JPH1056029A - Semiconductor device and its measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device with which the on-voltages of a plurality of semiconductor chips, which are parallel-connected can be made uniform, and to provide the manufacturing method of the semiconductor device. SOLUTION: A mounting substrate 13 is bonded on a metal base 11, and semiconductor chips 171 to 174 and diodes 201 to 204 are mounted on a base conductor 14 using the wiring pattern 122 on the mounting substrate 13. The first and the second conductor patterns 15 and 16 are formed along both edges of the base conductor 14, and the first conductor pattern 15 is divided into control electrode conductors 151 and 164. The emitter electrodes 181 to 184 of the semiconductor chips 171 to 174 are connected to the second conductor pattern 16 respectively, and the control electrodes 191 to 194 of the semiconductor chips 171 to 174 are connected to the control electrode conductors 151 to 154 respectively. Control voltage is applied to the control electrode conductor 151 of the semiconductor chip 171 to be measured, other control electrode conductors 152 to 154 are earthed, and the on-voltage of the semiconductor chip 171 is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a plurality of semiconductor chips connected in parallel and particularly suitable for controlling high power, and a measuring method therefor.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device which can be used for controlling a large amount of power and has a plurality of semiconductor chips connected in parallel is constituted, for example, as shown in FIG. That is, the mounting substrate 52 is joined to the metal base 51 constituting the heat radiation mechanism, and the mounting substrate 52 is formed by forming a conductor pattern 53 made of copper on both surfaces of an insulating substrate such as ceramics. The conductor pattern 53 is formed around the base conductor 541, and elongated first and second conductor patterns 542 and 543 are formed along both edges of the mounting board.

This semiconductor device comprises, for example, four semiconductor chips 551 to 554 and four diodes 561 to 564. These semiconductor chips 551 to 554 and diodes 561 to 564 are arranged alternately to form a base conductor 54.
It is attached to the surface of 1 by soldering.

Here, when the semiconductor chips 551 to 554 are each formed of a transistor, the back surface of each of the chips 551 to 554 is formed of a collector electrode, and the collector electrode is commonly connected to the base conductor 541. The control electrodes corresponding to the gate electrodes formed on the respective surfaces of the semiconductor chips 551 to 554 are respectively connected to the first conductor patterns 54 by the bonding wires 57.
2, and the emitter electrode is also connected to the second conductor pattern 543 by a bonding wire 58.

In this semiconductor device, as shown in FIG. 1B, a diode is provided between an emitter and a collector.
It is configured as a circuit in which four semiconductor chips 551 to 554 connecting 561 to 564 are connected in parallel. The gate of each of the semiconductor chips 551 to 554 is connected to the gate terminal G, the collector is connected to the collector terminal C, and the emitter is connected to the emitter terminal E.

In the case of such a semiconductor device configured by connecting a plurality of semiconductor chips in parallel, if there is a variation in the on-voltage of each of the semiconductor chips connected in parallel,
Current concentrates on chips with low on-voltage. That is,
In FIG. 7, A shows the characteristics of a transistor with a low on-voltage, and B shows the characteristics of a transistor with a high on-voltage. A large difference occurs between the collector currents a and b.
That is, current concentrates on a transistor having a low on-voltage, and the reliability of the semiconductor device is significantly reduced depending on the degree of variation of the on-voltage and operating conditions, and in some cases, the semiconductor chip is broken.

However, such a variation in the characteristics of the semiconductor chip cannot be determined after the semiconductor chip has been assembled as a semiconductor device and after it has been manufactured. As a countermeasure, a semiconductor chip with a uniform on-voltage may be selected and connected to a conductor pattern so that the semiconductor chip is connected in parallel. In the measurement of the on-state voltage, it is necessary to connect a conductor to the emitter, the collector and the gate of the chip. For this reason,
Problems such as contact resistance between the conductive wire and the electrode portion occurred, and it was difficult to obtain a highly reliable measurement result.

