Structure of joining printed circuit boards and process for producing the same

• US 4,950,527 A
• Filed: 12/05/1988
• Issued: 08/21/1990
• Est. Priority Date: 03/29/1985
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamada, Akira
• Primary Examiner(s): Ryan, Patrick
• Application Number:
  US07/282,949
• Time in Patent Office: 624 Days
• Field of Search: 228/254, 228/180.2, 428/209, 428/192, 428/901, 174/68.5, 361/397, 361/398, 361/414
• US Class Current: 428/192
• CPC Class Codes: H05K 1/0201 Thermal arrangements, e.g. for cooling, heating or preventing overheating
• CPC Class Codes: H05K 1/0206 by printed thermal vias
• CPC Class Codes: H05K 1/0212 Printed circuits or mounted components having integral heating means
• CPC Class Codes: H05K 2201/062 Means for thermal insulation, e.g. for protection of parts
• CPC Class Codes: H05K 2201/09172 Notches between edge pads
• CPC Class Codes: H05K 2201/09727 Varying width along a single conductor; Conductors or pads having different widths
• CPC Class Codes: H05K 2201/09781 Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
• CPC Class Codes: H05K 2201/10477 Inverted
• CPC Class Codes: H05K 2203/0195 Tool for a process not provided for in H05K3/00, e.g. tool for handling objects using suction, for deforming objects, for applying local pressure
• CPC Class Codes: H05K 2203/0415 Small preforms other than balls, e.g. discs, cylinders or pillars
• CPC Class Codes: H05K 3/363 by soldering
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 428/24917 including metal layer

Abstract

A structure of joining two printed circuit boards with solder. A reserve solder layer is applied on a pattern of joint leads of the printed circuit on a base plate of the first board. A similar pattern of high thermal conductivity to the pattern of joint leads of the second printed circuit board is formed on the opposite or back surface of the base plate thereof in almost or exact coincidence with the latter. To join the first and second boards, the latter is turned upside down and then its joint lead pattern is put on the solder layer in registry with that of the first board. And it is at a point on each patch of the thermal conductivity pattern that heat is then applied thereto to obtain the structure between the joint leads of the two printed circuit boards.

Claims

1. A printed circuit board for use in joining a plurality of printed circuit boards at joint pattern portions, thereof comprising,

a plurality of joint patterns on a base plate cut to a comb teeth like shape so that a joint end portion of said joint pattern takes the form of extensions of said joint pattern;

and

base portions of said comb teeth shaped extensions being formed to a pattern of narrower width than said joint pattern.

3. A printed circuit board according to claim 1, wherein said plurality of joint patterns of a first circuit board are joined to a plurality of joint patterns of another printed circuit board with a thermal welding electrically conductive material.

4. A printed circuit board according to claim 3, wherein the joint patterns of said another printed circuit board are wider than the width of said comb teeth-shaped extensions of said joint pattern of said first circuit board.

2. A printed circuit board for use in joining a plurality of printed circuit boards at joint pattern portions thereof, comprising,

a plurality of joint patterns on a base plate cut at a joint end portion of said joint pattern in such a way that said joint pattern extends like comb teeth;

and

cutouts termed in the base portions of said comb teeth shaped expansions of said joint pattern in a direction to cut in said joint pattern, the base portions of the comb teeth shaped extensions being cutout to have a width narrower than that of the joint pattern.

5. A printed circuit board according to claim 2, wherein said joint patterns of a first circuit board are joined to a plurality of joint patterns of another printed circuit board with a thermal welding electrically conductive material.

6. A printed circuit board according to claim 5, wherein the joint patterns of said another printed circuit board have a wider width than the width of said comb teeth-shaped extensions of said joint pattern of said first printed circuit board.