JPS62108594A - Hybrid integrated circuit - 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 Application of the Invention] The present invention relates to a hybrid integrated circuit, particularly a hybrid integrated circuit suitable for high-speed, high-frequency circuits.

[Background of the invention]

Hybrid integrated circuits have advantages such as small size, single functional block, high reliability, and improved electrical characteristics, and are widely used in various circuits. The manufacturing methods for hybrid integrated circuits can be broadly classified into thick film and thin film, but both differ only in the constituent materials and processes, and the basic structure of the circuit board is the same.

That is, the resistor and wiring are provided on the ceramic substrate,
Components such as active elements and capacitors are mounted on the substrate.

On the other hand, edited by Japan Microelectronics Association” I C
As described on page 10 of ``Integrated Mounting Technology'' (January 1980, published by Kogyo Kenkyukai), there is a technology in which a wiring system is configured on both sides of a board and connected through through holes.

However, in high-frequency circuits and high-speed circuits, it is desired to provide a sufficient high-frequency grounding system. In other words, it is required to connect the wiring system and the ground at a sufficiently short distance, but with a planar configuration, as miniaturization progresses, it is necessary to connect the wiring system to the ground at a sufficiently short distance.
The key is to form a ground wiring system with a short pattern.

Therefore, as shown in FIG. 2 (schematic cross-sectional view), the conventional technology is based on the entire back surface 2 of the ceramic substrate 1.

is grounded, and the through hole 4 connects the ground on the back surface 2 to the wiring system on the front surface 3, that is, the electrode 9 of the mounted component 8 bonded to the land portion 3A via a low melting point solder 7.

In the conventional technology with such a configuration, the distance from the wiring system (for example, the electrode 9) to the through hole 4 is large, and the thickness of the conductor in the through hole 4 portion is thin, so that it cannot be ignored in terms of DC and AC. Resistance exists. The resistance of the former has a large variation, and although it is impossible to say with certainty, it may be on the order of 100 mΩ. The latter resistance value is estimated to be 3 to 5 nH using the equation (formula (1) below) in the above-mentioned document P, 198. In addition, the skin depth of the 4th through hole also affects the high frequency.

However, the self-inductance of the Ls strip conductor,
W: Width of the conductor, L: Length of the conductor, μ, magnetic permeability in two vacuums.

[Purpose of the invention]

In view of the above, it is an object of the present invention to provide a hybrid integrated circuit that can reduce DC and high frequency inductance and downsize.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that a through hole is formed in an electrode portion that connects the electrodes of a mounted component, and the inside of the through hole is filled with a metal member.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a hybrid integrated circuit according to this embodiment. The same reference numerals as those shown in FIG. 2 indicate the same or corresponding parts.

In high-frequency, high-speed circuits, the target wiring system that should be connected to the ground (earth) is directly the active element or child terminal, but
Anything that cannot be connected directly in terms of potential is connected via a capacitor. Therefore.

In this embodiment, the connection land 5 of the mounted component on the board 1 and the back ground 2 of the board 1 are directly connected through the through hole 4, and a metal member 1, for example, Pb is inserted into the through hole 4.
Reflow is performed by filling 50 to 95% high melting point solder 6 in the form of a rod or paste. Therefore, the inside of the through hole 4 is filled with a metal member 6 made of high melting point solder.

Next, after printing a solder paste with a lower reflow temperature than this on the metal member 6 (usually - Ag solder), components 8 such as capacitors are mounted and reflowed,
The connection land 5 and the through hole 4 are connected by a low melting point solder 7. In this way, the through hole 4 filled with the metal member 6 can be formed directly under the electrode 9 of the component 8 to be grounded, so that the pattern on the back surface 2 of the substrate can be connected to the pattern on the back surface 2 of the substrate through the through hole 4. Can be connected.

According to this embodiment, flatness is almost ensured by the metal member 6 filled in the through hole 4, so one part 8
Conventional technology can be applied to the mounting process.

〔Effect of the invention〕

As explained above, according to the present invention, the object to be grounded and the ground can be directly connected by a metal member, so the DC resistance becomes a small value of about 1 mΩ, and the inductance is 0 in terms of AC. It becomes a small value of .5 to InH.

Furthermore, it is possible to apply to several Glk high-frequency circuits and sub-N5EC high-speed circuits.

In addition, according to the present invention, the through-hole portion and the electrode land can be formed at the same location, so there is an advantage that it is possible to achieve miniaturization.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an embodiment of a hybrid integrated circuit according to the present invention, and FIG. 2 is a schematic cross-sectional view of a conventional hybrid integrated circuit. 1... Board, 2... Back side, 4... Through hole. 5... Land portion, 6... Metal member, 7... Low melting point solder, 8... Mounting component, 9... Electrode. Figure 1, Figure 20

Claims (1)

[Scope of Claims] 1. A hybrid integrated circuit characterized in that a through hole is formed in an electrode portion for connecting an electrode of a mounted component, and the inside of the through hole is filled with a metal member. 2. The hybrid integrated circuit according to claim 1, wherein a high melting point solder is used as the metal member filled in the through hole, and a low melting point solder is used as the solder for connecting the mounted components.