JPS61271891A - Manufacture of hybrid ic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is characterized in that circuit patterns are formed on both opposing main surfaces of a circuit board, and a thick film printed resistor is formed on at least one of the main surfaces. The present invention relates to a method of manufacturing a hybrid IC.

(Prior Art) Generally, in this type of hybrid IC, the circuit patterns formed on both opposing main surfaces of the circuit board are:
They are interconnected through through holes formed in the thickness direction of the circuit board.

Conventionally, in order to form through holes in the circuit board of a hybrid IC, when printing a circuit pattern using conductive tape on a circuit board with holes drilled at the positions where the through holes are to be formed, the circuit board is removed using a suction jig. 1) This is called a printing suction method in which air is sucked and the conductive paste of the printed circuit pattern is drawn into the hole along with the sucked air to form a conductive film on the inner wall surface of the hole. method has been adopted.

By the way, with this printing suction method, it is difficult to draw the conductive paste into the holes of the circuit board along with the suctioned air, and to reliably form a conductive film on the inner wall surface of the holes formed in the circuit board. There was a problem in that it was difficult to form circuit boards with high densities, complex hole shapes, and through holes, resulting in low yields during the production of hybrid ICs.

Silver (Ag)-palladium (Pd) is generally used as a material for conductive paste, and m(Cu) paste has recently been used as a cheaper material, but those using copper paste require a nitrogen atmosphere. (As a result of restrictions on the solvent and binder materials used in baking, it is difficult for the copper paste to be sucked into the holes in the circuit board), and the thickness of the suctioned copper paste tends to be uneven. If it becomes uniform, cracks and cranks will occur during baking of the copper paste, making it even more difficult to obtain reliable through holes.

On the other hand, the through-hole plating method that is used to form through-holes on double-sided printed circuit boards requires that the thickness of the through-hole plating film be relatively uniform even if the hole forming the through-hole has a complicated shape. can be obtained, and its reliability is high.

Therefore, it is conceivable to adopt this through-hole plating method for manufacturing hybrid ICs, but when manufacturing hybrid ICs with thick-film printed resistors using metal glaze materials such as ruthenium oxide, through-hole plating If a thick-film printed resistor is formed after plating, the thick-film printed resistor and the through-hole plating film formed by through-hole plating may react, or the through-hole plating film may be oxidized during firing of the thick-film printed resistor. There is a problem with it.

In addition, contrary to the above, if through-hole plating is performed after forming a thick-film printed resistor, the thick film of the through-hole plating film will be removed due to the glass component that has risen to the surface during firing of the thick-film printed resistor. Connection to the printed resistor cannot be made reliably. Furthermore, if the thick-film printed resistor is formed before through-hole plating, the surface of the thick-film printed resistor will be contaminated with the thickening liquid, which will change the electrical characteristics of the thick-film printed resistor. It was not possible to perform through-hole plating after forming.

(Object of the Invention) The present invention has been made in order to solve the above-mentioned problems in the method of manufacturing a hybrid IC, and it is an object of the present invention to provide a high-precision thick-film printed resistor with high reliability in connection of circuit patterns using through holes. An object of the present invention is to provide a method for manufacturing a hybrid IC that is easy to manufacture.

(Structure of the Invention) Therefore, the present invention provides a method for manufacturing a hybrid IC having a thick film printed resistor, in which a thick film printed resistor and a circuit pattern are formed on a circuit board in advance, and a through-hole of the circuit board is provided. A through-hole plating film is formed on both main surfaces of the circuit board, leaving the hole where the hole is to be formed and its vicinity, and the circuit board is immersed in a plating solution to form a through-hole plating film on the hole and its vicinity of the circuit board. The feature is that after forming the circuit pattern, the elements are attached to the circuit pattern. That is,
When forming the through-holes of hybrid IC by through-hole plating, the present invention covers the thick-film printed resistor water formed on the circuit board with the Metzukiregis F film, and allows the thick-film printed resistor to pass through without coming into contact with the plating solution. Perform hole plating.

