JPH1065342A - Multilayer circuit board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a miniaturized board by reducing the occupied areas of passive elements, such as resistors and the like in a multilayer circuit board. SOLUTION: In a thick-film multilayer circuit board on which alumina substrate 25, wiring conductors 26 and insulators 28, 31 are alternately formed by printing, resistors are formed as follows. In the insulator 28, via holes 27 for wiring connection between circuit substrates are provided. Then in this via hole, a resistor 30 is built. Thereby, by reducing the occupied areas of passive elements such as a resistor and the like on the layer 31, miniaturizing the overall size of a board is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multilayer circuit board and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a conventional multi-layer circuit board (multi-layer hybrid IC), as shown in FIG. 4, a thick film resistor 1 as a passive element is connected between conductors 3 and 4 serving as terminals on the surface of a multi-layer board 2. Formed.

[0003]

However, the area occupied by the thick film resistor 1 including the conductors 3 and 4 is at least 1.
About 6 mm square is required. Therefore, when such a thick film resistor 1 is used, when the number of resistors is large, there is a problem that it is not possible to cope with a reduction in the size of the substrate (higher density).

SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer circuit board capable of reducing the area occupied by passive elements such as resistors and reducing the size of the board, and a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned object, and according to the first aspect, a resistor or a dielectric is incorporated in a hole portion for connecting a wiring between layers. On the surface of the layer, the area occupied by the resistor and the like is "0". Therefore, an excellent effect of reducing the area occupied by passive elements such as resistors on the layer and reducing the size of the substrate is exhibited.

According to the second aspect, in addition to the effect of the first aspect, there is an excellent effect that the resistor or the dielectric filled in the hole can be fired together with the laminated green sheet. Demonstrate.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIGS. 2A to 2D
Is a cross-sectional view of a substrate showing a manufacturing process thereof. In this embodiment, a case where a three-layer structure is adopted and a resistor is arranged in the uppermost layer will be described below. First, as shown in FIG.
Three alumina green sheets 11, 12, and 13 are prepared, and via holes (holes) 14, 15, and 16 are formed at predetermined positions of the uppermost green sheet 11. Then, as shown in FIG. 2B, the conductive paste 17 is formed in the via hole 15 by screen printing using a known method.
Fill. Next, the via holes 14 and 16 are filled with resistor pastes 18 and 19 by a screen printing method.

Next, as shown in FIG. 2C, a predetermined pattern of conductive pastes 20, 21 is printed on the surfaces of the green sheets 11, 12, 13 by screen printing. Then, as shown in FIG. 2D, the green sheets 11, 12, and 13 are pressed and pressed in a state of being stacked.
Thereafter, the pressed green sheets 11, 12 and 13 are fired.

As a result, the resistors (18, 1) are formed in the via holes (14, 16) for making wiring connections between the multilayer alumina substrates 22, 23, 24 as shown in FIG.
A multilayer circuit board incorporating 9) is formed. In this multilayer circuit board, resistors (18, 19) are incorporated in via holes (14, 16) for performing normal interlayer wiring connection, and the area occupied by the resistors on the surface of the substrate 22 is "0". In addition, even if the number of resistors is large, the occupied area can be reduced and the size of the substrate can be reduced.

That is, conventionally, the area occupied by the thick film resistor 1 needs to be at least about 1.6 mm □ including the conductors 3 and 4, but the area occupied by the resistor can be eliminated. In addition, the process of forming the resistor in the via hole portion can be easily performed without adding a special process to the conventional process, since it is only necessary to replace the conventional process of filling the via hole portion with the conductor. .

The present invention is not limited to the above embodiment. In the above embodiment, a resistor is incorporated as a passive element in the via hole, but a dielectric may be incorporated by screen printing. In the above-described embodiment, the green sheets 11, 12, and 13 are stacked to form a multilayer. However, as shown in FIG. 3, the conductive paste and the insulating paste are alternately printed to form a multilayer, and the via holes have resistance. A body or the like may be incorporated.

That is, a pattern of a conductive paste 26 is formed on one baked alumina substrate 25, and then an insulating paste (glass paste or glass paste) having via holes 27 communicating with the conductive paste 26 is formed on the alumina substrate 25. (Ceramic paste) 28 is printed. After that, the via holes 27 are filled with the conductor paste 29 and the resistor paste 30 by a screen printing method.

Further, similarly, it may be manufactured by multi-layering with the insulating paste 31 and then firing. Further, the substrate material is not limited to alumina, but may be a resin material such as glass ceramic or glass epoxy. Further, the structure of the present invention can be applied to a through-hole portion in a double-sided through-hole substrate.

[Brief description of the drawings]

FIG. 1 is a sectional view of a multilayer circuit board embodying the present invention.

FIG. 2A is a cross-sectional view for explaining a manufacturing process of a multilayer circuit board. (B) is sectional drawing for demonstrating the manufacturing process of a multilayer circuit board. (C) is sectional drawing for demonstrating the manufacturing process of a multilayer circuit board. (D) is sectional drawing for demonstrating the manufacturing process of a multilayer circuit board.

FIG. 3 is a cross-sectional view of another example of a multilayer circuit board.

FIG. 4 is a cross-sectional view of a conventional multilayer circuit board.

[Explanation of symbols]

 14, 16, 30 Via hole 18, 19 Resistor (resistor paste) 22, 23, 24 Alumina substrate 27 Via hole 28, 31 Insulating paste

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideki Nakagawara 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. Inside

Claims (2)

[Claims] 1. A multi-layer circuit board in which wiring conductors and insulators are alternately printed on a substrate, wherein the insulators are provided with holes for making wiring connections between layers of the circuit board. A multilayer circuit board, wherein a resistor or a dielectric is incorporated in the hole. 2. A method for manufacturing a multilayer circuit board, comprising laminating and firing a plurality of green sheets to which wiring conductors have been applied, wherein a hole portion for making a wiring connection between layers of the circuit board at a predetermined position of the green sheet. Forming a hole, filling the hole portion with a resistor or a dielectric, and firing the resistor or the dielectric together with the laminated green sheet at a time.