CA1134489A - High frequency semiconductor device - Google Patents

High frequency semiconductor device

Info

Publication number
CA1134489A
CA1134489A CA000348335A CA348335A CA1134489A CA 1134489 A CA1134489 A CA 1134489A CA 000348335 A CA000348335 A CA 000348335A CA 348335 A CA348335 A CA 348335A CA 1134489 A CA1134489 A CA 1134489A
Authority
CA
Canada
Prior art keywords
high frequency
circuit
substrate
semiconductor device
circuit substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000348335A
Other languages
French (fr)
Inventor
Yutaka Shimoji
Yukihiro Takeuchi
Shigeyuki Yamamura
Takao Shima
Kinjiro Kosemura
Norio Hidaka
Masami Fukuta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to CA000348335A priority Critical patent/CA1134489A/en
Application granted granted Critical
Publication of CA1134489A publication Critical patent/CA1134489A/en
Expired legal-status Critical Current

Links

Landscapes

  • Microwave Amplifiers (AREA)

Abstract

ABSTRACT
A high frequency semiconductor device comprises a circuit substrate containing circuit elements such as transistors, resistors and capacitors forming a self-contained functional device such as an amplifier with associated matching circuits which operates on high frequency signals and requires a DC bias voltage. The invention deals with packaging this device so that it is hermetically sealed, is robust and provides connections to external circuitry. This is achieved by means of a metal base having a raised platform which supports the circuit substrate. An insulating sub-strate is also mounted on the metal base and this substrate is shaped and disposed to surround the circuit substrate and have an upper surface which is level with that of the circuit substrate. Metallized strips are provided on this upper surface for connection with appropriate elements on the circuit substrate. A cover can be hermetically sealed with respect to the insulating substrate thus hermetically sealing the entire device.

Description

113~89 This in~ention relates to a high frequency semiconductor device, and more particularly, to the structure of such a device which incorporates a circuit substrate for mounting active elements such as transistors, and passive elements such as capacitors and resistors all mounted in a package.
According to existing technology, in order to form such a high frequency semiconductor device, for example, a single stage microwave amp-lifier, a transistor which is hermetically sealed to prevent degradation of characteristics and has leads for connection with other circuit elements is mounted on a circuit substrate. The transistor is connected with the other elements which are also mounted on the same circuit substrate and are requir-ed for forming an amplifier via circuits formed on said substrate. Then the circuit substrate is housed in a metal case.
Because the amplifier is hermetically sealed it occupies a large space, requiring a large size of circuit substrate in order to mount it and a resultant large case.
In the case of multi-stage amplifiers the overall size is large because each stage involves the use of a large size case.
According to one existing idea for solving this disadvantage, tran-sistor chips are mounted together with other necessary circuit elements on the circuit substrate provided on a metal base without individual hermetical sealing and then such circuit substrate is accommmodated in a metal case after which this metal case is hermetically sealed. This structure has an advantage that the physical dimensions are reduced but, at the same time, it has the disadvantage that perfect sealing becomes difficult because the hermetic sealing is required over longer distances.
An object of the present invention is to provide a high frequency semiconductor device which may be compact as a whole even when connected as a ~ulti-stage device, without detriment to the necessary hermetical sealing.

