Connector for a circuit card having means for forcing spring contacts into contact with the card after the card is put in position

Abstract

A connector for a circuit card comprises a connector block having spring contacts arranged in two rows and a connector housing removably engaging with the block. The card is supported by the housing and put in position, extending into the block between the spring contact rows, after the housing is brought into engagement with the block. The housing comprises lock means for keeping the spring contacts away from and forcing them into contact with the card before and after the card is put in position, respectively.

Description

BACKGROUND OF THE INVENTION

This invention relates to a connector for a circuit card, such as a ceramic substrate having at least one large-scale integrated circuit placed thereon and a plurality of leads or electric conductors leading thereto formed on the substrate.

On mounting a circuit card on a main plugboard or patchboard, such as printed circuit board, it has been the practice to resort to soldering or similar process for providing semipermanent electric connections between the card and the board, or more particularly, between the electric conductors of the former and like conductors of the latter. On the other hand, large scale integrated circuits have come into use in electronic computers and other apparatus in order to raise the reliability of the latter. It has therefore become necessary to provide readily disconnective electric connections, with the use of connectors, between the card and board to enable rapid replacement of the card when operation of the integrated circuit is put in disorder. Conventional connectors for the large-scale integrated circuit cards, however, are of the sophisticated edge connector type and exhibit the following defects upon insertion and removal of the card into and from the connector.

(1) The substrate of a large-scale integrated circuit card is usually made of a mechanically weak ceramic or similar material and is often broken. (2) In order to insure the reliability of electric connection, the spring contacts of the connector must be forced into contact with the card under an appreciable pressure. The electric conductors formed on the substrate are therefore subject to damages. Particularly, such damages are liable to occur at the terminal areas of the card which are surfacetreated in order to provide excellent electric connections. (3) Predetermined portions of the spring contacts are also surface-treated in order to insure electric connections. On the other hand, the substrate has sharp edges and is harder than the surface-treated portions. The substrate consequently often damages the surface-treated portions of the spring contacts particularly on inserting the card into the connector. (4) The card is manually handled on putting the card into and away from the connector. This very likely stains and damages the large-scale integrated circuit of the card.

Attempts for removing the above-mentioned and similar defects have mainly been directed to the electric conductors formed on the substrate. However, the attempts are thus far not satisfactory in that the large-scale integrated circuits are not sufficiently protected.

Connectors for circuit cards, other than the large-scale integrated circuit cards, have like defects.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a connector for a circuit card having a connector block and a removably engaging connector housing wherein spring contacts of the connector are not brought into substantial contact with the card during the operation of bringing the block and housing into engagement with and disengagement from each other.

It is another object of this invention to provide a connector of the type described, capable of minimizing the undesirable chances of staining and damaging the card during mounting the card on the connector.

It is still another object of this invention to provide a connector of the type described, that will not be damaged by the card during the above-mentioned operation.

It is a subordinate object of this invention to provide a connector of the type described, with which it becomes unnecessary to resort to specific measures for protecting electric conductors formed on a substrate of the card against failures.

A connector for a circuit card includes a connector block having a pair of side walls defining a card channel for freely slidably receiving the card until an edge of the card reader reaches the bottom of the channel. The connector block further has a plurality of spring contacts disposed along the respective side walls. The connector further comprises a connector housing adapted for removable engagement with the connector block. In accordance with this invention, the connector housing comprises a locking portion and a card supporting portion made integral with the locking portion. The locking portion has a pair of side walls defining an opening for snugly receiving the connector block side walls and freely receiving, during a first stage of the above-mentioned engagement, the spring contacts. Each of the connector housing side walls has an inwardly directed surface. The card supporting portion has spring means and a pair of opposing guide channels for freely slidably guiding the card. The spring means urges the above-mentioned edge of the card guided along the guiding channels towards end faces of the locking portion side walls that are remote from the card supporting portion whereby the card is held by the housing. The guide channels are brought into registration with the card channel in the direction of the thickness of the card held by the housing during and after the above-mentioned first stage. On the other hand, each of the spring contacts has a first bend projecting inwardly towards the card channel and a second bend protruding outwardly of the associated connector block side wall. The opposing first bends of the spring contacts allow free slide therebetween of the card held by the housing during the above-mentioned first stage and a subsequently following second stage of the above-mentioned engagement, during which second stage the abovementioned edge of the card held by the housing reaches the bottom of the card channel. The inwardly directed surfaces come into contact with and subsequently into sliding touch with the second bends prior to the abovementioned second stage. Eventually, the inwardly directed surfaces force the first bends into contact with the card held by the housing after the second stage and when the housing and block are brought into full engagement with each other.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 schematically shows a perspective view of four connectors according to a first embodiment of the instant invention together with circuit cards held by the connectors and a circuit board to which electric connections are provided by the connectors from the cards, one of the connectors having its connector housing removed and another having the connector housing partly cut away;

