JPH03147403A - Microwave integrated circuit - Google Patents

Abstract

PURPOSE:To realize a microwave integrated circuit offering highly precise assembling, suppressing the dispersion in the circuit characteristic small and improving the efficiency of the assembling by providing a projection part to a metallic plate and a ground pad to a dielectric substrate. CONSTITUTION:Dielectric substrates 3 are soldered respectively in matching with a projection part of a metallic plate 3. In this case, the lateral direction of the substrate 1 is decided by using a ground pad 8 as a guide. In this case, the position of soldering a FET chip 4 is made clear by the projection part of the metallic plate 3 and the ground pad 8 on the two substrates 1. Then the substrate 1 is soldered to the metallic plate 3 to solder the FET chip 4 to the ground position for the FET 4 to be formed and a microstrip line 2, a gate and drain pads 5, 6 are connected by a gold wire 7 to form the microwave integrated circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave integrated circuit, and in particular to a structure of a microstrip line in which semiconductor elements and dielectric substrates are semiconductor-attached at clearly defined locations.

[Conventional technology]

A circuit diagram of a conventional microwave integrated circuit is shown in FIG. 4, and a cross-sectional view thereof is shown in FIG. In the figure, (1) is a dielectric substrate, (a microstrip line) forms a matching circuit, (3) is a metal plate for grounding, and (4) is an FE
T chips, (5) and (6) are FET chips (four gate and drain pads, respectively, and (7) are gold wires.

Next, the operation will be explained. Here, the FET chip (
4), two dielectric substrates (1) forming the input/output matching circuit, and FET chip (4) and dielectric substrate (1)
The case of a microwave integrated circuit consisting of a microstrip line (2) formed above will be explained as an example.

In the microwave band, when matching the input and output of the FET chip (4), the input and output matching circuits are formed using microstrip lines (2) on the dielectric substrate (1), and the dielectric substrate (1) ) are placed at the input and output of the FET chip (4), and the dielectric substrate (1) and the FET chip (
After soldering 4), the gate and drain pads (5), (6) of the FET chip (4) and the microstrip line (2) were connected with a gold wire (7).

[Problem to be solved by the invention]

Conventional microwave integrated circuits were constructed as described above, so the dielectric substrate and FET chip were connected to a flat metal plate (3
) When soldering to the top of the board, there is no target to confirm the position, and the work is mainly done by visual inspection, which causes shifts in the board position and variations in the length of the gold wire each time the integrated circuit is assembled. , there were problems such as large variations in the characteristics of microwave integrated circuits.

This invention was made in order to solve the above-mentioned problems, and provides a microwave integrated circuit that can improve assembly accuracy and efficiency of assembly work when soldering dielectric substrates and FET chips. With the goal.

[Means to solve the problem]

In the microwave integrated circuit according to the present invention, convex portions are provided on the dielectric substrate and the metal plate to which the FET chip is soldered, and a grounding pad is further provided on the dielectric substrate forming the matching circuit of the FET chip. It is something.

[Function] In the microwave integrated circuit of the present invention, by providing a convex portion on the metal plate and further providing a grounding pad on the dielectric substrate, the microwave integrated circuit can be assembled with high precision. Variations in the characteristics of integrated circuits can be suppressed to a small level, and the efficiency of assembly work can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a plan view of a microwave 511 circuit showing an embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1. In the figure,
(1) is a dielectric substrate, (2) is a microstrip line, (3) is a metal plate, (4) is a FET chip, (5L (6
] are the gate pad and drain pad, respectively, of the FET chip (4), and (7) is the gold plate connecting the microstrip line (2) on the dielectric substrate (1) and the gate pad (5) or drain pad (6). It's a wire.

Figure 3 shows the FET chip (4) and gold wire (7) in Figure 1.
) is a plan view showing the state of [171] in which the kfU body board is attached. In the figure, (8) is a ground bat formed on the kfU body substrate).

Next, the operation will be explained.

First, as shown in Figure 3, the dielectric substrate (1) is soldered to the convex portions of the metal plate (3). At this time,
In the lateral direction of the dielectric substrate (1), the position of the dielectric substrate (1) is determined using the ground batt (8) as a landmark. At this time,
The position where the FET chip (4) is soldered is clearly located from the convex part of the metal plate (3) and the ground pad (8) on the two dielectric substrates (1).

Next, as shown in FIGS. 1 and 2, the dielectric substrate (1) is soldered to the metal plate (3) to form an F.
Attach the FET chip (4) to the ground position for the ET chip (4).
), and then solder the microstrip line (2
) and the gate and drain pads (5), (6) using a gold wire (7), a microwave integrated circuit can be formed.

In addition, although the case where the FET chip (4) is used was explained in the said Example, the FET chip may be other semiconductor elements, and it will produce the same effect as the said Example.

〔Effect of the invention〕

As described above, according to the present invention, since the convex portion is provided on the metal plate and the ground pad is formed on the dielectric substrate, soldering of the dielectric substrate and the FET chip can be carried out with high precision, thereby reducing variations in characteristics. It is possible to keep the amount low, and furthermore, it has the effect of improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a microwave integrated circuit according to an embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG.
FIG. 4 is a plan view showing the structure of the microwave integrated circuit before the assembly process, FIG. 4 is a plan view showing a conventional microwave integrated circuit, and FIG. 5 is a sectional view of FIG. 4. In the figure, (1) is a dielectric substrate, (2) is a microstrip line, (3) is a metal plate, (4) is a FET chip, (5) is a gate pad, (6) is a drain pad, (
7) indicates a gold wire, and (8) indicates a ground pad. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A dielectric substrate on which a microstrip line is formed,
1. A microwave integrated circuit comprising a semiconductor element and a gold wire, characterized in that a pattern for soldering the semiconductor element is formed on an end surface of the dielectric substrate adjacent to the semiconductor element.