JP2833601B2 - Manufacturing method of printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a printed wiring board, and more particularly to a method of manufacturing a printed wiring board using a build-up method.

[0002]

2. Description of the Related Art A conventional method for forming a dividing groove in a printed wiring board is to form a printed wiring board manufactured by a known technique, and then transport the printed wiring board to a place where a wheel cutter is rotating, and then use a machine. In general, the method of forming the dividing groove is generally used.However, when forming the dividing groove particularly in the case of a thin printed wiring board, the base material may be cracked or burr may be generated. There was a serious problem. As a method for solving this problem, according to JP-A-4-42594, as shown in FIGS. 4A to 4D, a flexible resin substrate 1 made of a polyimide resin having a copper foil 10 formed thereon is used.
1 is used to make a resist plate on the surface of the copper foil 10, and a predetermined portion of the copper foil 10 is etched away using the plate-formed photosensitive resist 13 to form an insulating resin substrate etching resist; A method is disclosed in which a predetermined number of holes and grooves of a predetermined shape such as the through-holes 12 and the dividing grooves 7 are collectively formed at the time of etching the base material by using the insulating resin base material etching resist. According to Japanese Patent Application Laid-Open No. 3-232293, FIG.
(A) and (b), as shown in FIG.
Local exposure, primary heat treatment and wet etching to simultaneously form the through-hole 12 and the dividing groove 7.

[0003]

The above-mentioned conventional method for manufacturing a printed wiring board has the following problems.
That is, Japanese Unexamined Patent Application Publication No. 4-42 shown in FIGS.
No. 594 and Japanese Unexamined Patent Application Publication No.
In the example described in Japanese Patent Application Publication No. 232293, both are only double-sided printed wiring boards (two-layer boards). Further, in the manufacturing process of simultaneously forming the dividing grooves and forming the through-hole holes, the dividing grooves are partially penetrated. Since the through-holes need to be penetrated, it was very difficult to determine the conditions for dissolving the base material.

An object of the present invention is to provide a method of manufacturing a printed wiring board in which a dividing groove and a through hole can be easily formed at the same time.

[0005]

According to the present invention, there is provided a method of manufacturing a printed wiring board using a build-up method, wherein a step of applying a photosensitive resin to an inner core material on which a circuit has been formed, a photo via hole and a dividing groove are provided. And forming a photo via hole and a cutting groove at the same time by exposing and developing by a photo method using a mask film for forming a mask film.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.

FIGS. 1 (a) to 1 (c), 2 (a) to
3 (c) and FIGS. 3 (a) to 3 (c) are cross-sectional views shown in the order of steps for explaining the method for manufacturing a printed wiring board according to one embodiment of the present invention. In the method for manufacturing a printed wiring board according to one embodiment of the present invention, first, as shown in FIG. 1A, a conductor pattern 1 and a photo via land 2 are formed by a conventionally known method. At this time, an epoxy resin having a thickness of 100 μm is used for the insulating base material 3 and the thickness of the copper foil is 12 μm. next,
As shown in FIG. 1B, a photosensitive insulating resin 5 is applied to both sides of the core layer 4 formed by the above-described method, with a thickness of 80 μm. Next, as shown in FIG. 1C, a mask film 8 for forming a photo via hole 6 and a dividing groove 7 is formed.
Is prepared in advance, and the mask film 8 is superposed on the photosensitive insulating resin 5 and exposed to UV light of 4 J / cm ² to perform exposure. At this time, the diameter of the photo via hole is 0.15 mm, and the width of the dividing groove is 0.15 mm. (Equivalent to the photo via hole diameter normally used in build-up boards)
As shown in FIG. 3A, the photo via hole 6b and the dividing groove 7 are simultaneously formed by performing development using a butyl-based solvent. Next, as shown in FIG. 2B, electroless copper plating and electrolytic copper plating are performed to form photovias 6a.

