JPH0362037B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a mold for laminating and bonding multilayer printed wiring boards, and in particular, to prevent "misalignment" between printed wiring boards constituting the multilayer printed wiring board. The present invention relates to a mold for laminating and adhering multilayer printed wiring boards, which is intended for manufacturing multilayer printed wiring boards that do not require the use of multilayer printed wiring boards.

[Background of the invention]

A conventional method for manufacturing a multilayer printed wiring board will be explained using drawings.

Figures 1 and 2 are for explaining a conventional method for manufacturing a multilayer printed wiring board. Figure 1 is a perspective view showing the material and guide pins of the multilayer printed wiring board, and Figure 2 is a FIG. 2 is a perspective view showing an example of a body and a lamination bonding mold for pressurizing the body.

First, as shown in FIG. 1, a plurality of printed wiring boards 1 and synthetic resin foils 2, in which guide holes 1a are pre-drilled at predetermined positions, are stacked alternately, and guide pins 3 are inserted into the guide holes 1a. The positioning between each printed wiring board 1 is determined by the method shown in FIG.
make. Then, in this state, the upper and lower ends of the guide pin 3 are fitted into the guide holes 4a and 6a of the upper mold 4 and the lower mold 6, and the upper mold 4 and the lower mold The upper mold 4 is sandwiched between the mold 6 in a sandwich shape, and loaded between the bed of a press (not shown) and a bolster (heating plate).
The laminate 5 is pressurized and heated by the lower mold 6 and the bolster. Thereafter, heat and pressure are removed, and the upper mold 4 and lower mold 6 for lamination adhesion are removed, thereby completing the lamination adhesion of each printed wiring board 1 of the laminate 5 and obtaining a multilayer printed wiring board. .

However, in multilayer printed wiring boards manufactured using the conventional method described above, "misalignment" often occurs between each printed wiring board 1 after lamination bonding, and when such misalignment occurs, the multilayer printed wiring board If through holes (not shown) are formed to connect the printed wiring boards 1, wiring errors may occur, resulting in defective products.

The causes of the deviation are thought to be the effects of dimensional changes of each printed wiring board 1 due to heating and pressure during wiring formation and lamination bonding, and dimensional changes of the synthetic resin foil 2 during lamination bonding. There is. Among these,
In particular, by heating during lamination bonding, the upper and lower molds 4,
This is largely due to the fact that there is a difference in thermal strain of about 0.1 mm between the printed wiring board 1 and the printed wiring board 1 (the thermal strain of the printed wiring board 1 is larger than that of the upper and lower molds 4 and 6). That is, due to the difference in thermal strain, the movement of the guide pin 3 inserted into the highly elongated printed wiring board 1 is restrained by the upper and lower molds 4 and 6. A local external force acts on the printed wiring board 1 in the vicinity of the printed wiring board 1, causing local deformation, which results in misalignment between the printed wiring boards 1.

Conventionally, measures have been taken to relieve the restraint of the guide pin 3, but this measure has been implemented in the third and fourth cases.
Explain using diagrams.

Figures 3 and 4 explain conventional measures to prevent misalignment between printed wiring boards, and Figure 3 shows a lamination adhesive mold with radial elongated guide holes. FIG. 4 is a perspective view showing a lamination adhesive mold having a guide hole with a clearance.

The lamination adhesive mold shown in FIG. 3 includes an upper mold 4A,
Guide holes 7 in the form of radial elongated holes are formed in the lower mold 6A so that the movement of the guide pins 3 caused by the elongation of the printed wiring board 1 during heating is not restricted. However, since the thermal strain of the printed wiring board 1 does not necessarily occur radially, the direction of the thermal strain does not match the longitudinal direction of the guide hole 7, which is a radial elongated hole, and the movement of the guide pin 3 is not completely free. , it will be restrained by the lamination adhesive mold.

On the other hand, the laminated adhesive mold shown in FIG. 4 has guide holes 8 in the upper mold 4B and lower mold 6B.
Although a clearance of 0.2 to 0.5 mm is provided, if there is a difference in the magnitude of thermal strain of each printed wiring board 1 and it is not uniform in the thickness direction of the multilayer printed wiring board (this itself , which is also one of the causes of misalignment), the guide pin 3 is tilted, and as a result, the guide pin 3 comes into contact with the hole edge of the guide hole 8, and the movement of the guide pin 3 is also restricted, and each printing after lamination bonding. A misalignment occurred between the wiring boards 1, and it was not possible to prevent the misalignment by any means.

