JP5579013B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device including a sensor unit that detects a current of an internal semiconductor element.

  2. Description of the Related Art Semiconductor devices incorporating a large number of insulated gate bipolar transistors (hereinafter referred to as “IGBT”) are used as power semiconductors for hybrid vehicles and electric vehicles.

  In the IGBT, when the energization amount increases due to some external factor such as noise, the parasitic thyristor is turned on, and the IGBT energization amount may be latched up to be difficult to control by the control voltage of the control electrode. . In the semiconductor device of Patent Document 1, the output current of a part of the IGBT in the IGBT chip is output from the sensor unit as a detection current, and latch-up is monitored based on the detection current.

  The detection current and main current of the IGBT chip are designed to have a constant ratio (example: 1/1000), and latch-up is based on the assumption that the detection current maintains this ratio. And monitored based on the detected current. However, it is common that the ratio between the detection current and the main current deviates from the design value due to manufacturing variations of the IGBT chip. When the ratio deviates from the design value, it becomes an obstacle in monitoring latch-up and causes a delay in detection of latch-up, which easily leads to damage to the IGBT chip.

  Therefore, adjustment is required for each IGBT chip so that the ratio between the detection current of the IGBT chip and the main current becomes the design value. In the adjustment of the ratio in the conventional IGBT chip, after the IGBT chip is sealed in the package, a resistor whose resistance value is adjusted so that the ratio becomes a design value is connected to the outside of the package.

Japanese Patent No. 2722453

  However, the conventional method of adjusting the ratio of the latch-up detection current of the IGBT chip by connecting the adjustment resistor outside the package increases the space for arranging the adjustment resistor and leads to an increase in the number of parts and work man-hours. Yes.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device capable of reducing the space of an adjusting resistor, reducing the number of adjustment parts, and reducing the number of adjustment work steps while dealing with variations in detection current generated in the manufacturing process with an adjusting resistor. That is.

The semiconductor device of the present invention is a semiconductor device provided with a sensor part for detecting a current flowing through a semiconductor element, and is exposed on the surface of the semiconductor device, which is exposed to an electrode for outputting a detection current. Comprises a metal layer connecting the electrode and the sensor part, and a plurality of resistors arranged between the electrode and the sensor part on the lower side of the metal layer. An ablation gap for releasing the short-circuit state is formed in the specific part, and a short circuit part for short-circuiting between both terminals is formed, and the electrode and the sensor unit are determined by a resistance value corresponding to the short-circuit part where the ablation gap is formed. A resistance value between and is set.

According to the present invention, the resistance value between the electrode and the sensor unit is set by the resistance value of the resistor corresponding to the specific short-circuit portion in which the ablation gap is formed. Thus, variations in the detected current of the semiconductor device can be eliminated. In addition, since the adjustment of the resistance value between the electrode and the sensor portion is performed by forming an ablation gap at a specific short-circuited portion , the arrangement space, the man-hour for the detection current adjustment work, and the number of parts should be reduced. Can do.

According to the present invention, by forming an ablation gap in a specific short-circuited portion, the resistance corresponding to the specific short-circuited portion is released from the short-circuit state. Thereby, it can switch efficiently from the state (short circuit state) which does not function as each resistance element to the state (short circuit cancellation | release state) which functions .

In the semiconductor device of the present invention, the ablation gap is preferably formed by trimming with a laser .

According to this configuration, the use of laser trimming for forming the ablation gap makes it possible to perform fine processing and further reduce the space of the adjustment resistor portion in the semiconductor device.

In the semiconductor device of the present invention, the plurality of resistors is preferably turned mutually different resistance values.

According to this configuration , since the resistance value of each resistor is different, it is possible to easily determine which resistor is to be functionalized as a resistance element of the adjustment resistor between the electrode and the sensor unit , and the electrode and the sensor unit. it is possible to precisely set the resistance value between the.

In the semiconductor device of the present invention, the semiconductor element is an insulated gate bipolar transistor element, the sense current is preferably a current for monitoring the latch-up of an insulated gate bipolar transistor element.

