GB2212332A - Fabrication of electrical circuits - Google Patents

Fabrication of electrical circuits Download PDF

Info

Publication number
GB2212332A
GB2212332A GB8726401A GB8726401A GB2212332A GB 2212332 A GB2212332 A GB 2212332A GB 8726401 A GB8726401 A GB 8726401A GB 8726401 A GB8726401 A GB 8726401A GB 2212332 A GB2212332 A GB 2212332A
Authority
GB
United Kingdom
Prior art keywords
substrate
pattern
conductive material
electrically conductive
indented
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8726401A
Other versions
GB8726401D0 (en
Inventor
Robert Mark Quilliam
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co PLC
Original Assignee
General Electric Co PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co PLC filed Critical General Electric Co PLC
Priority to GB8726401A priority Critical patent/GB2212332A/en
Publication of GB8726401D0 publication Critical patent/GB8726401D0/en
Publication of GB2212332A publication Critical patent/GB2212332A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
    • H05K3/101—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern by casting or moulding of conductive material
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
    • H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
    • H05K3/1258—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by using a substrate provided with a shape pattern, e.g. grooves, banks, resist pattern
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/09—Use of materials for the conductive, e.g. metallic pattern
    • H05K1/092—Dispersed materials, e.g. conductive pastes or inks
    • H05K1/095—Dispersed materials, e.g. conductive pastes or inks for polymer thick films, i.e. having a permanent organic polymeric binder
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09009—Substrate related
    • H05K2201/09036—Recesses or grooves in insulating substrate
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09009—Substrate related
    • H05K2201/09118—Moulded substrate
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/01—Tools for processing; Objects used during processing
    • H05K2203/0104—Tools for processing; Objects used during processing for patterning or coating
    • H05K2203/0108—Male die used for patterning, punching or transferring
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
    • H05K3/107—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern by filling grooves in the support with conductive material

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing Of Printed Wiring (AREA)
  • Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)

Abstract

Electrical circuits are fabricated on a substrate by causing an indented pattern to be impressed on the substrate 1 and then scraping conductive material 6 into the pattern 4. The indented pattern is preferably formed by moulding techniques. <IMAGE>

