JPH06140528A - Microwave semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To make it hard to cause the deterioration of high-frequency characteristic by directly connecting each second lead-out electrode to a lead frame under the state, wherein the side surface of a semi-insulating semiconductor substrate faces downward. CONSTITUTION:Under the state, wherein the side surface of a semi-insulating semiconductor substrate 20 of a microwave integrated circuit 10 faces downward, a second ground lead-out electrode 33, a second output lead-out electrode 34 and a second input lead-out electrode 35 are directly connected to a grounding lead 11a, an output lead 11b and an input lead 11c. Matching circuits 22, 25 and 28 are not located at the side surface of the semi-intsulating semiconductor substrate 20. Therefore, capacitances due to circuit wirings are not generated between the microwave integrated circuit 10 and the respective leads 11a, 11b and 11c, and radio-wave propagation does not occur. In this way, the microwave semiconductor device, wherein the deterioration of the high-frequency characteristic caused by inducance does not occur, can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave semiconductor device and its manufacturing method.

[0002]

2. Description of the Related Art Conventionally, microwave semiconductor devices have been used as devices for detecting, oscillating and amplifying high frequency electromagnetic waves in the millimeter wave band or submillimeter wave band. A conventional microwave semiconductor device has a microwave integrated circuit mounted on a lead frame and resin-sealed. That is, the microwave integrated circuit 1 is die-bonded to the header 3 of the lead frame 2 as shown in FIG. 9, and the input / output pads 3a, 3b, 3c, 3d,
3e is a bonding wire 4a, 4b, 4c, 4
leads 5a, 5 of the lead frame 2 via d, 4e
It is connected to b, 5c, 5d and 5e.

[0003]

In the microwave semiconductor device shown in FIG. 9, a plurality of bonding wires are used to reduce the impedance. In some cases, the high frequency characteristics of the microwave integrated circuit 1 are deteriorated.

Therefore, by removing the bonding wire that deteriorates the high frequency characteristics of the microwave integrated circuit 1 and shortening the distance between the microwave integrated circuit 1 and the lead frame 2 as much as possible, the impedance of the microwave semiconductor device is reduced. Is proposed. That is, in such a microwave semiconductor device, as shown in FIG. 10, the input / output pad (not shown) of the microwave integrated circuit 1 is connected to the header 3 of the lead frame 2 via the solder bumps 7a and 7b. There is.

However, in the microwave semiconductor device shown in FIG. 10, since the distance between the microwave integrated circuit 1 and the lead frame 2 is as small as several tens of μm, the solder bumps 7a and 7b are integrated in the microwave. A capacitance is generated together with the wiring pattern of the circuit 1. That is, the solder bumps 7a and 7b cause an increase in capacitance with respect to high frequencies. In addition, the solder bumps 7a and 7b are the solder bumps 7
There is a possibility that high-frequency reflection occurs between a and 7b, that is, it becomes a waveguide, the high-frequency characteristics of the microwave integrated circuit 1 change, and the characteristics deteriorate.

In view of the above, an object of the present invention is to provide a highly reliable microwave semiconductor device in which deterioration of the high frequency characteristics of the microwave integrated circuit does not easily occur.

[0007]

A microwave semiconductor device according to claim 1 for achieving the above object,
A microwave semiconductor device including a microwave integrated circuit built in a semi-insulating semiconductor substrate mounted on a lead frame, wherein one surface of the semi-insulating semiconductor substrate has a predetermined high frequency characteristic based on a circuit design. A plurality of first extraction electrodes respectively connected to the plurality of wiring patterns that are routed so as to obtain a region including each first extraction electrode at a predetermined distance from each other on one side surface of the semi-insulating semiconductor substrate. A plurality of notches and the inside of each notch,
A plurality of second extraction electrodes embedded so as to be connected to the respective first extraction electrodes, each of the second extraction electrodes being directly mounted on the lead frame.

