Semiconductor Devices

Abstract

The purpose of the present invention is to provide a semiconductor device that, during manufacturing thereof, allows easy switchover between mounting and non-mounting of a diagnostic element thereon. A semiconductor device (100) comprises: an insulating substrate (2) that has an obverse surface pattern (2b) provided on the obverse surface and a reverse surface pattern (2c) provided on the reverse surface; a semiconductor element (3) that is mounted on the obverse surface pattern (2b); a heat dissipation plate (1) that is bonded to the reverse surface pattern (2c) so as to include the insulating substrate (2) in a top view; a case (7) that is fixed at a peripheral portion on the heat dissipation plate (1) and that houses the insulating substrate (2) and the semiconductor element (3); and a diagnostic element (9) that is disposed inside the case (7) and that is for diagnosing deterioration of the semiconductor element (3). The diagnostic element (9) has a terminal (9a). The terminal (9a) is not electrically connected to the semiconductor element (3).

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor device. [Background technology]

[0002] Conventionally, power supply devices with built-in life detection capacitors (corresponding to diagnostic elements) have been proposed to detect the life of a product (see, for example, Patent Document 1). In the technology described in Patent Document 1, the life detection capacitor is electrically connected to the internal circuit of the product, and the life of the product is detected based on the capacitance of the life detection capacitor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-327162 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, the life detection capacitor is electrically connected to the internal circuit of the product as a diagnostic element, making it difficult to easily switch between including and not including the diagnostic element during manufacturing.

[0005] Therefore, an object of the present disclosure is to provide a semiconductor device that can easily switch between mounting and not mounting a diagnostic element during manufacturing. [Means for solving the problem]

[0006] The semiconductor device according to the present disclosure includes an insulating substrate having a surface pattern provided on a surface and a back pattern provided on a back surface, a semiconductor element mounted on the surface pattern, a heat sink that encompasses the insulating substrate in a top view and is joined to the back pattern, a case that is fixed to a peripheral portion of the heat sink and that houses the insulating substrate and the semiconductor element, and a diagnostic element that is disposed within the case and that diagnoses deterioration of the semiconductor element. 、 The diagnostic element has an external connection terminal. It is an electrolytic capacitor that The external connection terminals are not electrically connected to the semiconductor element. [Effects of the Invention]

[0007] According to the present disclosure, the presence or absence of a diagnostic element does not affect the product, and therefore, during manufacturing, it is possible to easily switch between mounting and not mounting a diagnostic element.

[0008] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a semiconductor device according to a first embodiment. [Figure 2] 4 is a graph showing characteristic values ​​of the semiconductor device according to the first embodiment and the diagnostic element included therein. [Figure 3] FIG. 10 is a cross-sectional view of a semiconductor device according to a third embodiment. [Figure 4] FIG. 10 is a cross-sectional view of a semiconductor device according to a fourth embodiment. [Figure 5] FIG. 10 is a cross-sectional view of a semiconductor device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] <First Embodiment> First Embodiment The first embodiment will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of a semiconductor device 100 according to the first embodiment.

[0011] As shown in FIG. 1, the semiconductor device 100 is a power module and includes a heat sink 1, an insulating substrate 2, a semiconductor element 3, multiple lead electrodes 4, a case 7, a sealing resin 8, a diagnostic element 9, and a lid 12.

[0012] The insulating substrate 2 is formed in a rectangular shape when viewed from above. The insulating substrate 2 includes an insulating base material 2a, a front pattern 2b provided on the front surface of the insulating base material 2a, and a back pattern 2c provided on the back surface of the insulating base material 2a. The insulating base material 2a is made of ceramic or the like. The front pattern 2b and the back pattern 2c are made of a metal such as copper.

[0013] The heat sink 1 is made of a metal such as copper and has a rectangular shape when viewed from above. The heat sink 1 encompasses the insulating substrate 2 when viewed from above and is bonded to the back surface pattern 2c with a bonding material 5. The bonding material 5 is, for example, solder.

