JPH0636468B2 - Method for manufacturing copper-clad laminated wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a copper having a wiring pattern made of thick copper or copper alloy formed on an insulating substrate having a thin insulating layer formed on the surface of a metal plate. The present invention relates to a method for manufacturing a laminated wiring board.

"Prior Art" In this type of copper-clad laminated wiring board, a copper foil wiring pattern having a thickness of several tens of μm is formed on a metal plate such as aluminum having an insulating layer formed on the surface or an insulating substrate made of ceramics or the like. Things
Since the insulating substrate provides high heat dissipation, heat resistance, and dimensional stability, the market is expanding as a printed wiring board for high power and high density mounting.

And recently, in accordance with the use to control higher power such as power transistors, power supply circuits, and large output amplifiers,
Demand for wiring boards in which copper foil with a wiring pattern that was thin in the past was thickened to about 1 mm has begun to occur.

[Problems to be Solved by the Invention] Therefore, in order to manufacture a copper-clad laminated wiring board having a thick wiring pattern as described above, the present inventors adhere a thick copper plate to an insulating substrate and fix it on the copper plate. We tried the method of etching by masking the wiring pattern.

However, in such a method for etching a thick copper plate, a great deal of time and effort is required, and the productivity is extremely poor,
In addition to being unprofitable, there is a drawback that the vicinity of the boundary of the wiring pattern is eroded by the sneaking of the etching solution, and the reliability of the wiring pattern is reduced.

Separately from this, I also tried a method of punching a copper plate into the shape of a wiring pattern and pasting this punched plate to an insulating substrate, but in this method the wiring pattern is divided into many fragments, It was difficult to accurately position and bond these pattern pieces to the substrate, which was not feasible.

"Means for Solving the Problems" The present invention has been made to solve the above problems,
From a thin plate made of copper or a copper alloy, a step of stamping and forming an integrally formed pattern plate composed of a plurality of pattern line portions forming a wiring pattern and a bridge portion for fixing these pattern line portions to each other; The step of sticking a removable sheet material in a post-process on the surface on which the burrs formed by the punching are projected, and the cross-linking portions of the pattern plate are punched from the surface opposite to the sheet material. Alternatively, a step of removing by grinding, and a step of joining the surface of the pattern plate opposite to the sheet material to the insulating layer of an insulating substrate formed by forming an insulating layer on the surface of a metal plate, and then a sheet And a step of removing the material from the pattern plate.

A solvent-soluble resin sheet, a flammable paper sheet, or the like may be used as the sheet material.

[Operation] According to this method, a pattern plate having a shape in which a bridging portion is bridged in advance is integrally molded between pattern shaft portions that are not connected to each other and form a pattern, and the pattern plate is attached to a sheet material. Moreover, since the cross-linking portion is mechanically removed and is fixed to the insulating substrate by adhesion, an error does not occur in the arrangement of each pattern line portion.

In addition, the patterned plate can be efficiently produced by punching etc. regardless of the thickness of the substrate, and after bonding to the sheet material, each cross-linked part can be easily removed by cutting, punching etc. This eliminates the need for laborious and time-consuming processes, enables mass production, and reduces manufacturing costs.

Further, a sheet material is attached to the surface of the pattern plate on the side where burrs are generated at the time of punching, and each cross-linked portion of the pattern plate is punched or ground from the surface on the side opposite to the sheet material to remove it. Since the surface opposite to the sheet material is bonded to the insulating layer of the insulating substrate, fine burrs generated at the peripheral edge of the pattern line portion do not bite into the surface of the insulating layer and lower the withstand voltage of the insulating layer. It is possible to prevent a decrease in withstand voltage of the circuit board due to burrs. At the same time, the insulation breakdown voltage inherent to the insulation layer can be obtained, so that the insulation layer can be thinned and the heat dissipation to the metal plate through the insulation layer can be improved. Therefore, according to the manufacturing method of the present invention,
It is possible to maximize both heat dissipation and dielectric strength of the copper clad laminated wiring board.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In this method, first, as shown in FIG. 1, from a thin plate made of copper or a copper alloy having a protective film such as Ni plating formed thereon, a plurality of independent pattern line portions 1 ... The pattern plate 3 including the bridge portions 2 for integrally connecting the pattern line portions 1 is integrally formed by punching or the like.

It is desirable that all the widths and lengths of the respective bridge portions 2 are unified to simplify the removal work. The formation positions of the bridging portions 2 ... should be such that the pattern line portions 1 ... Can be fixed with sufficient strength by the fewest bridging portions 2 ... And the bridging portions 2 ... Can be arranged along a straight line as much as possible. Should be. If the number of the cross-linking portions 2 is large, the work for removing the cross-linking portions is correspondingly time-consuming. Further, if they are arranged along a straight line, the efficiency of the removing work can be improved even when the number of the bridge portions 2 ... Is the same.

