MANUFACTURING METHOD OF PRINT WIRING BOARD

• Main Author: WATANABE MASATOSHI
• Format: Patent
• Language: English; Japanese
• Published: 03.09.2020
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS

To provide a manufacturing method of a print wiring board with excellent connection reliability even when a via hole has a small diameter.SOLUTION: A manufacturing method of a print wiring board includes (A) a step of forming an insulating layer containing a cured product of a resin composition containing an inorganic filler on the main surface having arithmetic mean roughness (Ra) of 500nm or less in an inner circuit board, and (B) a step of forming a via hole in the insulating layer by performing a sandblasting process using abrasive grains, and when the modified Mohs hardness of the inorganic filler in the insulating layer is A and the modified Mohs hardness of the abrasive grains in the sandblasting process is B, the relationship B-A≥2 is satisfied, and the average particle size of the abrasive grains is 0.5 μm or more and 5 μm or less.SELECTED DRAWING: None 【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の提供。【解決手段】（Ａ）内層回路基板の、算術平均粗さ（Ｒａ）が５００ｎｍ以下である主表面上に、無機充填材を含む樹脂組成物の硬化物を含む絶縁層を形成する工程、及び（Ｂ）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を形成する工程、を含み、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の関係を満たし、砥粒の平均粒径が、０．５μｍ以上５μｍ以下である、プリント配線板の製造方法。【選択図】なし