JPH02203595A - Multilayered wiring board - Google Patents

Abstract

PURPOSE:To reduce noise from a multilayered printed board by making distances between an element and power supply layers shorter so as to reduce inductance components and, at the same time, forming an insulating layer of a thin film section so as to reduce conductor intervals between the pairs of power supply layers. CONSTITUTION:A multilayered wiring board 10 composed of a thin film section 11 and thick film section 12 is formed against an integrated circuit element 1. Power supply layers 111 and 112 are arranged in the section 11 adjacent to the main surface side of the section 11 and power supply layers 121 and 122 are provided in the section 12. In addition, through holes for power supply 20 and signals 30 are provided. In order to reduce inductance components by making the distances between the element 1 and power supply layers shorter, the power supply layer pairs 111 and 112 and 121 and 122 are formed adjacent to an element 1 mounting surface by means of the section 11 and, at the same time, an insulating layer is formed of the section 11. Therefore, conductor intervals between the power supply layer pairs can be reduced extensively and the coupling between the power supply layers can be strengthened, resulting in an increase in electrostatic capacity. Thus noise can be reduced from the multilayered printed board.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer wiring board on which electronic components such as integrated circuit elements are mounted, and particularly to a multilayer wiring board suitable for mounting high-speed elements.

[Conventional technology]

A conventional multilayer wiring board is a ceramic multilayer wiring board using a green sheet lamination method, as described in JP-A-58-111396, in which an insulator layer between specific conductor layers is formed by a printing method, and the thickness between the conductor layers is adjusted. One example is one in which the conductor is made thinner than the green sheet laminated part to increase the capacitance between the conductor's eyebrows.

The above invention was made in order to suppress fluctuations in power supply potential caused by the operation of integrated circuit elements mounted on a multilayer wiring board.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, sufficient consideration is not given to the length of the path from the integrated circuit element to the conductor layer pair and the power supply layer forming the conductor layer pair, which poses a problem especially when high-speed elements are mounted. there were.

In other words, as devices operate at high speeds, the switching time of signals becomes shorter and they begin to contain large amounts of high-frequency components.As a result, the inductance component of the path from the device to the power layer can no longer be ignored, and sufficient space between the power layers is required. A situation has arisen in which plowing cannot be done effectively even if the capacitance is secured. Furthermore, if the power supplies whose fluctuating currents form a closed circuit are placed separately and separately, the noise induced by the fluctuating currents may adversely affect the conductor layer adjacent to the power supply layer, causing equipment malfunction. Ta.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to reduce the inductance and induced noise.

[Means to solve the problem]

In order to achieve the above objective, we focused on the power supply layer arrangement, which had not been sufficiently considered in the past, including AC characteristics, and placed the conductor layer pairs that form the power source pair, which serves as the source and shift of the fluctuating current, adjacent to each other, and integrated circuit elements. It is placed near the main surface on which it is mounted.

[Effect]

A fluctuating current generated by element operation flows through a through hole or the like that connects the element and the power supply layer, and at this time, a potential difference occurs between the element and the power supply layer due to the inductance of the through hole portion. In particular, as the switching speed of the elements increases, the potential difference becomes significant and cannot be ignored. By arranging the power supply layer near the main surface on which the element is mounted as in the present invention, the inductance of the through-hole portion can be reduced and the potential difference caused by the fluctuating current of the high-speed element can be sufficiently reduced.

In addition, since the same amount of current changes in opposite directions in the power supplies that are the source and sink of the fluctuating current, the potential fluctuations caused by the fluctuating current can be suppressed by pairing these power supplies and placing them adjacent to each other to strengthen electrical coupling. Since the noise is locally converged in both time and space, it is possible to reduce noise induced into conductors adjacent to these power supply layers and noise transmitted over long distances within these power supply layers.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1 is an integrated circuit element, 10 is a multilayer wiring board, and 11 is a thin film portion 12 is a thick film portion. Reference numerals 111 and 112 indicate power supply layers disposed adjacent to the main surface side of the thin film portion, and reference numerals 121 and 122 indicate power supply layers provided in the thick film portion. 20 is a power supply through hole, 3
0 indicates a signal through hole, and 40 indicates a pad for external connection.

In this example, a pair of electric g layers are made of a thin film and placed adjacent to the element mounting surface, thereby shortening the distance between the element and the power layer to reduce the inductance component, and forming an insulating layer with the thin film. This makes it possible to make the conductor spacing between the pair of power supply layers extremely small, thereby making it possible to strengthen the coupling between the power supply layers and increase the capacitance.

FIG. 2 shows the basic circuit of the ECL circuit. When an ECL is used as a circuit element, it is preferable to use the above-mentioned power supply pair as a part of the power supply pair of the emitter follower in which a fluctuating current is generated due to a logic operation.

In this example, a single-chip carrier was shown, but
It is clear that the invention can be applied to multilayer wiring boards for multichip modules.

〔Effect of the invention〕

According to the present invention, since the inductance between the integrated circuit element and the power supply layer can be reduced, the potential difference generated in the through-hole portion can be reduced, which is effective in reducing noise. In addition, noise in opposite directions caused by fluctuating currents can be locally canceled out, which is effective in reducing noise.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, and FIG. 2 is a basic circuit diagram of an ECL element. DESCRIPTION OF SYMBOLS 1... Integrated circuit element, 10... Multilayer wiring board, 11
... Thin film part, 12... Thick film part. 111, 112. 121. 122...power layer,
20, 30...through hole, 40...pad.

Claims (1)

[Claims] 1. In a multilayer wiring board formed by laminating and integrating a plurality of conductor layers with insulating layers interposed therebetween, specific conductor layers are laminated adjacently, and the conductor layer pair is used as the main body on which the integrated circuit element of the multilayer wiring board is mounted. A multilayer wiring board characterized by being arranged near the surface.