Description

FABRICATION OF ELECTRICAL CIRCUITS This invention relates to the fabrication of electrical circuits and is particularly, but not exclusively, concerned with the production of electronic circuitry on moulded substrates.
A number of techniques are known for manufacturing electronic circuitry on such things as printed circuit boards, flexible circuits, electronic packages and hybrid circuits.
Circuitry on a printed circuit board is formed by depositing a layer of conductive material, which typically is copper, onto an electrically insulating board.
Conductor patterns are photolithographically defined on the surface of the metal and then etched to give the desired pattern. Through-board connections are provided by drilling vias through the board and plating their surfaces with copper by electroless deposition followed by electro-plating.
In another method for producing electronic circuits on a substrate, areas of a moulded circuit board are selectively sensitised using a photo-sensitive material and copper deposited on those areas. In an alternative technique, the whole of the substrate surface is plated with a thin electroless copper. This is followed by standard photolithography, pattern plating of conductive tracks and final etch-back of unwanted thin copper between tracks to produce the finished pattern.
Although these known techniques produce satisfactory electrical circuits, they tend to be complicated, requiring a relatively large number of manufacturing steps, and are therefore expensive and slow to carry out.
The present invention seeks to provide an improved method for fabricating electrical circuits and to provide better circuits than have previously been available.
According to a first aspect of the invention a method for fabricating an electrical circuit comprises the steps of: forming an indented pattern in a surface of a substrate of electrically insulating material; and filling the indented pattern with electrically conductive material. The indented pattern may be completely or only partly filled. Such a method in accordance with the invention may be easily carried out and enables electrical circuits to be made quickly and relatively inexpensively in a small number of manufacturing steps. The substrate may be rigid or flexible, depending on the application for which the circuit is intended.
Preferably the indented pattern is formed by moulding, which is a particularly advantageous technique as it enables the whole pattern to be formed in one operation. When moulding is used to form the indented pattern, in one advantageous method, a tool is pressed into the surface of the substrate when the electrically insulating material is in a deformable state to form the pattern. In an alternative method, the electrically insulating material in a deformable state is injected into a mould, the interior surface of which defines the pattern.
Preferably, the electrically insulating material is a thermoplastic and is brought to a deformable state by heating it. Once the pattern has been formed, the substrate may then be cooled, to cause it to harden. The thermoplastic material may be one of the high temperature thermoplastics such as poly ether sulphone, poly ether imide, poly phenylene sulphide or poly ether ether ketone.
It is preferred that the electrically insulating material includes long fibre reinforcing although short fibre reinforcement could be used and also it is preferred that the fibres are glass.
Advantageously, the pattern includes an aperture which is extensive from one surface of the substrate to another, thus enabling electrical connection to be made through the substrate by filling the aperture with electrically conductive material.
It is preferred that the electrically conductive material is pushed into the indented pattern to fill it.
It is further preferred that the electrically conductive material is initially laid on the surface of the substrate and then scraped along it into the indented pattern.
Advantageously, it may be arranged that when the electrically conductive material is scraped along the surface, substantially none is left on the surface of the substrate except within the indented pattern. This method may be termed a "doctor blade" technique, a blade being used to scrape across the surface of the board, forcing electrically conductive material into each cavity of the pattern. In an alternative method, material may be introduced by an injection process to fill the cavities of the pattern. This is advantageous where the indented pattern is formed by injection moulding, one part of the mould being changed or replaced.
Preferably, the electrically conductive material is initially a deformable paste, and it is preferred that the paste is cured to harden it after it has filled the indented pattern.
According to a feature of the invention, a substrate bearing an electrical circuit is fabricated by a method in accordance with the invention.
According to a second aspect of the invention, a device comprises an electrically insulating substrate bearing a pattern of electrically conductive material located in indentations in the substrate. This is particularly advantageous as the conductive pattern is surrounded and supported by the edges of the substrate defining the indented pattern. Advantageously, the pattern includes an aperture which is extensive from one surface of the substrate to another.
A plurality of substrates may be stacked together to form a multi-layer structure.
Some ways in which the invention may be performed are now described by way of example with reference to the accompanying drawings, in which: Figures 1 to 4 schematically illustrate a method in accordance with the invention; and Figure 5 to 8 illustrate another method in accordance with the invention.
With reference to Figures 1 to 4 in a method for fabricating an electrical circuit, initially an electrically insulating substrate 1 of thermoplastic is heated so that it becomes deformable. In this case the thermoplastic is poly ether sulphone which is reinforced with long glass fibres. A metal tool 2 which is a flat plate having raised portions 3 on its surface, is then pushed into the substrate 1 so that the raised portions 3 form corresponding indentations in the surface of the substrate 1. The tool 2 is then withdrawn, leaving an impression on the substrate surface, as illustrated in Figure 2. The resulting indented pattern 4 includes a via 5 which extends from one surface of the substrate 1 to another. The thermoplastic substrate 1 is then cooled to harden it.
Electrically conductive paste 6 is placed on the surface of the substrate 1. A blade 7 is applied to the paste 6 and is drawn across the surface of the substrate 1 in the direction indicated by the arrow. As the blade 7 moves across the surface, it pushes the paste before it into the indented pattern 4 in the substrate surface, as illustrated in Figure 3. The blade 7 is moved close to the substrate surface such that, when it has completed its movement across it, no paste remains on the surface and the indented pattern 4, including the via 5, is filled.
The substrate 1 bearing the filled pattern 4 is then heated to a sufficiently high temperature to cause the conductive paste 6 to harden to form conductive tracks 8.
The process is then complete.
In another method described with reference to Figures 5 to 8, the substrate is formed by injection moulding.
Electrically insulating material is heated so that it becomes deformable and is injected into a cavity 9 of a mould formed by an upper mould 10 and lower mould 11. The electrically insulating material 12 conforms to the interior surface of the mould and is allowed to harden once it has filled the cavity 9.
The moulded substrate may then be removed, and electrically conductive material pushed into the indented pattern in the manner previously described with reference to Figures 1 to 4. However, in a preferred alternative step, the electrically conductive material is pushed into the indented pattern by a secondary injection moulding technique. The upper mould 10 is removed and replaced by another upper mould 13. Conductive paste 14 is injected into the mould and fills the indentations in the moulded substrate 12.
The substrate 12 is then removed from the mould, and is shown in plan view in Figure 7. The conductor pattern includes a via 15 which extends from one face to the other of the substrate 12 and includes sprues 16 which are then removed.
The finished circuit 17 is then stacked with other substrates 18 bearing conductive material and held in a jig 19. The temperature is increased so that the insulating material becomes soft and the substrates fuse into a single, multi-layer structure.

