacks, in particular by ensuring an exceptionally high quality of electrical transmission between the tabs that the printed circuit comprises and the transmission members of a support.

It is characterized by the fact that the contact between a lug of the integrated circuit with a member for transmitting a support is made by means of a cylindrical sleeve split into a thin elastic blade with a cross-sectional configuration in the shape of a heart, the free ends of the converging branches, corresponding to the ears of the configuration, being able to cooperate with one face of the lug of the integrated circuit, of which 2 opposite face cooperates with the opposite curved part, or belly, of the blade.

A circuit tab being in the shape of a rectangular parallelepiped, the cooperation of said opposite face with the curved surface takes place along linear zones, which is favorable for electrical transmission.

On the first face of the tab, the contact is made along the edges of the ends opposite the branches, also along linear zones.

A split socket having such a configuration can moreover be used to cooperate with a member other than a connection lug of an integrated circuit, and which may have a different cross section, and this for connection with an electrical circuit d 'another type.

In the following description, given by way of example, reference is made to the appended drawings, in which FIG. 1 is a partial schematic perspective view of a device according to the invention, FIG. 2 is a sectional view of part of the device according to the invention, but on a larger scale than in FIG. 1; Figure 3 is a view similar to Figure 2, but the section being made in a perpendicular plane; Figures 4 and 5 are perspective views, on a large scale, of a female contact device according to the invention; Figure 6 shows in end view the condition of the socket in the free state; Figures 7 to 10 show the condition of said socket when legs of various configurations are introduced therein; and FIGS. 11 to 13 schematically represent, in cross section, other connections according to the invention.

The electrical connection device according to the invention 11 (FIG. 1) is designed to be interposed between an integrated circuit 12 and, for example, a card 13 with printed circuits.

The integrated circuit '2, of a usual type, comprises a parallelepipedic body 14, made of insulating material, from which depend the connection lugs 15. These legs project from two opposite lateral faces 16 and 17 of the block 14. Each has a fastener 18, first perpendicular to the face with respect to which it protrudes, and which continues with a strip 19 substantially parallel to said face, said strip extending by a narrower part 21, or foot.

The manufacturing tolerances of said tabs are, as we know, relatively wide, the width of the part 21 can vary from 0.38 to 0.508 mm, and its thickness can vary from 0.2 to 0.3 mm. In addition, the peripheral edge 22 of a lug 15 is relatively irregular, which was far from being a drawback when the connection of a lug 15 is made by interposing a solder material between said lug and an eyelet that presents the printed circuit card 13, but which reduces the qualities of electrical transmission with the known supports intended to be interposed between the integrated circuit and the card.

The connection device according to the invention, or support, comprises a body 31 of insulating material, of parallelepiped shape, limited by parallel lateral faces 32 and 33, perpendicular faces 34 and 35, an upper face (in the representation) 36 and a lower face 37.

The body 31 is crossed by passages 38, in the same arrangement as the lugs 15 of the integrated circuit with which the support is intended to cooperate, and which open onto the face 36 following the openings 39 in configuration in sand heap, ie with opposite longitudinal oblique faces 41, 42 and transverse oblique faces 43, 44 (Figures 2 and 3).

Each opening 39, in the form of a funnel, opens into a chimney 45 of generally parallelepiped shape, bounded by an external surface 46, parallel to the longitudinal faces 32, 33 of the block 31, an internal face, also parallel, 47 and two perpendicular faces , respectively 48, 49.

Significantly halfway up block 31, that is to say midway between faces 36 and 37, the chimney 45, with a medium line 58, widens (Figure 3), being, in its lower part, limited by lateral faces 51 and 52 more distant from each other than the faces 48 and 49 and thus providing shoulders 53 and 54.

The longitudinal face 46 extends to the lower face 37 of the body 31 and the latter has annular projections 55, in line with each chimney 45, limited by internal oblique faces 57.

In addition, each longitudinal face 32 or 33 of the body 31 has, at its lower part, windows 71, which open into the chimneys 45, and which are limited by horizontal faces 72, 73 and vertical faces 74.75 .

