JPH0563364A - Manufacture of blind through hole multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To reduce via holes and realize high speed transmission and high density mounting, by making an 8-layered printed wiring board from two 4-layered boards using four printed wiring boards wherein holes are bored in copper clad boards and a pattern is formed on one surface of each board after copper plating. CONSTITUTION:Necessary holes are bored in a copper clad board 27 wherein copper foils 25 are stuck on the upper surface and the lower surface. By copper plating, printed wiring boards 31, 32, 33, 34 are formed wherein a necessary pattern is formed on one surface of each board. The wiring boards 31, 32 and the wiring boards 33, 34 are so laminated that the respective single surface patterns are made to face each other via prepreg 35, thereby forming 4-layered boards 36, 37. Necessary holes are bored in the boards 36, 37, and a pattern is formed on one surface of each board by copper plating 39. Thus 4-layered printed wiring boards 41, 42 are formed. The boards 41, 42 are so laminated that the patterns are made to face each other via prepreg 35, thereby forming an 8-layered board 43. Necessary holes are bored in the board 43, and patterns 46, 47 are formed on both surfaces, thereby forming an 8-layer printed wiring board 48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for manufacturing a blind through-hole multilayer printed wiring board.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a blind through-hole 8-layer printed wiring board, holes 2 are formed in a copper clad substrate 1 shown in FIG.
14 and after applying the copper plating 3 as shown in FIG.
, Two printed wiring boards 5 each having the pattern 4 formed on one side thereof and two printed wiring boards 6 having the patterns 4 formed on both sides thereof as shown in FIG. Pattern 5 and 6 on both sides as shown in FIG.
The printed wiring board 6 on which the pattern is formed is arranged on the inside, the printed wiring board 5 on which the pattern 4 is formed on one side is arranged on the outside, and the pattern 4 is used as an inner layer, and laminated and molded through the prepreg 7 to form an 8-layer substrate 8 After that, after making holes 9 in the 8-layer substrate 8 as shown in FIG. 17 and applying copper plating 10 as shown in FIG. 18, pattern 11 is formed on both sides as shown in FIG. 8
Making the layer printed wiring board 12.

As another manufacturing method, a printed wiring board 13 having a pattern 4 formed on one surface of a copper clad substrate 1 as shown in FIG. A four-layer board 14 is formed by laminating through the prepreg 7, a hole 15 is then formed in the four-layer board 14 as shown in FIG. 22, and copper plating 16 is applied as shown in FIG. As shown in FIG. 24, a pattern 17 is formed on one side to form a four-layer printed wiring board 18, and then two pieces of this four-layer printed wiring board 18 are used, with the one-sided pattern 17 on the inside, to form the prepreg 7 as shown in FIG. It is laminated through to form an eight-layer board 19, and then a hole 20 is made in this eight-layer board 19 as shown in FIG. 26, and copper plating 21 is applied as shown in FIG. 27, and then shown in FIG. Thus, the patterns 22 are formed on both sides to form the 8-layer printed wiring board 23.

By the way, in the 8-layer printed wiring boards 12 and 23 produced by the above manufacturing method, many holes 9 and 20 serving as via holes are formed in the multilayer substrates 8 and 19, so that the line length becomes long and high-speed transmission is achieved. It is not possible and high-density mounting is impossible.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to provide a method for manufacturing a blind through-hole multilayer printed wiring board capable of high-speed transmission and capable of high-density mounting.

[0006]

A method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention for solving the above-mentioned problems is to form a pattern on one surface after forming a hole in a copper-clad substrate and performing copper plating. Make four printed wiring boards,
Next, two of these printed wiring boards are laminated and formed with a pattern on one side inside with a prepreg to make two 4-layer boards, and then each 4-layer board is perforated and copper-plated and then on one side. A pattern is formed to make a four-layer printed wiring board, and then these two four-layer printed wiring boards are laminated and formed with a pattern on one side on the inside via a prepreg to make an eight-layer board. It is characterized in that an 8-layer printed wiring board is produced by forming a hole in a layered substrate, plating it with copper, and then forming patterns on both sides.

[0007]

According to the method for manufacturing a blind through-hole multilayer printed wiring board of the present invention described above, blind via holes are provided between the first and second layers and the seventh and eighth layers within a limited area, and between the third and fourth layers and the fifth and fifth layers. Because you can make many belly via holes between 6 layers, and you can also make many blind via holes between 1 to 4 layers and 5 to 8 layers.
The number of via holes of 1 to 8 layers can be reduced. Therefore, high-speed transmission is possible and high-density mounting is possible.