li344B9 Another object of the present invention is to provide a high fre-quency semiconductor device having such a configuration that a plurality of high frequency semiconductor devices respectively functioning as amplifiers are directly cascade-connected without intervention of a.ny elements so as to form, for example, a multi-stage amplifier circuit.
According to the present invention, there is provided a high fre-quency semiconductor device comprising a metal base serving as a support and ground for a function device which comprises at least one semiconductor elementJ
a DC circuit for operating said semiconductor element and a high frequency circuit for cascade-connecting said semiconductor element to an external cir-cuit; an insulating substrate which is frame-shaped and surrounds said function device and provides a plurality of independent metallized parts on its sur-face for the connection with an external circuit; and a sealing part which fits on to the insulating substrate and hermetically seals said function device.
Figure 1 is a perspective view of the uncovered outline of a high frequency semiconductor device according to the present invention;
Figure 2A is a plan view of a metal base or substrate;
Figure 2B is a cross-sectional view of Figure 2A along the line A-A';
Figure 3A is a plan view showing an insulating substrate mounted on the metal base of Figure 2;
Figure 3B is a cross-sectional view along the line A-A' of Figure 3A;
Figure 4A is a plan view showing an insulating frame mounted on the insulating substrate and a circuit substrate disposed on a mounting portion of the metal base substrate;
Figure 4B is a cross-sectional view along the line A-A' of Figure 4A;
Figure 5 is a plan view showing a cover 51 mounted on the insulating frame;
Figure 5B is a cross-sectional view along the line A-A' of Figure 5A;
Figure 6 is an enlarged view showing the ci.rcuit components of a ~34489 high frequency semiconductor device of the present invention, particularly a microwave amplifier circuit;
Figure 7 is a functional block diagram of the circuit shown in Figure 6.
Figure 8 shows an equivalent circuit of the amplifier shown in Figure7.
Figure 9 shows a three-stage microwave amplifier according to the present invention; and Figure 10 is a plan view of another embodiment of the present invention.
Figure 1 is a perspective view of a high frequency semiconductor device of the present invention, from which a cover for hermetical sealing has been removed. This high frequency semiconductor device is, for instance, a microwave amplifier. The insulating substrate 3 consisting of insulating material such as ceramic is provided on a metal base or substrate 1 provided with mounting screw holes 2. The substrate may be made of non-acidic copper.
The insulating substrate 3 is provided with a central opening, and herein the circuit substrate 4 on which various elements such as transistors, capacitors, inductors and directional couplers are mounted to form microwave amplifier circuits and matching circuits. Moreover, metallized layers or strips 5 and 6 for connecting between a microwave amplifier formed on the circuit substrate 4 and external circuits, are formed on the insulating substrate 3. The metal-lized strip 5 shown in Figure 1 is, for example, the one for receiving the high frequency signal input of a microwave amplifier circuit and it extends right to the outer edge of the insulating substrate 3 from the central opening of insulating substrate 3 as do the metallized strips 6. Directly opposite layer 5 and on the other side of circuit substrate 4 is another metallized strip 5 (not shown in Figure 1 but shown in Figure 3A) serving as a high frequency signal output, for example.
As clearly seen in Figure 3A there are four strips 6, two of which extend to the same edge of substrate 3 as one of the strips 5 and the other two of which extend to the same edge of substrate 3 as the other strip 5.

