JPH0228393A - Manufacture of copper-clad laminated wiring board - Google Patents

Abstract

PURPOSE:To prevent an error in arrangement of a pattern line part and lowering of position accuracy by forming a pattern plate which connected pattern line parts with a bridge part in a body, and removing the bridge part mechanically after stricking it to a metallic seat material, and bonding the individual pattern line parts as they are fixed to the metallic seat material. CONSTITUTION:A pattern plate 3 in united shape consisting of plural pattern line parts 1, constituting wiring patterns, and bridge parts 2 to fix these pattern line parts with each other is formed of a thin plate made of copper or copper alloy. And a metallic seat material 4 is stuck to one side of the pattern plate 3 such that it can be removed in the subsequent process, and then each bridge part 2 is removed by mechanical processing, etc., and further after joining the pattern plate 3 side onto an insulating substrate, the metallic seat material 4 is removed. Hereby, the error rarely occurs in arrangement of each pattern line part 1, and even if it goes through a heating process, etc., the lowering of position accuracy at the pattern line part 1 by thermal expansion, etc., hardly occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for manufacturing a copper-clad laminate wiring board in which a wiring pattern made of thick copper or copper alloy is formed on various insulating substrates.

"Conventional technology" This type of copper-clad laminated wiring board is made by forming a copper foil wiring pattern several tens of microns thick on an insulating substrate made of a metal plate such as aluminum or ceramics with an insulating layer formed on the surface. I did it,
Since the insulating substrate provides high heat dissipation, heat resistance, and 9-dimensional stability, the market is expanding as printed wiring boards for high power applications and high-density packaging.

Recently, it has been used for applications that control even higher power such as power transistors, power supply circuits, and high output amplifiers.
Demand is beginning to emerge for wiring boards in which the steel foil of the wiring pattern, which was conventionally thin, is thickened to about 1 mm.

"Problems to be Solved by the Invention" Therefore, in order to manufacture a copper-clad laminate wiring board with a thick wiring pattern as described above, the present inventors adhesively fixed a thick copper plate on an insulating substrate, and We tried a method of masking and etching the wiring pattern.

However, this method of etching thick copper plates requires a great deal of effort and time, resulting in extremely poor productivity.
In addition to being unprofitable, the etching solution corrodes the vicinity of the boundary of the wiring pattern, reducing the reliability of the wiring pattern.

Separately, we also attempted a method in which a copper plate was punched into the shape of a wiring pattern and the punched board was attached to an insulating board, but this method resulted in the wiring pattern being divided into many pieces. It was difficult to accurately position and adhere these pattern pieces to the substrate, and the feasibility was poor.

"Means for Solving the Problems" The present invention has been made to solve the above problems, and includes a plurality of pattern line portions constituting a wiring pattern and interconnection of these pattern line portions from a thin plate made of copper or copper alloy. A pattern plate with an integral shape consisting of a bridge portion for fixing the pattern plate is molded, a metal sheet material is attached to one side of the pattern plate so that it can be removed in a subsequent process, and each of the bridge portions is removed by machining or the like, Furthermore, after the pattern plate side is bonded onto the insulating substrate, the metal sheet material is removed.

``Function'' According to this method, a pattern plate in which unconnected pattern line parts are temporarily fixed to each other by a bridge part is integrally molded, this pattern plate is pasted on a metal sheet material, and the bridge parts are machined. Since the pattern line parts are removed by processing or the like and then adhesively fixed to the insulating substrate while being held by the metal sheet material, there is no error in the arrangement of each pattern line part. Furthermore, since the metal sheet material has a low coefficient of thermal expansion and high tensile strength, it is difficult for the positional accuracy of the pattern line portion to deteriorate due to thermal expansion or the like even after a heating process or the like.

In addition, pattern plates can be produced efficiently by punching, etc., regardless of the thickness of the substrate, and after bonding to a metal sheet material, each bridged portion can be easily removed by cutting, punching, etc. It does not require such laborious and time-consuming processes, is suitable for mass production, and can reduce manufacturing costs.

"Embodiment" Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In this method, first, a thin plate made of copper or copper alloy with a protective film such as Ni plating formed on the surface is prepared, and as shown in FIG. 1, a plurality of independent pattern line parts 1 . A pattern plate 3 consisting of a bridge portion 2 . . . which connects these pattern line portions 1 . . . together is integrally formed by punching or the like.

It is desirable that the width and length of each of the bridge parts 2 be the same in order to simplify the removal work, and in particular, if they are made into squares with no vertical or horizontal directionality, it will be convenient for the subsequent removal process. good. In addition, the formation positions of the bridging portions 2 are such that each pattern line portion l... can be fixed with sufficient strength by as few bridging portions 2 as possible, and each bridging portion 2... can be formed in the same straight line as possible. Consideration should be given to arranging them along the same lines.