Claims (22)

1. A method for fabricating an electrical circuit comprising the steps of: forming an indented pattern in a surface of a substrate of electrically insulating material; and filling the indented pattern with electrically conductive material.
2. A method as claimed in claim 1 wherein the indented pattern is formed by moulding.
3. A method as claimed in claim 2 wherein a tool is pressed into the surface of the substrate when the electrically insulating material is in a deformable state to form the pattern.
4. A method as claimed in claim 2 wherein the electrically insulating material in a deformable state is injected into a mould, the interior surface of which defines the pattern.
5. A method as claimed in claim 3 or 4 wherein the electrically insulating material is a thermoplastic and is brought to a deformable state by heating it.
6. A method as claimed in any preceding claim wherein the pattern includes an aperture which is extensive from one surface of the substrate to another.
7. A method as claimed in any preceding claim wherein the electrically conductive material is pushed into the indented pattern.
8. A method as claimed in claim 7 wherein the electrically conductive material is initially laid on the surface of the substrate and then scraped along it into the indented pattern.
9. A method as claimed in claim 8 wherein, when electrically conductive material is scraped along the surface, substantially none is left on the surface of the substrate except within the indented pattern.
10. A method as claimed in claim 7 and wherein the electrically conductive material is injected into a mould whereby it is pushed into the indented pattern.
11. A method as claimed in any preceding claim wherein the electrically conductive material is initially a deformable paste.
12. A method as claimed in claim 11 and wherein the paste is cured to harden it after it has filled the indented pattern.
13. A method as claimed in any preceding claim wherein the electrically insulating material includes long fibre reinforcing.
14. A method as claimed in claim 13 wherein the fibres are glass.
15. A method as claimed in any preceding claim and including the step of forming a multi-layer structure by fixing together a plurality of substrates bearing electrically conductive material.
16. A substrate bearing an electrical circuit fabricated by a method as claimed in any preceding claim.
17. A device comprising an electrically insulating substrate bearing a pattern of electrically conductive material located in indentations in the substrate.
18. A device as claimed in claim 17 wherein the pattern includes an aperture which is extensive from one surface of the substrate to another.
19. A device as claimed in claim 17 or 18 and including a plurality of substrates joined toqether to form a multi-layer structure.
20. A method substantially as illustrated in and described with reference to Figures 1 to 4 of the accompanying drawings.
21. A method substantially as illustrated in and described with reference to Figures 5 to 8 of the accompanying drawings.
22. A device substantially as illustrated in and described with reference to Figures 7 or 8 of the accompanying drawings.
GB8726401A 1987-11-11 1987-11-11 Fabrication of electrical circuits Withdrawn GB2212332A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8726401A GB2212332A (en) 1987-11-11 1987-11-11 Fabrication of electrical circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8726401A GB2212332A (en) 1987-11-11 1987-11-11 Fabrication of electrical circuits

Publications (2)

Publication Number Publication Date
GB8726401D0 GB8726401D0 (en) 1987-12-16
GB2212332A true GB2212332A (en) 1989-07-19

Family

ID=10626776

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8726401A Withdrawn GB2212332A (en) 1987-11-11 1987-11-11 Fabrication of electrical circuits

Country Status (1)

Country Link
GB (1) GB2212332A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5434107A (en) * 1994-01-28 1995-07-18 Texas Instruments Incorporated Method for planarization
US5744171A (en) * 1993-09-15 1998-04-28 Lsi Logic Corporation System for fabricating conductive epoxy grid array semiconductor packages
WO2001037622A2 (en) * 1999-11-18 2001-05-25 Orga Kartensysteme Gmbh Printed conductor support layer for laminating into a chip card, method for producing a printed conductor support layer and injection molding tool for carrying out the method for producing a printed conductor support layer
WO2001050825A1 (en) * 2000-01-04 2001-07-12 Elmicron Ag Method, facility and device for producing an electrical connecting element, electrical connecting element and semi-finished product
WO2003032245A1 (en) * 2001-10-01 2003-04-17 Orga Kartensysteme Gmbh Chip card and method for producing a chip card of this type
EP1360645A1 (en) * 2001-02-02 2003-11-12 SCHLUMBERGER Systèmes Portable object with chip and antenna
US7371975B2 (en) * 2002-12-18 2008-05-13 Intel Corporation Electronic packages and components thereof formed by substrate-imprinting
US7637008B2 (en) 2002-12-18 2009-12-29 Intel Corporation Methods for manufacturing imprinted substrates