[0014] The semiconductor element 3 is mounted on the surface of the insulating substrate 2. Specifically, the semiconductor element 3 is mounted on the surface pattern 2b via a bonding material 5. The semiconductor element 3 is electrically connected to the lead electrodes 4 by metal wires 6. Here, the number of semiconductor elements 3 is not limited to one, and there may be multiple semiconductor elements 3.

[0015] The semiconductor element 3 is, for example, an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET). The semiconductor element 3 may also include an electrically connected free wheeling diode (FWD). The semiconductor element 3 is made of silicon or a wide band gap semiconductor material. Wide band gap semiconductor materials include silicon carbide, gallium nitride semiconductor materials, diamond, etc.

[0016] The case 7 is formed in a rectangular frame shape when viewed from above. The case 7 is fixed to the peripheral edge of the heat sink 1 and houses the insulating substrate 2 and the semiconductor element 3. The case 7 is made of resin and has insulating properties.

[0017] The diagnostic element 9 is disposed in an upper portion within the case 7. Specifically, the diagnostic element 9 is disposed above the semiconductor element 3 within the case 7. The diagnostic element 9 is a member for diagnosing the deterioration of the semiconductor element 3, that is, the deterioration of the semiconductor device 100. The deterioration diagnosis of the semiconductor device 100 will be described later.

[0018] The lid 12 is attached above the diagnostic element 9 so as to cover the opening 7a of the case 7. Like the case 7, the lid 12 is made of resin and has insulating properties. Two through holes 12a and multiple through holes 12b are formed in the lid 12. Two terminals 9a of the diagnostic element 9 protrude to the outside through the two through holes 12a. That is, the two terminals 9a of the diagnostic element 9 are terminals for external connection and are not electrically connected to the semiconductor element 3. Therefore, the operation of the diagnostic element 9 does not affect the operation of the semiconductor element 3, and the operation of the semiconductor element 3 does not affect the operation of the diagnostic element 9. In this way, the presence or absence of the diagnostic element 9 does not affect the semiconductor device 100, which is the product, so that the diagnostic element 9 can be easily installed or not installed during manufacturing.

[0019] One end of each of the plurality of lead electrodes 4 is connected to the surface pattern 2b, and the other end thereof protrudes to the outside through a plurality of through holes 12b formed in the lid 12. The sealing resin 8 is, for example, an epoxy resin, and is filled inside the case 7.

[0020] Next, a description will be given of the deterioration diagnosis of the semiconductor device 100 using the diagnostic element 9 with reference to Fig. 2. Fig. 2 is a graph showing characteristic values ​​of the semiconductor device 100 according to the first embodiment and the diagnostic element 9 included therein.

[0021] Degradation of the semiconductor device 100 is related to degradation of the semiconductor element 3, and the breakdown timing of the semiconductor device 100 can be considered to be the same as the breakdown timing of the semiconductor element 3. Therefore, in diagnosing degradation of the semiconductor device 100, the breakdown timing of the semiconductor element 3 is used as the breakdown timing of the semiconductor device 100. As shown in FIG. 2 , the breakdown timing of the semiconductor device 100 is related to the characteristic value of the diagnostic element 9. The characteristic value of the diagnostic element 9 changes over time depending on the operating environment of the semiconductor device 100 or the temperature during operation. When the characteristic value of the diagnostic element 9 reaches a specific value, it is determined that the semiconductor device 100 has been broken. Therefore, by measuring the characteristic value of the diagnostic element 9, it is possible to diagnose the breakdown timing of the semiconductor device 100, i.e., the degradation of the semiconductor device 100.

[0022] 2 is the output voltage of the semiconductor device 100, which is discontinuous after breakdown of the semiconductor device 100. Also, the diagnostic element characteristic in FIG. 2 is the characteristic of the diagnostic element 9, which continuously and monotonically decreases before and after breakdown of the semiconductor device 100.

[0023] 2 shows the case where the characteristic value of the diagnostic element 9 monotonically decreases over time, but the characteristic value of the diagnostic element 9 may also monotonically increase over time. Furthermore, any material can be used as the diagnostic element 9 as long as its characteristic value is related to the breakdown timing of the semiconductor device 100.

