Method for making printed circuit boards

• US 5,390,412 A
• Filed: 04/08/1993
• Issued: 02/21/1995
• Est. Priority Date: 04/08/1993
• Status: Expired due to Term

• Current Assignee: George D. Gregoire
• Original Assignee: George D. Gregoire
• Inventors: Gregoire, George D.
• Primary Examiner(s): ECHOLS, PERCY W
• Application Number:
  US08/045,366
• Time in Patent Office: 684 Days
• Field of Search: 29/848, 29/849, 29/852, 29/853, 174/250
• US Class Current: 29/848
• CPC Class Codes: B29C 33/3878 used as masters for making successive impressions
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29C 33/56 Coatings , e.g. enameled or galvanised; Releasing, lubricating or separating agents in-mould coating B29C37/0028; using or applying separating agents B29C37/0067
• CPC Class Codes: B29L 2031/3425 Printed circuits
• CPC Class Codes: B44C 1/22 Removing surface-material, e.g. by engraving, by etching for multi-layer articles B44C3/005
• CPC Class Codes: H01K 3/22 Exhausting, degassing, filling, or cleaning vessels
• CPC Class Codes: H05K 1/02 Details
• CPC Class Codes: H05K 1/0284 Details of three-dimensional rigid printed circuit boards H05K1/119 takes precedence; shaping of the substrate H05K3/0014
• CPC Class Codes: H05K 1/111 Pads for surface mounting, e.g. lay-out
• CPC Class Codes: H05K 2201/09018 Rigid curved substrate
• CPC Class Codes: H05K 2201/09036 Recesses or grooves in insulating substrate recess in metallic substrate H05K2201/09745
• CPC Class Codes: H05K 2201/09118 Moulded substrate
• CPC Class Codes: H05K 2201/09581 Applying an insulating coating on the walls of holes
• CPC Class Codes: H05K 2201/09827 Tapered, e.g. tapered hole, via or groove bevelled, chamferred or tapered edge H05K2201/09154
• CPC Class Codes: H05K 2201/09863 Concave hole or via
• CPC Class Codes: H05K 2201/09981 Metallised walls
• CPC Class Codes: H05K 2203/0108 Male die used for patterning, punching or transferring
• CPC Class Codes: H05K 2203/0113 Female die used for patterning or transferring, e.g. temporary substrate having recessed pattern
• CPC Class Codes: H05K 2203/0315 Oxidising metal
• CPC Class Codes: H05K 3/0014 Shaping of the substrate, e.g. by moulding
• CPC Class Codes: H05K 3/025 : by transfer of thin metal foil formed on a temporary carrier, e.g. peel-apart copper
• CPC Class Codes: H05K 3/061 : Etching masks
• CPC Class Codes: H05K 3/107 : by filling grooves in the support with conductive material H05K3/045, H05K3/101, H05K3/1258 and H05K3/465 take precedence
• CPC Class Codes: H05K 3/205 : using a pattern electroplated or electroformed on a metallic carrier
• CPC Class Codes: H05K 3/384 : by plating
• CPC Class Codes: H05K 3/385 : by conversion of the surface of the metal, e.g. by oxidation, whether or not followed by reaction or removal of the converted layer
• 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 29/49158 : with molding of insulated base
• CPC Class Codes: Y10T 29/49165 : by forming conductive walled aperture in base
• CPC Class Codes: Y10T 428/24479 : including variation in thickness
• CPC Class Codes: Y10T 428/24537 : Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/2457 : Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/24917 : including metal layer

Abstract

A new and improved printed circuit board tool and method of making and using it, to produce three dimensional printed circuit boards having grooves with strongly bonded or laminated metallic pads therein. The printed circuit board tool includes a metallized male mold substrate having a plurality of groove forming projections disposed in the substrate surface. The method of making the metallized mold includes forming a female parent or predecessor master tool that may be used to produce a large number of the metallized male molds for producing new and improved three-dimensional printed circuit boards. The new and improved three-dimensional printed circuit board includes a substrate composed of a high heat deflective plastic, and a plurality of recesses or grooves molded into the substrate surface for receiving therein the fine pitch, closely spaced-apart leads of an integrated circuit. A plurality of metallized sunken pads or lands are adhered or bonded within the grooves for establishing an electrical path within each groove.