[Purpose of the invention]

The present invention provides a mold for laminating and adhering multilayer printed wiring boards, which eliminates the drawbacks of the above-mentioned prior art and can produce multilayer printed wiring boards with extremely small deviations between printed wiring boards. That is the purpose.

[Summary of the Invention] The structure of the lamination adhesive mold for a multilayer printed wiring board according to the present invention is to alternately stack a plurality of printed wiring boards with guide holes drilled at predetermined positions and synthetic resin foil,
A laminate formed by passing guide pins through the guide holes to position each of the printed wiring boards;
A multilayer printed wiring board that is loaded between a lower mold and applies pressure and heat to the laminate from above and below to bond the printed wiring boards together to produce a multilayer printed wiring board. In the lamination adhesive mold, stepped holes having a small diameter through which the guide pins can freely pass are provided at positions corresponding to the guide pins of the upper and lower molds, and the upper surface of the upper mold and the A sliding slide in which a backing plate is provided on the lower surface of the lower mold, and an insertion hole is bored through the shoulder of the stepped hole and the backing plate into which the upper and lower ends of the guide pin can be inserted. The jig is slidably inserted into the mold.

More specifically, in a laminate adhesive mold for producing a multilayer printed wiring board by pressurizing and heating a laminate of printed wiring boards, the laminate and the laminate adhesive mold when pressure and heat are applied. It has a sliding structure that does not restrict relative displacement within the mold surface with the mold and allows the guide pin to move without tilting with respect to the mold surface.

[Embodiments of the invention]

The present invention will be explained below with reference to Examples.

FIG. 5 is a sectional view of essential parts showing a lamination bonding mold for a multilayer printed wiring board according to an embodiment of the present invention, and a multilayer printed wiring board laminated and bonded using the mold, and FIG. FIG. 6 is a perspective view showing the positional relationship among the laminate, upper mold, lower mold, and backing plate in FIG. 5;

In each figure, 5 is a laminate of printed wiring boards, 3
is a guide pin inserted into this laminate 5. 10 is an upper mold, 11 is a lower mold, 10a, 1
Reference numeral 1a denotes a bushing press-fit hole drilled in the upper mold 10 and lower mold 11 at a position corresponding to the guide pin 3, and 13 denotes the bush press-fit hole 10a, 1.
A stepped bush 9 is press-fitted into the upper mold 1 and is provided with a shoulder 13a having a small diameter (=d ₁ ) through which the guide pin 3 can freely pass.
0, a backing plate 12 with punched holes 9a provided on the upper and lower surfaces of the lower mold 11 slides within the mold surface by the shoulder 13a of the stepped bush 13 and the backing plate 9. This is a sliding jig that is movably held and has an insertion hole 12a.
The upper and lower ends of the guide pin 3 can be inserted into the guide pin 2a. The stepped bush 13, sliding jig 12, and guide pin 3 are all made of a material (copper) having the same coefficient of linear expansion as the printed wiring board. And the small diameter of the stepped bush 13
The dimensions of d ₁ and large diameter d ₂ are as follows: When the laminate 5 is pressurized and heated to generate thermal strain and the guide pin 3 moves,
The dimensions are such that the guide pin 3 and the sliding jig 12 do not come into contact with the stepped bush 13.

With the laminated adhesive mold configured in this way,
The operation of manufacturing a multilayer printed wiring board by pressurizing and heating a laminate of printed wiring boards will be described.

The lower end of the guide pin 3 inserted into the laminate 5 is inserted into the insertion hole 12a of the sliding jig 12 of the lower mold 11, and the laminate 5 is placed on the lower mold 11.
Then, the insertion hole 12 of the sliding jig 12 of the upper mold 10
The upper end of the guide pin 3 is inserted into the hole a, and the lower surface of the upper mold 10 is brought into contact with the laminate 5 (the state shown in FIG. 5). This is loaded between the bed and bolster (heating plate) of a press (not shown).