[0024] As a degradation diagnosis method for the semiconductor device 100, module characteristics and diagnostic element characteristics are stored in a data server (not shown), and the stored data is used as machine learning data, thereby enabling degradation diagnosis of the semiconductor device 100 from the diagnostic element characteristics. Here, the module characteristics are acquired from product shipping test data, degradation test data, and operational data during actual product operation.

[0025] As described above, the semiconductor device 100 according to the first embodiment includes an insulating substrate 2 having a surface pattern 2b on its surface and a back surface pattern 2c on its back surface, a semiconductor element 3 mounted on the surface pattern 2b, a heat sink 1 that encloses the insulating substrate 2 in a top view and is joined to the back surface pattern 2c, a case 7 that is fixed to the peripheral portion of the heat sink 1 and that houses the insulating substrate 2 and the semiconductor element 3, and a diagnostic element 9 that is disposed within the case 7 and that diagnoses deterioration of the semiconductor element 3, the diagnostic element 9 having a terminal 9a that is not electrically connected to the semiconductor element 3.

[0026] Therefore, the presence or absence of the diagnostic element 9 does not affect the semiconductor device 100 as a product, and therefore, during manufacturing, it is possible to easily switch between mounting and not mounting the diagnostic element 9.

[0027] <Embodiment 2> Next, a description will be given of a semiconductor device 100 according to a second embodiment. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0028] In the second embodiment, the diagnostic element 9 is an electrolytic capacitor, and the structure of the semiconductor device 100 and the change over time in the characteristic values ​​of the electrolytic capacitor are the same as those in the first embodiment, so the description will be given using Figures 1 and 2. In the second embodiment, the diagnostic element 9 will be described as an electrolytic capacitor.

[0029] As shown in FIG. 1, the electrolytic capacitor is disposed above the semiconductor element 3 within the case 7. Two terminals 9a of the electrolytic capacitor protrude to the outside through two through-holes 12a. That is, the two terminals 9a of the electrolytic capacitor are terminals for external connection and are not electrically connected to the semiconductor element 3. Therefore, the operation of the electrolytic capacitor does not affect the operation of the semiconductor element 3, and the operation of the semiconductor element 3 does not affect the operation of the electrolytic capacitor. In this way, the presence or absence of the electrolytic capacitor does not affect the semiconductor device 100, which is the finished product, and therefore it is possible to easily switch between including and not including the electrolytic capacitor during manufacturing.

[0030] Although not shown, the two terminals 9a of the electrolytic capacitor are connected to a sensor for measuring the capacitance of the electrolytic capacitor. As shown in Fig. 2, the capacitance of the electrolytic capacitor decreases over time depending on the operating environment of the semiconductor device 100, the temperature during operation, and the like.

[0031] 2 is the output voltage of the semiconductor device 100, which is discontinuous after breakdown of the semiconductor device 100. Also, the diagnostic element characteristic (characteristic of the electrolytic capacitor) in Fig. 2 is the capacitance of the electrolytic capacitor, which continuously and monotonically decreases before and after breakdown of the semiconductor device 100.

[0032] The degradation diagnosis method for the semiconductor device 100 is the same as that in the first embodiment, and therefore the description thereof will be omitted.

[0033] As described above, in the semiconductor device 100 according to the second embodiment, the diagnostic element 9 is an electrolytic capacitor, and therefore the presence or absence of the electrolytic capacitor does not affect the semiconductor device 100 as a finished product, so that it is easy to switch between having and not having the electrolytic capacitor during manufacturing.

[0034] <Third Embodiment> Next, a semiconductor device 100A according to embodiment 3 will be described. Fig. 3 is a cross-sectional view of the semiconductor device 100A according to embodiment 3. Note that in embodiment 3, the same components as those described in embodiments 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

[0035] 3, in the third embodiment, the diagnostic element 9 is disposed on the surface pattern 2b in the periphery of the semiconductor element 3. By disposing the diagnostic element 9 in the vicinity of the semiconductor element 3, it becomes possible to acquire diagnostic element characteristics that reflect the temperature of the semiconductor element 3 in more detail. Note that in the third embodiment, the diagnostic element 9 may be an electrolytic capacitor.