According to this configuration , for a semiconductor device having an insulated gate bipolar transistor, it is possible to reduce the arrangement space of the adjustment resistor, reduce the number of parts, and reduce the adjustment man-hour while correcting the variation of the latch-up monitoring current in manufacturing. .

The figure which looked at the IGBT chip | tip from the output electrode side. The figure which shows the flow of the main current and detection current in an IGBT chip | tip. Sectional drawing which cut the IGBT chip | tip in the height direction in the boundary range of an emitter electrode-original electrode. Sectional drawing which cut the IGBT chip | tip in the height direction in the range containing only the IGBT element which outputs a main electric current. The equivalent circuit diagram of an IGBT chip. Sectional drawing which cut the IGBT chip | tip in the height direction in the range containing an adjustment resistance part. The detailed block diagram of 1st Example of an adjustment resistance part. The detailed block diagram of 2nd Example of an adjustment resistance part. The detailed block diagram of the principal part of 3rd Example of an adjustment resistance part.

  In FIG. 1, the IGBT chip 10 is formed in a square flat plate shape, and the multi-emitter part 11, the gate electrode 12, and the emitter electrode 13 are electrically separated from each other on a flat part on one side of the IGBT chip 10. It is deployed as a parcel area. In the plane portion, the multi-emitter portion 11 and the gate electrode 12 occupy two corners sharing one side of the square, and the remaining portion is occupied by the emitter electrode 13 that outputs the main current Im.

  The multi-emitter part 11 is provided with an original electrode 16 (described later) and a sense pad 17 as a sensor part in an exposed state and an adjustment resistor part 60 in an unexposed state. The gate electrode 12 is made of an integral metal and is connected to a gate terminal G of a package (not shown) that encloses the IGBT chip 10. The emitter electrode 13 is connected to an emitter terminal E of a package (not shown).

  In FIG. 2, the main current Im of the IGBT chip 10 is output from the emitter electrode 13, and the detection current Is is output from the sense pad 17 (FIG. 6) of the multi-emitter unit 11. Strictly speaking, the emitter electrode 13 is composed of a plurality of strip-like metal layers that are separated from each other and extend in parallel, and these strip-like metal layers are connected to each emitter terminal of a package (not shown) enclosing the IGBT chip 10. Individually connected, the main current Im from each emitter terminal merges outside the package.

  3 shows the boundary region between the emitter electrode 13 and the original electrode 16, and FIG. 4 shows only the IGBT element 44 that outputs the main current Im. The IGBT chip 10 is arranged in the height direction (the height direction is a flat IGBT). It is also the thickness direction of the chip 10). In the conventional IGBT chip, the original electrode 16 also serves as the sense pad 17, and the output current of the original electrode 16 is used as it is as the detection current Is. For convenience of explanation, the collector electrode side and the emitter electrode side will be referred to as “back side” and “front side” of the IGBT chip 10, respectively. The direction perpendicular to the height direction is referred to as the “plane direction” of the IGBT chip 10.

  In the IGBT chip 10, a large number of IGBTs are built in the same structure in the height direction of the IGBT chip 10. Among the IGBTs, the one whose output side is connected to the emitter terminal E is the IGBT element 44, and the one whose output side is connected to the original electrode terminal Eg is the IGBT element 45. The original electrode terminal Eg is used only for terminal connection of the voltmeter 73 in FIG. 7 when calculating an adjustment resistance value of the adjustment resistance unit 60 described later, and in a package enclosing the IGBT chip 10, It does not exist as a terminal. The emitter terminal E collects emitter currents from the IGBT elements 44 and outputs a main current Im (FIG. 2). The original electrode terminal Eg collects the emitter currents from the IGBT elements 45 and outputs the detection current Is (FIG. 2).

  The ratio of the number of IGBT elements 45 to the number of IGBT elements 44 in the entire IGBT chip 10 is 1/1000, for example, and the ratio of the detection current Is to the main current Im is also designed to be 1/1000 according to the number ratio of corresponding elements. Become. However, due to manufacturing variations of the IGBT chip 10, the detection current Is and the main current Im output from the original electrode terminal Eg and the emitter terminal E, respectively, if current adjustment by the adjustment resistor unit 60 described later is not performed. The actual ls / lm is usually deviated from 1/1000.

