JPH11207781A - Manufacture of microwave circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively conduct a wire bonding by reducing a surface roughness of a surface of an easily plating resin in combination with a hard plating resin. SOLUTION: In the case of combining an easily plating resin 1 and a hard plating resin 2, and integrally injection molding a base by two-color injection molding, an injection mold temperature of the easily plating resin is set to 150 deg.C or higher, or an injection speed of the resin 1 is set to 40 mm/sec. The microwave circuit board manufactured via these means can be controlled to reduce a roughness of a surface of the resin 1. The resin 1 is a liquid crystal polymer. And, the resin 2 may be a polyphenylene sulfide. And, an injection molding width of the injection molding may be 0.4 mm(min).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of manufacturing technology of a three-dimensionally molded circuit board, and more particularly to a method of integrally injecting a board by two-color injection molding using a combination of an easily-platable resin and a hard-to-plate resin. The present invention relates to a method for manufacturing such a three-dimensional circuit board to be molded.

[0002]

2. Description of the Related Art Conventionally, in this type of three-dimensionally formed circuit board,
Although a polyether sulfone or the like has been used as the easily-platable resin, a liquid crystal polymer has come to be used as the easily-platable resin from the viewpoint of preventing temporal deformation, preventing heat deformation, and rigidity.

[0003] As a manufacturing method, a three-dimensional circuit board obtained by integrally injection-molding the liquid crystal polymer, which is the above-mentioned easily-platable resin, with a hard-to-plate resin such as polyphenylene sulfide by two-color injection molding is first used. Then, the surface is roughened with a liquid crystal polymer as an easily plating resin, and a metal layer is formed to a certain thickness by electroless copper plating. Thereafter, a method of applying a protective plating layer of electroless nickel and further electroless gold plating has been adopted.

[0004] In this way, a plastic injection molded substrate with a plating circuit can be obtained. If there is no abnormality in the electric circuit or the like, there is no problem even if the surface roughness of the liquid crystal polymer used as the easily plating resin is rough. And didn't have to worry.

[0005]

As in the prior art described above, in this type of three-dimensional circuit board, the board is integrally injection-molded by two-color injection molding in combination with an easy-plating resin and a hard-plating resin. The three-dimensional circuit board obtained in this manner has to take such a manufacturing method from the viewpoint of cost and the like, and the board has been designed under a demand for wiring rationalization. There is an increasing demand for use as a part of a part.

For this reason, the connection with the small element has to be bonded by a wire. However, by doing so, the plating surface of the three-dimensional circuit board, and hence, an easily-platable resin;
It has become necessary to reduce the surface roughness of the liquid crystal polymer as much as possible.

Therefore, the problems to be solved by the present invention (objects)
Is to provide a method for manufacturing a three-dimensional circuit board, which can reduce the surface roughness in the surface roughening treatment on the surface of the easy-to-plate resin combined with the difficult-to-plate resin and ensure wire bonding. is there.

[0008]

Means for Solving the Problems The first means provided by the present invention is that when a substrate is integrally injection-molded by two-color injection molding by combining an easily-plateable resin and a hardly-plateable resin, In this method, the temperature of the injection mold of the reactive resin is set to 150 ° C. or higher.

Further, the second means provided by the present invention is a method for injecting an easy-plating resin when the substrate is integrally injection-molded by two-color injection molding using a combination of an easy-plating resin and a hard-plating resin. The speed is set to 40 mm / s.

[0010] By setting the temperature of the injection molding die as in the first means, or by setting the injection molding speed as in the second means, control is performed so as to reduce the surface roughness of the easily-platable resin. It becomes possible.

In the first means or the second means, it is preferable that the easily-platable resin is a liquid crystal polymer and the hard-to-plate resin is polyphenylene sulfide. The resin molding width by the injection molding is 0.4 mm (m
in).

[0012]

FIG. 1 shows an example of a sectional structure of a three-dimensional circuit board obtained by the manufacturing method of the present invention.

Thus, in the manufacturing method of this embodiment, a liquid crystal polymer is used as an easily plating resin, and polyphenylene sulfide is used as a hardly plating resin, and these are injection-molded by a two-color molding method.

