EP0224756A1

EP0224756A1 - A circuit board assembly

Info

Publication number: EP0224756A1
Application number: EP86115522A
Authority: EP
Inventors: Robert Kenneth Chapman; Paul Douglas Niles
Original assignee: Allied Corp
Current assignee: Allied Corp
Priority date: 1985-12-05
Filing date: 1986-11-08
Publication date: 1987-06-10
Also published as: IL80829A0; JPS62139279A

Abstract

A circuit board assembly includes an interlocked and removably mounted pair of connector parts (31,32) with one or the other of the connector parts having a like end portion receiving a circuit board (20) and its respective contacts electrically soldered to selective circuit elements thereon, the connector parts combining to form a connector housing (30) that is matable with a compatible connector housing (14) mounted on a mother board.

Description

This invention relates to electrical connections between circuit boards.
Electrical interconnections between circuit boards include a mother board, one or more daughter boards, and a multi-contact connector housing for electrically and mechanically connecting the circuit boards. In many applications the daughter boards are perpendicular to the mother board thus requiring special consideration as to the configuration of both the connector housing and the contacts. U.S. Patent 4,494,818 issued January 22, 1985 to Petersen et al, for "Mounting Member for Electrical Contacts" disposed a plurality of "brush-type" contacts in a connector housing which was mounted to the mother board and required the rearward end portion from each contact to be bent 90⁰ to terminate in plated through holes of the daughter board. While this arrangement provides a solution to the problem of rapidly positioning contact end portions whereby to interconnect selected circuit paths, the contact ends must be of different legth, the connector housing is quite wide in order to accomodate the pin bending thereby consuming valuable space on the mother board, and the connector housing arrangement and the progressively higher disposition of contact ends from the mother board necessarily elevates the daughter board from the mother board and consumes valuable apace on the mother board.
Modern electronic packaging increasingly demands dense packing of circuit boards without compromising heat dissipation, removability of daughter boards either for circuit inspection or exchange with circuit elements on another board, and maximization of board space for desired circuit elements while diminishing the space required by the overall circuit board arrangement.
This invention facilitates an electrical connection between circuit boards mounted perpendicularly to each other. The connection includes a pair of matable dielectric connector housings with one connector housing being disposed on a mother board and the other connector housing being connectable electrically and mechanically with a daughter board. The invention is characterized by the other connector housing including an interlocked and removably mounted pair of connector parts with one and the other of the connector parts having a like rearward end portion each receiving a daughter board and a like forward end portion each cooperating to define a housing portion for mating with the one connector housing. Each of the connector housings carry removable brush-type contacts with the rearward end portions of the respective contacts in each connector housing being substantially the same length, the end portions from the contacts in the connector parts converging to termini which are solderable to conductive circuit pads disposed along the marginal edge of the daughter board associated therewith.
A particular example of the invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 illustrates a mounting relation between a mother board and several daughter boards.
FIGURE 2 illustrates a partial section view of the mother board and a connector housing mounted thereon .
FIGURE 3 shows partial detail of contact retention in the connector housing shown in FIGURE 2.
FIGURES 4 and 5 illustrate interlocking removability of a mating connector housing with their daughter boards as shown in FIGURE 1.
FIGURE 6 is an enlarged view end section of the connector housings shown in FIGURE 5 when interlocked.
FIGURES 7-9 illustrate a connector housing having multiple rows of contacts and engagement of respective contact end portions with associated circuit paths on a daughter board.