li34489 The strips of each pair thus defined extend towards each other and end in pads 7 and 7', respectively which axe spaced slightly apart. Metallized strips 6 are used to connect via pads 7 and 7' circuit 4 to an external D.C. voltage source (not shown). The metallized strips described above are formed by the following process. A tungsten paste is coated by the screen printing method and baked, and thereaftèr nickel plating or gold plating is performed. ~I the insulating substrate 3, the insulating frame 8 consisting of ceramic material is provided to cross these metallized strips, and moreover a cover (not illust-rated) for sealing is placed thereon and sealing is effected.
On each metallized strip the insulating frame 8, a lead 9 for con-nection to external circuit components may be provided as indicated in Figure 1.
One of the leads 9 has been omitted to show one of the strips 6.
The high frequency semiconductor device described above will now be explained in more detail with reference to Figures 2-8.
Figure Z shows the metal base or substrate-l. The metal base 1 is provided with a mounting portion 21 on which the circuit substrate is mounted and projections 22, 22', 22" for grounding parts of the circuit on the circuit substrate 4. A support 23 for supporting the insulating substrate 3 is pro-vided as a wall surrounding the perimeter of mounting portion 21. Portion 21 is also formed with a peripheral recess which provides a shoulder 24 level with the top of support wall 23.
Figure 3 shows the condition where the insulating substrate 3 is mounted on the metal base substrate 1. The insulating substrate 3 is supported by shoulder 24 and support 23. The metal base substrate 1 and insulating substxate 3 are bonded together Witll silver solder 25. The insulating subst-rate 3 is provided with a central opening 31 for acco~mnodating the circuit sub-strate 4, and opening 31 is provided with widened portions 32 so that the plat-ing solution does not remain in the gap between the base 21 and shoulder 24 of support 23 and flows out therefrom when gold plating is performed on the metal base substrate 1 after mounting of the insulating substrate 3. At the surface of insulating substrate 3, the metallized strips 5 and 6 are formed.
Figure 4 shows the condition where the insulating frame 8 is mounted on the insulating substrate 3 and the circuit substrate 4 is mounted on portion 21 of metal base 1. The insulating substrate 3 and insulating frame 8 are bonded with alumina.
The metallized strips 5 are connected with the input and output ends of a directional coupler (not illustrated in Figure 4) via wires etc. at the inside of the insulating frame 8. The metallized strips 6 are connected via pads 7, 7' to elements formed on the circuit substrate 4 at the inside of the insulating frame 8. In Figure 4, various elements formed on the circuit sub-strate 4 are not illustrated since these will be explained later in detail.
Figure 5 shows the device after a cover 51 has been mounted on the insulating frame 8.
The cover 51 is made of an insulator such as ceramic or a metal element such as Kovar, and is bonded to the insulating frame 8 with an alloy AuSn (20) of gold 'Au) and tin ~Sn).
The insulating frame 8 and cover 51 form the sealing part of a high frequency semiconductor device of the present invention. The frame 8 and cover 51 could be formed integrally of a metal, for example, Kovar, which is a trade mark of Westinghouse Electric Corporation designating an alloy of iron (54%), nickel (29%) and cobalt (17%). However, in that case, it should be irrelevent that to prevent short-circuits between the metallized strips 5 and 6 an insulator has to be provided at the contact area of the metallized strips 5 and 6. Moreover, coupling between the metallized strips can be pre-vented by providing a metallized layer, which reaches the metal base substrate, between the metallized layers for a high frequency signal and DC signal.
The above description has involved mainly the case accommodating B

