US3776820A - Method of forming miniature electrical conductors - Google Patents

Method of forming miniature electrical conductors Download PDF

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Publication number
US3776820A
US3776820A US00289728A US3776820DA US3776820A US 3776820 A US3776820 A US 3776820A US 00289728 A US00289728 A US 00289728A US 3776820D A US3776820D A US 3776820DA US 3776820 A US3776820 A US 3776820A
Authority
US
United States
Prior art keywords
conductor
conductors
square
etching
mils
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.)
Expired - Lifetime
Application number
US00289728A
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English (en)
Inventor
E Johnson
B Hillis
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.)
Buckbee Mears Co
Original Assignee
Buckbee Mears Co
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 Buckbee Mears Co filed Critical Buckbee Mears Co
Application granted granted Critical
Publication of US3776820A publication Critical patent/US3776820A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
    • H05K3/06—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed chemically or electrolytically, e.g. by photo-etch process
    • 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
    • H05K3/108—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 semi-additive methods; masks therefor
    • 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
    • H05K3/22—Secondary treatment of printed circuits
    • H05K3/24—Reinforcing the conductive 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
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/03—Conductive materials
    • H05K2201/0332—Structure of the conductor
    • H05K2201/0335—Layered conductors or foils
    • H05K2201/0347—Overplating, e.g. for reinforcing conductors or bumps; Plating over filled vias
    • 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
    • H05K2201/09209—Shape and layout details of conductors
    • H05K2201/09654—Shape and layout details of conductors covering at least two types of conductors provided for in H05K2201/09218 - H05K2201/095
    • H05K2201/098—Special shape of the cross-section of conductors, e.g. very thick plated conductors
    • 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
    • H05K2203/03—Metal processing
    • H05K2203/0353—Making conductive layer thin, e.g. by etching
    • 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
    • H05K2203/07—Treatments involving liquids, e.g. plating, rinsing
    • H05K2203/0703—Plating
    • H05K2203/0723—Electroplating, e.g. finish plating
    • 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
    • H05K2203/11—Treatments characterised by their effect, e.g. heating, cooling, roughening
    • H05K2203/1184—Underetching, e.g. etching of substrate under conductors or etching of conductor under dielectrics; Means for allowing or controlling underetching
    • 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
    • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
    • H05K3/06—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed chemically or electrolytically, e.g. by photo-etch process
    • H05K3/061—Etching masks
    • H05K3/064—Photoresists

Definitions

  • This invention relates generally to miniature conductors and, more specifically, to a process for forming miniature electrical conductors having square corners.
  • the present invention comprises the discovery of a process for producing a substantially square or rectangular cross section conductor through the utilization of both etching and electroplating techniques.
  • the present invention comprises etching a conductor material to a predetermined shape such as an isosceles trapezoid and then electroforming material onto the isosceles trapezoid until one produces a conductor having square corners.
  • FIG. 1 shows a cross-sectional view of a material which has been etched away to form a base for electroplating on;
  • FIG. 2 shows a cross-sectional view of the base with material electroplated thereon.
  • a metal conductor such as copper on a dielectric material or support surface.
  • the support surface may be any typical type of dielectric. Typical of such dielectric support surfaces are polyimide films, however, no limitation is intended thereto. Referring to FIG. 1, we have designated certain reference characters and reference letters to assist in describing the process and relationships of the various dimensions of the article to be formed into a conductor.
  • FIG. 1 shows a dielectric material 11 having a conductor 13 with a resist material 12 located on top of conductor 13.
  • conductor 13 has been etched to its predetermined base shape which is an isosceles trapezoid. While FIG. 1 shows conductor 13 with straight well defined sides, in actual practice the etched sections are slightly curved and have somewhat of an irregular surface.
  • w represents the width of resist material 12 on conductor 13, W, represents the width of the top of the isosceles trapezoid formed by conductor 13, w; represents the width of the base of the isosceles trapezoid formed by conductor 13 and h; represents the height of the isosceles trapezoid.
  • the most important dimension of this process are the angles designated by Typically, should be maintained on the order of about 10 to 30 in order to obtain a conductor having the shape shown in FIG. 2.
  • FIG. 2 shows the final electroformed conductor 14 with the square corners.
  • conductor 14 has a square cross section, however, the cross section could also be rectangular.
  • the width of conductor 14 is designated by W2 and the height of conductor 14 is designated by k
  • W2 The width of conductor 14
  • k The height of conductor 14 is designated by k
  • EXAMPLE 1 In order to obtain a conductor with square cross section, a copper sheet of thickness il of 1.4 mils was placed on dielectric 11. The copper was selectively covered with a resist having a width w of 2 mils. The copper was then etched until the dimension W2 was approximately 1 mil and the dimension W1 was about 1.5 mils. With a thickness h of 1.4 mils, one obtains an angle on the order of 10. With these dimensions base conductor 13 has the shape of an isosceles trapezoid. Next, resist material 12 was removed and copper was electroplated on top of base conductor 13 until the dimension W2 and I1 were approximately 5 mils. When conductor 14 reached this size the corners of the conductors were substantially square.
  • EXAMPLE 2 In this example all the dimensions were identical to Example 1 with the exception that the thickness h was .7 mil rather than 1.4 mils. This produced an angle 5 which is approximately 20. With this angle the electroplating produced a conductor with a substantially square cross section and a final dimension of approximately 5 mils by 5 mils.
  • EXAMPLE 3 In another example, the dimension w was 2 mils, dimension W1 was 3 mils, the height h, was 1 mil and the width of the resist w was 4 mils. In this particular process the angle was approximately 27 and the final dimensions W2 and h were on the order of about 5 mils.
  • the suitable ranges of the angle have ranged from approximately 10 to 30 and the ratio w /w has been found to range from approximately 3 to 4 and the ratio h /h has ranged from approximately 2.8 to 8.0.
  • the ratio of the dimensions are not significant, only typical to obtaining a conductor with a square cross section.
  • the important and critical dimension is the maintaining of the angle in the range of 10 to 30 to produce a conductor which has square corners.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing Of Printed Wiring (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
  • Insulated Conductors (AREA)
US00289728A 1972-09-15 1972-09-15 Method of forming miniature electrical conductors Expired - Lifetime US3776820A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US28972872A 1972-09-15 1972-09-15