[0008]

EXAMPLE An example of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention will be described with reference to the drawings.
As shown in Fig. 1, 0.15 of copper foil 25 of 18μ and 35μ on both upper and lower surfaces is used.
After drilling the required holes (for blind via holes and belly via holes) 28 on the copper clad substrate 27 stretched on the base material 26 of mm thickness by NC drilling device, after the surface preparation, as shown in Fig. 2, electroless plating Method + electroplating method to plate copper to a thickness of 15 μm
Then, the printed wiring boards 31, 32, 33 and 34 were prepared by forming the required pattern 30 on one surface by photoresist photography as shown in FIG. Next, the printed wiring boards 31 and 32 and the printed wiring boards 33 and 34 are patterned on one side, respectively.
As shown in FIG. 4, four layers of substrates 36 and 37 are formed by laminating with 30 on the inside through a prepreg 35, and then each of the layers of four layers 3
After performing external processing and surface adjustment of 6 and 37, after making a required hole (for blind via hole) 38 with an NC drilling device as shown in Fig. 5, after performing smearing, surface finishing and cleaning inside the hole As shown in FIG. 6, copper plating 39 is applied to a thickness of 15 to 25 μm by electroless plating + electroplating, and the surface is prepared, and a pattern 40 is formed on one side by photoresist photography as shown in FIG. 4 layer printed wiring board 41,
Made 42. Next, the four-layer printed wiring boards 41, 42 are formed with the pattern 40 on one side facing inward as shown in FIG.
To form an 8-layer board 43, and then
After the outer shape and the surface of the layered substrate 43 are processed, as shown in FIG.
After opening, smearing, surface finishing and hole cleaning, copper plating 45 is applied to a thickness of 20 to 30 μm by electroless plating + electroplating as shown in FIG. Patterns 46 and 47 were formed on both sides by a photographic method as shown in FIG. 11 to form an 8-layer printed wiring board 48. Thereafter, the 8-layer printed wiring board 48 is subjected to liquid photoresist, solder coating, outer shape processing and the like.

According to the method of manufacturing the 8-layer printed wiring board 48 of this embodiment, the blind via holes are first formed between the 1st and 2nd layers, the 7th to 8th layers, and the belly via holes are formed between the 3rd to 4th layers and the 5th to 6th layers. A lot of blind via holes were made in the limited area during the drilling of 1 to 4 layers, and 5 to 8 layers were made in the limited area during the second drilling. Since the via holes between 8 layers can be reduced, the 8-layer printed wiring board 48 can be transmitted at high speed and high-density mounting can be achieved.

[0010]

As described above, according to the method for manufacturing a blind through-hole multilayer printed wiring board of the present invention, it is possible to easily manufacture a blind through-hole multilayer printed wiring board capable of high-speed transmission and capable of high-density mounting.

[Brief description of drawings]

FIG. 1 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 2 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 3 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 4 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 5 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 6 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 7 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 8 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 9 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 10 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 11 is a diagram showing steps of an embodiment of a method for manufacturing a blind through-hole multilayer printed wiring board according to the present invention.

FIG. 12 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 13 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 14 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 15 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 16 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 17 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 18 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 19 is a diagram showing steps of a method for manufacturing a conventional blind through-hole multilayer printed wiring board.

FIG. 20 is a diagram showing steps of a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 21 is a diagram showing steps of a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 22 is a diagram showing a step in a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 23 is a diagram showing steps of a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 24 is a diagram showing steps of a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 25 is a diagram showing a step in a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 26 is a diagram showing a step in a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 27 is a diagram showing a step in a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

FIG. 28 is a diagram showing a step in a method for manufacturing another conventional blind through-hole multilayer printed wiring board.

[Explanation of symbols]

 27 Copper clad board 28 Hole 29 Copper plating 30 Pattern 31, 32, 33, 34 Printed wiring board 35 Prepreg 36, 37 4 layer board 38 hole 39 Copper plated 40 Pattern 41, 42 4 layer printed wiring board 43 8 layer board 44 hole 45 Copper plating 46, 47 pattern 48 8-layer printed wiring board

Claims (1)

[Claims] 1. A copper-clad substrate is perforated, copper-plated, and then a pattern is formed on one side to form four printed wiring boards. Then, two of these printed wiring boards are placed on the inside with the pattern on one side. Two 4-layer boards are made by laminating through a prepreg, then each 4-layer board is punched, copper plated and then patterned on one side to make a 4-layer printed wiring board, then this Two 4-layer printed wiring boards are laminated and formed on one side with the pattern on one side through a prepreg to make an 8-layer board. After that, holes are punched on this 8-layer board, and copper plating is applied, then the patterns are formed on both sides. A method for manufacturing a blind through-hole multilayer printed wiring board, which comprises forming an eight-layer printed wiring board by forming.