Claims

1. A method of making a three dimensional printed circuit board, comprising:

forming a three dimensional female predecessor tool;

forming a three dimensional male mold tool using said three dimensional female predecessor tool;

coating said three dimensional male mold tool with a thin layer of a highly adhesive material;

pressing said three dimensional male mold tool into a deformable plastic material to deform the plastic material into a metallized substrate having a surface with a plurality of metallized grooves disposed therein;

admitting to said plurality of metallized grooves an etch resistant material; and

etching a desired electrical circuit pattern in the surface of said metallic material.

2. A method of making a three dimensional printed circuit board according to claim 1, wherein said step of forming a female tool comprises:

using a photo tool having emulsion areas thereon corresponding to a desired electrical circuit pattern;

dimensioning a copper plate to conform to the planar surface area of said photo tool;

coating at least one surface of said copper plate with a light sensitive material;

placing said photo tool on the coated surface of said copper plate;

exposing said photo tool disposed on said copper plate to high intensity light to form a desired pattern in said light sensitive material; and

etching said desired pattern in the surface of said copper plate to form said three dimensional predecessor tool.

3. A method of making a three dimensional printed circuit board according to claim 2, wherein said step of forming a male mold tool comprises:

coating said female predecessor master tool with a weak adhesion material;

depositing a thin layer of metallic material on the coated female processor master tool; and

separating said thin layer of metallic material from said female predecessor master tool to form the three dimensional male mold tool.

4. A method of making a three dimensional printed circuit board according to claim 1, wherein said step of forming a male mold tool comprises:

coating said female predecessor master tool with a weak adhesion material;

depositing a thin layer of metallic material on the coated female processor master tool; and

separating said thin layer of metallic material from said female predecessor master tool to form the three dimensional male mold tool.

5. A method of making a three dimensional printed circuit board according to claim 4, wherein said step of coating includes electroplating said weak adhesion material from an electrolytic solution of water and copper sulfate.

6. A method of making a three dimensional printed circuit board according to claim 4, wherein said low adhesion material is a graphite material.

7. A method of making a three dimensional printed circuit board according to claim 1, wherein said step of admitting includes:

removing selectively a sufficient quantity of said etch resistant material from individual ones of the metallized groove to expose the metallic surface in a top portion thereof.

8. A method of making a three dimensional printed circuit board according to claim 7, wherein the step of etching a pattern in said metallic material includes:

removing the exposed metallic surface from the top portion of the selected individual ones of the metallized grooves to form spaces between the top surface of the resulting printed circuit board and the top portions of the metallized grooves to help define solder dams within said grooves.

9. A method of making a three dimensional printed circuit board according to claim 1, wherein said step of pressing includes:

coating said three dimensional male mold tool with a strong adhesive material having substantial adhesive strength to the circuit board.

10. A method of making a three dimensional printed circuit board according to claim 9, wherein said strong adhesive material is an adhesion promoter.

11. A method of making a three dimensional printed circuit board according to claim 9, wherein said step of pressing includes:

heating said plastic material to a sufficient temperature to enable the material to deform under pressure;

stamping said plastic material with said male mold tool;

whereby a substrate blank is formed having a plurality of metallized grooves disposed within the surface thereof.

12. A method of making a three dimensional printed circuit board according to claim 11, further comprising:

electroplating the surface of said male tool with a metallic material.

13. A method of making a three dimensional printed circuit board according to claim 12, wherein said plastic material is a thermoplastic material.

14. A method according to claim 13, wherein said thermoplastic material is a palatable thermoplastic material selected from the group of polyethersulphone, polyetherimide, PBT, or PEEK.

15. A method according to claim 12, wherein said plastic material is a thermoset plastic, such as epoxy thermoset polyetherimides, or polyester based composites of the above-mentioned materials.

16. A method of making a three dimensional printed circuit board, comprising:

making a printed circuit board blank according to the method of claim 4; and

etching a desired electrical circuit pattern in the surface of said metallic material.

17. A method according to claim 1, further comprising:

electroplating the surface of said substrate with a metallic material.

18. A method of making a three dimensional printed circuit board blank:

forming a three dimensional female predecessor tool;

forming a three dimensional male mold tool using said three dimensional female predecessor tool;

electroplating the surface of said male tool with a metallic material;

coating said three dimensional male mold tool with a thin layer of an adhesion-promoting material;

pressing said three dimensional male mold tool into a deformable plastic material to deform the plastic material into a substrate having a surface with a plurality of metallized grooves disposed therein;

admitting to said plurality of metallized grooves an etch resistant material; and

etching and removing unwanted conductive material from the substrate for removal purposes.