Method of recycling printed circuit board

• US 7,107,661 B2
• Filed: 12/16/2002
• Issued: 09/19/2006
• Est. Priority Date: 12/18/2001
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakamura, Katsumi, Kond, Kouji, Kamimura, Rikiya, Taniguchi, Toshihisa, Sakaida, Atsusi
• Primary Examiner(s): JIMENEZ, MARC QUEMUEL
• Application Number:
  US10/381,054
• Publication Number:
  US 20040111854A1
• Time in Patent Office: 1,373 Days
• Field of Search: 294/034, 294/033, 294/031, 241/23, 241/DIG.38, 241/24.13, 241/24.18
• US Class Current: 29/403.4
• CPC Class Codes: B09B 5/00 Operations not covered by a single other subclass or by a single other group in this subclass
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• CPC Class Codes: B29B 2017/0255 using different melting or softening temperatures of the materials to be separated
• CPC Class Codes: B29B 2017/0456 Pressing tools with calibrated openings, e.g. in sizing plates, for disintegrating solid materials
• CPC Class Codes: B29B 2017/0464 Solid state shear extrusion pulverisation
• CPC Class Codes: B29L 2031/3425 Printed circuits
• CPC Class Codes: C22B 7/001 Dry processes
• CPC Class Codes: C22B 7/005 Separation by a physical processing technique only, e.g. by mechanical breaking
• CPC Class Codes: H05K 2201/0129 Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer
• CPC Class Codes: H05K 2203/178 Demolishing, e.g. recycling, reverse engineering, destroying for security purposes; Using biodegradable materials
• CPC Class Codes: H05K 3/22 Secondary treatment of printed circuits H05K3/1283 takes precedence; embedding circuits in grooves by pressure H05K3/107
• CPC Class Codes: H05K 3/4069 for via connections in organic insulating substrates
• CPC Class Codes: H05K 3/4614 the electrical connections between the circuit boards being made during lamination
• CPC Class Codes: H05K 3/4632 laminating thermoplastic or uncured resin sheets comprising printed circuits without added adhesive materials between the sheets
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling
• CPC Class Codes: Y10T 29/49751 Scrap recovering or utilizing
• CPC Class Codes: Y10T 29/49755 Separating one material from another
• CPC Class Codes: Y10T 29/49757 by burning or heating
• CPC Class Codes: Y10T 29/53 : Means to assemble or disassemble
• CPC Class Codes: Y10T 29/53274 : Means to disassemble electrical device

Abstract

The present invention provides a method and apparatus of recycling a printed circuit board for separating and retrieving a metallic material, which includes a printed metallic material, and an insulating material, both composing the printed circuit board. Both the metallic material and the insulating material, which are separated and retrieved, are possible for recycling. In the method for recycling the printed circuit board, hot filtration equipment 4a and resin-metal separation equipment 51 are used in hot filtration process P400. The waste printed circuit board 1 is heated and force-filtered so that only the insulating material 1a pass through the filter. Then, the insulating material 1a and the metallic material 1b are separated and retrieved. It is preferred that the insulating body base 23 of the printed circuit board 100 as the waste printed circuit board is made of thermoplastic resin or a mixture of thermoplastic resin and inorganic loading material. As a result, when the retrieved metallic material and the retrieved insulating material amount to necessities of recycling respectively, both the metallic material and the insulating material are possible for recycling.

Claims

1. A method of recycling a printed circuit board for separating and retrieving an insulating material and a metallic material from a waste printed circuit board, which is used in waste electric equipment or a waste produced in a process of manufacturing electric equipment, wherein the printed circuit board includes the insulating material and the metallic material, wherein the insulating material is made of either thermoplastic resin only or mixture of thermoplastic resin and inorganic loading material, and wherein the metallic material includes a printed metallic material, the method comprising the step of:

heating and force-filtering the printed circuit board in order to pass the insulating material only so that the insulating material and the metallic material are separated and retrieved and that at least either the insulating material or the metallic material is recycled.

2. A method of recycling a printed circuit board according to claim 1, wherein the force-filtering is attained by filtering the printed circuit board with heating and pressurizing.

3. A method of recycling a printed circuit board according to claim 1, wherein the printed circuit board comprises an insulating body base, which is made of the insulating material, and a conductive printed circuit, which is made of the metallic material and disposed on a surface of the insulating body base, and

wherein the printed circuit board is a multi-layer printed circuit board, which is formed in such a manner that a plurality of insulating body bases together with a plurality of conductive printed circuits is stacked and adhered by heating and pressurizing.

4. A method of recycling a printed circuit board according to claim 3, wherein a modulus of the thermoplastic resin is in a range of 1–

1000 MPa at a heating temperature at which heating and pressurizing in the step of force-filtering is performed.

5. A method of recycling a printed circuit board according to claim 3, wherein the insulating body base is composed of a resin film made of either the thermoplastic resin only or the mixture of thermoplastic resin and inorganic loading material, wherein the insulating body base involves a via-hole and a conductive product integrated in the via-hole, wherein the conductive printed circuits are electrically connected together with the conductive product, and

wherein the conductive product is made of metallic material only or the metallic material and either the thermoplastic resin comprising the insulating body base or the mixture of thermoplastic resin and inorganic loading material also composing the insulating body base.

6. A method of separating and retrieving a thermoplastic resin from a printed circuit board containing an insulating material containing the thermoplastic resin, which consists essentially of:

separating the printed circuit board into a component containing the thermoplastic resin and a component containing metallic material by simultaneously heating and force-filtering the printed circuit board at a temperature that melts the component containing the thermoplastic resin while the component containing metallic material remains solid, and passing the melted component containing thermoplastic resin through a filter without passing the solid component containing metallic material through the filter, and

retrieving each of the filtered component containing thermoplastic resin and the non-filtered component material containing metallic material; and

recycling at least one of the retrieved thermoplastic resin containing component and the retrieved component containing metallic material.