JPS63124597A - Manufacture of printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a printed wiring board, and particularly to a method for manufacturing a printed wiring board having a mixture of through holes and non-through holes.

[Conventional technology]

Conventionally, printed wiring boards having a mixture of through holes and non-through holes have been manufactured according to the steps shown in FIGS. 2(a) to 2(h). First, as shown in FIG. 2(a), a hole 3 is made in a printed wiring board (hereinafter referred to as a board) 1 having copper foil 2 bonded to its front and back surfaces.

Next, as shown in FIG. 2(b), the entire surface of the substrate 1 is plated to deposit a conductive layer 4, and through holes 3a are formed. Next, as shown in FIG. 2(c), a photosensitive resin 6 is filled into the hole 3 in which the through hole 3a is formed and photocured. Next, after removing the photosensitive resin 6 on the surface of the substrate 1, an etching resist layer 7 is formed on a part of the surface of the substrate 1, as shown in FIG. 2(d).

Next, as shown in FIG. 2(e), etching resist 1-layer 7 is etched.
After etching is performed on the entire surface of the substrate 1 using the etching mask as a sowing mask, the etching resist layer 6 and the photosensitive resin 5 are peeled off and removed to form a desired circuit pattern, as shown in FIG. 2(f). Next, place the substrate 1 at the desired position (see Fig. 2).
g>, a non-through hole 5a is bored. Next, a solder resist 8 was printed as shown in FIG. 2(h), and finally an outline process was performed to obtain a printed wiring board in which through-holes 3a and non-through-holes 5a coexisted.

[Problem that the invention seeks to solve]

The conventional printed wiring board manufacturing method described above has the following drawbacks.

(1) In recent years, ICs, LSIs, and resistors have been applied to printed wiring boards.

Automatic mounting machines are being used to mount various parts such as capacitors, and the proportion of their use is increasing year by year. In this case, the relative position accuracy between through hole 3a and non-through hole 5a is ±5
High accuracy within 0μ is required. On the other hand, when the through hole 3a and the non-through hole 5a are formed by separate drilling, the expansion and contraction of the substrate 1 during the manufacturing process, or the holes used when drilling the through hole 3a and the non-through hole 5a, respectively, may be caused by a shift in the relative position of the machine. The disadvantage is that the relative hole position accuracy between the through hole 3a and the non-through hole 5a deteriorates due to such factors. Two or three sheets are stacked, so-called stacked drilling. However, when drilling non-through holes 5a, if overlapping holes are drilled, the relative value δ accuracy between through holes 3a and non-through holes 5a will deteriorate significantly, so overlapping holes are not performed, and normally one hole is drilled per axis. are doing. As a result, work efficiency deteriorated significantly, and the cost of materials used in connection with the drilling work, such as backing plates, back-up materials, and drills, increased, making it difficult to manufacture inexpensive printed wiring.

The purpose of the present invention is to eliminate the above-mentioned conventional drawbacks, ensure the relative positional accuracy of both through-holes and non-through-holes, support automatic mounting of components, and improve work efficiency and reduce material costs. An object of the present invention is to provide a method for manufacturing a printed wiring board that can be measured.

Means for Solving Problems] The method for manufacturing a printed wiring board of the present invention includes the steps of simultaneously drilling holes for through-holes and non-through-holes in a printed wiring board having copper foil bonded on one side; A process of plating the entire surface to form a conductive layer on the inner wall surface of the hole and the copper foil surface, a process of filling a photosensitive resin between the holes, and a process of selectively photocuring the photosensitive resin inside the hole for the through hole. A step of chemically removing the uncured portion of the photosensitive resin, forming an etching resist layer on a part of the surface of the conductive layer, and using this etching resist layer as an etching mask to remove the uncured portion of the conductive layer. selectively etching away the exposed portion;
The method includes a step of removing the photosensitive resin and the etching resist layer.