[0036] As described above, in the semiconductor device 100A according to the third embodiment, the diagnostic element 9 is arranged on the surface pattern 2b in the peripheral portion of the semiconductor element 3, so that it is possible to acquire diagnostic element characteristics that reflect the temperature of the semiconductor element 3 in more detail, and this is expected to improve the accuracy of deterioration diagnosis in the semiconductor device 100A.

[0037] <Fourth Embodiment> Next, a semiconductor device 100B according to embodiment 4 will be described. Fig. 4 is a cross-sectional view of the semiconductor device 100B according to embodiment 4. Note that in embodiment 4, the same components as those described in embodiments 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted.

[0038] 4, in the fourth embodiment, the semiconductor device 100B includes a plurality of (for example, two) diagnostic elements 9. Two terminals 9a of each diagnostic element 9 are not electrically connected to the semiconductor element 3. Therefore, it is possible to acquire diagnostic element characteristics from each diagnostic element 9 individually.

[0039] Both of the two diagnostic elements 9 may be arranged above the semiconductor element 3 within the case 7, or may be arranged on the surface pattern 2b in the periphery of the semiconductor element 3. Alternatively, one of the two diagnostic elements 9 may be arranged above the semiconductor element 3 within the case 7, and the other may be arranged on the surface pattern 2b in the periphery of the semiconductor element 3.

[0040] 4, two diagnostic elements 9 are provided, but the number of diagnostic elements 9 is not limited to two and may be three or more. In addition, in the fourth embodiment, the diagnostic element 9 may be an electrolytic capacitor.

[0041] As described above, the semiconductor device 100B according to the fourth embodiment includes a plurality of diagnostic elements 9, and therefore data that takes into account the characteristics of a plurality of diagnostic elements can be used as machine learning data. This is expected to improve the accuracy of degradation diagnosis in the semiconductor device 100B.

[0042] <Fifth Embodiment> Next, a semiconductor device 100C according to embodiment 5 will be described. Fig. 5 is a cross-sectional view of the semiconductor device 100C according to embodiment 5. Note that in embodiment 5, the same components as those described in embodiments 1 to 4 are denoted by the same reference numerals and description thereof will be omitted.

[0043] As shown in FIG. 5 , in the fifth embodiment, the semiconductor device 100C includes a strain gauge 11 and a detection sample 10 to which the strain gauge 11 is attached, instead of the diagnostic element 9. The gauge lead 11a of the strain gauge 11 is an external connection terminal, and the gauge lead 11a protrudes to the outside through the through hole 12a. That is, the gauge lead 11a of the strain gauge 11 is not electrically connected to the semiconductor element 3. Therefore, the operation of the strain gauge 11 does not affect the operation of the semiconductor element 3, and the operation of the semiconductor element 3 does not affect the operation of the strain gauge 11. In this way, the presence or absence of the strain gauge 11 does not affect the semiconductor device 100C, which is the finished product, and therefore, it is possible to easily switch between including and not including the strain gauge 11 during manufacturing.

[0044] The detection sample 10 is bonded onto the surface pattern 2b with a bonding material 5. In order to obtain diagnostic element characteristics that reflect the temperature of the semiconductor element 3 in more detail, it is desirable that the detection sample 10 be bonded to the periphery of the surface pattern 2b.

[0045] Furthermore, in order to clearly grasp the thermal history, it is desirable that the detection sample 10 be made of a material having a linear expansion coefficient greater than that of the insulating substrate 2. Furthermore, since the detection sample 10 must function even when the semiconductor device 100C is destroyed, in a reliability test, the bond between the detection sample 10 and the insulating substrate 2 must be more durable than the bond between the semiconductor element 3 and the metal wire 6 and the bond between the insulating substrate 2 and the heat sink 1. The durability of the bond between the detection sample 10 and the insulating substrate 2 can be adjusted by changing the shape and bonding area of ​​the detection sample 10.