  In FIG. 3, the collector electrode 27 is exposed over the entire back surface of the IGBT chip 10 and connected to the collector terminal C of the package (not shown). The P + semiconductor substrate 28 is fixed to the surface side of the collector electrode 27. N − layer 29 is formed on the surface side of P + semiconductor substrate 28 by epitaxial growth. The collector electrode 27 and the P + semiconductor substrate 28 are common to all the IGBT elements 44 and 45 in the IGBT chip 10. 3 and 4, the plurality of P regions 30 are formed by selectively diffusing impurities from the surface of the N − layer 29. Two N + regions 31 are formed on the surface of each P region 30 by diffusing impurities from the portion while selecting a portion from the surface of the P region 30.

  Insulating film 34 is formed on the surface of P region 30 sandwiched between the surface of N − layer 29 and the surface of N + region 31. Insulating film 34 is also formed on the surface of N − layer 29 so as to be connected between adjacent IGBT elements 44 or between IGBT elements 45. As shown in detail in FIG. 4, the insulating film 34 includes a thick layer portion 47 that contacts the surface of the N − layer 29, and extends from both ends of the layer portion 47 to contact the surface of the P region 30. A thin layer portion 48. The gate electrode layer 35 is formed on the insulating film 34 with a substantially uniform thickness, is made of, for example, polysilicon, and is connected to the gate electrode 12 (FIG. 1). The insulating film 36 covers the surface of each gate electrode layer 35. The emitter electrode 13 and the original electrode 16 are made of a metal such as aluminum, and are formed on the surface side of the insulating film 36 so as to be electrically connected to both the P region 30 and the N + region 31. The emitter electrode 13 and the original electrode 16 are electrically separated from each other by a separation gap 41. The emitter electrode 13 is connected to an emitter terminal E of a package (not shown).

  As described above, each IGBT element 44 has a structure in which an N-channel double diffusion type MOSFET is formed on the P + substrate 28, and as will be apparent from an equivalent circuit of FIG. 5 described later, a pnpn thyristor. And an N-channel MOSFET composite element. During normal operation in which a positive voltage is applied to the collector terminal C, a predetermined load is connected to the emitter terminal E, and an appropriate control voltage is applied to the gate terminal G, holes are injected into the drain composed of the N− layer 29. Therefore, a low on-resistance is achieved. Further, since the gate terminal G is insulated from the active region of the transistor, no current flows. That is, the IGBT chip 10 has both the low on-resistance of the bipolar transistor and the high input impedance of the MOSFET. For example, by forming the IGBT chip 10 in which thousands of IGBT elements 44 are connected in parallel, A high-performance power transistor capable of flowing the current A is realized.

  FIG. 5 shows an equivalent circuit of the IGBT chip 10. The IGBT elements 44 and 45 have the same structure except that the connection terminals on the output side are the emitter terminal E and the original electrode terminal Eg, respectively. That is, the IGBT elements 44 and 45 are each composed of a pnp transistor 52, a MOSFET 53, an npn transistor 54, and a diffused resistor 57 in terms of an equivalent circuit.

  The emitter, base and collector of the pnp transistor 52 comprise a P + semiconductor substrate 28, an N− layer 29 and a P region 30, respectively. The source, gate, and drain of the MOSFET 53 include an N + region 31, a P region 30, and an N- layer 29, respectively. The emitter, base and collector of the npn transistor 54 are composed of an N + region 31, a P region 30 and an N − layer 29, respectively. The resistor 57 is interposed in the P region 30 as a diffused resistor between the collector of the pnp transistor 52 and the original electrode terminal Eg. The original electrode terminal Eg does not exist in a package (not shown) that encloses the IGBT chip 10, and is used only for the inspection of the IGBT chip 10 before being encapsulated in the package, for example, of the voltmeter 73 in FIG. It is used for terminal connection, and the original electrode 16 (FIG. 3) is the original electrode terminal Eg. The sensor terminal Es is provided in the package and connected to a sense pad (sensor unit) 17 shown in FIG. The adjustment resistor 60 is disposed in a region between the original electrode 16 and the sense pad 17 and adjusts a resistance value between the original electrode 16 and the sense pad 17. A specific configuration of the adjustment resistor 60 will be described later with reference to FIG.