When the number of crosslinked parts 2 is large, it takes time to remove the crosslinked parts. Further, by arranging them along a straight line, the efficiency of the removal work can be increased even when the number of bridge parts 2 is the same.

Next, as shown in Fig. 2, a long metal sheet material 4 is glued onto the bottom side of the pattern plate 3 obtained in this way when punched out (a slight crack of about a few μm will occur). Paste it. This metal sheet material 4 is removed (peeled off) in the subsequent process.
Iron, aluminum, stainless steel, etc. are relatively inexpensive and suitable materials, but other metals can also be used. The thickness of the metal sheet material 4 is, for example, about 0.05 to 0.5 mm depending on the processing machine used. Positioning feed holes 5 are formed at both ends of the illustrated metal sheet material 40 in the width direction, thereby improving work efficiency and positioning accuracy, and facilitating mass production.

To attach the metal sheet material 4 to the pattern board 3...
A method of applying a thin layer of adhesive such as epoxy to the joint surfaces and overlapping them, or of sandwiching a double-sided adhesive tape between the sheet material 4 and the pattern plate 3 and applying pressure is adopted. These adhesives or pressure-sensitive adhesive tapes must be able to be easily peeled off in subsequent steps, and suitable ones are those that can be melted or peeled off by heating at about 200 to 300°C, for example. Note that if double-sided adhesive tape is used, the production yield will be more stable than when adhesive is used, and it is convenient for mass production. If adhesive tape is used, after attaching the metal sheet material 4 to the pattern plate 3, wash it with an organic solvent to remove the adhesive of the adhesive tape exposed at the opening of the pattern plate 4. Good. By doing this, when removing the crosslinked part 2 by punching or the like, it is possible to reduce the generation of residue due to the adhesive around the crosslinked part 2, and also to prevent metal powder etc. from adhering to the exposed surface of the adhesive tape and having an adverse effect. There is no risk of it being harmful.

Next, paste the pattern board 3; NC the metal sheet material 4.
Set in a controlled grinding machine, punching machine, etc., with the metal sheet material 4 facing downward, the bridge portion 2 of the pattern plate 3...
Remove the chisel by grinding or punching. At that time, holes may be made in the metal sheet material 4 as shown in the figure P. Moreover, the bridge parts 2... may be removed one by one, or all of them may be removed at the same time.

Next, the pattern plate 3 side is adhered onto the insulating substrate 6 with the metal sheet material 4 facing upward. FIG. 3 shows an example of the process, in which the metal sheet material 4 is positioned by a pressure roller 7 on top of the substrates 6 which are sequentially sent in an aligned state on a conveyor or the like.
are successively joined.

As the insulating substrate 6, the following can be used.

■A substrate in which an insulating layer 9 is formed on the surface of a metal plate 8 such as aluminum, iron plate, silicon steel plate, copper plate, copper invar plate, etc. As the insulating layer 9, a synthetic resin having high heat resistance such as polyimide is suitable, and its thickness is set to several tens of micrometers to several hundred micrometers in consideration of heat dissipation and insulation properties. A thermosetting adhesive such as an epoxy adhesive is suitable for bonding this type of insulating substrate and pattern plate, and is usually cured by heating to about 400°C.

■A1□0.・Ceramics plate such as SiO□. In this case, a steel plate containing 200 to 500 ppm of oxygen (
After forming a pattern plate 3 using tough pitch copper and positioning and placing the pattern plate 3 on an A+, O 3.5in2 board, heating it to about 900'0 in a hydrogen atmosphere will cause the pattern plate 3 to form inside the tough pitch steel. Oxygen atoms diffuse to the substrate side, C++0 is generated at the interface, and there is an advantage that the pattern plate 3 is firmly diffusion-bonded by the glass reaction. Furthermore, it is naturally possible to join using silver solder or a thermosetting adhesive.

■Conventionally used materials such as glass epoxy coated plates. The joining method is the same as in ■.

Note that the thickness of the insulating substrate 6 is usually determined to be about several mra in consideration of desired heat dissipation and strength.

In addition, when heating at the time of joining, the metal sheet material 4
Since the adhesive or adhesive tape pasting the metal sheet material 4 melts, the metal sheet material 4 is peeled off from the pattern board 3 when the bonding has progressed to a certain extent. In addition, if heating is not used during bonding, the adhesive (adhesive) used to attach the metal sheet material 4
The metal sheet material 4 is peeled off by performing a treatment such as heating according to the conditions.

Thereafter, residual adhesive and pressure-sensitive adhesive are completely removed from the surface of the pattern plate 3 from which the metal sheet material 4 has been peeled off, and if necessary, cleaning and application of 7 lux are performed, as shown in FIGS. 4 and 5. A copper-clad laminate wiring board is obtained.