(Effects of the Invention) According to the present invention, through-hole plating is performed with the thick-film printed resistor formed on the circuit board covered with the through-hole plating film. The through-hole plating method, which is highly reliable in forming through-holes, can be used to manufacture hybrid ICs with thick-film printed resistors without being immersed in water. A hybrid IC with high performance can be obtained.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, as shown in Figure 1 (,), alumina (A120
A hybrid IC circuit board 1 made of materials such as , ) is prepared. A hole 1a penetrating in the thickness direction is previously formed in this circuit board l at a position where a through hole is to be formed.

As shown in FIG. 1(b), the circuit board 1 is printed with a metal glaze-based resistance material such as ruthenium oxide, which has high reliability as a resistor, and is heated to approximately 850°C.
The thick film printed resistor 2 is formed by baking at a temperature of .

Thereafter, on both opposing main surfaces of the circuit board 1, as shown in FIG.
A conductive paste made of a conductive material such as a saw is printed on the top) shown in c), and the temperature is lower than the baking temperature of the thick film printed resistor 2.
Baked at a temperature of about 00℃, circuit pattern 3-1.3
-2. ...and 4-1°4-2. ... are formed respectively.

Note that circuit pattern 3-1.3-2. ...and 4-
1.4-2. When copper is used as the material for the thick film printed resistor 2, in order to prevent the copper from oxidizing when the thick film printed resistor 2 is baked, after forming the thick film printed resistor 2, the circuit pattern 3-1. 3-2. ...and 4-1.4-2. ...
After printing, it is preferable to bake in a nitrogen (N2) atmosphere, but the circuit pattern 3-1.3-2. ...and 4-1.4-2. When silver-palladium, which can be baked in air, is used as the material for circuit pattern 3-1.3-2. ...and 4-1.4-
2. After forming..., the thick film printed resistor 2 can also be formed.

The above thick film printed resistor 2 and circuit pattern 3-1.3-
2. ...and above 4-1.4-2, there is a
), plating resist films 5 and 6 are formed leaving the hole 1a of the circuit board 1 where the through hole is to be formed and the vicinity thereof.

In this way, thick film printed resistor 2 and circuit pattern 3-1
．． 3-2. ...and 4-1.4-2. After forming the plating resist films 5 and 6 thereon, the whole is immersed in, for example, an electroless plating solution for copper. As shown in FIG. 1(e), through-hole plating is applied to the hole 1a of the circuit board 1 and its vicinity to electrically connect the circuit pattern 3-1 and the circuit pattern 4-1. A membrane 7 is formed.

Thereafter, the plating resist films 5 and 6 formed in the step of FIG. 1(d) are removed, and the circuit pattern 3-1.3-2 is removed.
．． ...and 4-1.4-2. Solder elements 8 such as capacitors and transistors to the necessary locations.

In this way, through-holes in a hybrid IC can be formed using a highly reliable through-hole plating method.

[Brief explanation of drawings]

Figure 1(a), Figure 1(b), Figure 1(C), Figure 1(
d) and FIG. 1(e) are explanatory diagrams of an embodiment of the method for manufacturing a hybrid IC according to the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Circuit board, 1a... Hole, 2... Thick film printed resistor, 3-1.3-2.・・・Oagebi 4-1
．． 4-2...Circuit pattern, 5,6...
・Plating resist film, 7...Through-hole plating film, 7...Element. Patent applicant Murata Manufacturing Co., Ltd. Representative Patent attorney Aoyama Baka 2 people No. 11
C.I.

Claims (1)

[Claims] (1) A circuit pattern is formed on each of the opposing main surfaces of the circuit board, a thick film printed resistor is formed on at least one of the main surfaces, and connections are formed on the circuit patterns on both main surfaces of the circuit board. In a method for manufacturing a hybrid IC in which parts are connected through through holes formed in the thickness direction of a circuit board, a thick film printed resistor and a circuit pattern are formed on the circuit board in advance, and the through holes of the circuit board are connected to each other through through holes formed in the thickness direction of the circuit board. A plating resist film is formed on both main surfaces of the circuit board, leaving the hole where the hole is to be formed and its vicinity, and the circuit board is immersed in a plating solution to form a through-hole plating film on the hole and its vicinity of the circuit board. A method for manufacturing a hybrid IC, which comprises attaching an element to a circuit pattern after formation.