JPH0575257A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To prevent the intrusion of a resin obtained by melting a prepreg into a previously bored and plated through-hole when the prepreg is held between printed wiring boards and heated and contact-bonded and the wiring boards are laminated regarding the manufacture of the multilayer printed wiring board with the hollow non-through through-hole. CONSTITUTION:Hollow plated through-holes 1a penetrated thigh at least one side of a plurality of printed wiring boards 1 laminated are formed previously, holes 2a corresponding to the plated through-holes 1a are bored to a prepreg 2 held between the printed wiring boards 1 laminated, a resin on the inner surfaces and peripheries of the holes is thermo-set beforehand and thermo-set resin sections 2a-1 are formed, and the prepreg 2 is held between the printed wiring boards 1 laminated and heated and contact-bonded and the wiring boards 1 are laminated in multilayers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board having a hollow non-through through hole into which a terminal pin such as a press fit pin can be inserted and connected.

A prepreg (Prepr) is provided between printed wiring boards.
eg: A glass prepreg is impregnated with a regulated resin varnish and dried, and a semi-cured sheet is sandwiched between them for thermocompression bonding to produce a multilayer printed wiring board, and the resin of the prepreg melts and softens. It is desired to prevent it from getting into the through hole.

[0003]

2. Description of the Related Art A conventional method for manufacturing a multi-layered printed wiring board is one method as shown in the side sectional view of the main part of FIG. 5) as a method of forming a non-through through-hole through hole by drilling up to the intermediate layer 12 and forming a non-through copper-plated through hole 11a by copper plating the through hole, or as another method of FIG. As shown in the side cross-sectional view of the printed wiring board, two printed wiring boards 13-1 and 13-2 are formed with hollow copper-plated through holes 13-1a and 13-2a. There is a method in which a prepreg 14 is sandwiched between 13-1 and 13-2, and the layers are superposed and thermocompression-bonded by a lamination press (not shown) to laminate.

[0004]

However, according to such a manufacturing method as described above, when the thickness of the multilayer printed wiring board becomes thicker and the through-hole pilot hole becomes deeper, the plating solution reaches deeper in the former method. There is a problem that a uniform plating layer cannot be formed on the inner surface of the hole and the reliability of the connection with the insertion terminal pin deteriorates.In the latter method, the resin of the prepreg is melted and softened at the time of thermocompression bonding. However, there is a problem in that the resin will adhere to the inner surface of the plated through hole and the reliability of the connection with the insertion terminal pin will be deteriorated.

In view of the above problems, according to the present invention, when a prepreg is sandwiched between printed wiring boards and laminated by thermocompression bonding, it is possible to prevent the molten resin of the prepreg from entering into a pre-opened plated through hole. An object of the present invention is to provide a method for manufacturing a printed wiring board.

[0006]

In order to achieve the above object, in the method for manufacturing a multilayer printed wiring board according to the present invention, a hollow plated through hole penetrating at least one side of a plurality of printed wiring boards to be laminated is formed. Preformed,
A hole corresponding to the plated through hole is opened in a prepreg sandwiched between the laminated printed wiring boards to form a thermosetting resin portion by pre-thermosetting the resin on the inner surface of and around the hole.
The prepreg is sandwiched between the printed wiring boards to be laminated, and thermocompression bonded to form a multilayer.

[0007]

[Function] A hollow plated through hole penetrating at least one side of a printed wiring board to be laminated is formed in advance, a hole corresponding to the plated through hole is formed in the prepreg, and the resin on the inner surface of the hole and the surrounding resin are thermoset in advance. By forming a thermosetting resin part, when heated during crimping,
The melted resin of the prepreg is blocked by the thermosetting resin portion and can be prevented from entering the plated through hole.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention will be described in detail below with reference to the embodiments shown in the drawings. The manufacturing method of the multilayer printed wiring board is as shown in FIGS. 1 (a) and 1 (b):
First, a hollow plated through hole 1a that penetrates at least one side of a plurality of laminated printed wiring boards 1 is formed in advance. (The figure shows a case where two printed wiring boards 1-1 and 1-2 are laminated, and a plurality of hollow copper-plated through holes 1-1a and 1-2a are formed on both sides.) , The printed wiring boards 1 to be laminated, that is, the prepregs 2 sandwiched between 1-1 and 1-2, are plated through holes 1-1a and 1-2a of both the printed wiring boards 1-1 and 1-2 to be crimped. The hole 2a corresponding to is opened beforehand.

