Patent ID: 6802120
Filing Date: 2004-10-12
Classification: H05K,Y10S,Y10T

Abstract:
A method of manufacturing a printed wiring board enabling insertion components to be mounted on both upper and lower sides thereof, comprising the steps of:a) providing first and second copper-clad laminates which will make the upper and lower sides of the printed wiring board, respectively, and which is provided with a plated through-hole thereon, respectively; b) hot-pressing said first and second laminates with each other with a first prepreg as a bonding sheet being sandwiched therebetween to form a first composite laminate; a resin component of the first prepreg having low flowability so that the respective through-holes are closed by the prepreg to form respective non-through holes; c) laminating a second prepreg, a resin component of the second prepreg having low flowability, on each of upper and lower surfaces of said first composite laminate, to form a second composite laminate, the second prepreg having an opening corresponding to each of the non-through holes; d) covering the respective non-through holes exposed on the upper and lower surfaces of said second composite laminate with heat resistant resin films to form a third composite laminate; e) laminating a one-side copper-clad laminate, having a base material layer and a copper layer thereon, on each of upper and lower surfaces of the third composite laminate while disposing the copper layer outside, followed by hot-pressing; f) etching each of the one-side copper-clad laminates to form outer layer circuit patterns, and to remove the copper layers positioned on the non-through holes to expose the base material layers; g) removing the base material layers covering the openings of the non-through holes by end mill processing, to expose the heat resistant resin film outside; and h) removing the heat resistant resin films from the non-through holes, so that the non-through holes can be used for mounting of the insertion components from both upper and lower side of the printed wiring board.