Next, as shown in FIG. 2, a long sheet material 4 is attached in an aligned state on the lower surface side (burrs of about several μm are formed) at the time of punching the pattern plates 3 obtained in this way, with an adhesive or the like. I will attach it. The sheet material 4 is to be removed in a later step, and the material thereof is made of a synthetic resin such as PET that dissolves in an organic solvent, or a material that can be peeled off in a later step by applying a relatively weak adhesive material on the back surface. Alternatively, a flammable paper or non-woven fabric having a low ash content is used, and a material having as little elongation as possible is preferable. In addition, positioning feed holes 5 are formed at both edges of the sheet material 4 in the width direction, so that the working efficiency and the positioning accuracy are improved.

Next, the sheet material 4 to which the pattern plate 3 is attached is set on an NC-controlled grinding machine or punching device, and the sheet material 4 is placed on the lower side, and only the bridge portions 2 of the pattern plate 3 are ground or punched. To remove. At that time, the sheet material 4 may be perforated as shown by P in the figure. In addition, bridge part 2
.. may be removed one by one, or all may be removed at the same time.

Next, the sheet material 4 is bonded onto the insulating substrate 6 with the pattern plate 3 side facing down. FIG. 3 shows an example of the process, in which the sheet materials 4 are sequentially joined while being positioned by the pressing roller 7 on the substrates 6 ... Which are sequentially aligned by a conveyor or the like. At that time, if necessary, an epoxy-based adhesive or brazing material is used.

As the insulating substrate 6, an insulating layer 9 is formed on the surface of a metal plate 8 such as an aluminum plate, an iron plate, a silicon steel plate, a copper plate, or a copper invar plate.
A substrate formed with can be used. As the insulating layer 9,
A highly heat-resistant synthetic resin such as polyimide is suitable, and its thickness is several tens of μ in consideration of heat dissipation and insulation.
m to several hundreds of μm.

The thickness of the insulating substrate 6 is usually set to about several mm in consideration of desired heat dissipation and strength.

After the joining is completed, next, the sheet material 4 is removed. When the sheet material 4 is made of a soluble resin, each insulating substrate 6 is immersed in an organic solvent bath to completely dissolve the sheet material 4. In addition, when the sheet material 4 is attached with an adhesive, the sheet material 4 is sequentially peeled from the insulating substrate 6. Further, when paper or the like is used, only the sheet material 4 is incinerated by passing the substrate 6 through the heating furnace.

Then, if necessary, cleaning and flux application are performed to obtain the copper-clad laminated wiring board shown in FIGS. 4 and 5.

According to the method for manufacturing a copper clad laminated wiring board comprising the above steps,
A pattern plate 3 in which bridging portions 2 are preliminarily laid between pattern line portions 1 which are not connected to each other is integrally molded, and the pattern plate 3 is attached to a sheet material 4, and the bridging portions 2 are mechanically connected. Since it is removed and bonded to the insulating substrate 6, no error occurs in the arrangement of the pattern line portions 1. Therefore, it is possible to manufacture a highly reliable copper clad laminated wiring board with high pattern accuracy, and since the sheet material 4 is attached, it is easy to carry the pattern board 3 such as carrying and positioning, thereby simplifying and improving the efficiency of the production line. Can be achieved.

Further, the pattern plate 3 can be efficiently manufactured by punching or the like regardless of its wall thickness, and each of the bridge portions 2 ... Mass production is possible without labor and time-consuming work, and the manufacturing cost can be reduced accordingly. Further, the sheet material 4 is attached to the surface of the pattern plate 3 on the side where burrs are generated at the time of punching, and the cross-linked portions 2
.. is removed from the surface opposite to the sheet material 4 by punching or grinding (at this time, burrs are formed toward the sheet material 4 side), and then the side opposite to the sheet material 4 of the pattern plate 3. Since the surface is bonded to the insulating layer 9 of the insulating substrate 6, it is possible to reliably prevent the fine burr generated at the peripheral edge of the pattern line portions 1 ... from being fixed toward the insulating layer 9. As a result, burrs of the pattern line portions 1 ... Do not bite into the surface of the insulating layer 9 to reduce the withstand voltage of the insulating layer 9 at all.
It is possible to prevent a decrease in withstand voltage of the circuit board due to burrs. At the same time, the insulating layer 9 can be thinned by the amount that the original withstand voltage of the insulating layer 9 can be obtained, and the heat dissipation to the metal plate 8 through the insulating layer 9 can be improved. Therefore, according to the manufacturing method of the present invention, it is possible to maximize both the heat dissipation and the dielectric strength of the copper-clad laminated wiring board.