  In FIG. 5, only a part of the entire IGBT chip 10 is shown as the IGBT elements 44, 45, but a sufficient number of the IGBT elements 45 exist in the IGBT chip 10, and in the IGBT chip 10, The total number of 45 is, for example, 1/1000 of the total number of IGBT elements 44. It is a current flowing into the collector terminal C. It is shunted to the IGBT element 44 side and the IGBT element 45 side, Ic flows into each IGBT element 44, and ic flows into each IGBT element 45. Hereinafter, although the current flowing through each part in one IGBT element 45 will be described, since the IGBT elements 44 and 45 have the same structure, the current in each part in the IGBT element 44 and other IGBT elements 45 is also the same.

  As is clear from the equivalent circuit of FIG. 5, the current ie of the IGBT element 45 is the sum of the electron current id flowing through the MOSFET 53 and the collector current (hole current) ih of the pnp transistor 52. That is, if the current flowing from one IGBT element 45 to the original electrode terminal Eg is assumed to be ie, a function of ie = id + ih is established. A control signal applied to the gate terminal G forms a channel in the P region 30 on the back surface side, and electrons are injected into the drain, that is, the N − region 29. On the other hand, holes are injected into the base of the pnp transistor 52, that is, the N− region 29 from the collector, that is, the P + region 28, and some of the injected holes are recombined with the electrons and disappear, and the rest is The collector current ih flows through the P region 30.

  In a range where the current flowing through the IGBT element 45 is small, the potential difference between both ends of the diffused resistor 57 in the P region 30 is small, and the base-emitter of the npn transistor 54 is kept short-circuited. In this state, npn transistor 54 does not operate, and IGBT element 44 operates as a composite element of N-channel MOSFET 53 and pnp transistor 52. In this case, since the base current of the pnp transistor 52 is controlled by the N-channel MOSFET 53, the current ih of the IGBT element 45 can be controlled by a control signal applied to the gate terminal G.

  When the current ie flowing through the IGBT element 45 increases due to some external cause such as noise applied to the gate terminal G, the electron current id and the hole current ih increase. At this time, if the hole current ih exceeds a certain value, the voltage drop at the diffusion resistor 57 exceeds the threshold value for conducting the npn transistor 54. That is, the base-emitter of the npn transistor 54 is forward-biased beyond its diffusion potential. As a result, the pnpn thyristor portion composed of the npn transistor 54 and the pnp transistor 52 becomes conductive. In this state, the output current ie of the IGBT element 45 cannot be controlled by the control signal applied to the gate terminal G. This is a phenomenon called latch-up.

  The IE output from all the IGBT elements 45 flows into the original electrode terminal Eg, and the detection current Is output from the original electrode terminal Eg is a total value of all IE. When the adjustment resistor 60 described later is omitted and the original electrode terminal Eg is used as a sense pad and the detection current Is is extracted from the sense pad to the outside of the IGBT chip 10, due to manufacturing variations of the IGBT chip 10, the main The ratio of the detection current is to the current Im deviates from the design value (in this example, 1/1000). In this IGBT chip 10, this shift is made to the design value by adjusting the resistance value of the adjusting resistor 60 that is built in the IGBT chip 10 and interposed between the sensor terminal Es and the original electrode terminal Eg. Will be corrected. This will be described below.

  In FIG. 6, the lower insulating layer 63 is formed on the surface of the N − layer 29 between the original electrode 16 and the sense pad 17. The plurality of resistors 64 are formed on the lower insulating layer 63 in an array at regular intervals between the original electrode 16 and the sense pad 17. The inter-resistive insulating layer 65 and the inter-terminal insulating layer 66 are formed prior to the formation of the short-circuit metal layer 67 and are formed on the surface side of the resistor 64 by exposing only both terminals of each resistor 64 to the surface side. Is done. The inter-resistance insulating layer 65 reaches the surface of the lower insulating layer 63 between two resistors 64 adjacent to each other in the column direction of the resistors 64 and insulates the two resistors 64 from each other. The inter-terminal insulating layer 66 covers the range between both terminals of each resistor 64 from the surface side.