FIG. 2 is an enlarged fragmentary cross-sectional view of a connector depicted in FIG. 1;

FIG. 3 shows a perspective view of a connector housing of a connector shown in FIG. 1, on a reduced scale together with a circuit card and with parts broken away;

FIG. 4 shows an enlarged partial cross-sectional view of a connector illustrated in FIG. 1 with the connector housing brought into partial engagement with a connector block of the connector;

FIG. 5 is a like view of the connector with the connector housing brought into full engagement with the connector block; and

FIG. 6 is a perspective view of connector blocks of several connectors according to a second embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 through 3, a connector for a circuit card 11 according to a first embodiment of the present invention is for disconnectively forming electric connections between terminal areas 12 (FIG. 3) of the card 11 and printed conductors (not shown) of a printed circuit board 16. The connector comprises a connector block 21 and a connector housing 22 adapted for removable engagement with the connector block 21.

Referring more particularly to FIGS. 1 through 3, the connector block 21 includes a pair of side walls 31 defining a card channel 32 for freely slidably receiving the card 11 until an edge 33 (FIG. 3) of the card 11 reaches a bottom 34 (FIG. 2) of the channel 32. In the example being illustrated, each side wall 31 is formed of a plurality of protrusions extending from a base 35 (FIG. 2) of the block 21. The side walls 31 and the base 35 may be made of a synthetic resin by molding. The connector block 21 further comprises a plurality of spring contacts 36 disposed along the respective side walls 31 between the adjacently aligned protrusions. The spring contacts 36 may be made of phosphor bronze, beryllium copper, or a similar electro-conductive resilient material. In the example being illustrated, each spring contact 36 has a contact tail on tip 37 planted in the base 35 and extended through the printed circuit board 16 to be soldered or otherwise mechanically and electrically connected to pertinent one of the printed circuits (not shown) as best illustrated in FIG. 2. The side walls 31 have tapered portion 38. In accordance with this invention, each spring contact 36 has a first bend 41 (FIG. 2) projecting inwardly towards the channel 32, a second bend 42 protruding outwardly of the tapered portion 38 of the associated side wall 31, and a free end 43 extending from the second bend 42 back toward a slit formed between the adjacently aligned protrusions of the relevant side wall 31. It will be seen from FIG. 2 that the opposing first bends 41 of the spring contacts 36 do not protrude into the channel 32 to allow free slide therebetween of the card 11 and that the tapered portions 38 of the side walls 31 are approximately equally sloped as the free ends 43 of the spring contacts 36 and then extended without materials taper towards free ends of the side walls 31. In this manner known in the art, at least inwardly directed surfaces of the first bends 41 are plated with gold or otherwise surface-treated to provide best possible electric contact with the terminal areas 12 of the card 11 which are similarly surface-treated.

Referring specifically to FIGS. 1 through 3 and referring to FIGS. 4 and 5, the connector housing 22 comprises a locking portion 46 and a card supporting portion 47. These portions 46 and 47 may be integrally made of a synthetic resin. Alternatively, the card supporting portion 47 may be possessed of a back plate 48 made of a thermally conductive metal in order to serve as a heat sink for the card 11. The card supporting portion 47 having a metal back plate 48 should be integrally united with a synthetic resin locking portion 46 by means of machine screws 49 or by any other means. The locking portion 46 has a pair of side walls defining an opening for snugly receiving the connector block side walls 31 and freely receiving, in a first stage of bringing the housing 2 and block 21 into engagement with each other, the spring contacts 36 as best shown in FIG. 4. Each of the connector housing side walls has an inwardly directed surface 51 (FIG. 4) and an end face 52 that is remote from the card supporting portion 47. The card supporting portion 47 has a pair of opposing guide channels 56 and 57 (FIG. 3) for freely slidably guiding the card 11 and spring means that comprises, in turn, a leaf spring 58 and a boss 59 either fixed or removably attached to a transverse member, such as the back plate 48, extending between the guide channels 56 and 57 in offset relation thereto in the adjacency of the free end of the card supporting portion 47. The spring means urges the above-mentioned edge 33 of the card 11 sliding along the guide channels 56 and 57 towards the end faces 52 of the locking portion side walls, whereby the card 11 is held by the connector housing 22. Preferably, a pair of narrow walls, such as 61, interconnecting the locking portion side walls is provided with a pair of end shoulders, such as 62, for insuring holding of the card 11 by the connector housing 22 even when the latter is disengaged from the connector block 21. In other words, the end shoulders 62 enable the connector housing 22 easily self-support the card 11. The guide channels 56 and 57 should be brought into registration with the card channel 32 at least in the direction of the thickness of the card 11 held by the housing 22 when the housing 22 and block 21 are brought into engagement with each other. Preferably, the guide channels 56 and 57 are left open at their ends remote from the end faces 52 of the connector housing side walls. It will be noticed that the inwardly directed surfaces 51 of the connector housing side walls are approximately equally sloped as the free ends 43 of the spring contacts 36 and then extended substantially parallel to the guide channels 56 and 57. It is preferred that second bends 42 be first brought into contact with the inwardly directed surfaces 51.