In the above structure, in the microwave integrated circuit, the second extraction electrode is provided on one side surface of the semi-insulating semiconductor substrate in a state of being embedded in each notch, and the second extraction electrode is provided. The microwave integrated circuit is directly mounted on the lead frame without using a bonding wire by connecting to the first extraction electrode connected to each wiring pattern. That is, since the second extraction electrodes are directly connected to the lead frame with the side surface of the semi-insulating semiconductor substrate of the microwave integrated circuit facing downward, each wiring is provided on the side surface of the semi-insulating semiconductor substrate. Since there is no pattern, neither capacitance due to circuit wiring nor radio wave propagation occurs between the microwave integrated circuit and the lead frame. Therefore, the deterioration of the high frequency characteristics due to the inductance does not occur.

According to a second aspect of the present invention, there is provided a method of manufacturing a microwave semiconductor device, wherein one surface of a semi-insulating semiconductor substrate is provided with a plurality of wiring patterns routed so as to obtain a predetermined high frequency characteristic based on a circuit design. Step of forming a plurality of first extraction electrodes to be connected, a predetermined interval is provided on one side surface of the semi-insulating semiconductor substrate, and a region including each first extraction electrode is cut out to form a plurality of cutouts. Step, a step of forming a plurality of second extraction electrodes by embedding a conductive material in each notch formed in the step so as to connect to each first extraction electrode, and each of the steps formed in the steps It includes a step of dicing the semi-insulating semiconductor substrate so that the second extraction electrodes are arranged on one side surface of the semi-insulating semiconductor substrate.

In the above-mentioned manufacturing method, each first portion is provided in each notch.
Embedded conductive material so that it is connected to the extraction electrode of
A plurality of second extraction electrodes are formed at a predetermined interval from each other, and the semi-insulating semiconductor substrate is diced so that each second extraction electrode is arranged on one side surface of the semi-insulating semiconductor substrate. The mounting surface of the second extraction electrode can easily be made substantially flush with the side surface of the semi-insulating semiconductor substrate. Therefore, the microwave integrated circuit can be directly mounted on the lead frame in a stable state.

[0011]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a schematic configuration of a microwave semiconductor device according to an embodiment of the present invention. The configuration of the microwave semiconductor device D according to the present embodiment will be described with reference to FIG.

The microwave semiconductor device D is as shown in FIG.
The microwave integrated circuit 10 has the lead 11 of the lead frame.
A predetermined area including the die bond area of the leads 11a, 11b, 11c is hermetically sealed by the mold resin 12 (shown by a broken line in the drawing) while being die-bonded to a, 11b, 11c. 2 is a perspective view of the microwave integrated circuit, FIG. 3 is a plan view thereof, FIG. 4 is a side view thereof, and FIG. 5 is an equivalent circuit diagram thereof. The configuration of the microwave integrated circuit 10 will be described with reference to FIGS. 2, 3, 4, and 5.

The microwave integrated circuit 10 is built in a semi-insulating semiconductor substrate 20 of, for example, GaAs or InP, as shown in FIGS. And
On the upper surface of the semi-insulating semiconductor substrate 20, a first ground extraction electrode 23 connected to a source matching circuit 22 in contact with the source 21 (see FIGS. 2 and 3) of the microwave integrated circuit 10 and a drain. A first output extraction electrode 26 connected to an input side matching circuit 25 in contact with 24 (see FIGS. 2 and 3), and an output side in contact with a gate 27 (see FIGS. 2 and 3) A first input extraction electrode 29 connected to the matching circuit 28 is provided.

Source matching circuit 22 and input matching circuit 25
The output-side matching circuit 28 is routed in a substantially spiral shape based on the circuit design so as to obtain a predetermined high frequency characteristic, and is multi-layered in a strip line shape. That is, the source matching circuit 22, the input matching circuit 25, and the output matching circuit 28 are inductance coils as shown in FIG.