Publications (1)

Publication Number Publication Date
US3776820A true US3776820A (en) 1973-12-04

Family

ID=23112815

Family Applications (1)

Application Number Title Priority Date Filing Date
US00289728A Expired - Lifetime US3776820A (en) 1972-09-15 1972-09-15 Method of forming miniature electrical conductors

Country Status (9)

Country Link
US (1) US3776820A (cs)
JP (1) JPS4964870A (cs)
BE (1) BE804867A (cs)
CA (1) CA993533A (cs)
DE (1) DE2344845A1 (cs)
FR (1) FR2200727B1 (cs)
GB (1) GB1423549A (cs)
IT (1) IT995313B (cs)
NL (1) NL7312289A (cs)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4175010A (en) * 1977-04-18 1979-11-20 U.S. Philips Corporation Method of reinforcing a conductive base pattern by electroplating and device obtained by means of the method
EP0895445A1 (fr) * 1997-07-30 1999-02-03 Mecanismos Auxiliares Industriales S.A. M.A.I.S.A. Perfectionnement des conceptions d'inter-pistes sur les circuits imprimés de puissances
US6348659B1 (en) * 1999-01-07 2002-02-19 Thomas & Betts International, Inc. Resilient electrical interconnects having non-uniform cross-section

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3144080B1 (fr) 2022-12-22 2025-05-30 Smrc Automotive Holdings Netherlands Bv Pièce de garniture intérieure de véhicule et son procédé de fabrication

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1318654A (fr) * 1961-12-19 1963-02-22 Normacem Soc Procédé de fabrication de circuits électriques et circuits obtenus par ce procéde

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4175010A (en) * 1977-04-18 1979-11-20 U.S. Philips Corporation Method of reinforcing a conductive base pattern by electroplating and device obtained by means of the method
EP0895445A1 (fr) * 1997-07-30 1999-02-03 Mecanismos Auxiliares Industriales S.A. M.A.I.S.A. Perfectionnement des conceptions d'inter-pistes sur les circuits imprimés de puissances
WO1999007194A1 (en) * 1997-07-30 1999-02-11 Lear Automotive Dearborn, Inc. Inter-tracks for power printed circuits
US6348659B1 (en) * 1999-01-07 2002-02-19 Thomas & Betts International, Inc. Resilient electrical interconnects having non-uniform cross-section

Also Published As

Publication number Publication date
FR2200727A1 (cs) 1974-04-19
IT995313B (it) 1975-11-10
DE2344845A1 (de) 1974-03-21
GB1423549A (en) 1976-02-04
CA993533A (en) 1976-07-20
BE804867A (nl) 1974-03-14
NL7312289A (cs) 1974-03-19
FR2200727B1 (cs) 1977-02-18
JPS4964870A (cs) 1974-06-24

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