Referring specifically to FIG. 4, the locking portion 46 may have a pair of shoulder walls 66 extending inwardly from the locking portion side walls to define a card slot 67 in registration with the guide channels 56 and 57. It will be noticed that the card 11 shown here has the terminal areas 12 on both principal surfaces of the substrate. The card 11, however, may have the terminal areas 12 on only one of the principal surfaces of the substrate. In the latter case, the card supporting portion 47 may have two pairs of juxtaposed guide channels, such as 56, on both sides of the back plate 48 or other transverse member, which guide channels are brought in combination into registration with the card channel 32 at least in the direction of the thickness of the cards, such as 11, when the housing 22 and block 21 are brought into engagement with each other.

Referring back and more particularly to FIG. 3, the card 11 may be mounted on the connector housing 22 by removing the dismountable spring means, such as 58 and 59, and by letting the card 11 slide into the guide channels 56 and 57 with the above-mentioned edge 33 of the card 11 having the terminal areas 12 therealong first into the open ends of the guide channels 56 and 57. Subsequently put in position, the card 11 is urged by the spring means 58 and 59 against the end shoulders 62 to be self-supported by the housing 22. Removal of the card 11 from the housing 22 would be self-explanatory.

Referring again and more particularly to FIG. 4, the connector housing 22 with the card 11 is now put into partial engagement with the connector block 21. At a first stage of the engagement, the opening defined by the connector housing side walls snugly receives the connector block side walls 31 and freely receives the spring contacts 36. As has already been mentioned, the guide channels 56 and 57 are brought into registration with the card channels 32. The opposing first bends 41 of the spring contacts 36 allow free slide therebetween of the card 11 held by the housing 22. At a subsequently following second stage of the engagement illustrated in FIG. 4, the above-mentioned edge 33 of the card 11 held by the housing 22 reaches the bottom 34 of the card channel 32. Either at this second stage or soon thereafter, the inwardly directed surfaces 51 of the connector block side walls 31 come into contact with the second bends 42 of the spring contacts 36 and subsequently into sliding touch therewith. It should specifically be pointed out that the spring contacts 36 are left free until the card 11 is put in position where the above-mentioned edge 33 of the card 11 reaches the bottom 34 of the card channel 32.

Referring now specifically to FIG. 5, the connector housing and block 22 and 21 are brought into full engagement with each other from the second stage illustrated with reference to FIG. 4. The second bends 42 of the spring contacts 36 have slidden along the inwardly directed surfaces 51 of the connector housing side walls until the inwardly directed surface 51 eventually force the first bends 41 of the spring contacts 36 into mechanical and electric contact with the terminal areas 12 of the card 11 that has already been put in the above-mentioned position. It is worthwhile to note that the contact of the first bends 41 to the terminal areas 12 or, roughly spoken, the card 11 occurs without any relative slide therebetween after the second stage of the engagement and that the engagement is carried out without direct touch to the card 11. Incidentally, the card 11 may slide relative to the housing 22 along the guide channels, such as 56, against the action of the spring means 58 and 59 (FIG. 3) so that the edge 33 may come out of contact with the end shoulder 62 (FIG. 3) either immediately before the second stage or as the engagement is brought from the second stage to the full engagement.

Reviewing FIGS. 4 and 5, operation of the connector according to this invention during relative disengagement of the connector housing 22 from the connector block 21 will be self-explanatory. It should, however, be again pointed out that no direct manual touch to the card 11 is unnecessary and that no slide occurs between the spring contacts 36 and the card 11.

Referring finally to FIG. 6, a connector according to a second embodiment of this invention makes use of the printed circuit board 16 as the base 35 (FIG. 2) of the connector block 21. More particularly referring to part (A) of FIG. 6, the contact tips 37 of a plurality of spring contacts 36 are put through pertinent ones of holes 71 formed through the board 16 in a regular array and fixed to the board 16. As shown in part (B), a side wall block 72 having side wall protrusions 73 in correspondence to the holes 71 is put on the board 16 so that the spring contacts 36 may extend between relevant portions of the side wall protrusions. In part (C), the side wall block 72 is fixed to the board 16 by means of machine screws (not shown) put through holes 74 therefor, by the use of a bonding agent, or by any other means. With this embodiment, it is possible to put the spring contacts 36 into the board holes 71 by means of a numerically controlled automatic machine. It is also possible to dip the board 16 having the spring contacts 36 put through the holes 71 as illustrated in part (A) in a solder bath to carry out the soldering. It is thus feasible to speed up the manufacture. In addition, it is easy to substitute a new spring contact for any one of the spring contacts 36 that may happen to be damaged.

