Printed wiring board manufacturing method
AssigneeMaruwa Co., Ltd.
InventorTsutomu Yamaoka
Life of this patent
Estimating the term…
Abstract
According to this manufacturing method, a copper foil is attached to both sides of an insulating material to form a substrate. First, a large number of through-holes is made in the substrate and the inside of the through-holes is made electrically conductive. Then, after one side of the substrate is coated with a photosensitive dry film having an outer masking layer attached thereto, a developing solution is caused to infiltrate into the through-bores from the other side to develop the photosensitive dry film as a plating resist. The photosensitive dry film is then exposed to be hardened. The outer masking layer is removed to copper-electroplate the inside of the through-holes and the like. Finally, the photosensitive dry film is removed to form a circuit pattern.
Claims8
A printed wiring board manufacturing method comprising the steps of:
- (a) making a large number of through-holes in a laminated sheet coated with copper, said laminated sheet having first and second sides and said through holes having through-hole interior surfaces;
- (b) making the through-hole interior surfaces electrically conductive;
- (c) coating the copper on the first side of the laminated sheet with a photosensitive dry film having an outer masking layer attached thereto;
- (d) allowing a developing solution to infiltrate into the through-holes from the second side;
- (e) developing the photosensitive dry film as a plating resist for hardening, said photosensitive dry film being developed in an area of outer peripheries of said through holes on said first side of the laminated sheet;
- (f) removing the outer masking layer;
- (g) copperizing the through-holes and the outer peripheries thereof;
- (h) removing the photosensitive dry film;
- and
- (i) forming a circuit pattern.
A printed wiring board manufacturing method comprising the steps of:
- (a) making a large number of through-holes in a laminated sheet coated with copper on first and second sides, said through holes having through-hole interior surfaces;
- (b) making the through-hole interior surfaces electrically conductive;
- (c) coating the first side of the laminated sheet with a first photosensitive dry film having a first outer masking layer attached thereto;
- (d) allowing a developing solution to infiltrate into the through-holes from the second side;
- (e) developing the first photosensitive dry film as a plating resist for hardening, said first photosensitive dry film being developed in an area of outer peripheries of said through holes on said first side of the laminated sheet;
- (f) removing the first outer masking layer;
- (g) coating the second side with a second photosensitive dry film having a second outer masking layer attached thereto;
- (h) allowing a developing solution to infiltrate into the through-holes from the first side;
- (i) developing the second photosensitive dry film as a plating resist for hardening, said second photosensitive dry film being developed in an area of outer peripheries of said through holes on said second side of the laminated sheet;
- (j) removing the second outer masking layer
- (k) copperizing the through-holes and the peripheries of the through-holes on said first and second sides;
- (l) removing said first and second photosensitive dry films;
- and
- (m) forming a circuit pattern.
A printed wiring board manufacturing method comprising the steps of:
- (a) making a large number of through-holes in a substrate made of a laminated sheet of which first and second sides of an insulating material are coated with a copper foil such that said substrate has first and second sides which are surfaced with the copper foil, and said through-holes having through-hole interior surfaces;
- (b) forming a conductive film on the through-hole interior surfaces of the through-holes;
- (c) coating a whole area of the first side of the substrate with a photosensitive dry film having an outer masking layer attached thereto;
- (d) allowing a developing solution to infiltrate into the through-holes from the second side of the substrate to dissolve and remove the photosensitive dry film in a vicinity of openings of the through-holes on the first side by a developing solution, thereby developing the photosensitive dry film as a plating resist for hardening;
- (e) stripping the outer masking layer;
- and
- (f) copper-electroplating the substrate to apply copper to the copper foil of the second side, to the conductive film of the through-hole interior surfaces of the through-holes, and to the vicinities of peripheries of the through-holes on the first side, thereby causing the through-holes to become electrically conductive;
- (g) stripping the photosensitive dry film;
- and
- (h) forming a circuit pattern in the copper foil on the first and second sides of the substrate.
Dependencies are inferred from the claim text.