In the chimney 45, which thus comprises a narrow part 76 and an enlarged part 77, is housed a female contact device 79 (FIGS. 4 and 5). This comprises a socket 81 constituted by a blade whose cross section is in the form of two loops or lobes 96, 97, connected by a back 83, with a relatively large radius of curvature; the back 83 continues on one side of a plane of symmetry 85 (FIG. 6) by an internal branch 84 forming part of the loop 96 and, on the other side, by an internal branch 86 forming part of the loop 97 ; the internal branch 84 is connected to the back 83 by a connection part 87 and the branch 86 is connected to the back 83 by a connection part 88.

In one embodiment, the radii of curvature of the various parts were as follows 0.6 mm for the main parts, that is to say the back 83 and the branches 84 and 86; and 0.15 mm for connections 87 and 88.

The sections 91 and 92 forming the ends respectively of the branches 84 and 86 are distant from the opposite face 93 from the central part 83 or back.

For cooperation with standardized tabs of an integrated circuit, the thickness of which varies between 0.2 and 0.3 mm, the distance between the sections 91 and 92 and the facing part 93 is approximately 0.2 mm.

With a blade constituting the socket 81 with a thickness of 0.1 mm, the distance between the facing surfaces 94 and 95 of the ends of the branches 84 and 86 respectively is approximately 0.1 mm. The sleeve 81 thus constitutes the two sheaths in the form of lobes 96 and 97.

Said socket 81 forms the upper end (in the figure) of a flat plate 101, of a thickness greater than that of the blade constituting the socket and which is for example of the order of 0.4 mm . The plate 101 is connected to the sleeve 81 by a portion of decreasing thickness 102 limited by curvilinear edges 107 and 108, the shape varying according to the manufacturing conditions.

The plate 101 has a general configuration of a rectangular frame with vertical sides 103 and 104, an upper horizontal side 99, a lower horizontal side 105 and is extended by a tab 106 whose configuration is adapted, depending on the version, to the type of fixing to be carried out (by welding, by mini-wrapping, etc.).

From the plate 101 comes, by cutting and bending, an oblique bar 111 limited by two parallel vertical edges 112 and 113 and a lower edge 114. The inclination of the oblique blade 111 is such that the lower edge 114 or edge is in look at the face 73 of the window 71.

Such a female connection member 79 is introduced through the lower orifice 115 of a chimney 45, the relative elasticity of the bar 111 allowing passage, although the distance between the faces 46 and 47 of the chimney 45 is smaller that the distance between the apex 116 of the bar 111 and the rear face 117 of the plate 10; the sides 103 and 104 cooperate with the internal surfaces 51 and 52 of the chimney and the rear face 117 of the plate 101 with the internal surface 47; the introduction movement is continued until the upper edge 120 of the sleeve 81 comes into contact with the internal surface of the upper wall 36 of the body 31, in which position the lower edge 114 of the bar 111 is opposite immediately on face 73 limiting window 71.

The dimensions of the bush 81 are such that the external lateral surface of the latter remains at a distance from the surfaces limiting the narrow part of the chimney 45.

Figure 6 shows the configuration of the cross section of the sleeve 81 when the latter is not under stress. The outline is similar to that of an inverted heart, the atria of which correspond to loops 96 and 97.

FIG. 7 shows the configuration of the socket 81 after introduction of an integrated circuit tab 15 when the foot 21 or narrow part of said tab has, in cross section, the minimum dimensions. The foot 21 has contact by its longitudinal edges 121 and 122 with generatrices of the internal surface 93 of the female contact or socket 81. The contact with the edges 91 and 92 takes place substantially along the external edges 123 and 124 thereof. The introduction of the tab 15 has caused a deformation of the two-lobe socket and the elasticity of the latter ensures pressure contact according to the generators 121, 122, 123 ', 124t
Figure 8 relates to the condition that takes the socket 81 in the case of the introduction of an integrated circuit lug whose foot has the minimum width and maximum thickness allowed by the tolerances allowed. The deformation of the elastic sleeve 81 is greater than in the condition shown in FIG. 7. The contact takes place along the same generatrices 121 and 122 of the internal surface 93 as in the condition shown in FIG. 7. In this configuration of the sleeve 81 corresponding to the maximum thickness, the two branches 84 and 86 are substantially in contact with each other along their internal zones 125, 126 and the edges 91 and 92 always have their edges 123 and 124 opposite the lug 15, however with greater pressure in line with the edges 123 and 124.

