MANUFACTURING METHOD OF PRINT CIRCUIT BOARD

• Main Author: WATANABE MASATOSHI
• Format: Patent
• Language: English; Japanese
• Published: 27.06.2023
• Subjects: ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GRINDING; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PERFORMING OPERATIONS; POLISHING; PRINTED CIRCUITS; TRANSPORTING

To provide a manufacturing method of a print circuit board, having excellent connection reliability even in the case where a via hole has a small diameter.SOLUTION: A manufacturing method of a print circuit board, contains: a step of forming an insulation layer 20 containing a hardening material of a resin component containing an inorganic filler on a main front surface 10a of which arithmetic average roughness (Ra) is 500 nm or less in an inner layer circuit board 10 providing a support substrate 11 and a metal layer 12 provided to a front surface of the support substrate; and a step of forming a via hole 50 to the insulation layer by performing a sand blast treatment using an abrasive grain. A thickness of the insulation layer is 20 μm or less, and a mean particle diameter of the abrasive grain is 0.5 μm or more and 5 μm or less. When modified Mohs hardness of the inorganic filler in the insulation layer is A, and modified Mohs hardness of the abrasive grain in the sand blast treatment is B, a following equation is satisfied: B-A≥2.SELECTED DRAWING: Figure 6 【課題】ビアホールが小径であっても接続信頼性に優れたプリント配線板の製造方法を提供する。【解決手段】プリント配線板の製造方法は、支持基板１１及び支持基板の表面に設けられた金属層１２を備える内層回路基板１０の、算術平均粗さ（Ｒａ）が５００ｎｍ以下である主表面１０ａ上に、無機充填材を含む樹脂組成物の硬化物を含む絶縁層２０を形成する工程と、砥粒を用いるサンドブラスト処理を行い、絶縁層にビアホール５０を形成する工程と、を含む。絶縁層の厚みは、２０μｍ以下であり、砥粒の平均粒径が、０．５μｍ以上５μｍ以下であり、絶縁層中の無機充填材の修正モース硬度をＡとし、サンドブラスト処理における砥粒の修正モース硬度をＢとしたとき、Ｂ－Ａ≧２の関係を満たす。【選択図】図６