[Example] Next, an example of the present invention will be described with reference to the drawings. FIGS. 1(a) to 1(d) are cross-sectional views of a printed wiring board shown in the order of steps for explaining an embodiment of the present invention.

First, as shown in Fig. 1(a), the NC drilling machine simultaneously drills holes 3 for through holes and holes 5 for non-through holes in a printed wiring board 1 with copper foil 2 bonded to both sides of the round surface. . Next, as shown in FIG. 1(b), the printed wiring board 1 is subjected to electroless steel plating and electrolytic copper plating to coat the conductive layer 4 and form the through holes 3a. Next, a through hole 3a with a conductive layer 4 and a hole 5 for a non-through hole is formed.
As shown in FIG. 1(C), an ultraviolet curing type photosensitive resin 6 is filled into the inside using, for example, a roll coater (not shown). Next, as shown in FIG. 1(d), both sides of the printed wiring board 1 are irradiated with 1 to 2 J/.2 ultraviolet rays through a mask 9.
The photosensitive resin 6 in the through hole 3a is selectively photocured. Next, as shown in FIG. 1(e), an organic solvent such as 1,1.1-1-lichloroethane is sprayed onto the uncured portion of the photosensitive resin 6 to dissolve and remove the uncured photosensitive resin. . Furthermore, after polishing and removing the photosensitive resin 6 on the front and back surfaces of the substrate 1, as shown in FIG. Etching resist layer 7
form. Next, as shown in FIG. 1 (g), using the etching resist layer 7 as an etching mask, the exposed portion of the conductive layer 4 is etched away to form a desired circuit pattern, and at the same time, the copper-plated conductive layer 4 on the inner wall of the hole 5 is also removed. Non-through holes 5a are formed by etching and removing.

Next, as shown in FIG. 1(h), after removing and removing the etching resist layer 7 and photosensitive resin 6 with an aqueous sodium hydroxide solution, a solder resist 8 is printed on the circuit pattern as shown in FIG. 1(i), and finally, A predetermined outer frame cutting process was performed to create a printed wiring board in which non-through holes 5a and through holes 3a coexist.

〔Effect of the invention〕

The present invention as described above has the following effects.

(1) Since through-holes and non-through-balls can be formed by simultaneous drilling, the relative positional accuracy of both holes is guaranteed.
Printed wiring boards compatible with automatic component mounting can be manufactured.

(2) Improve work efficiency and reduce material costs,
It is possible to manufacture inexpensive printed wiring boards.

[Brief explanation of the drawing]

1(a) to 1(i) are cross-sectional views of a printed wiring board shown in the order of steps for explaining one embodiment of the present invention, and FIG.
) to (h) are cross-sectional views of a printed wiring board shown in order of process for explaining a conventional method of manufacturing a printed wiring board. DESCRIPTION OF SYMBOLS 1... Printed wiring board, 2... Copper foil, 3... Hole (for through hole), 3a... Through hole, 4... Conductive layer, 5... (For non-through hole) > hole, 5a...
Non-through hole, 6... Photosensitive resin, 7... Etching resist layer, 8... Solder resist, 9...
mask. fi-i 1ff1 1f51 diagram

Claims (1)

[Claims] A process of simultaneously drilling holes for through holes and non-through holes in a printed wiring board with copper foil bonded on both sides, and plating the entire surface of the printed wiring board to coat the inner wall surface of the hole and the copper foil surface. a step of forming a conductive layer, a step of filling the hole with a photosensitive resin, a step of selectively photocuring the photosensitive resin in the hole for the through hole, and a step of curing the uncured portion of the photosensitive resin. a step of chemically removing the conductive layer; a step of forming an etching resist layer on a part of the surface of the conductive layer and selectively etching away the exposed portion of the conductive layer using the etching resist layer as an etching mask; 1. A method for producing a printed wiring board, the method comprising: removing a synthetic resin and an etching resist layer.