JPH0722164B2 - Transistor with built-in resistor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transistor with a built-in resistor, which is an individual component in which a thin film resistor is built into a single transistor.

[0002]

2. Description of the Related Art Generally, in an electronic device such as a video tape recorder including various electronic circuits, it may be disadvantageous in terms of function to integrate its constituent circuits into an integrated circuit (IC).
It may be difficult to form an IC due to the setting of circuit constants. I
In C, a diffused resistor is used as a resistance and a plurality of transistors are formed, but since each element is electrically isolated from other elements by isolation, the parasitic transistor effect cannot be ignored. Further, it is difficult to form a transistor having good high-frequency characteristics, a transistor having a high switching speed, a transistor having a high breakdown voltage, a large current, or the like with an IC. Therefore, in an electronic device including a circuit that is not suitable for being integrated into an IC, a circuit may be configured by using individual components such as a transistor and a chip resistor, and the component may be mounted on a printed circuit board together with an IC that forms a specific circuit. Has been done.

Next, FIG. 7 shows a relay drive circuit composed of individual components. A transistor circuit 2 forming a switching circuit is installed in this relay drive circuit. That is, an input terminal 8A is formed at the base of the transistor 4 via the resistor 6, an input terminal 8B is formed at the emitter thereof, and a resistor 10 is connected between the emitter and the base, and the input terminal 8B is also formed. Is the reference potential (G
ND) terminal 8C is commonly used. Between the collector of the transistor 4 and the voltage application terminal 12, the diode 1 together with the exciting coil 14A of the relay 14 are connected in parallel.
6 is connected. In this relay drive circuit, the transistor 4 is switched by the input voltage V _i applied between the input terminals 8A and 8B, whereby the exciting current of the exciting coil 14A of the relay 14 is controlled and the relay contact 14B is opened and closed.

FIG. 8 shows an inverter circuit composed of individual parts. The transistor circuit 2 shown in FIG. 1 is installed in this inverter circuit, a resistor 18 is connected instead of the relay 14 and the diode 16, and an output terminal 20 is formed at the collector of the transistor 4. Therefore, in this inverter circuit, the input voltage V _i applied to the input terminals 8A and 8B is applied to the transistor 4
Are inverted and the inverted output V _O is taken out from the output terminal 20.

[0005]

In such a relay drive circuit or inverter circuit, the transistor circuit 2 has different uses and functions, but has the same circuit configuration. When such a transistor circuit 2 is composed of individual components, the resistors 6 and 10 are separately mounted together with the transistor 4 on the printed circuit board, so that the printed circuit board is mounted in proportion to the number of the transistor circuits 2 installed. In addition to the increase in area, the number of wiring steps increases, the miniaturization and weight reduction of electronic devices are hindered, and electronic devices such as video tape recorders that require a plurality of transistor circuits 2 become expensive.

In the transistor circuit 2 composed of individual parts, the resistor 6 is a base input current limiting resistor for the transistor 4, and the resistance value determines the base current I _B required for conduction of the transistor 4. . The resistor 10 is a pull-down resistor, and when there is no input to the transistor 4, the resistance value lowers the base potential to the emitter potential, thereby turning off the transistor 4. The resistor 18 is a load resistor, and its resistance value is R _L , and the resistance values of the resistors 6 and 10 are R
₁ and R ₂ , the resistance value R ₁ is the load current I _L (= V _CC
It is necessary to set the value so as to obtain a base current I _B sufficient to pass / _RL ). Then, the transistor 4, the collector current I _C is relative to the base current I _B, the product h _FE of the current amplification factor of the transistor 4 h _FE and the base current I _B
Since it is given by I _B , it is necessary to satisfy the condition of I _B > V _CC / h _FE · R _L , the current amplification factor h _FE is set to the minimum value, and the base current I _B is 2 of the calculated value. It is being done to have a margin of ~ 5 times. In this case, the current I _B2 flowing through the resistor 10 is given by the base-emitter voltage V _BE and the resistance value R ₂ to V _BE / R ₂ , resulting in current loss.
The base current I _B and the resistance value R _{2 of} a value that compensates for this loss
Is set. These constants are set according to the circuit conditions in which the transistor circuit 2 is installed, and are set individually for each circuit in terms of design. In particular, as a parameter when switching the transistor 4,
Since it is determined by the current amplification factor h _FE , it is necessary to take a large margin, and in order to obtain proper switching characteristics when it is configured with individual parts, the current amplification factor h when the collector-emitter voltage V _CE is lowered _FE is required, but it is generally not guaranteed because of large fluctuations in the value, so 2 of the base current I _B calculated with the minimum value of the voltage published as described above.
The base current I _B is set to a value of ˜5 times. The reason why such a rough value setting is allowed is that in the saturation region of the transistor 4, the increase of the collector current I _C with respect to the increase of the base current I _B becomes extremely small, and the collector current I _C due to the setting error of the resistance value R ₁ is reduced. Because the change is small.

In the transistor circuit 2, the input voltage V _i is the base-emitter voltage V _{BE of the} transistor 4.
When it exceeds, the base current I _B flows and the base current I _B
When the input voltage just before _{the B} flows to the threshold voltage V _th, the threshold voltage V _{th is, V th = R 1 · I} B2 + R 2 · I B2 ··· (1) , and the current I _B2 are , I _B2 = V _BE / R ₂ , substituting this into equation (1) gives

[0008]

[Equation 1]

[0009] Therefore, the threshold voltage V _th is determined by the ratio of the resistance values R ₁ and R ₂ , and is equal to (R ₁ / R ₂ ) of the threshold voltage V _th in the transistor circuit having no pull-down resistor (resistor 10). You can see that it is +1) times. Where the base of transistor 4
Since the emitter-to-emitter voltage V _BE is about 0.6 V, the threshold voltage V _th is

[0010]

[Equation 2]

The input voltage V _i becomes the threshold voltage V _th
When it exceeds, the base voltage V _B of the transistor 4 is 0.6.
Beyond V, the base current I _B starts to flow into the transistor 4 and the transistor 4 is turned on.

In such a transistor circuit 2, the resistance value ratio of the resistors 6 and 10 influences the threshold voltage V _th which is the reference of the switching operation, and when the resistance value ratio fluctuates, the switching characteristics vary. Therefore, the resistors 6 and 10 are required to correspond to the characteristics of the transistor 4 and have relatively high precision in order to secure a necessary resistance value ratio.

Therefore, according to the present invention, a minimum resistance associated with a single transistor is built in, and arbitrary characteristics are set in the transistor and the resistance at the manufacturing stage.
It is configured as a single circuit element consisting of a transistor and a resistor, has the same terminal configuration as the transistor of individual parts, does not require the constant setting and selection of individual parts such as transistors and resistors, and is an individual part. An object of the present invention is to provide a transistor with a built-in resistor that can be handled as an individual component like a certain transistor.

[0014]

That is, a transistor with a built-in resistor according to the present invention comprises a first resistor (26) and a second resistor (30) installed on a single transistor (24). A transistor with a built-in resistor, which comprises a minimum semiconductor substrate (32) in which only a single transistor can be formed, and a collector, and a first conductive region formed on the semiconductor substrate as a base ( Three
4), the second conductive region selectively formed inside the base is used as an emitter (36), and the first and second resistors have an insulating layer (oxide film 38) covering the surface layer of the transistor. In addition to being installed on the upper side, one end of the first resistor is connected to the base by a wiring conductor (electrode 42), and the second resistor is connected between the base and the emitter of the transistor (emitter electrode 40). ), A collector terminal (28C) is provided on the semiconductor substrate, an emitter electrode (40) is provided on the emitter, and a base electrode (44) for the base is provided on the other end of the first resistor.
An emitter terminal (28E) formed in a container accommodating the semiconductor substrate is connected to the emitter electrode by lead bonding, and a base terminal (28B) formed in the container is connected to the base electrode by lead bonding. It is characterized by that.

[0015]

According to the transistor with a built-in resistor of the present invention, a minimum resistance incidental to a single transistor as an individual component is built in, and an arbitrary characteristic is set in the transistor and the resistor at the manufacturing stage. By configuring as a single circuit element consisting of a resistor and a resistor, the collector terminal originally possessed by the transistor as an individual component,
Since the emitter terminal and the base terminal are formed in the container, they have the same terminal configuration as the transistor of the individual component. Therefore, this transistor with a built-in resistor does not require the steps such as the constant setting and selection of the transistor or the resistor which are individual parts, and it is handled as an individual part like the transistor which is an individual part, and can be used in various circuits such as switching circuits and inverter circuits. Used in the circuit.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

1 to 3 show an embodiment of a transistor with a built-in resistor according to the present invention, FIG. 1 is an equivalent circuit of the transistor with a built-in resistor, and FIG. 2 is a structure of a surface portion of the transistor with a built-in resistor in which a protective film is omitted. 3 shows a cross section taken along the line AA of FIG.

As shown in FIG. 1, this transistor 22 with a built-in resistor is provided with a transistor 24, and the first and second minimum necessary for the transistor 24.
The resistors 26 and 30 are installed to form a single circuit element, that is, an element body. That is, a single transistor 24 is installed in the resistor built-in transistor 22, one end of the resistor 26 is connected to the base of the transistor 24, and a base terminal 28B is formed at the other end of the resistor 26. Further, a resistor 30 forming a bias circuit is connected between the base and the emitter, and these resistors 2
The resistance values and resistance value ratios of 6 and 30 are set arbitrarily.
An emitter terminal 28E is formed on the emitter and a collector terminal 28C is formed on the collector.

The transistor 22 with a built-in resistor is shown in FIG.
As shown in FIG. 3 and FIG. 3, the minimum semiconductor substrate 32 for forming a single transistor is installed, and the semiconductor substrate 32 is formed of silicon or the like. In the transistor 22 with a built-in resistor, the semiconductor substrate 32 is used as a collector, and the base 34 of the transistor 24 is formed by selectively disposing the first conductive region on the surface layer of the semiconductor substrate 32. The emitter 36 is formed by the second electrically conductive region that is physically installed.
That is, the transistor 24 installed in the transistor 22 with a built-in resistor is formed similarly to the transistor which is an individual component.

Then, an oxide film 38 made of SiO ₂ or the like is provided as an insulating layer on the surface of the semiconductor substrate 32, and the surface of the oxide film 38 has the first and second resistors 2 and 2.
Reference numerals 6 and 30 are formed by thin-film resistors made of Ni-Cr or polysilicon. A contact window is formed on the oxide film 38 covering the surface of the emitter 36, and the emitter 36 is formed by depositing aluminum, gold, or the like.
An emitter electrode 40 for the is formed. This emitter electrode 40 corresponds to the emitter terminal 28E,
It is extended as a wiring conductor and electrically connected to the upper surface of one end of the resistor 30. A contact window is formed on the oxide film 38 covering the surface of the base 34, and an electrode 42 is formed similarly to the emitter electrode 40. The electrode 42 extends as a wiring conductor on the upper surface of one end of the resistors 26 and 30, and one end of the resistors 26 and 30 and the base are electrically connected by the electrode 42. Also,
At the other end of the resistor 26, a base electrode 44 connected to the base terminal 28B is formed. The semiconductor substrate 32 that is the collector of the transistor 24, the emitter electrode 40 that is installed on the semiconductor substrate 32, and the base electrode 44 are collector terminals 28C and emitter terminals 28E that are pins that are installed in a container that houses the semiconductor substrate 32. , The base terminals 28B are electrically connected by lead bonding.

Then, the transistor 22 with a built-in resistor
Is formed by being incorporated in one package like the transistor which is an individual component. Therefore, one transistor 22 with a built-in resistor constitutes a circuit element composed of the transistor 24 and the resistors 26 and 30, and has the same structure as a normal transistor.
Since it has a terminal structure, it can be handled as one electronic component like a transistor as an individual component, and
Since the electrical characteristics of the transistor 24 and the resistance values and resistance value ratios of the resistors 26 and 30 can be set to arbitrary characteristics according to the application, for example, as shown in FIG. 4, in the conventional relay drive circuit (FIG. 7). A transistor 22 with a built-in resistor can be installed in place of the transistor circuit 2, and as shown in FIG. 5, a transistor 22 with a built-in resistor can be installed in place of the transistor circuit 2 in the inverter circuit (FIG. 8). Since it has a terminal structure similar to that of a transistor, it suffices to make the necessary connection to that terminal, and the handling thereof is the same as that of a transistor as an individual component, which is very simple. As described above, the transistor 22 with a built-in resistor can be widely used in switching circuits, inverter circuits, and the like.

Further, in the transistor 22 with a built-in resistor, by incorporating the resistors 26 and 30 together with the transistor 24, the respective resistance values of the resistors 26 and 30 can be arbitrarily set at the manufacturing stage of the transistor 22 with a built-in resistor, and the threshold voltage Since desired switching characteristics such as V _th can be arbitrarily set and the characteristics can be guaranteed, the switching characteristics can be confirmed only by the input voltage V _i . In particular, each resistor 26, 3
0 are both formed by thin film resistors and are formed on the transistor 24 under the same manufacturing conditions. The resistance values R ₁ and R ₂ or relative resistance value ratios are arbitrarily set at the manufacturing stage, and the same value is obtained. It can have electrical characteristics. The resistors 26 and 30 shown in FIG. 2 are formed to have the same width,
The resistance values R ₁ and R ₂ are set to the same resistance value. Therefore, in the transistor 22 with a built-in resistor, the current amplification factor h _FE of the transistor and the resistance ratio of the resistance values R ₁ and R ₂ are set at the design stage like the conventional transistor circuit 2 in which a resistor is added to the transistor which is an individual component. It is not necessary to adjust with, and a required switching characteristic can be selected using only the input voltage V _i as a parameter, and a highly reliable switching operation adapted to an arbitrary circuit condition can be realized. Conventionally, there is no need for parameter measurement, selection of resistors with high accuracy, setting of resistance value ratio, etc., which were required to obtain the switching characteristics required when using transistors as individual components, and measurement accuracy It is possible to realize an arbitrary switch circuit without being restricted by a circuit suitable for a high area of

In the saturation region of the transistor 22 with a built-in resistor, the resistance value R ₁ of the resistor 26 is used as a parameter for V.
_i (input voltage) -I _C (collector current) shown in FIG.
This V _i -I _C operation curve shows the case where the collector-emitter voltage V _CE of the transistor 24 is V _CE = 3 V (T = 25 ° C.), L ₁ is R ₁ = R ₂ = 2.2 kΩ, and L ₂ is R. ₁ = R
₂ = 10 kΩ, L ₃ shows the case of R ₁ = R ₂ = 47 kΩ.

As is apparent from FIG. 6, when the resistance value R ₁ = R ₂ fluctuates, V _i -I _C operating curve L ₁
L ₃ is substantially parallel to the collector current I _C axis direction. Therefore, in order to set an operating point that is less likely to be affected by resistance value fluctuations with respect to a desired power load, the transistor 2 with a built-in resistor is set so as to be in the flat region of the V _i −I _C operating curve.
You can select 2.

However, the V _i -I _C operating curve L ₁ ~
The larger the flat portion of L _3, the smaller the resistance values R ₁ and R ₂ , and therefore the larger the power consumption. Therefore, V _i −
If the operating point is near the rising edge of the I _C operating curve, the efficiency is the highest. Then, in order to prevent malfunction due to fluctuations in input voltage V _i and noise, an on (ON) and off (OFF) voltage region is set excluding a certain voltage range including the operating point, but the region is such a narrow range. Not V
As _i -I _C operating curve is logarithmic graph,
The transistor 22 with a built-in resistor can cover a wide range of load power. Further, since the resistors 26 and 30 are formed by thin film resistors, a relatively large resistance value error occurs in the thin film resistors, but since the fluctuation of the operating voltage due to this is small, the resistance value error can be ignored. Therefore,
By supplying the transistor 22 with a built-in resistor composed of the resistors 26 and 30 in a limited combination, it can be applied to most switch circuits having different power loads.

Since the transistor 24 and the resistors 26 and 30 are integrated into a minimum semiconductor substrate 32 which forms a single transistor 24, the chip is formed in the same manner as a normal single transistor. Compared to the conventional circuit configuration in which a resistor is externally connected to a transistor, there is no need to externally connect a resistor, the wiring man-hours can be simplified, and various devices can be made smaller and lighter. It is possible to reduce the mounting cost of the printed circuit board.

Further, in terms of the circuit configuration, since the resistor 26 which is the base input resistor is formed in the package of the transistor 24, the withstand voltage against external surges, static electricity, etc. can be improved and the base can be Since it is not pulled out to the outside, it is not easily affected by external noise, and high withstand voltage that cannot be formed by IC,
A large current circuit can be easily realized, and the device can be simplified.

Further, since the single transistor 24, which is the minimum active element, has no other active element adjacent to it, the stray capacitance between the emitter-base and the base-collector of only the transistor 24 is reduced, and the frequency is reduced. The characteristics, switching speed, etc. can be improved, and excellent characteristics that cannot be obtained with an IC can be achieved.
When the transistor 22 with a built-in resistor is compared with the IC, the transistor 22 with a built-in resistor shows that the reference potential (GN
D) Since there is no terminal, there is no restriction to use the transistor 24 with the grounded emitter, and the base terminal 28B
Can be biased below the emitter potential,
Complementary devices with the same characteristics can be easily formed. Further, in the transistor 22 with a built-in resistor,
Since the resistors 26 and 30 are formed of thin film resistors, isolation in the IC is not necessary, and the parasitic transistor effect does not occur. Therefore, no countermeasure is required.

[0029]

As described above, according to the present invention, the following effects can be obtained. (A) A three-terminal circuit element can be formed by installing the first and second resistors, which are thin-film resistors, together with the single transistor on the minimum semiconductor substrate on which a single transistor can be formed. Corresponding to the above, it is possible to realize by arbitrarily setting the operating values such as the switching characteristics such that the resistance values and the resistance value ratios of the first and second resistors arranged in parallel at the manufacturing stage. Since it is built in the same container as the above, it can be handled as an individual part like the transistor as an individual part, and can be widely used in switching circuits and inverter circuits. The same mounting form as the transistor of the component can be adopted.

(B) Since the first and second resistors are provided on the single transistor via the insulating layer, compared to the conventional transistor circuit in which a resistor is externally connected to the transistor which is an individual component. In addition to reducing the installation area of resistors on the printed circuit board, there is no need to externally connect the resistors, the wiring man-hours can be simplified, various equipment used can be made smaller and lighter, and the printed circuit board can be mounted. The cost can be reduced.

(C) Since the first and second resistors installed together with the transistor are thin film resistors formed under the same manufacturing conditions, they have the same characteristics and have a highly accurate resistance value or resistance ratio. In addition to being settable, it can be adapted to applications such as switching circuits and inverter circuits.

(D) The threshold voltage for switching the transistor can be guaranteed within a certain range by the resistance ratio of the first and second resistors, and the switching operation of the transistor can be controlled by the voltage between the base terminal and the emitter terminal. It can be used as a switching element, the range of switching operation can be confirmed only by the input voltage to the base terminal, and it can be used as a highly accurate inverter circuit.

(E) In addition, in a single transistor, which is an individual component, the base-emitter voltage is, for example, 0.6.
It is as low as V, and it is not possible to guarantee switching characteristics such as the threshold voltage of a switching circuit which is to be realized only by the voltage between the base and the emitter. Since the threshold voltage can be uniquely set by the addition and the voltage value can be set to about 1 to several V, the value can be easily measured, the switching accuracy can be established at the manufacturing stage, and the accuracy can be improved. It is possible to guarantee desired switching characteristics. That is, the first and second resistors are
Corresponding to the characteristics of the transistor, by setting the resistance value and resistance value ratio according to the application, it is possible to configure a basic functional circuit such as a switching circuit by the mutual relationship between the two. Or, there is no need to set constants, and you can select a transistor with a built-in resistor with arbitrary operating characteristics as a single circuit element.
It is possible to simplify the design and reduce the manufacturing cost of various devices.

(F) In addition, this transistor with a built-in resistor has a first resistor on the base input side of a single transistor,
Since the second resistor is provided between the base and the emitter to form one independent circuit element, the range of the load current can be clarified by the transistor and the first and second resistors, and the first and second resistors can be formed. The load current range can be set stepwise by setting the rough resistance value of the second resistor, and if several kinds of load current ranges are set, it can be applied to most switching circuits and set to a specific range. It is possible to appropriately select a switch having a required load current capability corresponding to a switch circuit or the like to which a transistor with a built-in resistor in the load current range is applied, and it is possible to expand the degree of freedom in circuit design and to simplify it. That is, in the transistor saturation region of the transistor with a built-in resistor, the first and second
Although a load current corresponding to the resistance value of the resistor is obtained, in order to set an operating point that is not easily affected by resistance value fluctuations for the desired power load, the collector current operation curve with respect to the input voltage is in the flat region. As described above, the transistor with a built-in resistor is selected, and the flat portion has a small value of the first and second resistors and a large power consumption. Therefore, if the operating point is near the rise of the collector current, the efficiency is the highest. Will be things. Also, to prevent malfunction due to input voltage fluctuations and noise, the switching voltage range can be set excluding a certain voltage range that includes the operating point, and a transistor with a built-in resistor can cover a wide range of load power. it can. Since the first and second resistors are formed of thin-film resistors, a relatively large resistance value error occurs in the thin-film resistors, but since the fluctuation of the operating voltage due to this is small, the resistance value error should be ignored. By supplying the resistance built-in transistor having the resistance value and the resistance value ratio of the first and second resistors in a limited combination, it can be applied to most switch circuits having different power loads.

(G) Further, the first resistor installed on the input side of the base can improve the withstand voltage against external surges, static electricity and the like. As compared with a transistor, it is less susceptible to external noise, and a high breakdown voltage and large current circuit that cannot be formed by an IC can be easily realized, and the element structure can be simplified.

(H) There is no reference potential (ground) terminal like IC, and the transistor is not restricted to be used with the emitter grounded, and the base terminal can be biased below the emitter potential. Therefore, it can be used in an arbitrary circuit form, and a complementary device having the same characteristics can be easily realized.

(I) Since the first and second resistors are formed of thin film resistors, isolation in the IC is not necessary and the parasitic transistor effect does not occur. Therefore, no countermeasure is required.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a transistor with a built-in resistor according to the present invention.

FIG. 2 is a plan view showing a configuration of a transistor with a built-in resistor shown in FIG.

3 is a cross-sectional view taken along the line AA of the transistor with a built-in resistor shown in FIG.

FIG. 4 is a circuit diagram showing an embodiment of the transistor with a built-in resistor of the present invention shown in FIG.

5 is a circuit diagram showing an embodiment of the transistor with a built-in resistor of the present invention shown in FIG.

FIG. 6 shows V _{i in the} transistor with a built-in resistor according to the present invention.
Is a diagram illustrating an example of a -I _C operating curve.

FIG. 7 is a conventional relay drive circuit using individual components.

FIG. 8 is a circuit diagram showing a conventional inverter circuit using individual parts.

[Explanation of sign]

 22 Transistor with Built-in Resistance 24 Transistor 26 Resistance (First Resistance) 28B Base Terminal 28C Collector Terminal 28E Emitter Terminal 30 Resistance (Second Resistance) 32 Semiconductor Substrate 34 Base 36 Emitter 38 Oxide Film (Insulation Layer) 40 Emitter Electrode (Wiring) Conductor) 42 electrode (wiring conductor) 44 base electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 29/73

Claims (1)

[Claims] 1. A first mounted on a single transistor
A resistor built-in transistor that forms a single element body with a second resistor and a second resistor, and the transistor is formed on the semiconductor substrate by a collector having a minimum semiconductor substrate capable of forming only a single transistor. The first conductive region serves as a base, the second conductive region selectively formed inside the base serves as an emitter, and the first and second resistors are provided on an insulating layer covering a surface layer of the transistor. In addition, one end of the first resistor is connected to the base with a wiring conductor, and the second resistor is connected with a wiring conductor between the base and the emitter of the transistor, and the semiconductor substrate has a collector terminal. An emitter electrode on the emitter, a base electrode for the base on the other end of the first resistor, and the semiconductor substrate on the emitter electrode. Vessel to form an emitter terminal connected with a lead bonding, built-in resistors transistors to the base electrode, characterized in that the base terminal formed on the container is connected with a lead bonding.