Method of connecting electronic element to base plate

• US 4,814,040 A
• Filed: 03/29/1988
• Issued: 03/21/1989
• Est. Priority Date: 04/03/1987
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ozawa, Kazuhito
• Primary Examiner(s): Powell, William A.
• Application Number:
  US07/174,715
• Time in Patent Office: 357 Days
• Field of Search: 156/629, 156/634, 156/656, 156/659.1, 156/902, 156/283, 156/306.6, 156/306.9, 29/846, 427/96, 427/98
• US Class Current: 216/20
• CPC Class Codes: H01L 21/67144 Apparatus for mounting on conductive members, e.g. leadframes or conductors on insulating substrates
• CPC Class Codes: H01R 4/04 using electrically conductive adhesives
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 1/095 for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 2201/023 Hard particles, i.e. particles in conductive adhesive at least partly penetrating an electrode
• CPC Class Codes: H05K 2201/0323 Carbon
• CPC Class Codes: H05K 2201/035 Paste overlayer, i.e. conductive paste or solder paste over conductive layer
• CPC Class Codes: H05K 2203/0522 Using an adhesive pattern
• CPC Class Codes: H05K 2203/0571 Dual purpose resist, e.g. etch resist used as solder resist, solder resist used as plating resist
• CPC Class Codes: H05K 2203/0723 Electroplating, e.g. finish plating
• CPC Class Codes: H05K 2203/1189 Pressing leads, bumps or a die through an insulating layer
• CPC Class Codes: H05K 3/061 Etching masks
• CPC Class Codes: H05K 3/323 by applying an anisotropic conductive adhesive layer over an array of pads
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

An electronic element is connected to a base plate provided with a metallic pattern and a conductive resist layer superposed thereon by a thermal compression process with an adhesive layer sandwiched between the element and the base plate. The adhesive layer contains many metallic particles which are larger than the layer thickness of the resist such that these metallic particles penetrate the resist layer and invade the metallic pattern by the thermal compression process.

Claims

1. A method of connecting an electronic element to a base plate comprising the steps of

forming a conductive pattern on said base plate and a conductive resist layer superposingly on said conductive pattern,

placing a connecting means between said base plate and said electronic element, said connecting means comprising an adhesive layer having metallic particles dispersed therethrough, said metallic particles being larger than the layer thickness of said resist layer, and

thermal compression of said base plate and said electronic element against each other with said connecting means sandwiched therebetween.

2. The method of claim 1 wherein said step of thermal compression is carried out with pressure of 20-60 kg/cm² at temperature 130-180°

C. for 5-10 seconds.

3. The method of claim 1 wherein said step of thermal compression is carried out such that said metallic particles penetrate said conductive resist layer and invade sai conductive pattern.

4. The method of claim 1 wherein said base plate comprises a polyester film, said conductive pattern is formed from an aluminum foil and is about 9 μ

m in thickness and said conductive resist layer is about 10-15 μ

m in thickness.

5. The method of claim 4 wherein said connecting means is shaped like a tape, having thickness of about 10-30 μ

m.

6. The method of claim 5 wherein said metallic particles comprise Ni and are about 30-40 μ

m in size.

7. The method of claim 4 wherein said conductive resist layer comprises thermosetting carbon ink.

8. The method of claim 1 wherein said conductive pattern is formed by etching an aluminum foil formed on said base plate.

9. The method of claim 1 wherein said conductive pattern comprises a low-resistance metallic paste material and is deposited on said base plate by printing.

10. The method of claim 8 wherein said conductive resist layer is formed by printing a conductive paste material on said conductive pattern.