Here, when the press is turned ON, the heating plates are energized to heat the laminate 5, and when the temperature of the laminate 5 reaches a predetermined temperature, the ram of the press heats the laminate 5 to a predetermined temperature. pressure is applied. The laminate 5 undergoes thermal strain due to the heating, and the guide pin 3 inserted into the laminate 5 moves. Since the guide pin 3 is held slidably only within the mold surface by the shoulder portion 13a and the backing plate 9, the guide pin 3 moves parallel to the mold surface in a state perpendicular to the mold surface without tilting. Moreover,
The small diameter d ₁ and large diameter d ₂ of the stepped bush 13 are large enough to prevent the guide pin 3 from coming into contact with the stepped bush 13 even if the guide pin 3 moves due to the thermal strain. Since the jig 12 and the stepped bush 13 have the same coefficient of linear expansion, the sliding jig 12 connects the backing plate 9 and the stepped bush 13 from above and below.
There is no possibility that the contact plate 9 and the sliding jig 12 will be pressed together, or that a clearance will not be created between the backing plate 9 and the sliding jig 12. Therefore, the sliding jig 12 slides smoothly, and the guide pin 3 is connected to the upper and lower molds 10 and 1.
1 shall not be restricted.

Then, after a predetermined period of time has elapsed, the pressure and heat are removed, the lamination adhesion is completed, and the ram is raised. The head of the guide pin 3 is struck, and the guide pin 3 falls downward through the punched hole 9a of the backing plate 9, thereby obtaining the desired laminated printed wiring board.

According to the embodiment described above, when bonding the laminate 5, the guide pin 3 inserted into the laminate 5 is perpendicular to the mold surface without being tilted.
In addition, since it can move freely without being restricted by the upper mold 10 and lower mold 11, defects that occur due to misalignment between printed wiring boards in conventional products are reduced to about 1/5. It has the effect of being able to
In addition, because the deviation is extremely small, printed wiring boards can be made even more multi-layered, from the conventional 10 layers to 20 layers. Furthermore, the wiring density of printed wiring boards can be improved, and the minimum distance between wiring lines can be reduced from that of conventional wiring.
It can be shortened from 0.25mm to 0.12mm.

A specific example will be explained.

The laminate 5 has a size of 500mm square and a board of 500mm square and a thickness of 0.2mm between five double-sided copper-clad printed wiring boards 1.
It is made by laminating two sheets of synthetic resin foil each measuring mm square and 0.1 mm thick. Guide pin 3 has an outer diameter of 15 mm,
The length is 25mm and the material is copper. The upper mold 10, the lower mold 11, and the backing plate 9 are all made of SS41 material with a square size of 750 mm, and the plate thickness of the upper mold 10 and the lower mold 11 is 20 mm. The stepped bush 13 has an outer diameter of 40 mm and a shoulder portion 13a.
The small diameter d ₁ = 15.8 mm, the large diameter d ₂ = 25.8 mm, and the material is copper. The sliding jig 12 has an outer diameter of 25 mm and an insertion hole 12.
It is annular with a diameter of 15 mm and a height of 12 mm, and the material is copper.

When this laminate 5 was laminated and bonded in the above-described method using the above-mentioned upper mold 10 and lower mold 11, the deviation between each printed wiring board 1 was 0.02 mm (in the conventional method, it was 0.1 mm). mm).

FIG. 7 is a cross-sectional view of a main part showing a mold for laminating and bonding a multilayer printed wiring board according to another embodiment of the present invention, and a multilayer printed wiring board that is laminated and bonded using the mold.

In FIG. 7, the same numbers as in FIG. 5 indicate the same parts. Further, 12b is a ball receiving groove formed on the upper and lower surfaces of the sliding jig 12A, and 14 is a ball (made of steel) loaded into this groove 12b.

With this configuration, the sliding jig 12A, the shoulder portion 13a of the stepped bush 13, and the backing plate 9 come into point contact, and the sliding jig 12A can slide extremely smoothly. be.

When the laminate 5 shown in the specific example was laminated and bonded using this lamination bonding mold, the deviation between each printed wiring board could be reduced to 0.01 mm.

