CN-121986553-A - Method for manufacturing printed wiring board

Abstract

Provided is a method for manufacturing a printed wiring board, wherein a metal carrier can be easily separated and recovered from an unnecessary support substrate. The method for manufacturing a printed wiring board includes a step of preparing a support substrate including a metal foil with a carrier and a resin base material provided on a first metal foil side of the metal foil with the carrier, the metal foil with the carrier including, in order, a first metal foil, a first release layer, a metal carrier, a second release layer, and a second metal foil, the first release layer having a peel strength greater than that of the second release layer, a step of forming a stacked wiring layer on the second metal foil of the support substrate to produce a support substrate with the stacked wiring layer, a step of separating an unnecessary substrate including the metal carrier, the first release layer, the first metal foil, and the resin base material from the support substrate with the stacked wiring layer via the second release layer, and a step of separating and recovering the metal carrier from the unnecessary substrate via the first release layer.

Inventors

• Takari Tetsushi
• SHIMIZU TOSHIYUKI

Assignees

• 三井金属株式会社

Dates

Publication Date

20260505

Application Date

20241008

Priority Date

20231101

Claims (10)

1. 1. A method for manufacturing a printed wiring board, wherein, The method for manufacturing the printed wiring board comprises the following steps: a step of preparing a support substrate including a carrier-equipped metal foil and a resin base material provided on a first metal foil side of the carrier-equipped metal foil, the carrier-equipped metal foil including, in order, a first metal foil, a first release layer, a metal carrier, a second release layer, and a second metal foil, the first release layer having a peel strength greater than that of the second release layer; forming a stacked wiring layer on the second metal foil of the support substrate to produce a support substrate with the stacked wiring layer; A step of separating an unnecessary substrate including the metal carrier, the first release layer, the first metal foil, and the resin base material from the support substrate with the stacked wiring layers via the second release layer, and And separating and recovering the metal carrier from the unnecessary substrate via the first release layer.
2. 2. The method for manufacturing a printed wiring board according to claim 1, wherein, The thickness of the metal carrier is greater than the thickness of each of the first metal foil and the second metal foil.
3. 3. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The thickness of the second metal foil is more than the thickness of the first metal foil.
4. 4. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The peel strength of the first release layer is 1.1 to 50 times that of the second release layer.
5. 5. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The first release layer has a peel strength of 2gf/cm or more and 100gf/cm or less.
6. 6. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The second release layer has a peel strength of 1gf/cm or more and 50gf/cm or less.
7. 7. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The difference between the peel strength of the first release layer and the peel strength of the second release layer is 1gf/cm or more and 50gf/cm or less.
8. 8. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The adhesive strength between the first metal foil and the resin base material is greater than the peel strength of the first release layer.
9. 9. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The metal carrier is copper foil.
10. 10. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein, The first metal foil and the second metal foil are copper foils.

Description

Method for manufacturing printed wiring board Technical Field The present disclosure relates to a method of manufacturing a printed wiring board. Background In recent years, in order to increase the mounting density of printed wiring boards and to reduce the size, the multilayering of printed wiring boards has been widely performed. Such multilayer printed wiring boards are often used for the purpose of weight reduction and downsizing in portable electronic devices. Further, the multilayer printed wiring board is required to be further reduced in thickness of the interlayer insulating layer and further reduced in thickness and weight as a wiring board. As a technique for satisfying such a demand, a method for manufacturing a multilayer printed wiring board using a coreless stacking method is adopted. The coreless stacking method is a method in which insulating layers and wiring layers are alternately stacked (stacked) to be multilayered without using a so-called core substrate. In the coreless stacking method, in order to enable easy separation of the support substrate and the multilayer printed wiring board, use of a carrier-equipped metal foil having a carrier, a separation layer, and a metal foil (for example, copper foil) in this order has been proposed. That is, a support substrate as a dummy core is formed by adhering a carrier side of a metal foil with a carrier to a resin base material, insulating layers and wiring layers are alternately laminated on the metal foil to obtain a stacked wiring layer, and then the stacked wiring layer is separated from the support substrate at a position of a release layer. For example, patent document 1 (WO 2019/188836) discloses a method for manufacturing a multilayer wiring board, in which a carrier side of a metal foil with a carrier is stuck to a temporary support such as a prepreg, insulating layers and metal foils are alternately laminated on the metal foil, various kinds of processing are performed, and then the temporary support is removed from the obtained laminate together with the carrier. Prior art literature Patent literature Patent document 1 wo2019/188836 Disclosure of Invention In this way, in the coreless stacking method using the metal foil with the carrier, the supporting substrate including the resin base material and the carrier is peeled off after the stacked wiring layers are formed. In this regard, the carrier is typically composed of a metal (e.g., copper), and thus, it is suitable as long as the carrier useful as a metal resource can be separated and recovered from the supporting substrate. However, in the present situation, since the resin base material and the carrier constituting the support substrate are firmly adhered, it is difficult to separate them, and the support substrate containing the metal is discarded as industrial waste or is inexpensively disposed of as a metal-containing resin material. Thus, a method capable of easily separating and recovering the carrier monomer is desired. The inventors of the present invention have now found that a metal carrier can be easily separated and recovered from an unnecessary support substrate by preparing a support substrate having a resin base and a metal foil with a carrier, the metal foil having a release layer and a metal foil having different peel strengths, adhered to both surfaces of the metal carrier, and forming a stacked wiring layer on the support substrate. Accordingly, an object of the present invention is to provide a method for manufacturing a printed wiring board capable of easily separating and recovering a metal carrier from an unnecessary support substrate. According to the present disclosure, the following manner is provided. Mode 1 A method for manufacturing a printed wiring board includes the steps of: a step of preparing a support substrate including a carrier-equipped metal foil and a resin base material provided on a first metal foil side of the carrier-equipped metal foil, the carrier-equipped metal foil including, in order, a first metal foil, a first release layer, a metal carrier, a second release layer, and a second metal foil, the first release layer having a peel strength greater than that of the second release layer; forming a stacked wiring layer on the second metal foil of the support substrate to produce a support substrate with the stacked wiring layer; A step of separating an unnecessary substrate including the metal carrier, the first release layer, the first metal foil, and the resin base material from the support substrate with the stacked wiring layers via the second release layer, and And separating and recovering the metal carrier from the unnecessary substrate via the first release layer. Mode 2 The method for manufacturing a printed wiring board according to mode 1, wherein a thickness of the metal carrier is larger than a thickness of each of the first metal foil and the second metal foil. Mode 3 The method for manufacturing a printed wiring board