In order to solve the problem of the contact resistance, the contact end of the conductive wire to the electrode may be strongly pressed against the electrode portion of the semiconductor chip. However, if the pressing force is increased, the semiconductor chip may be broken. There is a limit in reducing this contact resistance. Therefore, even if there is a variation in the characteristics of a plurality of semiconductor chips connected in parallel substantially, and particularly there is a semiconductor chip having a greatly different on-voltage, it cannot be detected.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has been made in consideration of the existence of variations in on-voltage in a plurality of semiconductor chips connected in parallel after assembly as a semiconductor device. It is an object of the present invention to provide a semiconductor device capable of easily and reliably detecting and measuring, and eliminating the same, and a measuring method thereof.

[0010]

According to the present invention, there is provided a semiconductor device in which a mounting substrate having a conductor wiring pattern formed on an insulating substrate is joined to a metal base for heat radiation, and a wiring pattern formed on a surface of the mounting substrate is provided. A plurality of semiconductor chips of at least one kind are mounted on a base conductor pattern composed of a plurality of semiconductor chips, and other electrodes different from the electrodes connected to the base conductor of each of the plurality of semiconductor chips are respectively connected to the wiring pattern. Is connected to a plurality of divided electrode conductors. Here, when the semiconductor chip is configured by a transistor, each control electrode is connected to each of a plurality of electrode conductors configured by a conductor pattern, and by sequentially connecting the electrode conductors, a plurality of semiconductor chips are connected, for example. Be connected in parallel.

The method for measuring a semiconductor chip includes applying a control voltage to one electrode conductor having a conductor pattern corresponding to one of the plurality of semiconductor chips, and applying a control voltage to each of the other semiconductor chips. The other divided electrode conductor is set to the ground potential, so that the potential between the electrode conductor connected to the one semiconductor chip and the base conductor is measured.

In such a semiconductor device, a plurality of semiconductor chips are, for example, connected in parallel and configured as one device. When each semiconductor chip is a transistor, a control electrode is particularly provided. It is connected to the electrode conductor of the conductor pattern which is divided and independently formed. Therefore, by selecting one of the electrode conductors using a tester or the like and grounding the other divided electrode conductors, for example, the on-voltage of each of the plurality of semiconductor chips can be independently set in the process of assembling. Can be measured and detected. Then, by connecting the divided conductor patterns in common, a plurality of semiconductor chips are connected and set, for example, in parallel, and the semiconductor device is completed. That is, by contacting the contact of the tester with the conductor pattern, the on-voltage of the semiconductor chip mounted on the metal base and connected to the predetermined conductor pattern can be individually measured, for example. The on-voltage can be measured without applying unnecessary contact pressure to the chip, and the on-voltage variation among a plurality of semiconductor chips connected in parallel can be detected, thereby effectively improving the reliability of the semiconductor device. You.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. (A) of FIG.
(B) and (B) show the configuration of the first embodiment, and include a heat dissipating metal base 11 made of a metal material having good heat conductivity. On the surface of the metal base 11, a mounting substrate 13 composed of wiring patterns 122 and 123 made of copper is bonded to both surfaces of an insulating substrate 121 composed of ceramics by an insulating adhesive.

Here, as shown in FIG.
For example, when the mounting substrate 13 is formed in a rectangular shape, the wiring pattern 122 on the front side has a rectangular base conductor 14 so as to extend in the longitudinal direction, and extends along both sides of the base conductor 14. Thus, the first and second conductor patterns 15 and 16 are formed. And the base conductor
On the surface of 14, a plurality of, for example, four semiconductor chips 171 to 174 of the same type, each constituting a transistor, are arranged at equal intervals and fixed by soldering.

Here, a collector electrode is formed on the back surface of each of the semiconductor chips 171 to 174, and this collector electrode is connected to the base conductor 14, so that the base conductor 14 is a collector conductor.

On the surface of each of the semiconductor chips 171 to 174, transistor emitter electrodes 181 to 184 are formed, and further, control electrodes 191 to 194 serving as gates are formed. And, the emitter electrodes 181 to 184 are
Each is connected to the second conductor pattern 16 by two bonding wires.

The control electrodes 191 to 194 are respectively connected to the first
The first conductor pattern 15 is divided into four parts corresponding to the semiconductor chips 171 to 174, respectively, and independent control electrode conductors are provided.
151 to 154 are formed, and the semiconductor chip 17 is connected to each of these control electrode conductors 151 to 154.
The control electrodes 191 to 194 are connected via bonding wires.