In the method of drilling holes in the prepreg 2, the prepreg 2 is placed on the die 3 of the punching press and punched by the punch 4, as shown in the side sectional view of the main part of FIG. After punching, the heat transfer rod 5 provided in the center of the punch 4 is heated by the built-in sheath heater 6 to heat the tip of the punch 4, and the heated punch 4 is punched in the hole 2a of the prepreg 2. The resin on the inner surface of and around the insertion hole 2a is heated and heat-cured to form a thermosetting resin portion 2a-1. (Note that 7 in FIG. 2 is a heat insulating material) The heating temperature and time are appropriately set.

Alternatively, as another method of drilling holes in the prepreg 2, as shown in the side sectional view of the main part of FIG. 3, the holes are drilled by the laser beam 8 of the laser hole drilling machine, and at the same time, the resin on the inner surface and the periphery of the holes 2a is heated. Thermosetting resin part 2a as in the previous method
Form -1. (Note that 9 is a laser head, and 10 is a backing plate.) If the holes are close to each other, the deformed holes may be connected to each other. In short, the plated through hole of the printed wiring board is made to escape and the inner surface and The surrounding resin may be thermoset. As for the processing of the deformed hole, the hole processing by the laser beam can flexibly cope with various shapes, as compared with the hole processing by the former punch.

Next, the prepreg 2 is sandwiched between the printed wiring boards 1-1 and 1-2 to be laminated by a lamination press (not shown).
After sandwiching them, they are aligned with each other by positioning means (not shown) provided on the peripheral edge, and then thermocompression bonding is performed to stack them to complete a multilayer printed wiring board.

As described above, the holes formed in the prepreg corresponding to the plated through holes of the printed wiring board to be laminated are thermoset resin by thermosetting the resin on the inner surface and the surroundings in advance before laminating. Since it does not melt out, it is possible to prevent the resin from entering into the plated through hole at the time of crimping even if a hollow plated through hole that penetrates the printed wiring board is opened in advance before being laminated on the printed wiring board. Therefore, it is possible to form a hollow non-penetrating plated through hole that can be effectively used deeply in the multilayer printed wiring board,
The reliability of the connection between the through hole and the insertion terminal pin can be ensured.

[0013]

As described above in detail, according to the present invention,
It is possible to form a hollow non-through plated through hole that can be effectively used deeply in a multilayer printed wiring board, and it is possible to ensure the connection reliability between the through hole and the insertion terminal pin, which is extremely useful in industry.

[Brief description of drawings]

FIG. 1 is an exploded side sectional view of an essential part showing an embodiment according to the present invention and a sectional side view of an essential part showing a multilayer printed wiring board after lamination thereof.

FIG. 2 is a side sectional view of an essential part showing a drilling method for the prepreg of FIG.

FIG. 3 is a side sectional view of an essential part showing another drilling method for the prepreg of FIG.

FIG. 4 is a side sectional view of an essential part showing a manufacturing method according to a conventional technique.

FIG. 5 is a side sectional view of an essential part showing another manufacturing method according to the prior art.

[Explanation of symbols]

 1 is a printed wiring board 1a is a plated through hole 2 is a prepreg 2a is a hole 2a-1 is a thermosetting resin part 4 is a punch 8 is a laser beam

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mari Hagiwara 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (3)

[Claims] 1. A hollow plated through hole penetrating at least one side of a plurality of printed wiring boards (1) to be laminated.
(1a) is formed in advance, and the plated through hole (1a) is formed in the prepreg (2) sandwiched between the laminated printed wiring boards (1).
A hole (2a) corresponding to the hole (2a) is opened, and the resin on the inner surface of the hole (2a) and the surrounding resin is previously thermoset to form a thermosetting resin portion (2a-1), and the prepreg (2) is laminated on the printed wiring board A method for manufacturing a multilayer printed wiring board, which comprises sandwiching the substrates (1) and thermocompressing them to laminate them in multiple layers. 2. The hole (2a) of the prepreg (2) according to claim 1.
Is punched with a punch (4), and the punch (4) that has been heated after the hole has been punched is inserted into the hole (2a) to heat and thermoset the resin on the inner surface and the surrounding area of the multilayer printed wiring board. Production method. 3. Hole (2a) in the prepreg (2) according to claim 1.
Is a method of manufacturing a multilayer printed wiring board, characterized by performing hole processing with a laser beam (8), and heating and thermosetting the resin on the inner surface and surroundings of the hole (2a).