JPH0129441B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a high frequency, high output transistor,
In particular, it concerns the configuration of high-frequency, high-output transistors used in the UHF band.

(b) Background of the technology Transistors using semiconductors or ICs with integrated transistors have come to be used instead of conventional electron tubes in amplifier circuits of electronic devices due to their advantages of low power consumption and high reliability. As the frequency increases, the use of semiconductors becomes more technically difficult.

The high frequency high power transistor according to the present invention includes:
A UHF band power amplification transistor, for example,
It is used in UHF-TV relay broadcasting transmitters and power amplification circuits for the transmission output of mobile radio equipment. At this level of frequency, it is not possible to obtain the desired output with a single unit transistor element, so normally multiple bipolar unit transistor elements are connected in parallel to form a single transistor, and its input Because the impedance is low, some of the transistors are equipped with matching circuits.

Therefore, the above-mentioned demand for increased output of devices must be met by increasing the number of unit transistor elements, but this not only complicates the process but also causes problems as the number increases. Therefore, it is desired to increase the output without increasing the number of unit transistor elements.

(c) Prior art and problems Figure 1 shows a plan view a, a side sectional view b, and a side sectional view b, showing the structure of an embodiment of a conventional high frequency high power transistor.
The figure is an enlarged plan view of the semiconductor chip forming the unit transistor element, FIG. 3 is an enlarged plan view of the semiconductor chip forming the capacitor of the internal matching circuit, and FIG. 4 is the equivalent circuit diagram. , 11 is a grounding board, 12 is an insulating board, 1
3 is a grounding plate, 14 is a collector terminal plate, 15 is an insulating frame, 16 is an input terminal, 17 is an output terminal, 2 and 3 are semiconductor chips, 21 is a unit transistor element, 2
2 is a base electrode, 23 is an emitter electrode, 24, 2
5 is a connecting element, 31 is a capacitor, 32 is a capacitor electrode, 41, 42, 43, 44 is a connecting wire, 5
indicates the package lid.

The structure of the high frequency, high power transistor shown in FIG. 1 is approximately as follows.

That is, the package body 1 is made of, for example, a copper plate, and has a grounding board 11 for mounting and grounding and heat radiation, and a plate made of, for example, beryllium (sintered beryllium oxide), which has excellent insulation and thermal conductivity. A grounding plate 13 for ground connection and a collector terminal plate 14 for leading out the collector of a unit transistor element are connected to an insulating substrate 12 formed in the form of a film using metallized material such as molybdenum or manganese, and formed into a frame shape using an insulating material such as aluminum oxide. The formed insulating frame 15 is made of, for example, a Kovar (iron-nickel-cobalt alloy) plate, and the input terminals 16 and output terminals 17, which are the input and output terminals of this transistor, are laminated and integrated as shown in the figure, and the metal parts are coated with gold, etc. It is decorated with a nometsuki pattern.

Unit transistor element 21 in charge of amplification function
are silicon bipolar transistors, and as shown in FIG. It is derived from the bottom of the . In addition, for convenience of testing during the manufacturing process of the semiconductor chip 2, the distance between the adjacent base electrodes 22 and the emitter electrode 23 is
The connecting elements 24 and 25 are formed in the form of straight strips of a conductor such as aluminum on the insulating layer on the surface of the semiconductor chip 2. and,
A semiconductor chip 2 is mounted on a collector terminal plate 14 of a package body 1, and a collector electrode is connected to the collector terminal plate 14.

The capacitor 31 (not shown), which is a component of the internal matching circuit responsible for converting the input impedance, is a silicon MOS structure capacitor, and as shown in FIG. 3, two capacitors are formed on the semiconductor chip 3. and the upper electrode is two capacitor electrodes 3
2, and the lower electrode is common and led out to the bottom surface of the semiconductor chip 3. The semiconductor chip 3 is mounted on the ground plate 13 of the package body 1, and the lower electrode is grounded.

Further, by wire bonding using, for example, a wire made of gold, etc., the wires are bonded between the input terminal 16 and the capacitor electrode 32, between the capacitor electrode 32 and the base electrode 22, and between the emitter electrode 23 and the ground plate 1.
3, and between the collector terminal plate 14 and the output terminal 17 as shown in FIG.
After forming 42, 43, and 44, the package body 1 is covered with a package lid 5 and sealed to complete the present high frequency, high output transistor.

Therefore, this high-frequency, high-output transistor has a configuration in which four unit transistor elements 21 are connected in parallel with their emitters grounded to increase the output, and two sets of internal matching circuits are provided.
Since each of the connecting lines 41 to 44 has an inductance value mainly due to its length, it becomes an element forming a circuit, and the equivalent circuit is as shown in FIG. Here, the code appended to the circuit symbol is the code of the element that acts dominantly on the circuit symbol. Incidentally, the reason why there are multiple connection wires 41 connected to one capacitor electrode 32 as shown in FIG. 1 is to adjust the inductance value of the connection wire 41 part in the internal matching circuit to a predetermined value. This is because the number of connection wires 44 connecting the collector terminal plate 14 and the output terminal 17 is provided in plurality in order to reduce the inductance value of this portion.

