Patent Application
20080080152
Referring now to the drawings, and more particularly to
First edge connector 14 and second edge connector 18 together define a card edge connector 24 (
A soldered edge connector as described above provides a strong electrical joint that inhibits float between first PCB 12 and second PCB 16. The four (or quadruple) solder joints defined at the inside corners of each finger 30 and second PCB 16 substantially eliminate possible breakage that could occur with weaker joints, and also provide improved heat transfer from first PCB 12 to second PCB 16, or vice versa depending upon the heat generated by the respective electrical components.
With a soldered edge connector 24 as described above, a solder joint is formed at each finger 30 which interconnects a pair of first conductor pads 32 with four second conductor pads 28. However, it may also be possible to form a solder connection at each finger 30 with a different number of metallurgically bonded conductor pads 28 and 32. For example, it may be possible to solder together a pair of conductor pads 28 on a same side of an opening 26 with a single conductor pad 32 on the adjacent side of first PCB 12. Further, it may be possible to solder together a pair of conductor pads 28 on opposite sides of an opening 26 (but same side of second PCB 18) with a pair of conductor pads 32 on opposite sides of first PCB 12.
Referring now to
Flat base 36 abuts second PCB 16 and provides a wide, stable base to prevent tipping of first PCB 12 relative to second PCB 16. Wings 38 are positioned on laterally opposite sides of base 36. The distal end of each wing 38 includes a snap-in feature 44 which snap engages with a corresponding hole 46 formed in second PCB 16. In the embodiment shown, each snap-in feature 44 is in the form of a harpoon snap feature and each hole 46 is configured as a substantially round hole; however, snap-in feature 44 and hole 46 can be differently configured depending upon the application.
In the embodiment shown, each wing 38 is a generally L-shaped wing including a leg 48, and a stiffening flange 50 extending between leg 48 and snap-in feature 44. Coupling the distal ends of wings 38 with second PCB 16 outside the outboard ends of wide, flat base 36 provides a stable mounting between first PCB 12 and second PCB 16 with a perpendicularity of between +/−2 degrees, preferably with a perpendicularity of between +/−1 degree.
Each circuit board carrier 20 includes a pair of slot guides 40, with each slot guide 40 including a pair of projections 52 spaced apart to receive without substantial clearance a lateral side edge of first PCB 12 therebetween. Of course, it will be appreciated that circuit board carrier 20 can be configured with a single slot guide 40 or more than two slot guides 40, depending upon the application.
Retainer 42 is positioned at and end of circuit board carrier 20 generally opposite from wide, flat base 36. Retainer 42 functions to retain a distal edge 54 of first PCB 12 (opposite first edge connector 14) and prevent float of first PCB 12 in directions toward and away from second PCB 16. In the embodiment shown, retainer 42 is in the form of a retainer lip which lies over and retains a notch 56 at distal edge 54 of first PCB 12. The retainer lip may be a segmented retainer lip, such as shown in the drawings, which can deflect slightly to apply a biasing force against distal edge 54, depending upon the length of and corresponding clearance with first PCB 12.
With a conventional circuit board guide as described above, the guide is installed into the motherboard and the daughterboard is slid into the guide until the edge connectors of the daughterboard and motherboard are mated together. With the circuit board carrier 20 of the present invention, fingers 30 of first edge connector 14 of first PCB 12 are inserted into openings 26 of second edge connector 18 of second PCB 16. A circuit board carrier 20 is then positioned such that slot guides 40 receive a lateral side edge of first PCB 12 therebetween and snap-in features 44 lie adjacent a respective hole 46. Circuit board carrier 20 is then pushed so that the lip on the harpoon snap feature 44 snaps into the back side of hole 46. At the same time the harpoon snap feature 44 locks into place within hole 46, retainer lip 42 seats against or closely adjacent to distal edge 54 of first PCB 12. Circuit board carriers 20 are made from a heat resistant material, such as glass-filled nylon, so that conductor pads 28 and 32 can be soldered together using a wave soldering process as described above.
Using a soldered edged connector between first PCB 12 and second PCB 16, it will be appreciated that it is not intended to remove first PCB 12 from second PCB 16 after the wave soldering operation.
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