[0008] Thereafter, as shown in FIG.
The photosensitive insulating resin 5 is again applied to both sides of the core 9 that has been built up twice, to a thickness of 80 μm. Next, FIG.
As shown in FIG. 2A, the photo via hole 6b is again placed in the same place as the dividing groove 7 created in FIG.
b and a mask film 8 for forming the dividing groove 7 are prepared in advance, and the mask film 8 is overlaid on the photosensitive insulating resin film 5 and irradiated with 4 J / cm ² UV light for exposure. At this time, the diameter of the photo via hole 6b is 0.15 mm, and the width of the dividing groove 7 is 0.15 mm. (Equivalent to the diameter of a photo via hole normally used in a build-up substrate) Next, as shown in FIG. 3B, development is performed with a butyl-based solvent to form a photo via hole 6b and a dividing groove 7 at the same time. At this time, development is performed until the dividing groove 7 reaches the core layer 4. The butyl-based solvent is developed only in the unexposed portions of the photosensitive resin, and the photo via lands 2 and the insulating base material 3 are not dissolved, so that the dividing grooves 7 do not penetrate. Next, as shown in FIG. 3C, electroless copper plating and electrolytic copper plating are performed to form photovias 6a.

As a result, the photo via 6a and the dividing groove 7
Can be formed simultaneously. Therefore, since it can be manufactured by the conventional build-up method without adding a manufacturing process, it can also be applied to the manufacture of a multilayer printed wiring board, and can be divided into arbitrary shapes having a high degree of freedom at arbitrary locations at the same time as the formation of the photo via holes 6b. Grooves 7 can be formed, and development can be performed until the photosensitive insulating resin 5 is no longer dissolved, so that it is not necessary to divide difficult manufacturing conditions. Boards can be manufactured.

[0010]

As described above, the present invention can be manufactured by a conventional built-up method without adding a manufacturing process, and can be used to divide an arbitrary shape with a high degree of freedom at an arbitrary place at the same time as forming a photo via hole. Grooves can be formed. Further, since it is not necessary to divide difficult manufacturing conditions, a multilayer printed wiring board having a dividing groove can be easily manufactured.

[Brief description of the drawings]

FIGS. 1A to 1C are cross-sectional views illustrating a method of manufacturing a printed wiring board according to an embodiment of the present invention in the order of steps for explaining the method.

FIGS. 2A to 2C are cross-sectional views illustrating a method of manufacturing a printed wiring board according to an embodiment of the present invention in the order of steps.

FIGS. 3A to 3C are cross-sectional views shown in a process order for describing a method of manufacturing a printed wiring board according to an embodiment of the present invention.

FIGS. 4A to 4D are cross-sectional views sequentially illustrating steps for explaining an example of a conventional method for manufacturing a printed wiring board.

5 (a) and 5 (b) are cross-sectional views of through-hole holes in a dividing groove of an example of a conventional printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor pattern 2 Photo via land 3 Insulating base material 4 Core layer 5 Photosensitive insulating resin 6a Photo via 6b Photo via hole 7 Dividing groove 8 Mask film 9 Core built up once on both sides 10 Copper foil 11 Flexible resin base material 12 Through hole Hole 13 Photosensitive resist 14 External support bar 15 Chemically cut glass plate

Claims (2)

(57) [Claims] In a method of manufacturing a printed wiring board by a build-up method, a step of forming a conductor pattern and a photo via land on an insulating base material of epoxy resin, and forming the conductor pattern and the photo via land on the insulating base material Applying a photosensitive insulating resin to both sides of the formed core layer, contacting a mask film, irradiating with UV light, exposing and developing to form a photo via hole and a dividing groove simultaneously, electroless copper plating and electrolytic copper A step of forming photovias by plating and forming a core that has been built up once on both sides; applying a photosensitive resin to both sides of the core again, contacting a mask film, irradiating UV light, exposing and developing the photovia holes And a step of simultaneously forming a photo via hole and a dividing groove again in the same place as the dividing groove, and forming a photo via by performing electroless copper plating and electrolytic copper plating. And a process for producing a printed wiring board. 2. The method for manufacturing a printed wiring board according to claim 1, wherein said exposing and developing are performed with a butyl solvent.