JPH05259643A - Manufacture of multilayer wiring board - Google Patents

Abstract

PURPOSE:To reduce a manufacturing time and cost, and to improve productivity by laminating a composite layer sheet, made of predrilled insulating resin layer 3 and an adhesive layer 5, together so that a processing time for a drilling process can be reduced. CONSTITUTION:When a composite layer sheet 5 is laminated on a double-sided copper-clad laminated plate 3 by a vacuum laminator, a bore 8 formed on the sheet 5 is positioned on a circuit 4 formed on the laminated plate 3. Here, the surface of the circuit 4 has been subjected to an oxidation and reduction treatment, whereby a superior adhesion is obtained. After the lamination, a through hole 9 that passes through the sheet 5 and the laminated plate 3 is formed by drilling or the like, and then the laminate is subjected to a smear treatment. Then, the laminate is also subjected to zeeder treatment and electroless plating, so that plating layers 10 and 11 are formed over the throughholes 8 having a closed-off end and the throughhole 9. Further, the laminate undergoes an etching treatment, whereby an outer layer circuit 12 is formed. Thereby, only the formation of a throughhole is required in a drilling process, and hence a plurality of sheets of multilayer wiring boards can be processed at one time, and thus productivity is increased.

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 wiring board.

[0002]

2. Description of the Related Art A multilayer wiring board is manufactured, for example, as follows. That is, a double-sided copper-clad laminate having an inner layer circuit formed on the central substrate is used. Then, a prepreg made of a glass cloth resin-impregnated cloth is laminated on both sides of this laminated plate. Next, a circuit-formed copper-clad laminate, a prepreg, and a copper foil are sequentially laminated on the surface of the prepreg. After the lamination, pins are set up in the reference holes provided on the left and right of the laminated plate, prepreg, etc., and aligned, pressed, and heated and pressed. After pressing, the board is applied to the multilayer board. Then, fix the end with tape or the like so that this plate does not move. In this state, a non-through hole is formed from the copper foil on the surface to the circuit one layer below using a drill or a laser. Then, a through hole is formed using a drill or the like. After forming the through holes, the contact plate is removed, and electroless copper plating treatment and electrolytic copper plating treatment are performed to form a plating layer in each hole. Next, the copper foil on the surface is etched to form a circuit.

[0003]

In order to reduce the manufacturing time, it is sufficient to stack a plurality of multi-layer boards in the punching step. However, in this state, although the through hole can be formed, the non-through hole cannot be formed. Therefore, there is a drawback that the holes have to be formed one by one, the work takes time, the productivity is low, and the manufacturing cost is hindered.

An object of the present invention is to provide a method for manufacturing a multilayer wiring board, which is capable of improving the above drawbacks, shortening the manufacturing time and improving the productivity, and reducing the manufacturing cost.

[0005]

In order to achieve the above object, the present invention is a process for laminating a composite layer sheet having holes made of an insulating resin layer and an adhesive layer on the surface of an inner layer circuit board. And a step of performing a plating treatment after this step to form a plated layer in the hole and an outer layer circuit, and to provide a method for manufacturing a multilayer wiring board.

The insulating resin layer contains a thermosetting resin such as an epoxy resin, an epoxidized polybutadiene resin, a phenol resin, a modified polyamideimide resin or a modified polyimide resin as a main component, and contains polybutadiene, styrene butadiene rubber, acrylonitrile rubber or phenoxy resin. For example, a compound containing a flexible polymer compound and an inorganic filler is used. Then, the insulating resin layer and the adhesive layer are laminated to form a composite layer sheet, and then a hole is punched in advance using a punching machine.

[0007]

Since the composite layer sheet including the insulating resin layer and the adhesive layer, which are preliminarily provided with holes, is laminated on the surface of the inner layer circuit board, the step of forming the non-through holes can be omitted. Therefore, in the punching step, only the through holes need to be formed, a plurality of sheets can be processed at one time, and the productivity is increased.

[0008]

EXAMPLES The present invention will be described below based on examples. Example 1: As shown in FIG. 1 (a), a central substrate is provided with a two-layer circuit 1 on an inner layer, and copper foils 2 are attached to both outer surfaces of the inner layer. To use. Then, the surface of the copper foil 2 is etched to form a circuit 4 as shown in FIG. Then, the surface of the circuit 4 is subjected to redox treatment.

The composite layer sheet 5 has an insulating resin film 6 having a thickness of 180 μm and a thickness of 2 as shown in FIG.
0 μm adhesive film 7 is laminated to make the total thickness 2
The diameter is set to 00 μm, and a hole 8 having a diameter of 0.2φ is provided in advance.

Next, as shown in FIG. 1D, the composite layer sheet 5 is laminated on the double-sided copper-clad laminate 3 with a vacuum laminator. At this time, the holes 8 provided in the composite layer sheet 5 are arranged on the circuit 4 provided in the laminate 3. Since the surface of the circuit 4 is subjected to the redox treatment, the adhesion is good.

After laminating, as shown in FIG. 1 (e), a hole 9 penetrating the composite layer sheet 5 and the laminated plate 3 is formed by a drill or the like. After forming the through hole 9, smearing is performed to remove the smear.

After the smearing treatment, a jider treatment and an electroless plating treatment are performed to form plating layers 10 and 11 in the non-through holes 8 and the through holes 9, respectively, as shown in FIG.

After forming the plating layers 10 and 11, FIG.
As shown in (g), the outer layer circuit 1 is subjected to etching treatment.
Form 2.

After the outer layer circuit 12 is formed, solder resist printing is performed as shown in FIG.
3 is formed.