With a conventional connector of the type described, the characteristics and reliability were degraded after about 50 times of connection and disconnection between an integrated circuit card and a printed circuit board. In contrast, the characteristics and reliability were not objectionably degraded with a connector according to this invention until about two hundred times of connection and disconnection. It has been necessary with a conventional connector to use a gold layer of a thickness between 15 and 20 microns for the terminal areas 12 of the card 11 and the spring contacts 36. In contrast, the thickness may be only 2 to 3 microns for a connector according to this invention. This considerably saves the cost of manufacture.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims

We claim:

1. A connector for electrically connecting a printed circuit card having a plurality of contacts adjacent one edge of said card to a main printed circuit board comprising;

a. at least one connector block having a base portion affixed to said main printed circuit board, a slot to receive a printed circuit card, and a portion of reduced width opposite said base portion adjacent said card receiving slot;

b. a plurality of electrical spring contacts protruding through said connector block base portion on each side of said card receiving slot, said spring contacts having one end in electrical contact with said main printed circuit board, each of said electrical spring contacts having a first portion projecting inwardly towards said card receiving slot, a second portion projecting outwardly laterally beyond said reduced width portion of said connector block and a third portion projecting inwardly toward said card receiving slot at an angle to the central axis of said card receiving slot, such that no portion of said electrical spring contacts extend into said card slot in said connector block;

c. printed circuit card holding means allowing manual handling of said card without physically touching the card itself; and

d. housing means attached to said card holding means and releasably attachable to said connector block means to deform said electrical spring contacts into the slot in said connector board and, hence, into contact with said card after said card has been inserted into said slots by the card holding means.

2. The connector of claim 1 wherein said housing means has an opening defined by side, top and bottom walls, a first portion of the inner surface of said side walls contacting the base portion of said connector block, a second portion of the inner surface of said side walls having a wedge portion protruding inwardly so as to engage said third portion of said electrical spring contacts.

3. The connector of claim 2 wherein the angle of said wedge portion is the same as the angle of the third portion of said electrical spring contacts.

4. The connector of claim 2 wherein said printed circuit card holding means comprises a pair of members having a generally U-shaped cross section, said members engaging opposite sides of said card and having one end attached to said housing means.

5. The connector of claim 4 wherein a back plate connects corresponding legs of said U-shaped members.

6. The connector of claim 4 wherein said back plate is composed of metal having high thermal conductivity and is in contact with said printed circuit card.

7. The connector of claim 4 wherein spring means attached to said back plate contacts one edge of said card to urge said card toward said housing means.

8. A connector for electrically connecting a printed circuit card having a plurality of contacts adjacent one edge of said card to a main printed circuit board comprising:

a. at least one elongated connector block having a base portion affixed to said main printed circuit board, said connector block having a slot extending centrally and lengthwise thereof and having a width to receive a printed circuit card;

b. a plurality of electrical spring contacts protruding through said connector block base portion on each side of said card receiving slot, each of said spring contacts having one end in electrical contact with said main printing circuit board, a first portion adjacent said card receiving slot projecting inwardly towards said slot, and a second portion adjacent the distal end bent so as to protrude laterally beyond said connector block, said contacts being positioned such that no portion extends into said card receiving slot; and

c. a connector housing comprising a card supporting portion having a pair of members, each having a pair of legs defining a guide channel for slidably guiding said printed circuit card, said guide channel being substantially equal in width to the width of said card receiving slot, a back plate connecting corresponding legs of said members, and spring means mounted on said back plate, said housing being releasably attachable to said connector block to push said electrical spring contacts at the second portions to urge the first portions into said card receiving slot with the guide channels brought into substantial alignment with said card receiving slot, said spring means urging said printed circuit into said card receiving slot when the housing is attached to said connector block, whereby said electrical spring contact second portions are brought into electrical contact with said contacts of said printed circuit card after said card has been pushed into said card receiving slot with substantially no force exerted perpendicularly of said printed circuit card.

9. The connector of claim 8 wherein said connector block comprises a pair of side walls defining said card receiving slot, the second portions of said electrical spring contacts protruding laterally outwardly of said connector block side walls, and wherein said connector housing comprises a pair of side walls defining an opening for releasably and snugly receiving said connector block side walls, said opening communicating with the guide channels, said housing side walls being capable of pushing said electrical spring contacts at said second portions to urge the first portions into said card receiving slot as the side walls of said connector are received in said opening.

10. The connector of claim 8 wherein said connector housing comprises shoulder means at the ends of said guide channels remote from said spring means for receiving the printed circuit board urged thereto along said guide channels by said spring means.