The condition shown in Figure 9 corresponds to the introduction into the elastic sleeve 81 of a foot 21 having the maximum width allowed by the tolerances and the minimum thickness. The foot then cooperates by its edges 127 and 128 with the generators 129 and 131 of the part 93 further from the mean plane 85 than the generators 121 and 122. The opposite face 132 of the foot 21 or contact 133 always cooperates with the same edges 123 and 124 from the ends of the branches 84 and 86 of the socket 81.

The condition shown in Figure 10 corresponds to the introduction of a foot 136 having a width of 0.508 mm (maximum width) and a thickness of 0.3 mm (maximum thickness).

The pressure is then established between the generators 137 and 138 of the part 93 for the face 139 of the foot 136 and with the edges 123 and 124, external, of the branches 84 and 86.

In all cases, the electrical conduction between the feet or legs of the integrated circuit with the connection device according to the invention is of excellent quality
The deformations of the female socket 81 vary relatively little compared to the large variations in dimensions of the tab 15.

 There are always four contact lines between the socket and the tab.

The introduction of the feet or legs of the integrated circuit into the various chimneys is easy.

The tabs 106 that the support 11 includes can have any shape for the electrical connections to be made, either for soldering on a printed circuit board, or for mini-wrapping, or for another mounting.

The female connection members according to the invention can be used for connection with robotic bodies other than the legs of an integrated circuit.

FIG. 11 shows a cylindrical spindle 151, or male member, cooperating with a split cylindrical socket 152 according to the invention having a back 153 extending by two curved branches 154 and 155 with curved returns 156 and 157, the external end faces 158 and 159 are applied under pressure against the external surface 161 of the spindle 151 by pushing the latter against the internal surface 162 of the curved back 153.

FIG. 12 shows the same female socket cooperating with a member m 171, or spindle, knife-shaped with two oblique faces 172 and 173 cooperating with the ends 158 and 159 of the branches 156 and 157, these urging against the curved internal surface 162 the longitudinal edges 174 and 175 of intersection of the faces 176 and 177 of the knife with the rear face 178.

The split bushing according to the invention can also ensure the electrical connection with a part 181 with a cylindrical bore 182, the contact being ensured by cooperation of the convex zones 183 and 184, symmetrical with respect to the mean plane 185, with the cylindrical bore, l elasticity of the branches 156, 157 further ensuring the cooperation of the convex part 186 of the back 153 with the cylindrical bore.

Claims (13)

Claims. 1. Electrical connection member with split socket, in particular for a connection lug of an integrated circuit, characterized in that the socket is constituted by an elastic blade with two lobes with a cross section substantially in the shape of a heart. 2. An electrical connection member according to claim 1, characterized in that the internal branches of the split socket are spaced from one another. 3. Electric connection member according to claim 1, characterized in that the edges of the internal branches are at a distance from the curved back. 4. Female electrical connection member according to one of the preceding claims, characterized in that the sleeve is part of a plate for mounting in an insulating body. 5. Electrical connection, characterized in that it comprises a socket according to one of claims 1 to 4, dependent on a plate comprising, opposite the socket, a malt member.  6. Electrical connection device, characterized in that it comprises at least one member. according to one of claims 1 to 5. 7. Device. electrical connection according to claim 6, characterized in that it comprises a multiplicity of organs - arranged so as to be suitable for receiving the connection tabs of an integrated circuit. 8. An electrical connection device according to claim 7, characterized in that an oblique bar formed by cutting is dependent on the plate. 9. Device according to claim 8, characterized in that the insulating body of the device has through windows facing the oblique bars. 10. An electrical connection device, characterized in that, with the member according to one of claims 1 to 4, a cylindrical pin cooperates inserted in the space provided between, on the one hand the ends of the branches, and on the other hand, the back facing the socket. 11. An electrical connection device according to claim 10, characterized in that the cylindrical pin is of circular section. 12. Electrical connection device according to claim 10, characterized in that the pin is of prismatic section. 13. Electrical connection device, characterized in that the electrical connection member according to one of claims 1 to 4 cooperates, by its external surface, with a bore.