As a specific method, as shown by reference numeral 1 in FIG. 1, one predetermined mold made of a liquid crystal polymer is first made, and then a mold having a cavity formed with the whole substrate is formed. Set the mold 1 in the cavity,
A method in which polyphenylene sulfide is filled and molded into the remaining space, and injection molding is performed so as to be integrally combined with the circuit forming portion 1 and the insulating portion 2 so as to form an electric circuit pattern on the substrate surface. And In FIG. 1, reference numeral 3 denotes a plating circuit surface made of a liquid crystal polymer; a portion for setting the surface roughness; and 4, an insulating surface made of polyphenylene sulfide.

When injection molding is performed by the above-described method, the liquid crystal polymer used as the easily-platable resin will have a molded article having a rough surface if the injection conditions are not properly set.

Therefore, when injection molding a liquid crystal polymer used as an easily plating resin, the temperature of the mold for injection molding should be 150 ° C. or higher, and the injection speed for injection molding should be 40 mm / mm.
s.

In the three-dimensional circuit board obtained under the conditions described above with a resin molding width of 0.4 mm (min), the surface 3 was roughened with a liquid crystal polymer, and a predetermined thickness was formed by electroless plating. Then, a metal layer was formed, and then a protective plating layer of electroless nickel plating and electroless gold plating was sequentially applied.

With respect to the three-dimensional circuit board obtained under the above two conditions, bonding was performed using gold wires, and the surface roughness of the liquid crystal polymer was measured. As a result, in the three-dimensional circuit board under any conditions, the roughness of the surface to be plated was reduced, and the bonding was successfully performed.

As a comparative example, the above-mentioned method was tried also when the conditions set by the present invention were removed.
The results were as follows. When the temperature of the mold for injection molding is lower than 150 ° C., the roughness Rz of the surface to be plated is 30.
When the injection speed for injection molding is less than 40 mm / s or more, the roughness Rz of the surface to be plated is 30 μm or more, and the bondability is NG.

The above embodiment is shown as a preferred embodiment of the present invention to the last, and can be modified within the technical concept of the present invention. For example, the present invention can be realized by combining the above-mentioned conditions of a mold temperature for injection molding of 150 ° C. or higher and an injection speed for injection molding of 40 mm / s. In addition, polyphenylene sulfide and liquid crystal polymer used for the difficult-to-plate resin and the easily-plateable resin are also preferable materials, and if there is a material to replace them,
The use of these alternative materials is acceptable.

[0021]

According to the present invention as described above, the surface roughness of the surface of the easy-to-plate resin combined with the hard-to-plate resin can be reduced by the surface roughening treatment to ensure the wire bonding. It is possible to achieve an intended object (object) of providing a method of manufacturing a three-dimensional circuit board that can be performed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional structural explanatory view of a three-dimensional circuit board obtained by a method of manufacturing a three-dimensional circuit board according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal polymer (easy plating resin) 2 polyphenylene sulfide (hard plating resin) 3 surface to be plated 4 insulating surface

Claims (6)

[Claims] When a substrate is integrally injection-molded by two-color injection molding using a combination of an easily-platable resin and a hard-to-plate resin, the temperature of the injection mold of the easily-plateable resin is set to 150 ° C. or higher. A method for manufacturing a three-dimensional circuit board. 2. The method according to claim 1, wherein said easily-platable resin is a liquid crystal polymer, and said hard-to-plate resin is polyphenylene sulfide. 3. The resin molding width of the injection molding is 0.4 mm.
The method according to claim 1 or 2, wherein (min). 4. A three-dimensional circuit board wherein an injection speed of an easily plating resin is set to 40 mm / s when a substrate is integrally molded by two-color injection molding by combining an easily plating resin and a hardly plating resin. Manufacturing method. 5. The method according to claim 4, wherein said easily-platable resin is a liquid crystal polymer, and said hard-to-plate resin is polyphenylene sulfide. 6. A resin molding width by the injection molding is 0.4 mm.
The production method according to claim 4 or 5, wherein (min).