A semiconductor chip 17 is provided on the surface of the base conductor 14.
Each of the diodes 201 to 204 includes, for example, a freewheel diode (FWD) adjacent to each of the diodes 201 to 174.
For example, a cathode electrode is connected to the surface of the base conductor 14 by soldering. The anode electrodes of the diodes 201 to 204 are respectively connected to the second electrodes via bonding wires.
Is connected to the conductor pattern 16 of FIG.

With this configuration, the semiconductor chip 171
The collectors of the semiconductor chips 171 to 174 are commonly connected to the second conductor pattern 16, and the emitter electrodes 181 to 184 of the semiconductor chips 171 to 174 are commonly connected to the second conductor pattern 16. Control electrode
191 to 194 are independently connected to the divided control electrode conductors 151 to 154 of the first conductor pattern 15, respectively. In such a connection state, it is possible to measure the on-voltage of each of the plurality of semiconductor chips 171-1784.

Specifically, the electrode can be led out by pressing a contact terminal against a predetermined conductor pattern portion of the mounting board 13 or sandwiching the terminal with a clip. For example, when the on-voltage of the semiconductor chip 171 is to be measured, Supplies a gate voltage to the control electrode conductor 151 to which the control electrode 191 of the semiconductor chip 171 is connected, and applies and sets a collector voltage to the base conductor 14 and an emitter voltage to the second conductor pattern 16. Then, the other control electrode conductors 152 to 15
4 is for connecting to the second conductor pattern 16;
Conductor pattern 16 is kept at the ground potential. When the voltage between the base conductor 14 and the second conductor pattern 16 is measured in such a state, the on-voltage of the semiconductor chip 171 is measured. In the case of a normally-off type transistor such as an IGBT, the on-state voltage becomes extremely large unless a bias is applied to the control electrode,
The on-voltage of each transistor can be measured.

Such measurement is performed independently for each of the semiconductor chips 171 to 174.
The on-voltage measurement of each of the semiconductor chips 171 to 174 can be performed without directly applying a pressing force to each of the semiconductor chips 171 to 174. The terminal of the measuring means for measuring the on-voltage can be derived by, for example, pressing a contact of a tester or sandwiching a clip with respect to a wiring pattern formed on the mounting substrate 13, so that a plurality of semiconductor chips 171-1 to -17- During the process of assembling the semiconductor device in which the semiconductor chips 171 to 174 are connected in parallel, there is no possibility that the semiconductor chips 171 to 174 may be damaged.
4 can measure ON voltage.

According to such a method, the contact end of the measuring means can be brought into contact with the conductor pattern at a considerably high pressure, unlike the characteristic confirmation for measuring the on-voltage for confirming the characteristic in the chip state. And voltage sense can be connected from separate contact terminals, so that highly accurate measurement is possible.

Therefore, for example, if there is a semiconductor chip having a significantly different on-voltage among the four semiconductor chips 171 to 174 constituting the semiconductor device, the semiconductor chip is removed and replaced at this stage. can do.

Each of the semiconductor chips 171 to 171 mounted as described above
When the measurement of the ON voltage at 174 is completed, the divided control electrode conductors 151 to 154 constituting the first conductor pattern 15 are divided.
Are integrally connected by connecting conductors 211 to 213. These connecting conductors 211 to 213 can be simultaneously formed in a connecting step of outer leads 221 to 223 as shown in FIG. With the formation of 211 to 213, the semiconductor chips 171 to 174 are connected in parallel as shown in FIG.

In the semiconductor device having such a configuration, the semiconductor chips 161 to 174 are simultaneously connected in parallel in the manufacturing process of the outer leads 221 to 213. Thereby, the semiconductor device can be assembled. After completion of such a connection step, the area indicated by the chain line in FIG. 8B is molded with a resin to complete the semiconductor device.

In this embodiment, the outer leads 22
1 to 223, the connection conductors 211 to 213 can be manufactured. However, as shown in FIG.
Outer leads 231 to 234 are formed for each of the fifteen divided electrode conductors 151 to 154, and the outer leads are formed.
Each of 231 to 234 may be connected by jumpers 241 to 244. Also, as shown in FIG. 2B, the electrode conductors 151 to 154 can be connected to each other by thin metal wires 251 to 253.

