Process for producing printed wiring board

• US 4,790,894 A
• Filed: 05/06/1987
• Issued: 12/13/1988
• Est. Priority Date: 03/12/1987
• Status: Expired due to Fees

• Current Assignee: Howmet Research Corporation
• Original Assignee: Hitachi Condenser Company Limited
• Inventors: Yamauchi, Hitoshi, Homma, Masaji
• Primary Examiner(s): Kittle, John E.
• Assistant Examiner(s): RYAN, PATRICK J
• Application Number:
  US07/046,515
• Time in Patent Office: 587 Days
• Field of Search: 156/250, 228/180.2, 29/423, 29/424, 428/209, 428/131, 428/137, 428/192, 428/901
• US Class Current: 156/250
• CPC Class Codes: H01L 23/145 Organic substrates, e.g. plastic
• CPC Class Codes: H01L 23/49805 the leads being also applied on the sidewalls or the bottom of the substrate, e.g. leadless packages for surface mounting
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/10727 Leadless chip carrier [LCC], e.g. chip-modules for cards
• CPC Class Codes: H05K 2201/10984 Component carrying a connection agent, e.g. solder, adhesive soldering leadless components having an array of bottom contacts H05K3/3436; BGA components H05K2201/10734
• CPC Class Codes: H05K 2203/045 Solder-filled plated through-hole [PTH] during processing wherein the solder is removed from the PTH after processing
• CPC Class Codes: H05K 3/0052 Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: H05K 3/3442 having edge contacts, e.g. leadless chip capacitors, chip carriers
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence
• CPC Class Codes: H05K 3/42 Plated through-holes or plated via connections
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 29/4981 Utilizing transitory attached element or associated separate material
• CPC Class Codes: Y10T 29/49812 Temporary protective coating, impregnation, or cast layer

Abstract

A base board having a plurality of semicircular through-holes filled with solder at side walls produced by filling through-holes with solder can be connected electrically to printed circuit boards with large connecting strength and high reliability.

Claims

1. A process for producing base boards for printed wiring boards which comprises:

forming through-holes in predetermined portions of a base sheet,

filling solder in the through-holes, and

cutting the base sheet to provide a plurality of adjacent base boards having semicircular through-holes filled with solder at side walls extending along adjacent base boards.

2. A process according to claim 1, wherein the cutting is conducted along a center line of a linear arrow of circular through-holes.

3. A process according to claim 1, wherein the through-holes are formed by at least two parallel rows of circular through-holes with a pitch between the centers of a pair of through-holes in adjacent rows being equal to that of the blade thickness of a cutter, and the cutting is conducted along the width of the pitch.

4. A process according to claim 1, wherein the base sheet is made from glass reinforced epoxy resin.

5. A process according to claim 1, wherein the base sheet is made from a glass reinforced thermoplastic resin or a glass reinforced thermoplastic resin.

6. A process according to claim 5, wherein the thermoplastic resin is a phenol resin, an epoxy resin a polybutadiene resin or a polyimide resin.

7. A process according to claim 5, wherein the thermoplastic resin is a polyester resin, a polysulfone resin, or a polyphenylene oxide resin.

8. A process according to claim 5, wherein the base sheet is made from a glass reinforced resin material