The first ground extraction electrode 23, the first output extraction electrode 26, and the first input extraction electrode 29 are shown in FIG.
As shown in FIG. 3, the semi-insulating semiconductor substrate 20 is arranged on the edge portion with a predetermined space. Further, as shown in FIG. 4, the one side surface of the semi-insulating semiconductor substrate 20 includes a first ground extraction electrode 23, a first output extraction electrode 26, and a first input extraction electrode 29, which are spaced apart from each other by a predetermined distance. The ground notch 3 having a region notched to the lower surface of the substrate 20.
0, an output notch 31, and an input notch 32 are provided.

Notch portion 30 for ground and notch portion 31 for output
The input notch 32 is formed in a taper shape so as to widen toward the lower side in FIG. Then, in the ground notch 30, the output notch 31, and the input notch 32, the first ground extraction electrode 23,
First output extraction electrode 26 and first input extraction electrode 29
To connect to the second ground extraction electrode 33, the second
The output extraction electrode 34 and the second input extraction electrode 35 are embedded.

The second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 are connected to the ground lead 11a and the output with the side surface of the semi-insulating semiconductor substrate 20 facing downward. The lead 11b for input and the lead 11c for input are die-bonded (see FIG. 1). The mounting surfaces of the second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 are formed so that the microwave integrated circuit 10 is mounted on the lead frame in a stable state. It is substantially flush with the side surface of the insulating semiconductor substrate 20.

Thus, the microwave integrated circuit 10 is die-bonded to the leads 11a, 11b, 11c of the lead frame, so that the source is grounded and the drain and gate are open as shown in FIG. Therefore, the amplifier circuit has a low noise characteristic. In the above-described configuration, the microwave integrated circuit 10 has the second ground with the ground cutout 30, the output cutout 31, and the input cutout 32 provided on one side surface of the semi-insulating semiconductor substrate 20. An extraction electrode 33, a second output extraction electrode 34, and a second input extraction electrode 35 are provided,
The second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 are connected to each matching circuit 2
First ground extraction electrode 2 in contact with the source, drain and gate via 2, 25 and 28
3, since the first output extraction electrode 26 and the first input extraction electrode 29 are connected, the microwave integrated circuit 10 is
It is possible to perform die bonding on the leads 11a, 11b, 11 of the lead frame without using a bonding wire.

That is, with the side surface of the semi-insulating semiconductor substrate 20 of the microwave integrated circuit 10 facing downward, the second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35. Are directly connected to the ground lead 11a, the output lead 11b, and the input lead 11c, the side surfaces of the semi-insulating semiconductor substrate 20 do not have the matching circuits 22, 25, 28, and the microwave integrated circuit 1
0 and the leads 11a, 11b, 11 do not cause capacitance due to circuit wiring or radio wave propagation.
Therefore, in the microwave integrated circuit 10, deterioration of high frequency characteristics due to inductance does not occur.

FIG. 6 is a schematic vertical sectional side view showing a method of manufacturing a microwave integrated circuit in the order of steps, and FIG. 7 is a view showing a dicing line. A method of manufacturing the microwave integrated circuit 10 will be described with reference to FIGS. In the following description, it is assumed that two microwave integrated circuits 101 and 102 are formed on one semi-insulating semiconductor substrate 20 (see FIG. 7).

First, as shown in FIG. 6A, a transistor operating region, that is, a source, is formed on the semi-insulating semiconductor substrate 20.
A drain and a gate (not shown) are formed, and the source, the drain and the gate are brought into contact with the source matching circuit, the output matching circuit and the input matching circuit (not shown). Then, on the upper surface of the semi-insulating semiconductor substrate 20, the first ground extraction electrode 23 is formed in the source matching circuit.
, The first output extraction electrode 26 is connected to the output side matching circuit, and the first input extraction electrode 29 is connected to the input side matching circuit.