FIG. 3 shows a fourth embodiment, in which the second conductor pattern 16 is divided into four corresponding to the semiconductor chips 171 to 174 to form emitter electrode conductors 161 to 164. The emitter electrodes 181 to 184 of the semiconductor chips 171 to 174 and the emitter electrode conductors 161 to 164
Are connected by bonding wires. Also, diodes 201 to 204 and emitter electrode conductors 161 to 164, respectively.
Each of them is also connected by a bond wire.

Here, the same measurement can be performed even if the semiconductor chip is not limited to a transistor but is a diode. That is, the on-voltages of the diodes 201 to 204 can be measured independently for each chip. In the case of this semiconductor device, a semiconductor chip 171-174, which is an IGBT, and a diode 2 which is an FWD
01 to 204 are respectively connected one by one in parallel, and the semiconductor chips 171 to 174 and the diode 201 are connected.
204204 The forward current directions are different. For this reason, the semiconductor chip 171 is operated by a simple changeover switch.
By switching the polarity of the voltage applied to the diodes 201 to 204 and the diodes 201 to 204, the ON voltages of the respective diodes can be individually measured.

In the fifth embodiment shown in FIG. 4, four semiconductor chips are formed by using two mounting substrates 131 and 132.
171 to 174 and diodes 201 to 204 are mounted so that a parallel circuit is formed. Base conductors 141 and 142 are formed on the mounting substrates 131 and 132, respectively, and the control electrode conductors 151 to 154 and the emitter electrode conductors 161 to 164 which are further divided are mounted on the mounting substrates 131 and 132.
3 and connected by the connection conductors 261 and 262 and the jumper wire in the same manner as in the example of FIG. 3, and the number of the substrate portions may be plural.

For example, in the sixth embodiment shown in FIG. 5, four mounting boards 131 to 134 are used, and the base conductors 141 to 134 formed on each of the mounting boards 131 to 134 are used.
144 Semiconductor chips 171-174 and diode 201
Are mounted by soldering.
Control electrode conductors 151 to 134 are mounted on the mounting substrates 131 to 134, respectively.
154 and emitter electrode conductors 161 to 164 are formed, and these control electrode conductors 151 to 154 and emitter electrode conductor 16 are formed.
1 to 164 are connected by connecting conductors 263 and 264 and a jumper wire so that the semiconductor chips 171 to 174 are connected in parallel. Even in this case, the semiconductor chip 17 is not connected in parallel by the connection conductors 263 and 264 and the jumper wire.
The measurement of the on-voltage of each of 1 to 174 is enabled.

As described above, the number of mounting boards and the number of semiconductor chips mounted on each board can be arbitrarily set. When there are a plurality of boards, the same on-voltage as that of the measured on-voltage is used. Can be combined to form a final semiconductor device.

In the above embodiments, an example is shown in which both a transistor and a die transistor are mounted. However, in the first to sixth embodiments, only the transistor or the fourth and sixth transistors are mounted. In the embodiment, only the diode may be mounted. Also,
Not only transistors but also thyristors may be mounted.

[0033]

As described above, in the semiconductor device according to the present invention, when the semiconductor chips connected in parallel are mounted on the mounting board, the characteristics of the semiconductor chips that handle a large current are individually and individually determined. This makes it possible to measure with high accuracy, and in the stage of assembling a product, it is possible to eliminate and replace a product having a large variation in characteristics such as ON voltage. Further, when the semiconductor device is divided into a plurality of substrates, a substrate on which chips having similar characteristics are mounted can be selectively combined, and a semiconductor device having a combination of characteristics of semiconductor chips can be reliably provided. And the reliability of this type of semiconductor device is improved.

[Brief description of the drawings]

FIG. 1A is a plan view illustrating a first example of a semiconductor device according to an embodiment of the present invention, and FIG. 1B is a side view illustrating the same.

FIGS. 2A and 2B are second and third views, respectively.
FIG.

FIG. 3 is a configuration diagram illustrating a fourth embodiment.

FIG. 4 is a configuration diagram illustrating a fifth embodiment.

FIG. 5 is a configuration diagram illustrating a sixth embodiment.

