JPH0779108B2 - Microwave integrated circuit module - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave integrated circuit module used at high frequencies.

2. Description of the Related Art In recent years, the frequencies used have tended to become higher and higher due to the development of semiconductors and related technologies and the development of communication technologies typified by satellite broadcasting. Among them, particularly in the frequency band from several GHz to several tens GHz, development of an excellent semiconductor integrated circuit device has been earnestly desired.

An example of a conventional semiconductor integrated circuit device will be described below with reference to the drawings. FIG. 2 shows a conventional microwave semiconductor integrated circuit device, in which a field effect transistor (hereinafter abbreviated as FET) is used as an active element and a microstrip line is used as a transmission line. Here, 1 is a microstrip line made of a metal film formed by a vacuum deposition method or a plating method, 2
Is a ceramic substrate such as alumina, 3 is a metal carrier 5
FET mounted with the source grounded above, 8 bonding pads for the gate (left side) and drain (right side), 9 bonding wires, 10 parallel stubs for impedance conversion, 11 applies DC bias to the FETs , And 12 similarly represent drain power supply terminals, respectively.

The conventional microwave semiconductor integrated circuit device is configured as described above, the FET is operated by applying the DC bias from the gate and the drain, and the circuit using the microstrip line is used to match the external circuit. .
That is, impedance matching is performed by making the line width thicker or thinner, or by providing a stub.

Problems to be Solved by the Invention However, in the above configuration, since the connection between the FET 3 and the microstrip line 1 is performed by the bonding wire 9, the wire length cannot be ignored as the frequency becomes higher, and the above matching Therefore, it becomes necessary to take the bonding wire into consideration. However, it is very difficult to accurately control the length and shape of the wire. In addition, it takes a lot of work time to provide the bonding wire, resulting in a decrease in yield. Furthermore, there was a problem in reliability.

In view of the above problems, the present invention has the bonding pad surface of the active element (FET) connected on the transmission line (microstrip line) so as to face each other, and the ground plane formed on the back of the active element and the substrate. When connecting the ground plane formed on the back of the jig with a jig made of a low resistance metal, a U-shaped low resistance metal is used as the jig, and the jig, the active element and the By sandwiching the part that comes into contact with the ground plane of the substrate with a conductive rubber, and grounding it, matching conditions can be facilitated, high-frequency characteristics can be improved, yield can be improved, and reliability can also be improved. A microwave semiconductor integrated circuit device that can be used.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is directed to connecting the bonding pad surface of an active element to a transmission line so as to face each other, and further to a ground plane formed on the back side of the active element and The configuration is such that the ground plane formed on the back of the substrate is connected by a U-shaped low-resistance metal jig using a conductive rubber spring mechanism.

The present invention can solve the conventional problems because it has a structure in which the bonding pad surface of the active element can be directly connected to the transmission line, unlike the structure using the conventional bonding wire by the above structure.

Embodiment A microwave integrated circuit module according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 (a) is a plan view showing an embodiment of the present invention. In this figure, 1 is a microstrip line formed of a metal film (eg, Cr-Au) formed by a vacuum deposition method or a plating method, 2 is a ceramic substrate such as alumina,
3 is a FET with the bonding pad surface facing the microstrip line 1 and is connected, and 4 is a through on the back of FET 3.
A U-shaped jig made of low-resistance metal with a structure of connecting to a ground plane formed by using a hole and grounding it.
Reference numeral 5 is a metal carrier used for mounting the substrate 2 and the FET 3 described above. 1 (b) is A- of FIG. 1 (a).
It is sectional drawing of the part cut | disconnected by the broken line shown by A '. The parts shown in 1 to 5 are the same as the above, 6 is a bump made of a metal material used for connecting the microstrip line and the bonding pad of the FET, and 7 is a ground plane in the microstrip line. The grounding conductor formed in the above, and usually the same material as the microstrip line is used. Reference numeral 8 is a conductive rubber for connecting the grounding surface formed on the back side of the FET and the U-shaped low resistance metal jig and the grounding conductor formed on the back surface of the ceramic substrate to the jig.

In the microwave integrated circuit module configured as described above, the FET is operated by applying a DC bias from the gate and the drain, as in the conventional example shown in FIG. Further, the point that impedance matching is performed by widening or narrowing the width of the line or providing a stub can be applied as usual. However, according to the present invention, the bonding pad surface of the FET 3 is connected to the microstrip line 1 so as to face each other, and the through hole for conducting the front and back ground planes formed in the source pad on the FET surface is electrically connected. The bonding pad surface of the FET3 is connected to the grounding surface formed on the backside of the FET3 by connecting a U-shaped jig 4 made of a low resistance metal using a conductive rubber spring mechanism to the grounding surface. Can be directly connected to the microstrip line 1, which improves the high-frequency characteristics by facilitating the matching conditions in the circuit section, and improves the yield because the work of wire bonding is omitted, and the reliability is improved. It is possible to provide a microwave semiconductor integrated circuit device that also improves performance.

As another configuration example of the embodiment, the method of grounding the source of the FET may be a method other than the through hole, such as a lap plating method in which the side surface of the element is covered with a conductor for conduction. Furthermore, although the FET is used as the active element here, other active elements such as HBT (hetero bipolar transistor) and HEMT (high electron mobility transistor) can be considered.

EFFECTS OF THE INVENTION As described above, according to the present invention, the bonding pad surface of the active element is connected so as to face the transmission line, and the ground surface formed on the back surface of the active element and the ground surface formed on the back surface of the substrate. Is connected by a U-shaped jig made of low-resistance metal using a conductive rubber spring mechanism, and the bonding pad surface of the active element can be directly connected on the transmission line. Therefore, it is possible to provide a microwave semiconductor integrated circuit device in which a matching condition in a circuit portion is facilitated, high-frequency characteristics are improved, and a wire bonding work is omitted so that yield is improved and reliability is also improved. You can

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a microwave integrated circuit module of the present invention, FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a U-shaped low resistance metal jig and each of them. AA 'of FIG. 1 (a) in which connection with the ground plane was made using conductive rubber.
FIG. 2 is a cross-sectional view taken along the broken line shown in FIG. 2, and FIG. 2 is a plan view showing the configuration of a conventional microwave semiconductor integrated circuit device. 1 ... Microstrip line, 2 ... Substrate, 3 ...
FET, 4 ... Jig, 5 ... Metal carrier, 6 ... Metal bump, 7 ... Ground conductor, 8 ... Conductive rubber.

Claims (1)

[Claims] 1. In a microwave integrated circuit module including a transmission line formed on a microwave circuit board and an active element, a bonding pad surface of the active element is connected so as to face the transmission line, and When connecting the ground plane formed on the back of the active element and the ground plane formed on the back of the substrate with a jig made of a low resistance metal, a U-shaped low resistance metal is used as the jig. A microwave integrated circuit module used for grounding by sandwiching a conductive rubber between the jig, the active element, and a portion of the substrate that contacts the grounding surface.