Next, as shown in FIG. 6B, the first ground lead-out electrode 23, the first output lead-out electrode 26 and the first input lead-out electrode 29 are formed at predetermined intervals by taper etching. So that the semi-insulating semiconductor substrate 20 is penetrated from the lower surface so that the ground notch 30,
A ground through hole 30a, an output through hole 31a, and an input through hole 32a, which will be the output notch 31 and the input notch 32, are formed.

Subsequently, as shown in FIGS. 6C and 6D, the ground through hole 30a, the output through hole 31a, and the input through hole 32 are formed by the lift-off method.
A conductive material (wiring material) 40 such as Al is embedded in a and is connected to the first ground extraction electrode 23, the first output extraction electrode 26, and the first input extraction electrode 29,
Second ground extraction electrode 33, second output extraction electrode 34
And the second input extraction electrode 35 is formed. That is,
As shown in FIG. 6C, after applying a resist (not shown) on the entire lower surface of the semi-insulating semiconductor substrate 20, the wiring material 40 is applied to the substrate 20 so as to fill the through holes 30a, 31a, 32a. Deposit on the entire bottom surface. And FIG.
As shown in (d), the through holes 30 are formed together with the resist.
The wiring material 40 other than the regions a, 31a, 32a is removed by etching or the like. Then, the second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 are embedded in the ground through hole 30a, the output through hole 31a, and the input through hole 32a. , The first ground extraction electrode 23, the first output extraction electrode 26, and the first input extraction electrode 29.

When the formation of the second ground extraction electrode 33, the second output extraction electrode 34 and the second input extraction electrode 35 is completed, the second ground extraction electrode 3 is formed as shown in FIG.
3, the second output extraction electrode 34 and the second input extraction electrode 35 are arranged along one side surface of the semi-insulating semiconductor substrate 20 along the dicing line DL (shown by a chain line in the figure). Is divided into two. At this time, the second ground extraction electrode 33, the second output extraction electrode 34, and the second
The input / output electrode 35 of is provided in a state of straddling the dicing line DL. Therefore, if the semi-insulating semiconductor substrate 20 is cut along the dicing line DL, the ground cutout 30, the output cutout 31, and the input cutout are formed on one side surface of the substrate 20 of each of the microwave integrated circuits 101 and 102. Part 32 and the second ground extraction electrode 3
3, the second output extraction electrode 34 and the second input extraction electrode 35 respectively appear.

When the manufacturing of the microwave integrated circuit 10 is completed, it is put into the assembly process of the microwave semiconductor device D.
FIG. 8 is a perspective view showing a method of assembling the microwave semiconductor device in the order of steps. A method of assembling the microwave semiconductor device D will be described with reference to FIG. First, FIG.
As shown in (a), by the stamping method or the dispenser method, the ground lead 11a of the lead frame,
A resin adhesive such as Ag paste is applied on the output lead 11b and the input lead 11c, and the semi-insulating semiconductor substrate 2 of the microwave integrated circuit 10 is applied to the resin adhesive.
After pressing it with the side of 0 facing down,
Heat to activate the adhesive. As a result, the second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 of the microwave integrated circuit 10 are electrically connected to the ground lead 11a, the output lead 11b, and the input lead 11c. Connect to each other. Regarding the method of mounting the microwave integrated circuit 10, the microwave integrated circuit 10 may be die-bonded by an Au-Si eutectic alloy method or the like.

Next, as shown in FIG. 8B, a predetermined area including the die bond area of each lead 11a, 11b, 11c is hermetically sealed with the molding resin 12 by, for example, a transfer molding method or an injection molding method. Stop. Then, the microwave semiconductor device D is completed through a lead cutting process, a cleaning process, and the like. The second ground extraction electrode 3 in FIGS. 6C and 6D above
3. In the step of forming the second output extraction electrode 34 and the second input extraction electrode 35, the second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 are formed by the lift-off method. Formed and second in the process of FIG.
The second ground extraction electrode 33, the second output extraction electrode 34, and the second input extraction electrode 35 are diced so that they are aligned on one side surface of the semi-insulating semiconductor substrate 20. Output extraction electrode 34 and second
The mounting surface of the input / output electrode 35 of the semi-insulating semiconductor substrate 2
It can easily be made substantially flush with the 0 side surface. Therefore, the microwave integrated circuit 10 can be stably mounted on the leads 11a, 11b, 11c of the lead frame.

