Method for forming resist pattern, method for producing circuit board, and circuit board

• US 8,143,533 B2
• Filed: 05/17/2006
• Issued: 03/27/2012
• Est. Priority Date: 05/17/2006
• Status: Expired due to Fees

• Current Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited), Mitsubishi Paper Mills Limited
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited), Mitsubishi Paper Mills Limited
• Inventors: Kaneda, Yasuo, Irisawa, Munetoshi, Toyoda, Yuji, Komuro, Toyokazu, Fukase, Katsuya, Sakai, Toyoaki
• Primary Examiner(s): Chen, XiaoLiang
• Assistant Examiner(s): Milakovich, Nathan
• Application Number:
  US12/227,377
• Publication Number:
  US 20090236137A1
• Time in Patent Office: 2,141 Days
• Field of Search: 174/262
• US Class Current: 174/262
• CPC Class Codes: H05K 1/116 Lands, clearance holes or other lay-out details concerning the surrounding of a via
• CPC Class Codes: H05K 2201/09545 Plated through-holes or blind vias without lands
• CPC Class Codes: H05K 2203/0191 Using tape or non-metallic foil in a process, e.g. during filling of a hole with conductive paste
• CPC Class Codes: H05K 2203/0574 Stacked resist layers used for different processes
• CPC Class Codes: H05K 2203/1184 Underetching, e.g. etching of substrate under conductors or etching of conductor under dielectrics; Means for allowing or controlling underetching
• CPC Class Codes: H05K 2203/1394 Covering open PTHs, e.g. by dry film resist or by metal disc
• CPC Class Codes: H05K 3/002 by liquid chemical etching
• CPC Class Codes: H05K 3/108 by semi-additive methods; masks therefor characterised by metallic etch mask H05K3/062; electroplating methods or apparatus H05K3/241
• CPC Class Codes: H05K 3/426 initial plating of through-holes in substrates without metal

Abstract

There are provided a method for forming a resist pattern for preparing a circuit board having a landless or small-land-width through-hole(s) to realize a high-density circuit board, a method for producing a circuit board, and a circuit board. A method for forming a resist pattern, comprising the steps of forming a resin layer and a mask layer on a first surface of a substrate having a through-hole(s), and removing the resin layer on the through-hole(s) and on a periphery of the through-hole(s) on the first surface by supplying a resin layer removing solution from a second surface opposite to the first surface of the substrate, and a method for producing a circuit board using the method for forming a resist pattern, and a circuit board.

Claims

1. A method for producing a circuit board, comprising the steps of:

(a) preparing an insulating substrate having a through-hole(s), which has a first conductive layer on a first surface, on a second surface opposite to the first surface and on an inner wall of the through-holes(s);

(b) covering the first conductive layer and an opening of the through-hole(s) on the first surface with a photocrosslinkable resin layer and a mask layer by forming the photocrosslinkable resin layer and the mask layer on the first surface;

(c) uncovering the first conductive layer on the periphery of the through-hole(s) on the first surface by supplying a photocrosslinkable resin layer removing solution from the second surface and removing the photocrosslinkable resin layer on the through-hole(s) and on a periphery of the through-hole(s) on the first surface;

(d) subjecting the photocrosslinkable resin layer on the first surface to pattern exposure;

(e) covering the first conductive layer and an opening of the through-hole(s) on the second surface with a photocrosslinkable resin layer and a mask layer by forming the photocrosslinkable resin layer and the mask layer on the second surface;

(f) removing the mask layer on the first surface;

(g) uncovering the first conductive layer on the first surface and the first conductive layer on a periphery of the through-hole(s) on the second surface by supplying a photocrosslinkable resin layer removing solution from the first surface and removing an uncured photocrosslinkable resin layer on the first surface and the photocrosslinkable resin layer on the through-hole(s) and on the periphery of the through-hole(s) on the second surface;

(h) subjecting the photocrosslinkable resin layer on the second surface to pattern exposure;

(i) removing the mask layer on the second surface;

(j) uncovering the first conductive layer on the second surface by supplying a photocrosslinkable resin layer removing solution from the second surface and removing an uncured photocrosslinkable resin layer on the second surface;

(k) forming a second conductive layer on the first conductive layer uncovered on the inner wall of the through-hole(s) and the periphery of the through-hole(s) and on the first surface and the second surface by electrolytic plating;

(l) uncovering the first conductive layer on the first surface and the second surface by removing the cured photocrosslinkable resin layers on the first surface and the second surface; and

(m) removing the uncovered first conductive layer by flash etching.

2. The method for producing a circuit board according to claim 1, wherein the step (f) is performed before the step (e).

3. The method for producing a circuit board according to claim 1, wherein the step (f) is performed before the step (d).

4. The method for producing a circuit board according to claim 1, wherein the step (g) comprises the steps of (g1) uncovering the first conductive layer on the first surface by supplying the photocrosslinkable resin removing solution from the first surface and removing the uncured photocrosslinkable resin layer on the first surface and (g2) uncovering the first conductive layer on the periphery of the through-hole(s) on the second surface by supplying the photocrosslinkable resin removing solution from the first surface and removing the photocrosslinkable resin layer on the through-hole(s) and on the periphery of the through-hole(s) on the second surface, and the step (e) is performed between the step (g1) and the step (g2).