~3~489 the circuit substrate of a high frequency semiconductor deYice of the present invention. ~ow, a microwave amplifier circuit formed on the circuit substrate will be explained.
Figure 6 shows a high frequency semiconductor device of the present invention, specifically a microwave amplifier. The amplifier circuit formed on the circuit substrate 4 is a balance type amplifier circuit, showing nearly symmetrical characteristics in the right and left sides. As shown in Figure 7, in the circuit configuration of this circuit substrate, a microqave input signal fed to the input terminal IN of the directional (hybrid) coupler HC 1 is divided into a couple of signals therein and these divided signals are respectively amplified by the amplifiers 71 and 72, and then combined by the hybrid coupler HC 2. Thus, an amplified microwave signal is output from the output terminal OUT.
Here, each end of the hybrid couplers HC 1 and HC 2 is respectively terminated by the resistors RSl and RS2. Ca, Cb, Cc and Cd denote DC blocking capacitors. The amplifiers 71 and 72 have a similar structure and an equiv-alent circuit of the amplifier 71 is shown in Figure ~.
In this figure, 81 is the input end of amplifier 71 and the input matching circuit is composed of inductors L2, L3 and capacitor C2, while the output matching circuit is formed by inductors L4, L5 and capacitor C4; the gate self-bias circuit is formed by inductor Ll, resistors Rl and R2, capac-itor C3; and the drain bias circuit is formed by inductor L6, resistor R3 and capacitor C5. 82 denotes the output end, while 83 denotes the DC bias input end.
Figure 6 shows an enlarged vie~Y of the circuit substrate 4 on which an a~plifier circuit is formed and the area near to the hole part of the in-sulating substrate 3.
As can be seen from the figure, the input end IN of the hybrid 1~344~39 coupler HC 1 and the output end OUT of the hybrid coupler HC 2 are respect-ively connected with the metallized strips 5, formed on the insulating sub-strate, termination resistors Rsl, Rs2 and capacitors C2, C4, are connected to the projections 22, 22', 22 " of the metal base 1. Moreover, the edges 7, 7' of metallized strips 6 for the DC power supply are connected to a resistor R4 by wires and the resistor R4 is connected to one electrode of a capacitor C6 the other electrode of which is connected to the metal base 1 for grounding as shown in Figure 6. A wire bridges the resistor R~ and the input end 83 of the bias circuit and thereby a bias voltage is supplied from an exte m al circuit to the resistor R3 forming a bias circuit. It is also possible to bridge the metallized pads 7 and 7' by a wire in order to supply the externally supplied bias voltage to the metallized pad 7' from pad 7, but resonance sometimes occurs between the facing metallized pads 7 and 7' and therefore grounding is made through the resistor M and capacitor C6 in order to prevent such resonance. Various elements of these circuits may be obtained as monolithic elements.
According to the present example of a microwave signal amplifier, what is i~,portant is that the whole circuit including amplification element such as a field effect transistor and ancillary circuits such as input/output matching circuit and directional coupler etc. are housed in a single case.
Thus, a high frequency semiconductor device itself operates as a self-contained amplifier without requiring connection with any external matching circuit etc.
Where the device is used as a single stage amplifier, leads 9 are simply applied to the metallized strips. A multi-stage amplifier can also be formed using the deyice as shown in Figure 9.
When the ~icrowave amplifiers 91, 92, 93 are fixed side-by-side to a metal case 94 by screws through holes 2 in the metal bases 1, the metall-li3~89 ized strips 6 for DC and 5 for high frequency are arranged face to face re-spectively. Thus, the microwave signal input from the input connector 9~ of the metal case is amplified by amplifiers 91, 92, 93 of ~he three stages and then output from the output connector 99. Wire or conductive ribbon may be used for the connections. Thus, the high frequency metallized strip 5 of the microwave amplifier 91 is connected to the strip line 95, the DC metallized strips 6 are connected to the bias terminals 96 provided in the metal case 94 and the high frequency metallized layer 5 of the microwave amplifier 93 is connected to the strip line 97. The bias voltage which is required for the function of the three amplifier stages 91, 92 and 93 is supplied only by con-necting the bias power supply to the bias terminals 96. The metal case 94 requires a cover but it doesn't require to be hermetically sealed because each amplifier stage is already hermetically sealed.
As described above, a high frequency semiconductor device of the present invention is completely self-contained. Therefore, in order to form a system by using these devices, it is not necessary to connect a matching circuit as an external circuit and the system can be formed with a block diagram concept at the system design stage. For this reason, system assembl-ing can be made very easily.
Figure 10 is a view similar to Figure 3A but showing another embod-iment of the present invention indicating the structure before an insulating frame is installed. The circuit substrate 4' which is housed in the central opening of the insulating substrate 3 as before differs from the substrate 4 previously used.
In this embodiment, the hybrid couplers HCl, HC2 which are mounted on the circuit substrate 4 in the first embodiment are provided, instead, on the insulating substrate 3. The hybrid coupler used particularly in the bal-ance type amplifier circuit of a high frequency semiconductor device cannot ~13~4~9 be reduced in size since the coupling part requires a length of 1/4 of the wavelength of signal used.
Thus, the disposition of hybrid couplers on the insulating substrate permits reduction in size of the circuit substrate 4'. In the case where an expensive sapphire is used as the circuit substrate, many more circuit sub-strates can be obtained from a sheet or wafer and therefore the cost per circuit substrate can be reduced, thus realizing a low cost supply of the devices. Not only the hybrid coupler but also other elements may be formed on the insulating substrate.
As explained above, the present invention is capable of offering a high frequency semiconductor device which is small in size, provides suffic-ient sealing and ensures easy system assembling.

