JPH0685434A - Manufacturing method of ceramic circuit board - Google Patents

Abstract

PURPOSE:To realize the manufacturing method of ceramic circuit board having high reliability thereupon by a method wherein the deterioration in the reliability due to any developed whisker or blur is avoided while forming a fine patterns with high precision. CONSTITUTION:The first circuits 3 are formed on a resin film 1 coated with a mold release agent 2 and after coating the second circuits 5 with a thermoplastic resin on a previously formed ceramic board 6, the first circuits 3 and the second circuits 5 are aligned with one another to be baked after the pattern transfer by heating and pressurzzing steps. Through these procedures, the first circuits 3 in fine patterns can be formed between the second circuits 5 in fine patterns thereby enabling the ceramic circuit boards having fine patterns to be manufactured with high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ceramic circuit board which can be used for circuit formation of electronic equipment and has high precision wiring.

[0002]

2. Description of the Related Art In recent years, a ceramic circuit board is superior in heat conductivity, heat resistance, and chemical durability to an organic material substrate, so that its use is expanding as an alternative to the organic material substrate. In addition, with the miniaturization and diversification of electronic devices, they have come to be widely used as substrates capable of high-density wiring and high-density mounting. Furthermore, it is expected that the demand for semiconductor bare chip mounting boards will increase in the future, and it is thought that a method for manufacturing a ceramic circuit board that is composed of a conductor that is optimal for easy use with fine wiring and high reliability is required. .

An example of a conventional ceramic circuit board will be described below with reference to the drawings.

FIG. 5 shows the structure of a conventional ceramic circuit board. As shown in FIG. 5, the conventional ceramic circuit board contains Ag powder or Cu powder as a main component on a ceramic substrate 8 made of alumina or the like. Then, a conductive paste obtained by adding lead borosilicate glass or borosilicate glass and a thermoplastic resin to this is printed to form the conductor layer 9 and the through-hole conductor 10. Further, the ceramic circuit board is completed by firing the ceramic board thus configured.

[0005]

However, in such a conventional structure, the shape of the conductor layer 9 formed by screen-printing the conductor paste is affected by the bleeding 11 of the paste, the whiskers 12, or the screen through which the paste penetrates. It is difficult to realize the design accuracy because of problems such as a decrease in the linearity of the contour portion. In particular, when a plurality of fine patterns are printed at fine intervals, for example, a plurality of 60 μm-wide lines are printed at intervals of 60 μm, due to the delicate plate separation,
Compared with printing a plurality of 60 μm-wide lines at 120 μm intervals, line whiskers 12 and bleeding 11 were remarkably generated, and there was a very serious problem in terms of reliability.

The present invention is intended to solve the above problems,
It is an object of the present invention to provide a method for manufacturing a ceramic circuit board, which can form a fine pattern with high accuracy and can obtain high reliability.

[0007]

In order to achieve the above object, a method of manufacturing a ceramic circuit board according to the present invention comprises a resin film coated with a release agent made of a silicone resin or the like, metal powder, glass and an organic vehicle. A step of forming a first circuit with an electrode paste containing as a main component, a step of applying a thermoplastic resin to the surface of the ceramic substrate on which the second circuit and the through-hole conductor are already formed by a metal or the like, From the step of aligning the surface of the first circuit on the resin film with the surface of the second circuit of the ceramic substrate at a predetermined position, and from one surface different from the surface of the first circuit on the resin film. A step of heating and pressurizing, a step of peeling the resin film to transfer the first circuit to the surface of the ceramic substrate, and then firing at a predetermined temperature to decompose and remove the thermoplastic resin. It becomes 1 the circuit the step of metallizing, those as adapted to use PPS, engineering plastic such as PEI as the resin film.