In each of the embodiments described above, the bushing press-fit holes 10a and 11a are formed at positions corresponding to the guide pins 3 of the upper and lower molds, and the stepped bushes 13 are press-fitted therein to form the stepped bushings. Although attached holes are formed in this embodiment, drilled holes may be provided at positions corresponding to the guide pins 3 of the upper and lower molds, and these holes may be used as stepped holes. In this case, by making the material of the sliding jig have the same coefficient of linear expansion as the upper and lower molds, the sliding jig can be can be slid smoothly.

Furthermore, it is most desirable that the material of the guide pin 3 is copper, which has the same coefficient of linear expansion as the printed wiring board, but since the outer diameter of the guide pin 3 is small, the guide pin 3 and the guide hole 1a during heating are The difference in thermal strain is very small, so it does not necessarily have to be copper, but may be steel, for example.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a mold for laminating and adhering multilayer printed wiring boards, which can manufacture multilayer printed wiring boards with extremely small deviations between printed wiring boards. .

[Brief explanation of drawings]

1 and 2 are for explaining a conventional method for manufacturing a multilayer printed wiring board.
The figure is a perspective view showing an example of a laminate and a lamination adhesive mold that presses it. Figures 3 and 4 are illustrations of conventional measures to prevent misalignment between printed wiring boards. FIG. 3 is a perspective view showing a lamination adhesive mold in which a guide hole with a radial elongated hole is bored, and FIG. 4 is a perspective view showing a lamination adhesive mold in which a guide hole with a clearance is bored. 5 is a sectional view of a main part showing a mold for laminating and bonding a multilayer printed wiring board according to an embodiment of the present invention, and a multilayer printed wiring board laminated and bonded using the mold, and FIG. , 5th
FIG. 7 is a perspective view showing the positional relationship of the laminate, the upper mold, the lower mold, and the backing plate in the figure.
FIG. 2 is a cross-sectional view of essential parts of a multilayer printed wiring board that is laminated and bonded in this manner. DESCRIPTION OF SYMBOLS 1...Printed wiring board, 1a...Guide hole, 2...Synthetic resin foil, 3...Guide pin, 5...Laminated body, 9...Packing plate, 10...Upper mold, 10a...Button press-fit hole, 1
1... Lower mold, 11a... Bush press-fit hole, 12,1
2A...Sliding jig, 12a...Insertion hole, 12b...Groove,
13...Stepped bush, 13a...Shoulder, _d1 ...Small diameter.

Claims (1)

[Claims] 1. A plurality of printed wiring boards with guide holes drilled in advance at predetermined positions and synthetic resin foil are stacked alternately, and guide pins are passed through the guide holes to position each printed wiring board. A laminate made of the above is loaded between upper and lower molds, and pressure and heat are applied to the laminate from above and below to bond the printed wiring boards, thereby producing a multilayer printed wiring board. offered to
In the lamination adhesive mold for multilayer printed wiring boards, the top,
A stepped hole having a small diameter through which the guide pin can freely pass is provided at a position corresponding to the guide pin of the lower mold, and a patch plate is provided on the upper surface of the upper mold and the lower surface of the lower mold, respectively. A sliding jig, which has an insertion hole in which the upper and lower ends of the guide pin can be inserted, is slid into the mold by the shoulder of the stepped hole and the backing plate. A mold for laminating and adhering multilayer printed wiring boards, characterized by being freely clamped. 2 The stepped holes in the upper and lower molds are formed with stepped bushings press-fitted into the corresponding locations, and the material of the sliding jig is made of a material that has the same coefficient of linear expansion as the stepped bushings. A mold for laminating and bonding a multilayer printed wiring board according to claim 1. 3. For lamination adhesion of multilayer printed wiring boards as set forth in claim 2, wherein the guide pins, sliding jig, and stepped bushings are made of materials that have the same linear expansion coefficient as the printed wiring board. Mold. 4. Drill ball receiving grooves on the upper and lower surfaces of the sliding jig, load balls into these grooves, and make point contact between the sliding jig, the shoulder of the stepped bushing, and the backing plate. A mold for laminating and bonding a multilayer printed wiring board according to claim 3. 5 The stepped holes of the upper and lower molds are made into holes drilled at the corresponding locations, and the material of the sliding jig is made of a material that has the same coefficient of linear expansion as the upper and lower molds. A mold for laminating and bonding a multilayer printed wiring board according to claim 1.