In addition, the insulating layer 9 is formed by the burr which is only about several μm.
The lowering of the withstand voltage means that the insulating layer 9 on the metal plate 8 must be thinned as much as possible to improve heat dissipation and withstand voltage. This is a finding that was found under the technical problems that are difficult to achieve at the same time, which is peculiar to a high-power wiring board using a board, and when considering the peculiarities of this kind of wiring board, the above-mentioned effects have a technical significance. Is to have.

In addition, although the long sheet material 4 is used in the above-described embodiment, the size may be one corresponding to one pattern plate 3.

Further, in the above-described embodiment, the pattern plate 3 is fixed to only one surface of the substrate 6, but different pattern plates may be fixed to both surfaces of the substrate 6, or the back surface of the insulating substrate 6 for heat dissipation may be used. You may join a metal plate.

[Advantages of the Invention] As described above, according to the method for manufacturing a copper-clad laminated wiring board of the present invention, a pattern board having a shape in which bridging portions are preliminarily bridged between pattern line portions that are not connected to each other is integrally formed. After molding and pasting this pattern plate to the sheet material, the cross-linking part is mechanically removed and bonded to the insulating substrate, so there is no error in the placement of each pattern line part, and the pattern accuracy and reliability are improved. A high copper-clad laminated wiring board can be manufactured.

In addition, the pattern plate can be efficiently manufactured by punching or the like regardless of its wall thickness, and the removal work of each bridging portion can be easily performed by cutting or punching.
It does not require labor and time-consuming work such as etching, enables mass production, and reduces manufacturing costs.

Furthermore, a sheet material is attached to the surface of the pattern plate on the side where burrs are generated during punching, and each cross-linked portion of the pattern plate is punched or cut from the surface opposite to the sheet material to remove it. Since the surface opposite to the sheet material is bonded to the insulating layer of the insulating substrate, fine burrs generated at the peripheral edge of the pattern line portion do not bite into the surface of the insulating layer and lower the withstand voltage of the insulating layer. It is possible to prevent a decrease in withstand voltage of the circuit board due to burrs. At the same time, the insulation breakdown voltage inherent to the insulation layer can be obtained, so that the insulation layer can be thinned and the heat dissipation to the metal plate through the insulation layer can be improved. Therefore, according to the manufacturing method of the present invention,
It is possible to maximize both heat dissipation and dielectric strength of the copper clad laminated wiring board.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 5 are all for explaining one embodiment of a method for manufacturing a copper clad laminated wiring board according to the present invention. FIG. Second plan view showing a shape example
The figure is a plan view showing a state where the pattern board is attached to the sheet material and the cross-linking portion is removed, FIG. 3 is a side view showing the step of adhering the pattern board to the substrate, and FIG. 4 is the obtained copper-clad laminated wiring board. FIG. 5 is an enlarged sectional view of FIG. 5, and is a plan view of the wiring board. 1 ... Pattern line part, 2 ... Bridge part, 3 ... Pattern plate, 4 ... Sheet material, 5 ... Feed hole, 6 ... Insulating substrate, 8 ... Metal plate, 9 ... Insulating layer, P …… The part where the bridge is removed.

Continuation of the front page (56) Reference JP 61-110489 (JP, A) JP 49-126274 (JP, A) JP 62-134991 (JP, A) JP 55-18554 (JP , A) Japanese Patent Publication Sho 48-28121 (JP, B1)

Claims (3)

[Claims] 1. A step of stamping and forming a monolithic pattern plate composed of a plurality of pattern line portions constituting a wiring pattern and a bridge portion for mutually fixing the pattern line portions from a thin plate made of copper or a copper alloy. A step of attaching a sheet material that can be removed in a subsequent step to the surface of the pattern plate on which the burr formed by the punching is projected, and the cross-linking portions of the pattern plate on the side opposite to the sheet material. A step of removing the surface of the pattern plate by punching or grinding, and a surface opposite to the sheet material of the pattern plate on the insulating layer of the insulating substrate formed by forming an insulating layer on the surface of the metal plate. And a step of removing the sheet material from the pattern board after joining, the method for producing a copper-clad laminated wiring board. 2. A resin sheet which is soluble in a solvent is used as the sheet material, and after the pattern plate is adhered to the insulating substrate, the sheet material is dissolved in the solvent and removed. Manufacturing method of copper clad laminated wiring board. 3. A copper clad laminated wiring board according to claim 1, wherein a flammable sheet is used as the sheet material, and the sheet material is burned and removed after the pattern board is bonded to the insulating substrate. Manufacturing method.