Next, with respect to the first embodiment and the conventional example 1,
The interlayer adhesion and the peel strength of the copper foil were determined, and a thermal shock test was conducted.

The manufacturing method of Conventional Example 1 is as follows. Conventional Example 1: As shown in FIG. 2 (a), two double-sided copper-clad laminates 22 each having a circuit 21 formed on both sides thereof are laminated via a prepreg 23 of a glass cloth resin impregnated cloth, and the opposite sides are also laminated with each other. The prepregs 24 and 25 of the same material are piled up. Further, copper foils 26 and 27 are overlaid on the prepregs 24 and 25, respectively. Then, the reference holes 2 provided in the laminated plate 22, the prepregs 23 to 25, and the copper foils 26 and 27, respectively.
Align pins 8 to 33 with each other through pins 34. After alignment, press and heat and press to bring them into close contact with each other. The thickness of each prepreg 23 to 25 is 200 μm. After pressing, as shown in FIG. 2B, a copper foil 26 and 27 up to the following circuit 21 is 0.2.
Drill a hole 35 of φ. Moreover, a hole 36 penetrating each layer is opened by a drill. After drilling holes 35 and 36, FIG.
As shown in (c), electroless copper plating and electrolytic copper plating are performed to form plating layers 37 and 38 in the holes 35 and 36, respectively. Further, as shown in FIG. 2D, the outer layer circuit 39 is formed by etching. Then, solder resist printing is performed to form the solder resist layer 40.

The interlayer adhesion, copper foil peeling strength, and thermal shock test evaluations and circuit patterns are as follows.

I) Interlayer adhesion The sample is dipped in a solder bath at a temperature of 260 ° C., and the time at which swelling occurs in the poor adhesion portion is measured. As the circuit pattern, the JIS-C5012 multilayer printed board composite test pattern G is used.

Ii) Copper foil peeling strength A portion of the surface copper foil was peeled off in advance, the peeled portion was fixed with a pin, and peeled at a speed of 5 mm / min using an autograph. The load was calculated. The circuit pattern is the same as that used for interlayer adhesion.

Iii) Thermal shock test JIS-C5012 temperature / humidity cycle 65 ° C., 93%,
By repeating 4 Hr, 25 ° C., 80%, and 1 Hr, the number of cycles at which the resistance of the plated layer of the through hole increased to 10% of the initial value was determined. The circuit pattern is JIS-
A composite test pattern L for C5012 multilayer printed board is used.

The measurement results are shown in Table 1.

[Table 1]

As is clear from Table 1, according to Example 1, the same result as that of Conventional Example 1 can be obtained. Further, the interlayer adhesion and the peel strength of the copper foil sufficiently satisfy the JIS standard values.

The changes in the insulation resistance between the layers of the present invention and the conventional example were measured. The manufacturing conditions of Example 2 of the present invention and Conventional Example 2 are as follows. The circuit patterns used for the measurement are JIS-C50 in both the example and the conventional example.
A composite test pattern M for a 12-layer printed board is used.

Example 2 The same conditions as in Example 1 were used except that the composite layer sheet was laminated to an insulating resin film having a thickness of 80 μm and an adhesive film having a thickness of 20 μm so as to have a thickness of 100 μm.

Conventional Example 2: Same conditions as in Conventional Example 1 except that the thickness of the prepreg of the glass cloth resin-impregnated cloth is 100 μm.

Then, the test was conducted with the sample at a temperature of 85 ° C. and a humidity of 8
DC100V is applied to the circuit in an atmosphere of 5% RH and left for 1000 hours. Insulation resistance is DC25
0 V was applied and the value was measured for 1 minute.

The measurement results are shown in Table 2. The margin below.

[Table 2]

As is clear from Table 2, according to Examples 1 and 2, almost the same insulation resistance as that of Conventional Example 1 and Conventional Example 2 can be obtained. In particular, the thinner example 2 obtained better results than the conventional example 2.

[0029]

As described above, according to the manufacturing method of the present invention, since the composite layer sheet consisting of the insulating resin layer and the adhesive layer, which are preliminarily provided with holes, is laminated, the processing time in the punching step is increased. Can be shortened, the manufacturing time can be shortened as a whole,
A multilayer wiring board having improved productivity and reduced manufacturing cost can be obtained. Further, according to the manufacturing method of the present invention, it is not always necessary to use the glass cloth resin-impregnated cloth. Therefore,
When holes are drilled with a laser, glass threads remain and the shape of the holes does not deteriorate after the plating treatment, or the plating does not adhere, and it is possible to reduce defects and obtain a highly reliable multilayer wiring board. Furthermore, when drilling with a drill, if it is necessary to use a glass cloth resin impregnated cloth that has relatively high cutting resistance, the life of the drill can be extended and less drill replacement work is required. A multilayer wiring board with improved productivity and reduced cost can be obtained.

[Brief description of drawings]

FIG. 1 shows a drawing of a manufacturing process according to an embodiment of the present invention.

FIG. 2 shows a drawing of a manufacturing process of a conventional example.

[Explanation of symbols]

3 ... Double-sided copper-clad laminate, 5 ... Composite layer sheet, 6 ... Insulating resin film, 7 ... Adhesive film, 8 ... Hole, 1
0, 11 ... Plating layer, 12 ... Outer layer circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyoshi Yokoyama 413 Kushimoda, Ninomiya-cho, Haga-gun, Tochigi Prefecture Hitachi AIC Co., Ltd.

Claims (1)

[Claims] 1. A step of laminating a composite layer sheet having a hole formed of an insulating resin layer and an adhesive layer on the surface of an inner layer circuit board, and a plating treatment is performed after this step to form a plating layer in the hole. And a step of forming an outer layer circuit.