JPS61180496A - Formation of circuit board - 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] [Field of Industrial Application] The present invention relates to a method for forming a circuit board, and relates to a method for forming a circuit board (C), in which a thick film resistor mainly composed of an organic material is formed on a circuit board mainly composed of an organic material. The present invention relates to an improvement in a method for forming a circuit board.

[Conventional technology]

Conventionally, a method of forming a resistor mainly composed of an organic material such as carbon on a printed circuit board mainly composed of an organic material such as a glass epoxy substrate 9 or a paper phenolic substrate is shown in Fig. 2 α to ζ: The steps are performed in the order shown in d. That is, the circuit group viI above C above:
Copper forming the wiring pattern is reduced, and copper pattern 3 is formed.
The first step is to form (FIG. 2 α).

A second step of printing and curing the conductor pattern 4 to obtain an ohmic connection between the copper pattern 3 and the resistor (second factor b)
.

A third step (FIG. 2C) of printing and curing an undercoat layer 2 for protection of the resistor.

The fourth step is to print and harden the resistor 5 (@2 Figure cL).

A fifth step (FIG. 2e) of printing and curing the orbacode layer 6 for protecting the resistor 5.

[Problem that the invention seeks to solve]

When printing is performed in the order of the steps α to - in FIG. 2, the following problems occur in the resulting circuit board.

(2) When printing the undercoat layer 2, if the undercoat layer 2 overlaps the copper pattern 3, stable resistance cannot be obtained, so alignment is very difficult.

■ Because it is difficult to align the undercoat layer 2,
Is it necessary to reduce the dimensions of the undercoat layer 2? When the dimensions of the undercoat layer 2 are reduced, the undercoat layer 2
A gap 7 is created between the conductor pattern 4 and the conductor pattern 4, and the resistance value becomes unstable.

[Means for solving problems]

In order to solve the conventional problems, the process of forming a resistor on a substrate of the present invention includes a first process of printing and curing an undercoat layer on the substrate, and a reduction treatment of the copper forming the wiring pattern to form the copper pattern. A second step of forming a conductor pattern, a third step of printing and curing a conductor pattern, a fourth step of printing and curing a resistor, and a fifth step of printing and curing an overcoat. It is said that

[Effect]

In the present invention, the process order is to print and harden the undercoat layer, then print and harden the copper pattern, and then print and harden the conductor pattern, so even if the dimensions of the undercoat are reduced, the copper The gap between the pattern and the undercoat is filled with the conductive pattern, making the shape of the resistor stable and stabilizing the resistance value. This will be explained below with reference to the drawings.

〔Example〕

FIGS. 1a to 1e are diagrams for explaining the order of each step of the present invention.

A first step (FIG. 1 α) of printing and curing the C-dotted coating layer 2 on the circuit board 1.

A second step ($1 Fig. 6
).

A third step (FIG. 1C) is to print a conductor layer for ohmic connection between the copper pattern 6 and the resistor and harden it to form the conductor pattern 4.

The fourth step is to print the resistor 5 and harden it to form a resistor pattern ('#IIi Figure d).

A fifth step ('$1 Figure C) of printing and curing the overcoat layer 6 that protects the resistor 5.

〔Effect of the invention〕

As described above, according to present invention C, after printing and curing the undercoat layer (reducing the copper forming the two-distribution pattern to form the copper pattern, then printing and curing the conductor pattern). After curing, the process order of printing and curing the resistor to form a resistor pattern is as follows: Even if the dimensions of the undercoat layer are small, the gap between the copper pattern and the undercoat layer is small. is filled with a conductor pattern, and compared to conventional formation methods, the printing accuracy of the undercoat layer is not required to be as strict, and the shape of the resistor is stable, resulting in a circuit with a stable resistance value. A substrate can be manufactured.

[Brief explanation of the drawing]

Figures 1 α to 1e are diagrams illustrating the process sequence of the method for forming a circuit board according to the present invention, 'i! II2/Figures α to e are diagrams for explaining the process order of a conventional circuit board forming method. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Undercoat layer, 3... Copper pattern, 4... Conductor pattern, 5... Resistor, 6...
・Overcoat layer

Claims (1)

[Claims] A method for forming a circuit board, in which a resistor whose main component is an organic material is formed on a circuit board whose main component is an organic material by printing an undercoat layer on the circuit board. , a first step of curing, a second step of reducing copper forming a wiring pattern on the circuit board to form a copper pattern, and a conductor layer making an ohmic connection between the copper pattern and the resistor. a third step of printing and curing to form a conductor pattern; a fourth step of printing and curing the resistor; and a fifth step of printing and curing an overcoat layer to protect the resistor. A method for forming a circuit board, comprising the steps of: