JP2007134442A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change a set temperature of a semiconductor device, and to accurately control the temperature of the semiconductor device. <P>SOLUTION: On a semiconductor substrate 17, a temperature detector 11, control unit 12, temperature set 13, output 14, heater 15, and semiconductor circuit 16, are formed. The temperature detector 11 outputs a temperature detection signal corresponding to the temperature of the semiconductor substrate 17 to the control unit 12. The temperature set 13 creates a temperature setting signal which is a reference voltage for setting the temperature of the semiconductor substrate 17, and then outputs it to the control unit 12. The control unit 12 calculates a differential signal between the temperature detection signal and the temperature setting signal, and then controls the heater 15 so that the differential signal may become small. The heater 15 heats the semiconductor substrate 17, based on the output from the control unit 12. The semiconductor circuit 16 is heated to the set temperature and is kept at the constant temperature. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor device, and more particularly to a semiconductor device that controls the temperature of the semiconductor device itself to be kept constant.

  Usually, in order to perform a high temperature test of a semiconductor device (semiconductor chip) sealed in a package, it is necessary to use a heat generating device such as a thermostatic bath or a thermostreamer. However, using a heat-generating device is a big problem, so as a method for performing a high-temperature test without using a heat-generating device, etc., the semiconductor device itself is provided with a heating element and the heating element is heated to raise the temperature of the semiconductor device. A method of performing a high temperature test is known (see Patent Document 1).

  The semiconductor device described in Patent Document 1 includes a temperature detection unit 103, a control unit 104, and a heat generation unit 105 as shown in FIG. The temperature detector 103 detects a temperature change by a bridge circuit including the transistor Tr101 and the resistors R101, R102, and R103, and outputs the voltage or current change as a bridge signal. The control unit 104 includes a differential amplifier composed of transistors Tr102 and Tr103 having load resistances R104 and R105, respectively, amplifies the bridge signal by the differential amplifier, and supplies the amplified signal to the base of the transistor Tr104 that performs voltage-current conversion. Change the bias voltage. As a result, the collector current of the transistor Tr104, that is, the current flowing through the heat generating portion 105 changes in proportion to the bridge signal. The heat generating resistor HR of the heat generating unit 105 generates heat over the entire length by the flowing current, and heats the semiconductor device with a heat generation amount corresponding to the current amount.

  As a method for accurately detecting the temperature of a semiconductor device, a technique disclosed in Patent Document 2 is known. The semiconductor device disclosed in Patent Document 2 includes a temperature detection circuit 201 including a current mirror circuit 203 and a differential amplifier circuit 202, as shown in FIG. In the current mirror circuit 203, transistors Tr201, Tr202, Tr203, and a current source IA form a current mirror, and currents N * I1, I1 flow through the diodes D201, D202, respectively. The differential amplifier circuit 202 amplifies the voltage difference ΔV between the voltages V1 and V2 generated in the diodes D201 and D202 by the differential amplifier circuit 202, respectively. A voltage difference ΔV, that is, a voltage corresponding to the temperature is obtained as the output voltage V3 of the differential amplifier circuit 202. Further, the comparator 204 compares the voltage V3 with the output voltage of the reference voltage circuit 205.

Japanese Patent Laid-Open No. 62-156850 JP 2000-213992 A

ただし、Ｖｄｄは、電源電圧、Ａは、差動増幅回路の増幅率である。 In the semiconductor device described in Patent Document 1, the control unit 104 includes the voltage V1 of the formula (1) obtained by dividing the power supply voltage Vdd by the resistor R101 (resistance value R1) and the resistor R102 (resistance value R2), and the power supply voltage Vdd. A voltage difference V2-V1 from the voltage V2 of the equation (2) obtained by subtracting the voltage Vtr1 (T) of the transistor Tr101 corresponding to the temperature from is amplified. Then, the heating unit 105 is controlled by supplying the bias voltage V4 shown in Expression (3) to the base of the transistor Tr104.

However, Vdd is a power supply voltage and A is an amplification factor of the differential amplifier circuit.

  As is apparent from the equation (3), the bias voltage V4 is affected by the amplification factor A, the errors in the resistance values R1 and R2, and the nonlinear change in the voltage Vtr1 with respect to the temperature T. Therefore, it is difficult to accurately control the heat generating portion 105, and it is difficult to keep the temperature of the semiconductor substrate constant. In addition, since there is no function to detect the temperature of the semiconductor substrate and the function to set the temperature of the semiconductor substrate to an arbitrary temperature, the temperature of the semiconductor substrate itself cannot be known and the temperature of the semiconductor substrate can be set freely. I can't.

  On the other hand, the semiconductor device disclosed in Patent Document 2 merely discloses a device capable of accurately detecting the temperature, and does not have a function of setting the temperatures of the heat generating portion and the semiconductor device to arbitrary temperatures. Further, since there is no function for detecting the temperature of the semiconductor device, the temperature of the semiconductor device itself cannot be known.

  A semiconductor device according to one aspect of the present invention is a semiconductor device in which a required circuit is formed on a semiconductor substrate, and outputs a heat generating part for heating the semiconductor device and a temperature detection signal corresponding to the temperature of the semiconductor device. A temperature detection unit that generates a temperature setting signal of the semiconductor device, a control unit that obtains a difference signal between the temperature detection signal and the temperature setting signal, and controls the heat generating unit so that the difference signal is reduced; .

  According to the present invention, the temperature setting unit is provided and the heating unit is controlled by a voltage proportional to the temperature difference between the semiconductor device temperature and the set temperature, so that the set temperature of the semiconductor device can be changed and the semiconductor device The temperature can be accurately controlled.

  A semiconductor device according to an embodiment of the present invention includes a temperature detection unit (11 in FIG. 1), a control unit (12 in FIG. 1), and a temperature setting unit (13 in FIG. 1) on a semiconductor substrate (17 in FIG. 1). And a heating part (15 in FIG. 1) and a semiconductor circuit (16 in FIG. 1). The temperature detection unit outputs a temperature detection signal corresponding to the temperature of the semiconductor substrate to the control unit. The temperature setting unit generates a temperature setting signal serving as a reference voltage for setting the temperature of the semiconductor substrate and outputs the temperature setting signal to the control unit. A control part calculates | requires the difference signal of a temperature detection signal and a temperature setting signal, and controls a heat generating part so that this difference signal may become small. The heat generating unit heats the semiconductor substrate based on the output of the control unit. The semiconductor circuit is heated to a set temperature and maintained at a constant temperature.

  The semiconductor device configured as described above can increase the temperature and set the temperature of the semiconductor device alone without using a heating device such as a thermostatic bath or a thermostreamer. Further, the temperature of the semiconductor device can be held at the set temperature. Therefore, even if the temperature of the external environment changes, the semiconductor circuit can obtain circuit characteristics independent of temperature characteristics by keeping the temperature of the semiconductor device constant.

  FIG. 1 is a layout view of a semiconductor chip according to a first embodiment of the present invention. The semiconductor chip includes a temperature detection unit 11, a control unit 12, a temperature setting unit 13, an output unit 14, a heat generation unit 15, and a semiconductor circuit 16 on a semiconductor substrate 17. The semiconductor circuit 16 is a circuit to be subjected to a high temperature test, and a temperature detection unit 11, a control unit 12, a temperature setting unit 13, an output unit 14, and a heat generation unit 15 are disposed around the semiconductor circuit 16. The temperature detector 11 detects the temperature of the semiconductor substrate 17, that is, the semiconductor circuit 16 on the semiconductor substrate 17. The control unit 12 compares the detected temperature with the temperature set by the temperature setting unit 13, and controls the heat generation unit 15 to generate heat or stop the heat generation so that the difference is eliminated. . The output unit 14 outputs a signal corresponding to the set temperature to the outside of the semiconductor chip.

  Next, details of the main part will be described. FIG. 2 is a circuit diagram of the temperature detection unit 11, the control unit 12, the temperature setting unit 13, the output unit 14, and the heat generation unit 15. The temperature detection unit 11 includes diodes D1 and D2, current sources I1 and I2, resistors R1, R2, R3, and R4, and an operational amplifier OP1. The cathode of the diode D1 is grounded, and the anode is connected to one end of the current source I1 and the resistor R1. The cathode of the diode D2 is grounded, and the anode is connected to one end of the current source I2 and the resistor R3. The other end of the resistor R1 and one end of the resistor R2 are connected to the inverting input terminal of the operational amplifier OP1. The other end of the resistor R3 and one end of the resistor R4 are connected to the non-inverting input terminal of the operational amplifier OP1. The other end of the resistor R4 is grounded. The output terminal of the operational amplifier OP1 is connected to the other end of the resistor R2, and is connected to the inverting input terminal of the operational amplifier OP2 in the control unit 12 as an output of the temperature detection unit 11. Note that the current sources I1 and I2 may be configured to be provided outside the semiconductor chip and to supply current to the temperature detection unit 11 via a terminal.

  The temperature detector 11 senses the temperature of the semiconductor device using the voltages generated in the diodes D1 and D2 by the currents of the current sources I1 and I2, and converts the temperature into voltages VF1 and VF2. Then, the subtractor circuit constituted by the subsequent resistors R1, R2, R3, R4 and the operational amplifier OP1 takes the difference between the two diode voltages VF1, VF2 converted from the temperature, and the voltage depending on the temperature of the semiconductor device Vt is output.

  The temperature setting unit 13 includes an input terminal 20 provided in the package, and inputs a voltage Vb corresponding to the set temperature from the external reference voltage source 21 to the control unit 12 through the input terminal 20. The control unit 12 includes an operational amplifier OP2, amplifies the difference between the voltage Vt corresponding to the temperature of the semiconductor device and the voltage Vb corresponding to the set temperature given from the outside, and outputs the voltage Verr. The output unit 14 includes an output terminal 22 provided in the package, and outputs a voltage Verr to a voltmeter 23 provided outside the package.

  The heat generating part 15 has a source connected to the drain of each of the PchMOS transistors P1, P2,... PM and a PchMOS transistor P1, P2,. NchMOS transistors N1, N2,... NM that are grounded and have gates commonly connected to the output of the operational amplifier OP2. The heat generating unit 15 generates heat by passing a current through these transistors according to the magnitude of the voltage Verr.

ただし、ｋはボルツマン定数（＝１．３８×１０^−２３）［Ｊ／Ｋ］、Ｔは温度［Ｋ］、ｑは電荷量（＝１．６２×１０^−１９）［Ｃ］、Ｉはダイオードに流れる電流、Ｉｓは飽和電流である。 Next, the circuit operation of FIG. 2 will be described in detail. The temperature detection unit 11 detects the temperature of the semiconductor device by the diodes D1 and D2 using the characteristic of the forward drop voltage VF of the diode proportional to the temperature change shown in the equation (4), and determines the temperature of the semiconductor device. Conversion to voltages VF1 and VF2.

Where k is Boltzmann's constant (= 1.38 × 10 ⁻²³ ) [J / K], T is temperature [K], q is the amount of charge (= 1.62 × 10 ⁻¹⁹ ) [C], and I is a diode. Current Is flowing through, Is is a saturation current.

ただし、Ｔｃは半導体装置温度［Ｋ］、Ｎ×ＩｃはダイオードＤ２に流す電流、Ｉｃは、ダイオードＤ１に流す電流である。 Further, the voltage VF1 and VF2 are subtracted by using a subtraction circuit including resistors R1, R2, R3, and R4 and an operational amplifier OP, and a voltage ΔVF that is a difference between the voltage VF1 and the voltage VF2 is extracted. At this time, the output voltage Vt of the operational amplifier OP1 is expressed by Expression (5).

Here, Tc is the semiconductor device temperature [K], N × Ic is a current flowing through the diode D2, and Ic is a current flowing through the diode D1.

  The voltage Vt is represented only by physical constants k and q, a constant N, and the semiconductor device temperature Tc, as shown in Expression (5). Therefore, the temperature detection unit 11 takes the difference between the voltages VF1 and VF2 to convert the temperature of the semiconductor device into a voltage determined by the semiconductor device temperature and a constant that does not depend on device characteristics such as device variations. However, since the currents Ic and N × Ic flowing from the current sources I1 and I2 partially flow into the subtraction circuit, the current flowing through the diodes D1 and D2 changes, and errors occur in the voltages VF1 and VF2. It is necessary to increase the input impedance of the subtraction circuit so as to be within the allowable error.

The temperature setting unit 13 sets the temperature of the semiconductor device. Since the temperature of the semiconductor device is represented by the voltage of Expression (5), the voltage obtained by replacing Tc in Expression (5) with the set temperature Ts is a voltage corresponding to the set temperature. Therefore, in order to compare the semiconductor device temperature with the set temperature in the control unit 12, the voltage Vb represented by the expression (6) corresponding to the set temperature is supplied from the external reference voltage source 21 via the input terminal 20. To the input terminal of the operational amplifier OP2.

ただし、Ａは演算増幅器ＯＰ２の増幅率である。 The control unit 12 subtracts and amplifies the voltage Vt corresponding to the temperature of the semiconductor device and the voltage Vb corresponding to the set temperature by a differential amplifier circuit composed of the operational amplifier OP2, and calculates the difference between the semiconductor device temperature and the set temperature. Outputs voltage depending on temperature difference. That is, the output of the operational amplifier OP2 includes an equation (dependent on the temperature difference between the semiconductor device temperature and the set temperature, which is a subtraction / amplification result of the voltage Vt corresponding to the semiconductor device temperature and the voltage Vb corresponding to the set temperature ( The voltage Verr indicated by 7) is output.

However, A is an amplification factor of the operational amplifier OP2.

The output unit 14 outputs the voltage Verr depending on the temperature difference between the semiconductor device temperature and the set temperature to the outside of the package. That is, the output unit 14 can output temperature difference information between the temperature of the semiconductor device and the set temperature. Here, the output terminal 22 is provided in the package, and the voltage Verr depending on the temperature difference between the semiconductor device temperature and the set temperature is measured with the voltmeter 23 at the output terminal 22 to obtain the equation (7) for Tc. (8) Therefore, the temperature of the semiconductor device can be detected.

  As another application example, there is a method in which an LED or the like is provided in place of the voltmeter 23 and the light is emitted and notified if the temperature difference between the temperature of the semiconductor device and the set temperature falls within a certain allowable range. Further, a wireless modulation circuit is provided in the output unit 14 without providing the output terminal 22, and a signal of the voltage Verr having temperature difference information between the temperature of the semiconductor device and the set temperature is transmitted to the outside by a wireless signal, There is also a method of reading the signal Verr and detecting the temperature of the semiconductor device.

ただし、Ｍは、トランジスタの数、μは移動度、Ｃｏｘは酸化膜容量、Ｗはゲート幅、Ｌはゲート長、Ｖｔｈは閾値である。 The heat generating unit 15 operates so that a current flows through a resistance component in the circuit according to the magnitude of the voltage Verr depending on the temperature difference between the temperature of the semiconductor device and a set temperature, and heat is generated or the heat generation operation is stopped. The temperature of the semiconductor device is raised and maintained by heat generation and heat generation stop. In this embodiment, a plurality of transistors N1 to NM and P1 to PM are used in parallel. The number of transistors is determined by the amount of current necessary for raising the temperature to the set temperature and the amount of current that can be passed through one transistor from the viewpoint of transistor reliability. When the voltage Verr, which is a control signal, is equal to or higher than the threshold value of the transistors N1 to NM, that is, Verr ≧ Vth (Vth: threshold value), the heat generating unit 15 is turned on. A current Id in the heating circuit shown in 9) is supplied.

However, M is the number of transistors, μ is mobility, Cox is oxide film capacitance, W is gate width, L is gate length, and Vth is a threshold value.

ただし、ΔＴは、温度変化［℃］、Ｌは発熱部からの距離、λは熱伝導率［Ｗ／ｍＫ］、Ｓは発熱部の表面積［ｍ^２］、Ｑは発熱量［Ｗ］、Ｃは熱容量［Ｊ／℃］、ｔは経過時間、Ｖｄｄは電源電圧である。 When the current Id in the heating circuit flows to the transistor (resistance component), the transistor generates heat, and the temperature rises according to the relational expression shown in the equation (10) between the amount of heat and the temperature change, and the temperature of the semiconductor device rises. Let

Where ΔT is the temperature change [° C.], L is the distance from the heat generating part, λ is the thermal conductivity [W / mK], S is the surface area [m ² ] of the heat generating part, Q is the heat generation amount [W], C Is the heat capacity [J / ° C.], t is the elapsed time, and Vdd is the power supply voltage.

  Conversely, when Verr <Vth, the heat generation operation is stopped. When the temperature of the semiconductor device is lower than the set temperature, that is, when the voltage Verr is increased, the heat generating unit 15 generates heat by causing a large amount of current to flow, and raises the temperature of the semiconductor device so that the temperature difference between the semiconductor device temperature and the set temperature is Operates to shrink. In this way, the temperature of the semiconductor device can be raised and kept at a constant temperature. The heat generating circuit current Id can be configured by a circuit in which a Pch transistor is replaced with a resistance element or a circuit using a bipolar transistor, and may be a circuit having a resistance component and capable of current control by the voltage Verr.

  As described above, the temperature detection unit 11 takes the voltage difference between the diodes D1 and D2 to thereby determine the temperature V of the semiconductor device based on only the physical constants k and q and the constant N (see Expression (5)). Convert to The control unit 12 at the subsequent stage takes the difference between the voltage Vt corresponding to the temperature of the semiconductor device and the voltage Vb corresponding to the set temperature given by the temperature setting unit 11 and takes the difference between the temperature of the semiconductor device and the set temperature. A proportional voltage Verr is output. The control unit 12 adjusts the amount of heat generated by the heat generating unit 15 so that the voltage Verr proportional to the difference between the temperature of the semiconductor device and the set temperature is substantially 0, that is, the temperature difference between the temperature of the semiconductor device and the set temperature is eliminated. To control.

  By operating as described above, the semiconductor device according to the present embodiment can accurately control the heat generating portion 15 and can maintain the temperature of the semiconductor device at a constant temperature. The set temperature can be freely changed by calculating the voltage Vb corresponding to the temperature to be set from the equation (6) and changing the voltage Vb. Furthermore, the internal temperature can be detected from the equation (8) by outputting the voltage Verr through the output terminal.

  FIG. 3 is a layout view of a semiconductor chip according to the second embodiment of the present invention. The semiconductor chip is provided on the semiconductor substrate 17a with temperature detection units 11a, 11b, 11c, 11d, control units 12a, 12b, 12c, 12d, temperature setting units 13a, 13b, 13c, 13d, output units 14a, 14b, 14c, 14 d, heat generating portions 15 a, 15 b, 15 c, 15 d, and a semiconductor circuit 16. The semiconductor circuit 16 is a circuit to be subjected to a high temperature test, and on the outer sides of the four sides, there are a temperature detection unit 11a, a control unit 12a, a temperature setting unit 13a, an output unit 14a, a heating unit 15a, and a temperature. Detection unit 11b, control unit 12b, temperature setting unit 13b, output unit 14b, heat generation unit 15b, temperature detection unit 11c, control unit 12c, temperature setting unit 13c, output unit 14c, heat generation unit 15c, temperature detection unit 11d, A control unit 12d, a temperature setting unit 13d, an output unit 14d, and a heat generating unit 15d are arranged. The temperature detectors 11a, 11b, 11c, and 11d are the same as the temperature detector 11 in FIG. 1, and the controllers 12a, 12b, 12c, and 12d are the same as the controller 12 in FIG. The temperature setting units 13a, 13b, 13c, and 13d are the same as the temperature setting unit 13 in FIG. 1, and the output units 14a, 14b, 14c, and 14d are the same as the output unit 14 in FIG. Reference numerals 15a, 15b, 15c, and 15d are the same as those of the heat generating portion 15 in FIG.

  Since the semiconductor chip of the first embodiment detects the temperature of only one point on the semiconductor substrate, it is difficult to keep the temperature of the semiconductor device substantially uniform when the temperature distribution is generated in the semiconductor device. It is. On the other hand, in the semiconductor chip shown in FIG. 3, by providing a plurality of sets, for example, four sets of circuits on the semiconductor substrate, the temperature of each point in the semiconductor device is detected, and variation in the temperature distribution of the semiconductor device is reduced. The temperature of the semiconductor device can be kept substantially uniform. In FIG. 3, the temperature setting units 13a, 13b, 13c, and 13d are provided corresponding to the control units 12a, 12b, 12c, and 12d, respectively, in order to make the temperature of the entire semiconductor device substantially uniform. For example, a single temperature setting unit may be provided for each control unit.

1 is a layout view of a semiconductor chip according to a first embodiment of the present invention. It is a circuit diagram in the principal part which concerns on 1st Example of this invention. FIG. 6 is a layout view of a semiconductor chip according to a second embodiment of the present invention. It is a circuit diagram of the conventional semiconductor device. It is a circuit diagram of another conventional semiconductor device.

Explanation of symbols

11, 11a, 11b, 11c, 11d Temperature detection unit 12, 12a, 12b, 12c, 12d Control unit 13, 13a, 13b, 13c, 13d Temperature setting unit 14, 14a, 14b, 14c, 14d Output unit 15, 15a, 15b, 15c, 15d Heat generating portion 16 Semiconductor circuit 17, 17a Semiconductor substrate 20 Input terminal 21 Reference voltage source 22 Output terminal 23 Voltmeter D1, D2 Diode I1, I2 Current sources N1, N2,... NM Nch transistors P1, P2, ..PM Pch transistors OP1, OP2 Operational amplifiers R1, R2, R3, R4 Resistance

Claims (5)

A semiconductor device in which a required circuit is formed on a semiconductor substrate,
A heat generating part for heating the semiconductor device;
A temperature detection unit that outputs a temperature detection signal corresponding to the temperature of the semiconductor device;
A temperature setting unit for generating a temperature setting signal of the semiconductor device;
A control unit that obtains a difference signal between the temperature detection signal and the temperature setting signal and controls the heat generating unit so that the difference signal becomes smaller;
A semiconductor device comprising:   2. The semiconductor device according to claim 1, further comprising an output unit that outputs the difference signal to the outside so that the difference signal can be observed from the outside.   The semiconductor device according to claim 1, wherein the temperature detection signal is generated based on a difference in forward voltage drop between two diodes.   2. A plurality of sets of the heat generating unit, the temperature detecting unit, the temperature setting unit, and the control unit are provided on one semiconductor substrate, respectively, and the temperature of each unit in the semiconductor substrate is controlled. 4. The semiconductor device according to any one of items 3 to 3. A plurality of sets of the heat generating unit, the temperature detecting unit, and the control unit are provided on one semiconductor substrate, and each of the control units is controlled based on the temperature setting signal generated by the temperature setting unit. The semiconductor device according to claim 1, wherein:

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