[0008]

Therefore, according to the present invention, the circuit pattern formed on the resin film is positioned and transferred to the circuit pattern previously formed on the ceramic substrate so as to be located between the lines of the circuit pattern. In addition, the synthesized circuit pattern can be formed finely and accurately, and a highly reliable ceramic circuit board can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a ceramic circuit board according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1, FIG. 2, FIG. 3 and FIG. 4 show a method of manufacturing a ceramic circuit board according to an embodiment of the present invention. First, as shown in FIG. 1, a release agent 2 made of a silicone resin is applied onto a resin film 1 made of polyphenylene sulfide (PPS), and then a Cu powder, glass, and an electrode paste containing an organic vehicle as a main component are used to form a second paste. The circuit 3 of No. 1 is formed by screen printing. At this time, the pattern of the first circuit 3 is a fine line (60 μm width), but the line interval is 120 μm or more. Next, as shown in FIG. 2, a thermoplastic resin 7 containing an acrylic resin as a main component is thinly applied (10 μm or less) on one surface of a ceramic substrate 6 formed in advance. The second circuit 5 has fine lines with a width of 60 μm and the line interval is 120 μm. Next, the resin film 1 shown in FIG. 1 in which the first circuit 3 is formed on the release agent 2 is inverted as shown in FIG. 2 and aligned with a predetermined position. At this time, the first circuit 3 and the second circuit 5 are
Arrange the lines alternately. Next in FIG.
As shown in FIG. 3, when the layer is heated and pressed, the layer of the heat-heatable resin 7 is deformed and the first circuit 3 on the resin film 1 adheres to the surface of the ceramic substrate 6. At this time, since the resin film 1 has a small thermal expansion, the first circuit 3 and the second circuit 5 can be accurately measured.
Are formed without contact. After cooling, when the resin film 1 is peeled off, the first circuit 3 embedded in the thermoplastic resin 7 remains on the ceramic substrate 6. Then, by firing at 900 ° C. in N ₂ , the ceramic circuit board having the structure shown in FIG. 4 is completed.

As described above, according to the above-described embodiment, since the first circuit 3 and the second circuit 5 in which the fine patterns set at sufficient intervals are formed with good quality are formed by the transfer, the fine circuit pattern is formed. Moreover, it is possible to obtain a highly accurate ceramic circuit board that does not generate whiskers or bleeding.

Although PPS is used as the resin film 1 in this embodiment, other engineering plastics may be used.

[0013]

As is clear from the description of the above embodiment,
In this embodiment, a step of forming a first circuit with an electrode paste and a second circuit and a through-hole conductor are already formed of a metal or the like on a resin film coated with a release agent such as a silicone resin. A thermoplastic resin is applied to the surface of the ceramic substrate, the first circuit on the resin film and the second circuit on the ceramic substrate are positioned, heated and pressed, separated, transferred, and fired. Therefore, it is possible to form a fine pattern with high accuracy and to provide a highly reliable ceramic circuit board.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a first step (resin film) of a method for manufacturing a ceramic circuit board according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing a second step (positioning) of the manufacturing method.

FIG. 3 is a sectional view of an essential part showing a third step (transfer) of the manufacturing method.

FIG. 4 is a sectional view of a main part of a ceramic circuit board completed by the manufacturing method.

FIG. 5 is a sectional view of a main part of a conventional ceramic circuit board.

[Explanation of symbols]

 1 Resin Film 2 Mold Release Agent 3 First Circuit 4 Cu Through Hole (Through Hole Conductor) 5 Second Circuit 6 Ceramic Substrate 7 Thermoplastic Resin Layer

Claims (2)

[Claims] 1. A step of forming a first circuit on a resin film coated with a release agent made of a silicone resin or the like with an electrode paste containing metal powder, glass and an organic vehicle as a main component, and a metal or the like. A step of applying a thermoplastic resin to the surface of the ceramic substrate on which the second circuit and the through-hole conductor are formed, and the surface of the first circuit on the resin film and the surface of the second circuit on the ceramic substrate. With a predetermined position, heating and pressurizing from one surface of the resin film different from the surface of the first circuit, and peeling the resin film to form the first circuit with the ceramic. A method of manufacturing a ceramic circuit board, comprising: a step of transferring to a substrate surface; and a step of thereafter baking at a predetermined temperature to decompose and remove the thermoplastic resin to metallize the first circuit. 2. The method for producing a ceramic circuit board according to claim 1, wherein the resin film is an engineering plastic such as polyphenylene sulfide (PPS) or polyether imide (PEI).