Electric circuit arrangement and method of making the same

• US 3,885,304 A
• Filed: 12/27/1973
• Issued: 05/27/1975
• Est. Priority Date: 03/23/1972
• Status: Expired due to Term

• Current Assignee: Adolf Kugelmann, Anton Kaiser, Helmut Keller
• Original Assignee: Adolf Kugelmann, Anton Kaiser, Helmut Keller
• Inventors: Kaiser, Anton, Keller, Helmut, Kugelmann, Adolf
• Primary Examiner(s): Lanham, C. W.
• Assistant Examiner(s): Walkowski, Joseph A.
• Application Number:
  US05/428,910
• Time in Patent Office: 516 Days
• Field of Search: 29/626,627,577,588-591,488,577 174/68S,52PE 317/11R,11A,11C,11CC 264/135,272
• US Class Current: 29/832
• CPC Class Codes: H01L 2023/4031 Packaged discrete devices, e.g. to-3 housings, diodes
• CPC Class Codes: H01L 2023/4043 heatsink to have chip
• CPC Class Codes: H01L 2023/4062 heatsink to or through board or cabinet
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/24 solid or gel at the normal operating temperature of the device H01L23/3135 takes precedence
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/4006 with bolts or screws
• CPC Class Codes: H01L 23/538 the interconnection structure between a plurality of semiconductor chips being formed on, or in, insulating substrates H05K takes precedence; manufacture or treatment H01L21/4846 ; mountings per se H01L23/12; materials H01L23/49866
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H05K 1/18 : Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: H05K 2203/1316 : Moulded encapsulation of mounted components
• CPC Class Codes: H05K 2203/304 : Protecting a component during manufacturing
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/3447 : Lead-in-hole components H05K3/3415 takes precedence
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49171 : with encapsulating

Abstract

A circuit board of electrically insulating material is provided with a printed circuit including one or more circuit strips. A discrete electrical component, or several of them, is mounted on the circuit board in circuit with the circuit arrangement and at least one semi-conductor unit is provided on the circuit board and electrically connected with the circuit thereof.

Claims

1. A method of making an electric circuit arrangement, comprising the steps of providing an electrically insulating circuit board having opposite major surfaces and holes extending intermediate said surfaces and electrically conductive circuit strips on both of said major surfaces;

mounting on one of said major surfaces a semiconductor unit having exposed electrical terminals;

electrically connecting said terminals with respective ones of said strips using bond wires;

mounting surround means defining a chamber around said mounted semiconductor unit on said one major surface;

depositing a protective covering of polymerizable material into said surround means of sufficient quantity so as to encapsulate said semiconductor unit and said bond wires and form a meniscus above said semiconductor unit;

mounting on said one major surface a plurality of discrete electrical components having conductive leads which extend through said respective ones of said holes to said other major surface and to respective circuit strips thereof; and

soldering said leads at said other major surface to the respectively associated circuit strips by contacting said leads with a surgedeposition soldering bath.

2. A method of making an electric circuit arrangement, comprising the steps of providing an electrically insulating circuit board having opposite major surfaces and holes extending intermediate said surfaces and electrically conductive circuit strips on one of said major surfaces;

applying a coating of an anti-solder lacquer substance which is nonwettable by liquid solder on a portion of said circuit strips on said one major surface;

mounting on another portion of said one major surface which has not been applied with said anti-solder lacquer a semiconductor unit having exposed electrical terminals;

electrically connecting said terminals with respective ones of said strips using bond wires;

mounting surround means defining a chamber around said mounted semiconductor unit on said portion of said one major surface which has been applied with said anti-solder lacquer;

depositing a protective covering of polymerizable material into said surround means of sufficient quantity so as to encapsulate said semiconductor unit and said bond wires and form a meniscus above said semiconductor unit;

mounting on the other of said major surfaces a plurality of discrete electrical components having conductive leads which extend through said respective ones of said holes to said one major surface and to respective circuit strips thereof; and

soldering said leads at said one major surface to the respectively associated circuit strips by contacting said leads with a surge-deposition soldering bath, whereby contact between the solder and said semi-conductor unit is prevented by an air pocket formed by said meniscus as well as by said protective covering of polymerizable material itself.

3. A method as defined in claim 2, wherein said step of mounting said semiconductor unit includes bonding said semiconductor unit with an electrically conductive substance.

4. A method as defined in claim 2, wherein said step of mounting said semiconductor unit includes bonding said semiconductor unit with a nonconductive electrical substance.

5. A method as defined in claim 2, wherein said step of depositing a protective covering includes depositing a layer of synthetic resin material on said portion of said circuit strips.

6. A method as defined in claim 2;

and further comprising the step of providing heat sinks which remove heat from said semiconductor unit.

7. A method as defined in claim 2, wherein said step of mounting said surround means includes mounting an annular member.

8. A method as defined in claim 2, wherein said step of applying said anti-solder lacquer is applied before said step of mounting said semiconductor unit.

9. A method as defined in claim 2, wherein said step of mounting said surround means includes mounting an annular cap with an opening so that said protective covering may be deposited through said opening and form a cylindrically-shaped mass.

10. A method for making an electrical circuit as defined in claim 2, wherein said step of depositing a protective covering includes forming said meniscus of concave configuration.