_ g

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A high frequency semiconductor device comprising a metal base serving as a support and ground for a function device which comprises at least one semiconductor element, a DC circuit for operating said semi-conductor element and a high frequency circuit for cascade-connecting said semiconductor element to an external circuit; an insulating substrate which is frame-shaped and surrounds said function device and provides a plurality of independent metallized parts on its surface for the connection with an external circuit; and a sealing part which fits on to the insulating sub-strate and hermetically seals said function device.
2. A high frequency semiconductor device as claimed in claim 1, in which said metallized parts include a metallized part for a high frequency connection and one for a DC power connection.
3. A high frequency semiconductor device as claimed in claim 1, in which said plurality of metallized parts are so positioned such that several high frequency semiconductor devices can be cascade-connected.
4. A high frequency semiconductor device as claimed in claim 1, in which a circuit element is located on said insulating substrate.
5. A high frequency semiconductor device as claimed in claim 1, in which; at least a component element of said function device is formed monolithic.
CA000348335A 1980-03-25 1980-03-25 High frequency semiconductor device Expired CA1134489A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA000348335A CA1134489A (en) 1980-03-25 1980-03-25 High frequency semiconductor device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA000348335A CA1134489A (en) 1980-03-25 1980-03-25 High frequency semiconductor device

Publications (1)

Publication Number Publication Date
CA1134489A true CA1134489A (en) 1982-10-26

Family

ID=4116554

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000348335A Expired CA1134489A (en) 1980-03-25 1980-03-25 High frequency semiconductor device

Country Status (1)

Country Link
CA (1) CA1134489A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5847451A (en) * 1995-09-29 1998-12-08 Canon Kk Multi-layered printed circuit board, and grid array package adopting the same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5847451A (en) * 1995-09-29 1998-12-08 Canon Kk Multi-layered printed circuit board, and grid array package adopting the same

Similar Documents

Publication Publication Date Title
US5057805A (en) Microwave semiconductor device
US4783697A (en) Leadless chip carrier for RF power transistors or the like
EP0595346B1 (en) Composite microwave module assembly and its connection structure
US6455925B1 (en) Power transistor package with integrated flange for surface mount heat removal
US4427991A (en) High frequency semiconductor device
US5225709A (en) Package having a structure for stabilizing and/or impedance-matching a semiconductor IC device accommodated therein
WO2001056083A2 (en) Ldmos power package with a plurality of ground signal paths
EP0117434A1 (en) Hybrid microwave subsystem
CA1301949C (en) Device for interconnection and protection of a bare microwave componentchip
JPH0318112A (en) Fitting structure for chip type noise filter
JP2609634B2 (en) Chip module
CA1134489A (en) High frequency semiconductor device
JP2755250B2 (en) Semiconductor integrated circuit
US7196909B2 (en) AC coupling circuit having a large capacitance and a good frequency response
JPH0354839A (en) Integrated circuit support and method for manufacturing the same, integrated circuit for this support, and package
EP0020787B1 (en) High frequency semiconductor unit
US6282098B1 (en) Electronic circuit module, electronic circuit module connecting structure and connecting member, and method for connecting the same
JPS6271301A (en) Microwave integrated circuit device
US20250125286A1 (en) Semiconductor device
KR100562349B1 (en) Semiconductor device
JPS5834758Y2 (en) Package for microwave equipment
JPH04129402A (en) Package for microwave circuit
JPS6043022B2 (en) Microwave device module
JPS63258054A (en) Semiconductor integrated circuit device
JPH0272654A (en) Ic package and connecting structure thereof

Legal Events

Date Code Title Description
MKEX Expiry