  In FIG. 6, a plurality of short-circuit metal layers 67 exist between the original electrode 16 and the sense pad 17. This is because a state before the laser trimming described later is performed. When the IGBT chip 10 is formed, the cutting gap 68 is not formed, and the respective short-circuit metal layers 67 are connected together. And connected to the original electrode 16 and the sense pad 17. The ablation gap 68 is selectively formed when adjusting the resistance value of the adjustment resistor 60 between the original electrode 16 and the sense pad 17, and the short-circuit metal layer 67 is electrically connected in the column direction of the resistance 64 by the ablation gap 68. Divided into a plurality of sections separated from each other. Each resistor 64 becomes a resistance element of the adjustment resistor 60 by forming a cutting gap 68 on the surface side thereof. The resistance value of the adjustment resistor unit 60 is uniquely determined by the resistance value of each resistor 64 serving as a resistance element and the connection relationship between the resistance elements (eg, series connection or parallel connection).

  The resistor 64 has a short-circuit metal layer 67 in the resistance 64 at the stage before the ablation gap 68 is formed from the surface side in the inter-terminal insulating layer 66 formed on the surface side, that is, at the beginning of the fabrication of the IGBT chip 10. The two terminals are short-circuited. For this reason, the resistor 64 has its resistance function disabled and is not in operation as a resistance element of the adjustment resistor 60. On the other hand, when the cutting gap 68 is formed in the inter-terminal insulating layer 66 formed on the surface side of the resistor 64 from the surface side, the short circuit between both terminals of the resistor 64 due to the short-circuit metal layer 67 is released. Then, the resistor 64 recovers the resistance function and becomes operable as a resistance element of the adjustment resistor unit 60.

  Hereinafter, for convenience of explanation, the resistor 64 in which both ends are short-circuited by the short-circuit metal layer 67 is referred to as “invalid resistance” of the adjustment resistor portion 60, and both-end short-circuit by the short-circuit metal layer 67 is released by the formation of the cutting gap 68. The resistor 64 is referred to as an “effective resistor” of the adjustment resistor unit 60. The ineffective resistance means the resistance 64 that does not function as a resistance element between the original electrode 16 and the sense pad 17, and the effective resistance functions as a resistance element between the original electrode 16 and the sense pad 17. It means the resistor 64 in the state of being in operation. Since the resistor 64 changed from the ineffective resistor to the effective resistor becomes a resistance element of the adjustment resistor unit 60, only the effective resistance of the adjustment resistor unit 60 is involved in determining the resistance value of the adjustment resistor unit 60.

  In FIG. 7, five resistor strings are interposed between the original electrode 16 and the sense pad 17 in a state of being connected in parallel to each other. Each resistor string is composed of five resistors 64 connected in series with each other. In the example of the adjustment resistor unit 60 of FIG. 7, all the resistors 64 have the same resistance value. At the time of manufacturing the IGBT chip 10, one short-circuit metal layer 67 is connected to the original electrode 16 and the sense pad 17 at both ends in any resistor row and continuously without being cut off by the cutting gap 68. It is extended. Then, both ends of all the five resistors 64 on the back surface side are short-circuited, and the entire resistor 64 is held as an invalid resistor. As a result, the resistance value of the adjusting resistor 60 as the resistance between the original electrode 16 and the sense pad 17 is zero. In this state, the detection current Is output from the sense pad 17 is the same as Is output from the original electrode 16, and is usually a ratio to the main current Im due to manufacturing variations of the IGBT chip 10. Is deviated from the design value of the IGBT chip 10.

  In order to make the ratio of the detection current Is to the main current Im equal to the design value of the IGBT chip 10 with respect to the detection current Is output from the sensor terminal Es, some of the resistors 64 are changed from reactive resistors to effective resistors. Be changed. To change the resistor 64 from an ineffective resistor to an effective resistor, the portion of the short-circuit metal layer 67 that is in parallel with the resistor 64 is cut off by laser trimming to form a cutting gap 68. Done. Specifically, an enlarged screen of the multi-emitter unit 11 (including the adjustment resistor unit 60) is displayed on a predetermined display using a microscope, and a trimming portion is marked on the enlarged screen. An operator irradiates the mark with laser light.