In the high-frequency, high-output transistor having this configuration, a plurality of identical elements making up the circuit, that is,
Although it is desirable that the unit transistor elements 21, capacitors 31, connection lines 41, 42, 43, etc. be exactly the same, there are variations in reality. In particular, potential differences occur between the plurality of base electrodes 22 and between the emitter electrodes 23 mainly due to variations in the characteristics of the unit transistor elements 21 and variations in the inductance value of the connection wire 43, and the connection element 24 with a small inductance value , 25, etc., the complete parallel operation state is broken, and each unit transistor element no longer functions sufficiently, resulting in a reduction in output. Ta.

(d) Object of the Invention In view of the above-mentioned drawbacks of the conventional art, the object of the present invention is to provide a high-frequency signal that connects a plurality of unit transistor elements in parallel, and enables each unit transistor element to function in parallel in a fully functional state. To provide the configuration of the output transistor.

(e) Structure of the Invention The above object is to connect a base or emitter connected to an input terminal via an internal matching circuit, an emitter or base grounded via a first inductance, and a collector connected to an output terminal. In a high-frequency, high-output transistor in which a plurality of unit transistor elements are connected in parallel, base electrodes and emitter electrodes of each unit transistor element are connected via second and third inductances, and The second and third inductances are achieved by high-frequency, high-output transistors characterized in that their inductance values are larger than the inductance value of the first inductance.

Further, according to the present invention, the internal matching circuit includes:
A plurality of electrodes are connected in parallel, and the electrodes of the adjacent internal matching circuits having the same function are connected through a fourth inductance, and the fourth inductance is connected to the other electrodes connected to the internal matching circuit. It is desirable to have an inductance value larger than the largest inductance value among the fifth inductances.

Further, according to the present invention, the second, third, and fourth inductances connecting the base electrodes, the emitter electrodes, and the internal matching circuits of the unit transistors are connected to the semiconductor chip using bent strip-shaped conductor patterns. It is characterized by being formed on the top.

(f) Embodiments of the invention Examples of the invention will be described below with reference to the drawings. The same reference numerals indicate the same objects throughout the figures.

FIG. 5 is an equivalent circuit diagram of an embodiment of a high-frequency, high-output transistor according to the present invention, FIG. 6 is a plan view a and a side sectional view b showing its structure, and FIG. 7 is a diagram showing the formation of a unit transistor element thereof. FIG. 8 is an enlarged plan view of a semiconductor chip on which a capacitor of an internal matching circuit is formed.
2a, 3a are semiconductor chips, 24a, 25a, 3
3a each indicates a connecting element.

The main cause of the drawbacks of the conventional example is, as mentioned above, due to variations in the plurality of identical elements constituting the circuit. A potential difference occurs between the electrodes 23, and a signal current flows between the electrodes through the connecting elements 24, 25 having a small inductance value, and the completely parallel operating state is disrupted, causing each unit transistor element to no longer function satisfactorily.

Therefore, in order to make each unit transistor element function satisfactorily, it is sufficient to suppress the flow of signal current between the base electrodes 22 and between the emitter electrodes 23.

For this purpose, it would be ideal to reduce the variation of multiple identical elements to 0 in Fig. 4, but even if it is possible to make efforts to reduce the variation, it is virtually impossible to reduce it to 0. . The next possibility is to delete the connecting elements 24 and 25 that connect the base electrodes 22 and the emitter electrodes 23, but this deletion can be done by testing during the manufacturing process of the semiconductor chip 2 mentioned above. It has been found that not only the convenience is lost, but also the following inconveniences occur.

That is, since the semiconductor element has a characteristic that the amplification factor increases as the frequency decreases in the high frequency band, the potential difference between the electrodes becomes a seed and causes oscillation at a frequency lower than the frequency band used. In other words, the connecting elements 24 and 25 also had the function of suppressing the generation of potential difference between the electrodes in the DC band from this low frequency.

For these reasons, by connecting the electrodes with an element that makes it difficult for a signal current in the used frequency band to flow, but allows a current in a frequency band lower than the used frequency band to easily flow, it is also possible to achieve multiple internal matching. When a circuit is provided, in order to cope with the potential difference caused by variations in the internal matching circuit, each unit transistor element can be made to function satisfactorily by adding connection of elements based on a similar idea.

The present invention makes the above configuration possible by utilizing the characteristics of inductance, gives an appropriate inductance value to the element, and allows easy implementation.

FIG. 5 is an equivalent circuit diagram thereof, and the difference from FIG. 4 is that 24 and 25 are replaced with 24a and 25a having an inductance value larger than the appropriate inductance value, that is, the inductance value of 43,
In addition, 33 has an inductance value greater than the larger of the inductance values of 41 and 42.
This is the addition of a. Here, 24a, 25
The reason why the inductance values of a and 33a are set as described above is based on the following idea.

base electrode 22 of unit transistor element 21;
Regarding the inductance value of 24a and 25a connected to the emitter electrode 23, when looking at the variation in the ground inductance 43 of the emitter electrode 23 from the base, ΔLb=ΔLe(1+β) where ΔLe: value of variation in the inductance value of 43 ΔLb : Equivalent value of ΔLe viewed from the base β: It was found empirically that the high frequency current amplification factor was 21, and ΔLb was a value close to the inductance value of about 43. Therefore, 24a
By making the inductance value of 25a larger than ΔLb, that is, the inductance value of 43, and the inductance value of 25a larger than the inductance value of 43, the above-mentioned aim can be achieved in practical terms.