Referring now to the drawings, FIGURE 1 illustrates a mother board 10 having on a planar top surface 11 thereof an array of circuit elements (not shown), a pair of first connector housings 14, and a pair of second connector housings 30 each carrying a pair of planar daughter boards 20, each daughter board having on respective of its flat top and bottom surfaces 22, 24 an array of circuit elements 25 and conductive circuit paths (see FIG. 9). Each of the boards 10,20 are typically rectangular in shape and the daughter boards dispose termini of its circuit paths laterally along one marginal edge of the board in a side-by-side relation. The daughter boards 20 mount perpendicularly to the mother board 10 and are laterally separated by an air gap 26 whereby to allow heat dissipation.
FIGURE 2 shows connector housing 14 as being a one-piece dielectric body having an array of passages 16 extending between top and bottom faces thereof. Each passage includes medially of the faces an angled retention step 18 and each opens on the bottom face to define a pair of arcuate openings 17.
A brush-type contact 40 is disposed in each passage 16, including a holder 41, a bundle of conductive wires 43 carried by the holder, and a rearward end portion 45. The contact is generally shown in U.S.Patent 3,725,844 "Hermaphroditic Electrical Contact" issuing April 3, 1973 to McKeown. In addition, a tubular sleeve 42 is interference fit about the holder 41 and includes a medial circumferencial ridge 44 and a pair of resilient tangs 46, the tangs and ridge cooperating to engage the interior wall of the passage whereby to interference fit the contact therewithin and the tangs being adapted to engage the retention steps to prevent unwanted forward movement and withdrawal of the contact from the passage. As shown, the rearward end portion of the contact could be soldered to plated through holes 12 in the mother board or be provided with a compliant portion.
FIGURE 3 shows detail of a resilient tang 46 engaged in the interior wall 19 of the passage 16.
FIGURE 4 shows the dielectric second connector housing 30 as comprising interlockingly separable first and second housing members 31, 32, each including a plurality of through passages and each being adapted to removably interlock together to form a connector housing for mating with a recess 15 in the first connector housing 14. Each housing number includes a planar sidewall 33, 35 with each sidewall being confrontable and including an interlockable dovetail arrangement wherein the housing members may be interlocked or separated by relative transverse movement. As shown, housing member 33 includes a dovetail keyway 35 for receiving a dovetail key 36 disposed on housing member 32, and each includes flanges 37, 38 which are brought into register when the two housing numbers are assembled, the flanges including apertures sized to receive a bolt for securing the assembly together, the apertures registering with an opening in the daughter board (e.g., see FIGURE 7) whereby the assembly is locked together. The rearward end of each housing member 31, 32 includes a respective slot portion 31a or 32a each sized to receive a marginal edge of the daughter board inserted therewithin.
FIGURE 5 shows housing members 31, 33 about to be interlocked with each housing member receiving a daughter board 20 within its slot. Each connector member includes a plurality of brush contacts 50 which have a rearward end portion 55 which is soldered to the marginal edge of the respective daughter board.
FIGURE 6 shows a view of the assembled connector members 31, 32 whereby to form the second connector housing 30. Forward end portions of each connector member cooperate to define a housing portion adapter to be received in the recess 15 whereby to mate with the first connector. Each contact 50 includes a holder 51, a sleeve 52, a plurality of mating wires 53 disposed in the sleeve, and the rearward portion 55, each rearward end portion being disposed in side-by-side relation and converging to a terminus which is soldered to a respective circuit path along the margin of the board.
FIGURE 7 shows an embodiment wherein an array of 3 linear rows of contacts have their rearward end portions converging towards solder paths on a daughter board 20 with the rearward end portions being substantially the same length but laterally interdigitated whereby to increase the number of surface mount positions along the current board marginal edge.
FIGURE 8 shows a side view of the rearward end portions of the contacts engaging the daughter board 20.
FIGURE 9 shows the top view of the daughter board and the solder paths disposed on the marginal edge thereof.

Claims

1. A circuit board assembly comprising a first circuit board having on a planar top surface thereof an array of first circuit elements, a pair of planar second circuit boards each having on its respective flat faces an array of second circuit elements and supported on said top surface, support means including a dielectric first housing for supporting the second circuit boards on said first circuit board whereby the plane of each is perpendicular to the plane of the first circuit board, and means including mating sets of conductive contacts for electrically interconnecting selected circuit elements disposed on the circuit boards with a plurality of first contacts being disposed in said first housing each having a rearward end portion for completing an electrical circuit path with a selected first circuit element and a mating forward end portion for mating with another contact, characterized in that:

said support means includes a dielectric second housing comprising interlockingly separable first and second housing members one and the other said housing member being mechanically connected to one respective said second circuit board and forward portions of each housing member when interlocked cooperating to define a housing portion which will mate with the first housing, each said housing member including a planar sidewall and an array of second contacts with each said sidewall being confrontable and including an interlockable dovetail arrangement wherein the housing members are interlocked or separated by relative movement in a direction towards or away from the first circuit board when the dielectric housings are mated, and each said second contact has a rearward portion completing an electrical circuit path with a selected second circuit element and a forward end portion for mating with a respective one of said first contacts.

2. The circuit board assembly as recited in Claim ₁ wherein each said first and second housing member includes a rearward flange and securing means engaging the respective second circuit board for securing said housing members to the circuit board.

3. The circuit board assembly as recited in Claim 1 wherein each said housing member includes at least two planar rows of through passages with the passages in each row being disposed in a side-by-side relation and the rearward end portion of each said contact from one and the other row, respectively, converging to its terminus, each said contact terminus being solderable to a circuit element on one or the other side of its second circuit board.

4. The circuit board assembly as recited in Claim 1 wherein each said housing member includes a first and second array of contact receiving passages with each said array comprising a pair of rows each said row being disposed in a plane parallel one to the other and disposing its respective passages in a side-by-side relation, the rearward end portion of each said second contact from one and the other pair of passage arrays, respectively, converging to its terminus, each said terminus from one and the other said array of passage rows being laterally interdigitated and solderable to a circuit element on one or the other side of its respective second circuit board.

5. The circuit board assembly as recited in-Claim 4 wherein each of the second contacts are interconnected by a frangibly connected carrier strip with the carrier strips from the first and second row of each array of contact pairs being secured prior to soldering each respective terminus to its associated circuit element.

6. A multi-contact electrical connection comprising a first circuit board electrically and mechanically connected to a pair of second circuit boards by a dielectric connector housing carrying conductive contacts each electrically interconnected to electrical circuit elements on the respective circuit boards, said connection disposing said second circuit boards in parallel spaced-apart relation and perpendicularly to said first circuit board, said housing including an interlocked and removably mounted pair of connector parts with one and the other said connector part having a like end portion receiving one said second circuit board and its respective contacts electrically soldered to selective circuit elements thereon.