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1404697A (en) * 1972-10-11 1975-09-03 Siemens Ag Production of fine conductor path structures on ceramic substrates
GB2033667A (en) * 1978-11-06 1980-05-21 Powers C D Improvements in circuit boards
EP0037988A1 (en) * 1980-04-11 1981-10-21 Braun Aktiengesellschaft Method of applying electrically conductive paths to an insulating support
EP0051378A2 (en) * 1980-11-03 1982-05-12 AMP INCORPORATED (a New Jersey corporation) Circuit board having cast circuitry and method of manufacture
GB2109640A (en) * 1981-10-02 1983-06-02 Marconi Co Ltd Waveguide construction
GB2124037A (en) * 1982-07-19 1984-02-08 Gen Electric Co Plc Methods of forming patterns on substrates
EP0133917A2 (en) * 1983-08-08 1985-03-13 International Business Machines Corporation Process for forming a pattern of electrically conductive lines on the top of a ceramic substrate
EP0138673A2 (en) * 1983-09-21 1985-04-24 Allied Corporation Method of making a printed circuit board
EP0178409A2 (en) * 1984-10-19 1986-04-23 International Business Machines Corporation Improved MLC green sheet process

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1404697A (en) * 1972-10-11 1975-09-03 Siemens Ag Production of fine conductor path structures on ceramic substrates
GB2033667A (en) * 1978-11-06 1980-05-21 Powers C D Improvements in circuit boards
EP0037988A1 (en) * 1980-04-11 1981-10-21 Braun Aktiengesellschaft Method of applying electrically conductive paths to an insulating support
EP0051378A2 (en) * 1980-11-03 1982-05-12 AMP INCORPORATED (a New Jersey corporation) Circuit board having cast circuitry and method of manufacture
GB2109640A (en) * 1981-10-02 1983-06-02 Marconi Co Ltd Waveguide construction
GB2124037A (en) * 1982-07-19 1984-02-08 Gen Electric Co Plc Methods of forming patterns on substrates
EP0133917A2 (en) * 1983-08-08 1985-03-13 International Business Machines Corporation Process for forming a pattern of electrically conductive lines on the top of a ceramic substrate
EP0138673A2 (en) * 1983-09-21 1985-04-24 Allied Corporation Method of making a printed circuit board
EP0178409A2 (en) * 1984-10-19 1986-04-23 International Business Machines Corporation Improved MLC green sheet process

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5744171A (en) * 1993-09-15 1998-04-28 Lsi Logic Corporation System for fabricating conductive epoxy grid array semiconductor packages
US5434107A (en) * 1994-01-28 1995-07-18 Texas Instruments Incorporated Method for planarization
WO2001037622A2 (en) * 1999-11-18 2001-05-25 Orga Kartensysteme Gmbh Printed conductor support layer for laminating into a chip card, method for producing a printed conductor support layer and injection molding tool for carrying out the method for producing a printed conductor support layer
WO2001037622A3 (en) * 1999-11-18 2002-05-23 Orga Kartensysteme Gmbh Printed conductor support layer for laminating into a chip card, method for producing a printed conductor support layer and injection molding tool for carrying out the method for producing a printed conductor support layer
WO2001050825A1 (en) * 2000-01-04 2001-07-12 Elmicron Ag Method, facility and device for producing an electrical connecting element, electrical connecting element and semi-finished product
EP1320287A1 (en) * 2000-01-04 2003-06-18 Elmicron AG Electrical connecting element and semi-finished product
EP1360645A1 (en) * 2001-02-02 2003-11-12 SCHLUMBERGER Systèmes Portable object with chip and antenna
WO2003032245A1 (en) * 2001-10-01 2003-04-17 Orga Kartensysteme Gmbh Chip card and method for producing a chip card of this type
US7371975B2 (en) * 2002-12-18 2008-05-13 Intel Corporation Electronic packages and components thereof formed by substrate-imprinting
US7594321B2 (en) 2002-12-18 2009-09-29 Intel Corporation Substrate-imprinting methods
US7637008B2 (en) 2002-12-18 2009-12-29 Intel Corporation Methods for manufacturing imprinted substrates

Also Published As

Publication number Publication date
GB8726401D0 (en) 1987-12-16

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