6A is a plan view illustrating a conventional semiconductor device, and FIG. 6B is a circuit diagram thereof.

FIG. 7 illustrates an on-voltage characteristic of a semiconductor chip.

[Explanation of symbols]

11 ... metal base, 121 ... insulating substrate, 122, 123 ... first and second wiring patterns, 13 ... mounting substrate, 14 ... base conductor, 15, 16 ... first and second conductor patterns, 151 to 15
4 ... control electrode conductors, 171 to 174 ... semiconductor chips, 181 to
184: Emitter electrode, 191-194 ... Control electrode, 201-20
4… Diode, 221-223… Outer lead.

Claims (14)

[Claims] 1. A mounting board in which a conductor wiring pattern is formed on an insulating substrate, and at least one kind connected and mounted on a base conductor pattern formed by the wiring pattern formed on the surface of the mounting board. A plurality of semiconductor chips configured, and a plurality of electrode conductors configured by the wiring pattern, each of which is connected to another electrode different from the electrode connected to the base conductor of each of the plurality of semiconductor chips. A semiconductor pattern comprising: a plurality of semiconductor chips, wherein the plurality of semiconductor chips can be connected to each other by using a plurality of electrode conductors formed by the conductive pattern. 2. The semiconductor device according to claim 1, wherein each of said plurality of semiconductor chips comprises a transistor, and a common electrode of each of said semiconductor chips is connected to an electrode conductor constituting said conductor pattern. 3. A plurality of electrode conductors constituting said conductor pattern are connected by connecting conductors, respectively.
13. The semiconductor device according to claim 1. 4. The semiconductor device according to claim 3, wherein said connection conductor is constituted by an outer lead led out. 5. The semiconductor according to claim 3, wherein said connection conductor is constituted by an outer lead formed on each of a plurality of electrode conductors constituting said conductor pattern and a jumper wire connecting each of said outer leads. apparatus. 6. The semiconductor device according to claim 3, wherein said connection conductor is constituted by a bonding wire connecting each of a plurality of electrode conductors constituting said conductor pattern. 7. The semiconductor device according to claim 1, wherein each of said plurality of semiconductor chips comprises a transistor, and a control electrode of each transistor is connected to an electrode conductor obtained by dividing said conductor pattern. 8. The plurality of semiconductor chips are each constituted by a transistor, and control electrodes of the respective transistors are respectively connected to electrode conductors obtained by dividing the first conductor pattern, and further form a second conductor pattern. 2. The semiconductor device according to claim 1, wherein an emitter electrode of each of said plurality of semiconductor chips is commonly connected to said second conductor pattern. 9. The second conductor pattern is composed of a plurality of divided electrode conductors corresponding to the plurality of semiconductor chips, respectively, and each of the electrode conductors is connected to an emitter electrode of the semiconductor chip. 9. The semiconductor device according to claim 8, wherein: 10. The plurality of at least one type of semiconductor chip is constituted by a diode, and at least one of an anode and a cathode of each of the plurality of diodes is connected to each of the divided electrode conductors of the conductor pattern. Item 2. The semiconductor device according to item 1. 11. The semiconductor device according to claim 1, wherein the base conductor is divided into a plurality of parts, and one or more semiconductor chips are mounted on each of the divided base conductors. 12. The semiconductor device according to claim 10, wherein said divided base conductors are separately mounted on a plurality of mounting boards. 13. A plurality of semiconductor chips of at least one kind are mounted on a base conductor pattern formed of the wiring pattern on a mounting substrate having a conductor wiring pattern formed on an insulating substrate. In a semiconductor device in which another electrode different from an electrode connected to the base conductor of each semiconductor chip is connected to each of conductor patterns formed of a plurality of divided electrode conductors formed by the wiring pattern, A control voltage is applied to the electrode conductor of one divided conductor pattern corresponding to one semiconductor chip among the semiconductor chips, and the other divided electrode conductors corresponding to each of the other semiconductor chips are set to the ground potential. So that the potential between the electrode conductor and the base conductor corresponding to the one semiconductor chip is measured independently. Measurement method of a semiconductor device, characterized in that. 14. The method according to claim 13, wherein a contact of a tester is pressed against each of the base conductor and the electrode conductor.