  When measuring the value of the detection current Is, a voltmeter 73 (FIG. 6) is connected to the original electrode 16 and the sense pad 17 at both ends, and the adjustment resistor 60 and the voltmeter 73 are the original electrode 16-sense pad 17. Are connected in parallel with each other. The voltage V between the original electrode 16 and the sense pad 17 is measured by a voltmeter 73.

  When the resistance value of the adjustment resistor unit 60 is R, a relationship of Is = V / R is established for the detection current Is as a current passing through the adjustment resistor unit 60, and the detection current Is can be detected based on the relationship. it can. The resistance value R of the adjustment resistor unit 60 is determined so that the detection current Is has a ratio of the design value to the main current Im.

  In FIG. 7, a total of 25 resistors 64 are formed in a uniform distribution (matrix arrangement) in the range between the original electrode 16 and the sense pad 17 without overlapping in the plane direction. The matrix (row number, column number) is used to indicate each resistor 64. That is, in FIG. 7, there are a total of five columns of resistors 64 extending in the vertical direction between the original electrode 16 and the sense pad 17, but column numbers 1 to 5 are defined in order from the left to the right column. Furthermore, in each vertical column of the resistors 64, there are five resistors 64 in the vertical direction, but row numbers 1 to 5 are defined in order from the original electrode terminal Eg side to the sensor terminal Es side. In FIG. 7, the effective resistance is (5,1), (4,2), (5,2), (3,3), (4,3), (5,3), (2,4), Resistor 64 of (3,4), (4,4), (5,5), (1,5), (2,5), (3,5), (4,5), (5,5) The other resistors 64 are reactive resistors.

In FIG. 7, all the resistors 64 are unit resistors r. Therefore, the resistance value R of the adjustment resistor 60 is such that five resistance strings between the original electrode 16 and the sense pad 17 are connected in parallel with each other, and the number of effective resistors in each resistance string is in order from the left resistor string. Since 1, 2, 3, 4, and 5, the following relationship is established between R−r, and R is determined.
1 / R = 1 / r + 1 / (2 · r) + 1 / (3 · r) + 1 / (4 · r) + 1 / (5 · r) = 60 / (137 · r)

  Regarding the resistance row of the resistor 64 between the original electrode 16 and the sense pad 17, there are a plurality of rows (five rows) in FIG. 7, but a single row in FIG. Further, in the resistors 64 of FIG. 7, all the resistors 64 have the same resistance value, whereas the resistors 64 in FIG. 8 have different resistance values. The resistance values of the five resistors 64 in FIG. 8 are 0.1Ω, 0.2Ω, 0.4Ω, 0.8Ω, and 1.0Ω, respectively, and are arranged in ascending order from the original electrode 16 to the sense pad 17. It has been.

  The first decimal places 1, 2, 4, and 8 of 0.1Ω, 0.2Ω, 0.4Ω, and 0.8Ω are binary numbers “0001”, “0010”, “0100”, and “1000”, respectively. Is associated with. Thus, the resistance value of the adjustment resistor section 60 can be set in the range of 0.1Ω to 2.5Ω in increments of 0.1Ω. In the example of FIG. 8, assuming that the resistors 64 are arranged in 5 rows × 1 columns, the two resistors 64 of (1, 1) and (1, 2) are effective resistors, and the resistance of the adjustment resistor unit 60 is The value is 0.3Ω.

  In FIG. 7 and FIG. 8, the cutting gap 68 is formed by trimming with a laser to make each resistor 64 an effective resistor. On the other hand, in FIG. 9, a large current is passed between both terminals of each resistor to burn out the conductor portion of the short-circuit metal layer 67 connected in parallel to both ends of each resistor 64, thereby forming the cutting gap 68. Form.

  Each resistor 64 has terminals 77 and 78 on the original electrode 16 side and the sense pad 17 side, and the short-circuit metal layer 67 has wide portions 81 and narrow portions 82 alternately in the column direction of the resistors 64. . The wide portion 81 occupies a range from the terminal 78 of the resistor 64 on the original electrode 16 side adjacent to the resistor 64 in the column direction to the terminal 77 of the resistor 64 on the sense pad 17 side. The terminal 77 and the terminal 78 are excluded, and the range from the terminal 77 to the terminal 78 is occupied.