Regarding the inductance value of 33a connected to the capacitor electrode 32 of the internal matching circuit, a similar practical effect can be obtained by making it larger than the maximum inductance value among the other inductances connected to 32. I can do it.

When doing this, the inductance values of 24a, 25a, and 33a are about several nH, so 24a, 25a, and 33a
a, 25a can be formed in the form of a connecting element by devising a pattern in the area of the connecting elements 24, 25 in the semiconductor chip 2 shown in FIG.
3a can be similarly formed on the semiconductor chip 3 shown in FIG.

FIG. 6 shows the structure of an embodiment of the high frequency, high power transistor according to the configuration of the present invention, which has been realized in this way.The difference from the high frequency, high power transistor shown in FIG. 1 is that the semiconductor chips 2 and 3 are Semiconductor chip 2a with no change in external dimensions and arrangement of electrodes connecting connection lines 41, 42, 43, 44;
The other structures are exactly the same except that 3a is substituted.

The semiconductor chips 2a and 3a are as shown in FIGS. 7 and 8, and in the semiconductor chip 2a,
In place of the connecting elements 24 and 25 shown in FIG. 2, connecting elements 24a and 25a are formed with different patterns. The patterns 24 and 25 are straight strips, but the patterns 24a and 25a are bent strips.By doing this, the inductance value of the former is less than 1 nH, while the inductance value of the latter can be several nH. It becomes possible. In the semiconductor chip 3a, the two capacitor electrodes 32 shown in FIG. 3 are connected by a connecting element 33a similar to the connecting elements 24a to 25a.

By applying the configuration of the present invention explained above, the inventor of the present application has achieved an output frequency of 900MHz.
We were able to obtain a 15W high frequency, high power transistor. This is a 50% increase in output compared to the previous configuration's output of 10W.

(g) Effects of the Invention As explained above, according to the configuration according to the present invention, a plurality of unit transistor elements can be connected in parallel, and a parallel operation state in which each unit transistor element can function satisfactorily is possible. It is possible to provide a configuration of a high-frequency, high-output transistor, which has the effect of making it possible to increase the output without increasing the number of unit transistor elements.

[Brief explanation of drawings]

Figure 1 shows a plan view a, a side cross-sectional view b, and a second
The figure is an enlarged plan view of the semiconductor chip forming the unit transistor element, FIG. 3 is an enlarged plan view of the semiconductor chip forming the capacitor of the internal matching circuit, FIG. 4 is the equivalent circuit diagram, and FIG. An equivalent circuit diagram of an embodiment of a high-frequency, high-output transistor according to the structure of the invention, FIG. 6 is a plan view a and a side sectional view b showing its structure, and FIG. 7 is an enlarged plan view of a semiconductor chip forming the unit transistor element. FIG. 8 is an enlarged plan view of a semiconductor chip on which a capacitor of an internal matching circuit is formed. In the drawing, 1 is a package body, 11 is a grounding board, 12 is an insulating board, 13 is a grounding plate, 14 is a collector terminal board, 15 is an insulating frame, 16 is an input terminal, 17 is an output terminal, 2, 2a, 3, 3a is a semiconductor chip, 21 is a unit transistor element, 22 is a base electrode, 23 is an emitter electrode, 24, 24
a, 25, 25a, 33a are connecting elements, 31 is a capacitor, 32 is a capacitor electrode, 41, 42,
43 and 44 are connecting lines, and 5 is a package lid.

Claims (1)

[Claims] 1. A unit transistor having a base or emitter connected to an input terminal via an internal matching circuit, an emitter or base grounded via a first inductance, and a collector connected to an output terminal. In a high-frequency, high-output transistor in which a plurality of elements are connected in parallel, base electrodes and emitter electrodes of each of the unit transistor elements are connected via second and third inductances, and the second and third inductances are A high frequency, high output transistor, wherein the third inductance is larger than the inductance value of the first inductance. 2. A plurality of the internal matching circuits are connected in parallel, and electrodes of adjacent internal matching circuits having the same function are connected through a fourth inductance, and the fourth inductance is connected to the internal matching circuit. Claim 1, characterized in that the fifth inductance has an inductance value larger than the largest inductance value among the other fifth inductances connected to the fifth inductance.
High-frequency, high-output transistor described in Section 1. 3. The plurality of unit transistors are formed on the same semiconductor chip, and the second and third inductances are formed as bent band-shaped conductor patterns on the semiconductor chip. A high frequency, high output transistor according to claim 1. 4. A patent characterized in that the plurality of internal matching circuits are formed on the same semiconductor chip, and the fourth inductance is formed as a bent band-shaped semiconductor pattern on the semiconductor chip. A high frequency, high output transistor according to claim 2.