Contact array assembly for a computer-controlled printed circuit board testing apparatus

Abstract

A contact array assembly for use with a computer-controlled printed circuit oard testing apparatus includes an array of contacts into segments individually and releasably supported by supporting rods resting in a base plate. The space so created is utilized for accommodating the electronic circuitry components associated with these contact array segments and connected through plug-type connectors to a two-dimensional addressing and control logic on the base plate. These constructional units, referred to as modules or driver plates, are identical and may replace each other in any of the positions on the base plate. The invention results in a printed circuit board testing apparatus which may be designed for a very large number of contacts, but can be operated initially with a reduced amount of electronic circuitry and may be expanded later on, as desired.

Description

This application is a continuation of now abandoned application Ser. No. 669,307, filed Nov. 7, 1984 now abandoned.

BACKGROUND OF THE INVENTION

The practice of electronically testing industrially fabricated printed circuit boards has gained wide acceptance. Thus, the quality of the boards may be judged prior to further processing, such as the installation of comparitivelypositiona plane extending parallel with the contact plane 26 of array 36, the outline of each contact module or driver plate 30 is limited by the outline of top contact connector 10 adjacent the contact plane. The height dimension of each module or unit in the vertical direction, however, may be chosen freely by the designer according to requirements. Each one of the contact modules 30 may be placed at any of the plug-in positions (128 such positions are in the illustrated exemplary embodiment) on base array plate 44 or a base grid plate or controller circuit board 42, respectively, and due to its mechanical construction, the module is suited to transmit to base plate 18 the contact pressure acting on its end surface through its own supporting rods without placing a high mechanical load on bottom contact connector 26 or on controller circuit board 42. Insulation layer 40 is positioned between base plate 10 and controller circuit board 42.

The subdivision of the contact plane and the accommodation of a major portion of the electronics associated with each contact array segment 38 in the space directly below it in the plug-in driver plates/contact modules 30 constructed to transmit high loads offer to the buyer of printed circuit board testing apparatus the possibility of buying only the number of modules 30 needed for the testing tasks he faces. The positions 38 not occupied by active driver plates/contact array modules 30 on the base array plate 44 are preferably filled with dummy modules or plates, i.e., inactive contact array modules or driver plates which have the same outer shape and mechanical characteristics as the active modules or plates, but carry no expensive electronics, in order to transmit the high mechanical loads from contacts 32.

The aforementioned savings are increased by the fact that a given number of active driver plates or modules 30 may be used to test circuit boards having a variety of shapes as the active driver plates or modules and the dummy modules may, by a small number of simple manual operations, be moved to other positions so as to accommodate new and differently shaped circuit boards. Thus, any driver plates or modules that are useless in a specific area can be readily moved to positions where they are needed. As a result, the invention creates the possibility of providing a printed circuit board testing apparatus which is basically designed to accommodate very large contact arrays but obviates the necessity of purchasing all of the expensive electronics required for a maximum size of circuit boards that may never have to be tested.

At the same time, the electronics on the contact modules available can be used to optimum efficiency because the modules may be moved at will (within the limits of the boundaries) for adaptation to a variety of shapes of printed circuit boards.

Having described the invention in connection with specific embodiments thereof, modifications which would be apparent to those skilled in the art can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited to the disclosed embodiment except as required by the appended claims.

Claims

1. In an assembly for use with a computer-controlled printed circuit board testing apparatus for determining whether the electrical connections of printed circuit boards to be tested correspond to computer-memorized connections of a master printed circuit board, the testing apparatus being of the type including controlling computer logic, and a plurality of contact members supported by the apparatus to be pressed by a printed circuit board to be tested such that electrical connections of the printed circuit board to be tested contact the contact members via a mount provided to receive the printed circuit board, the contact members being arranged within a grid-like array of equally sized segments, said assembly including means for electrically connecting the contact members to the controlling computer logic, and means for absorbing the pressure of the printed circuit board to be tested being pressed against the contact members via the mount, the improvement wherein said assembly comprises comprising:

a base plate to be supported in spaced relationship below the contact members of the testing apparatus;

said connecting means including a plurality of modules of identical construction extending upwardly from said base plate;

each said module including an upper connector having an outer contour defining a respective segment and defining therebelow a space limited by said outer contour, said upper connector having an arrangement of contacts to be connected to the contact elements members of the testing apparatus upon a printed circuit board to be tested being pressed thereon via the mount, and upper surfaces of said upper connectors defining a contact plane;

each said module including electronic components confined within the respective said space and connected to said contacts of the respective said upper connector; and

each said module including a lower connector means, located within the respective said space and connected to the respective said electronic components, for electrically connecting said respective electronic components to the controlling computer logic of the testing apparatus;

wherein said pressure absorbing means comprises, for each said module, at least one supporting rod directly connected to and supporting the respective said upper connector and extending downwardly through the respective said space and releasably supported by said base plate;

whereby said modules may be selectively relocated on said base plate and selected said modules may be removed from said assembly or additional modules may be added thereto, such that said assembly may be employed to test printed circuit boards of various different sizes and shapes.