According to the method for manufacturing a copper-clad laminate wiring board consisting of the above steps,
A pattern plate 3 is integrally molded with cross-linked portions 2 placed between mutually independent pattern line portions l, and this pattern plate 3 is pasted on a metal sheet material 4, and then the cross-linked portions 2 are formed.
. . is removed and each pattern line portion 1 . Never. Further, the metal sheet material 4 has a small coefficient of thermal expansion,
Since the tensile strength is large, elongation and warping are less likely to occur during heating, and it is possible to prevent a decrease in positional accuracy of the pattern line portions l caused by these. Therefore, a highly reliable copper-clad laminate wiring board with high pattern accuracy can be manufactured, and since it is attached to the metal sheet material 4, the pattern board 3...
・Easy to handle, such as transportation and positioning, simplifying and increasing the efficiency of the production line.

In addition, the pattern plate 3 can be manufactured efficiently by punching, etc., regardless of its wall thickness, and each bridge portion 2... can be easily removed by cutting, punching, etc., as described above, so etching is not required. There is no such labor-intensive and time-consuming work, and mass production is possible, which reduces manufacturing costs. Furthermore, even after the bridge parts 2 are removed, they are held by the metal sheet material 4 until they are bonded to the insulating substrate 6.
There is also the advantage that a slight burr generated during punching of the pattern plate 3 can be reliably bonded to the side opposite to the insulating substrate 6, and there is no risk of the burr damaging the insulating layer 9 of the insulating substrate 6.

Furthermore, by using the metal sheet material 4, the bridge portion 2.
Even when punching..., compared to when using sheet materials made of other materials, there is less generation of particles and debris, and the punching equipment is less likely to malfunction due to these deposits, and the insulating substrate There is no fear of reaction with the material of the insulating layer 9 of No. 6.

Although the long metal sheet material 4 is used in the above embodiment, a metal plate having a size corresponding to one or more pattern plates 3 may be used instead. In that case,
The peeled metal sheet material 4 can be easily reused.

Further, in the above embodiment, the pattern plate 3 is fixed to only one side of the insulating substrate 6, but a configuration may be adopted in which different pattern plates are fixed to both sides of the insulating substrate 6. You may also join heat sinks such as Further, as a method for removing the crosslinked portions 2, it is also possible to use means such as laser beams and etching.

"Effects of the Invention" As explained above, according to the method for manufacturing a copper-clad laminate wiring board according to the present invention, a pattern board in which pattern line parts are connected by bridge parts is integrally molded, and this is attached to a metal sheet material. Furthermore, since the bridge portion is mechanically removed and the individual pattern line portions are bonded to the insulating substrate while being fixed to the metal sheet material, errors in placement of the pattern line portions do not occur. Further, since the metal sheet material has a low coefficient of thermal expansion and a high tensile strength, it is difficult to stretch or warp when heated, and it is possible to prevent a decrease in the positional accuracy of the pattern line portion caused by these. Therefore, a copper-clad laminated wiring board with high pattern accuracy and high reliability can be manufactured, and since it is attached to a metal sheet material, handling of the pattern board is easy, and the production line can be simplified and made more efficient. Further, the pattern plate can be manufactured efficiently by punching or the like regardless of its wall thickness, and each bridge portion can be easily removed by machining or the like, so it can be mass-produced at low cost. Furthermore, by using metal sheet material, there is less generation of particles and debris when punching the crosslinked part compared to when sheet materials of other materials are used, and processing equipment may malfunction due to the adhesion of these particles. It also has the advantage of being less difficult.

[Brief explanation of the drawing]

1 to 5 are for explaining one embodiment of the method for manufacturing a copper-clad laminate wiring board according to the present invention, and FIG. 1 is a plan view showing an example of the shape of a pattern board; Figure 2 is a plan view showing the state in which the pattern plate is attached to a metal sheet material and the bridge portion has been removed, Figure 3 is a side view showing the process of bonding the pattern plate to the substrate, and Figure 4 is the resulting copper cladding. FIG. 5 is an enlarged cross-sectional view of the laminated wiring board, and FIG. 5 is a plan view of the same wiring board. DESCRIPTION OF SYMBOLS 1... Pattern line part, 2... Bridge|bridge part, 3... Pattern board, 4... Metal sheet material, 5... Spread hole, 6...
...Insulating substrate, 8...Metal plate, 9...Insulating layer, P.
...Bridge portion removal location.

Claims (1)

[Claims] An integral pattern plate consisting of a plurality of pattern line parts constituting the wiring pattern and a bridge part for fixing these pattern line parts to each other is formed from a thin plate made of copper or copper alloy, and one side of this pattern plate is The metal sheet material is affixed so as to be removable in a subsequent process, each of the bridge portions is removed by machining, etc., and the pattern plate side is adhesively fixed onto an insulating substrate, and then the metal sheet material is removed. A method for manufacturing a copper-clad laminate wiring board.