  Since the narrow portion 82 has a current passing area smaller than that of the wide portion 81, the tip of the pin electrode is pressed against the wide portion 81 on both sides of each narrow portion 82, and the gap between the pin electrodes is reduced. When a current is passed over a predetermined value, a sufficiently high heat is generated in the narrow portion 82, and the narrow portion 82 is burned out smoothly by this high heat, and the excision gap 68 is formed. At this time, some current flows through the resistor 64, but the current is slight and the resistor 64 is not damaged.

  In this way, the IGBT chip 10 outputs Is corrected by the adjustment resistor 60 in the IGBT chip 10 from the sense pad 17 so that the ratio of Is / Im becomes the design value with respect to the manufacturing variation. The Is from the sense pad 17 during the operation of the IGBT chip 10 is monitored. Then, in the package incorporating the IGBT chip 10, if the Is output to the outside of the package from the terminal connected to the sense pad 17 of the IGBT chip 10 exceeds the threshold value, it is assumed that latch-up has occurred, and the IGBT chip 10 The voltage application to the collector terminal C is immediately stopped, the operation of the IGBT chip 10 is stopped, and damage to the IGBT chip 10 is prevented.

  In the embodiment of FIG. 7, the width of the short-circuit metal layer 67 covering each resistor row from the surface side is equal to the width of the resistor 64. The width of the short-circuit metal layer 67 does not need to match the width of the resistor 64 as long as a part of the vertical direction can be cut without trouble by laser trimming, and may be longer or shorter than the width of the resistor 64. Good.

  In the embodiment, the detection current Is is output from the IGBT chip 10 as the detection current, but the current is correlated with Im, and the ratio to Im varies due to manufacturing variations of the IGBT chip 10. If it is a current, a current other than Is can be adopted as the detection current.

  For example, in the IGBT element 45 of FIG. 5, the MOSFET 53 and the npn transistor 54 are omitted, and only the pnp transistor 52 is left. Then, the drain of the MOSFET 53 of one IGBT element 44 is connected to the base of the remaining pnp transistor 52, the collector of the remaining pnp transistor 52 is connected to the original electrode 16, and the collector from each remaining pnp transistor 52 is connected. Current is collected at the source electrode 16. Furthermore, the current value is corrected by the adjustment resistor unit 60, and the corrected current output from the sense pad 17 can be used as a detection current (the detection current can also be used as a latch-up monitoring current) (Patent Literature). 1 corresponds to the configuration of FIG.

  In addition to the above-described embodiments and modifications, the present invention includes various configurations modified within the scope of the gist.

DESCRIPTION OF SYMBOLS 10 ... IGBT chip | tip, 11 ... Multi emitter part, 12 ... Gate electrode, 13 ... Emitter electrode, 16 ... Original electrode, 17 ... Sense pad, 27 ... Collector electrode, 35 ... gate electrode, 44, 45 ... IGBT element, 67 ... short-circuit metal layer, 68 ... excision gap, 82 ... narrow part.

Claims (4)

A semiconductor device including a sensor unit for detecting a current flowing through a semiconductor element,
An electrode for outputting a detection current;
A metal layer that is exposed on the surface of the semiconductor device and connects the electrode and the sensor unit at the time of fabrication;
A plurality of resistors arranged below the metal layer and between the electrode and the sensor unit;
The metal layer has a short-circuit portion that short-circuits between both terminals of each resistor, and a specific portion is formed with an excision gap that releases the short-circuit state,
A semiconductor device , wherein a resistance value between the electrode and the sensor unit is set by a resistance value of a resistor corresponding to a short-circuit portion in which the ablation gap is formed . The semiconductor device according to claim 1,
The semiconductor device according to claim 1, wherein the ablation gap is formed by laser trimming . The semiconductor device according to claim 1 or 2 ,
The plurality of resistors have different resistance values from each other . The semiconductor device according to any one of claims 1 to 3,
The semiconductor element is an insulated gate bipolar transistor element;
The semiconductor device according to claim 1, wherein the detection current is a current for monitoring latch-up of the insulated gate bipolar transistor element .

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