The present invention is not limited to the above embodiments, and it goes without saying that many changes and modifications can be made within the scope of the present invention.

[0028]

As is apparent from the above description, according to the microwave semiconductor device of the first aspect of the present invention, capacitance is caused by circuit wiring or radio wave propagation is caused between the microwave integrated circuit and the lead frame. Since it does not occur, the deterioration of the high frequency characteristics due to the inductance does not occur.

According to the manufacturing method of the second aspect, since the mounting surface of the second extraction electrode can be easily made substantially flush with the side surface of the semi-insulating semiconductor substrate, the microwave integrated circuit can be kept stable. It can be mounted directly on the lead frame.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a microwave semiconductor device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a microwave integrated circuit.

FIG. 3 is a plan view of the same.

FIG. 4 is a side view of the same.

FIG. 5 is an equivalent circuit diagram of the same.

FIG. 6 is a schematic vertical sectional side view showing a method of manufacturing a microwave integrated circuit in the order of steps.

FIG. 7 is a diagram showing a dicing line.

FIG. 8 is a perspective view showing a method of assembling the microwave semiconductor device in the order of steps.

FIG. 9 is a perspective view showing a method of mounting a microwave integrated circuit using a conventional bonding wire.

FIG. 10 is a perspective view showing a conventional method of mounting a microwave integrated circuit using solder bumps.

[Explanation of symbols]

 D Microwave semiconductor device 10, 101, 102 Microwave integrated circuit 11a Ground lead 11b Output lead 11c Input lead 12 Mold resin 20 Semi-insulating semiconductor substrate 21 Source 22 Source matching circuit 23 First ground extraction electrode 24 Drain 25 Output Side Matching Circuit 26 First Output Extracting Electrode 27 Gate 28 Input Side Matching Circuit 29 First Input Extracting Electrode 30 Ground Cutout 31 Output Cutout 32 Input Cutout 30a Ground Through Hole 31a Output Through Hole 32a Input through hole 33 Second ground extraction electrode 34 Second output extraction electrode 35 Second input extraction electrode

Claims (2)

[Claims] 1. A microwave semiconductor device including a microwave integrated circuit built in a semi-insulating semiconductor substrate mounted on a lead frame, wherein one surface of the semi-insulating semiconductor substrate is based on a circuit design. A plurality of first extraction electrodes that are respectively connected to a plurality of wiring patterns that are routed so as to obtain a predetermined high-frequency characteristic, and one side surface of the semi-insulating semiconductor substrate with a predetermined distance from each other. A plurality of cutouts in which a region including the extraction electrode is cutout, and a plurality of second extraction electrodes embedded so as to be connected to the respective first extraction electrodes in the respective cutouts; The microwave semiconductor device in which the extraction electrode of is directly mounted on the lead frame. 2. A step of forming, on one surface of a semi-insulating semiconductor substrate, a plurality of first extraction electrodes connected to a plurality of wiring patterns routed so as to obtain a predetermined high frequency characteristic based on a circuit design. A step of forming a plurality of notches on a side surface of the semi-insulating semiconductor substrate with a predetermined distance from each other, and forming a plurality of notches in the region including each first extraction electrode, in each notch formed in the step, A step of forming a plurality of second extraction electrodes by embedding a conductive material so as to be connected to each first extraction electrode, and each second extraction electrode formed in the step is one of the semi-insulating semiconductor substrate. A method of manufacturing a microwave semiconductor device, comprising a step of dicing a semi-insulating semiconductor substrate so as to be lined up on a side surface.