2. The improvement claimed in claim 1, wherein each said module further includes a multi-layer circuit board within the respective said space and secured to the respective said supporting rod, and the respective said electronic components of the testing apparatus are disposed on said circuit board.

3. The improvement claimed in claim 1, wherein said supporting rod has a reduced size lower end fitting into a complementary shaped opening in said base plate.

4. The improvement claimed in claim 1, wherein each said module includes two said supporting rods extending from the respective said upper connector.

5. The improvement claimed in claim 1, wherein said base plate has therein a grid of openings receiving reduced size end portions of said supporting rods.

6. The improvement claimed in claim 1, wherein each said upper connector comprises a plug-in connector having an outer configuration defining said contour.

7. The improvement claimed in claim 6, further comprising a plurality of contact pins acted on by the comprising contact members of the testing apparatus and extending into said plug-in connectors to contact said contacts thereof.

8. The improvement claimed in claim 7, further comprising a perforated grid plate through which extend said contact pins for a plurality of said connectors.

9. The improvement claimed in claim 1, wherein each said lower connector means comprises a plug-in connector located above said base plate a sufficient distance to remain unloaded by contact pressure acting on the respective said upper connector.

10. The improvement claimed in claim 1, wherein said base plate has thereon means defining a plurality of contact positions aligned with respective said spaces.

11. The improvement claimed in claim 10, further comprising a control circuit board forming part of the controlling computer logic of the testing apparatus and supported on said base plate, said control circuit board including said contact position defining means.

12. The improvement claimed in claim 11, wherein said contact position defining means comprises upright contact pins extending upwardly from said control circuit board at positions to be connected to respective said lower connector means.

13. The improvement claimed in claim 12, further comprising an insulating plate positioned between said base plate and said control circuit board.

14. A In a contact module for use with a computer-controlled printed circuit board testing apparatus for determining whether the positions of the electrical connections of printed circuit boards to be tested correspond to computer-memorized information connections of a master printed circuit board, the testing apparatus being of the type including controlling computer logic, a base plate, a plurality of contact members supported by the apparatus to be pressed by a printed circuit board to be tested such that electrical connections of the printed circuit board to be tested contact the contact members via a mount to receive the printed circuit board, the contact member being arranged within a grid-like array of equally sized segments, means for electrically connecting the contact members to the controlling computer logic, and means for absorbing the pressure of the printed circuit board to be tested being pressed against the contact members via the mount, the improvement wherein said contact module including includes the connecting means and the pressure absorbing means of the testing apparatus and comprising:

an upper connector having an outer contour defining a respective segment and defining therebelow a space limited by said outer contour, said upper connector having an arrangement of contacts to be connected to the contact elements members of the testing apparatus upon a printed circuit board to be tested being pressed thereon via the mount, and said upper connector having an upper surface extending in a contact plane to be defined by upper surfaces of uppers upper connectors of an assembly formed by a plurality of said similar modules;

at least one supporting rod directly connected to and supporting said upper connector and extending downwardly therefrom through said space, said supporting rod having at a lower end thereof means for releasable connection to the base plate of the testing apparatus;

electronic components confined within said space and connected to said contacts of said upper connector; and

lower connector means, located within said space and connected to said electronic components, for electrically connecting said electronic components to the controlling computer logic of the testing apparatus.

15. A module as claimed in claim 14, further comprising a multi-layer circuit board within said space and secured to said supporting rod said and electronic components of the testing apparatus being disposed on said circuit board.

16. A module as claimed in claim 14, wherein said upper connector comprises a plug-in connector having an outer configuration defining said contour.

17. A module as claimed in claim 16, further comprising a plurality of contact pins to be acted on by the comprising contact members of the testing apparatus and extending into said plug-in connector to contact said contacts thereof.

18. A module as claimed in claim 14, wherein said lower end of said supporting rod is of reduced size to be fitted into a complementary shaped opening in the base plate of the testing apparatus.

19. A module as claimed in claim 14, comprising two said supporting rods extending from said upper connector.

20. A module as claimed in claim 14, wherein said lower connector means comprises a plug-in connector.