[0046] The detection sample 10 expands and contracts depending on the operating environment of the semiconductor device 100C or the temperature during operation. Strain in the detection sample 10 accumulates over time, and the accumulated strain in the detection sample 10 is measured by the strain gauge 11. The strain in the detection sample 10 measured by the strain gauge 11 is used as a diagnostic element characteristic, and degradation diagnosis of the semiconductor device 100C is performed in the same manner as in the first embodiment. Here, the strain gauge 11 and the detection sample 10 may be provided at multiple locations.

[0047] It is also possible to attach strain gauges 11 directly onto the surface pattern 2b without bonding the detection sample 10 onto the surface pattern 2b. In this case, the strain of the surface pattern 2b measured by the strain gauges 11 is used as the diagnostic element characteristic. Also, strain gauges 11 may be provided at multiple locations.

[0048] Furthermore, instead of the gauge lead 11a being an external connection terminal, a separate external connection terminal may be provided and the gauge lead 11a may be connected to the external connection terminal, which is a separate member.

[0049] As described above, in the semiconductor device 100C according to the fifth embodiment, the diagnostic element 9 is the strain gauge 11, and the external connection terminal is connected to the gauge lead 11a of the strain gauge 11.

[0050] Therefore, the presence or absence of strain gauge 11 does not affect the semiconductor device 100C as a finished product, and therefore, during manufacturing, it is possible to easily switch between mounting and not mounting strain gauge 11.

[0051] The diagnostic element 9 also includes a detection sample 10 to which a strain gauge 11 is attached, the detection sample 10 being placed on the surface pattern 2b, and the external connection terminals being gauge leads 11a.

[0052] Therefore, by using the strain of the detection sample 10 as the diagnostic element characteristic, it is expected that the accuracy of degradation diagnosis in the semiconductor device 100C will be improved compared to when the strain of the surface pattern 2b is used as the diagnostic element characteristic.

[0053] Although this disclosure has been described in detail, the above description is illustrative in all respects and is not restrictive. It is understood that countless variations not illustrated can be envisioned.

[0054] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate. [Explanation of symbols]

[0055] 1 heat sink, 2 insulating substrate, 2b surface pattern, 2c back surface pattern, 3 semiconductor element, 7 case, 9 diagnostic element, 9a terminal, 10 detection sample, 11 strain gauge, 11a gauge lead, 100, 100A, 100B, 100C semiconductor device.

Claims

1. an insulating substrate having a surface pattern provided on a surface thereof and a back surface pattern provided on a back surface thereof; a semiconductor element mounted on the surface pattern; a heat sink that includes the insulating substrate when viewed from above and is joined to the rear surface pattern; a case fixed to a peripheral portion of the heat sink and accommodating the insulating substrate and the semiconductor element; a diagnostic element disposed in the case for diagnosing deterioration of the semiconductor element; the diagnostic element is an electrolytic capacitor having an external connection terminal, The semiconductor device, wherein the external connection terminal is not electrically connected to the semiconductor element.

2. an insulating substrate having a surface pattern provided on a surface thereof and a back surface pattern provided on a back surface thereof; a semiconductor element mounted on the surface pattern; a heat sink that includes the insulating substrate when viewed from above and is joined to the rear surface pattern; a case fixed to a peripheral portion of the heat sink and accommodating the insulating substrate and the semiconductor element; a diagnostic element disposed in the case for diagnosing deterioration of the semiconductor element; the diagnostic element is a strain gauge having an external connection terminal, The semiconductor device, wherein the external connection terminal is connected to a gauge lead of the strain gauge and is not electrically connected to the semiconductor element.

3. 3. The semiconductor device according to claim 1, wherein the diagnostic element is disposed on the surface pattern in a peripheral portion of the semiconductor element.

4. 3. The semiconductor device according to claim 1, further comprising a plurality of said diagnostic elements.

5. the diagnostic element includes a detection sample to which the strain gauge is attached; the detection sample is placed on the surface pattern; 3. The semiconductor device according to claim 2, wherein said external connection terminal is said gauge lead.

Images