The present disclosure relates to a semiconductor module.
The present application is based on and claims priority to Japanese Patent Application No. 2018-042050, filed on Mar. 8, 2018, the entire contents of the Japanese Patent Application are hereby incorporated herein by reference.
Semiconductor modules having semiconductor chips that enable large currents to flow are used in electric vehicles and other power applications. In semiconductor modules, rod-shaped external terminals may be connected to electrode pads of semiconductor chips.
[Patent Document 1] Japanese Laid-open Patent Publication No. 2017-92185
According to one aspect of the present embodiment, a semiconductor module includes: a circuit board; a semiconductor chip having a first electrode pad on a first surface, bonded to the circuit board at a second surface that is opposite to the first surface, and having side surfaces intersecting the first surface and the second surface; an external terminal electrically connected to the first electrode pad; and an insulating member configured to fix the external terminal. By the insulating member contacting the side surfaces of the semiconductor chip at a plurality of locations, parallel movement and rotational movement of the semiconductor chip relative to the insulating member in a plane parallel to the first surface are restricted. The external terminal penetrates the insulating member.
In recent years, enhancements in semiconductor chips have enabled further miniaturization of semiconductor chips that enables large currents to flow. However, upon miniaturizing an external terminal along with the miniaturization of a semiconductor chip, the current that flows through the external terminal is limited. Also, upon miniaturizing a semiconductor chip while using an external terminal having a size that enables a large current to flow, due to a positional deviation between the external terminal and an electrode pad, a problem such as a bonding failure and a short circuit may occur.
Therefore, the present disclosure has an object to provide a semiconductor module in which it is possible to prevent a positional deviation between an external terminal and an electrode pad from occurring easily.
According to the present disclosure, it is possible to prevent a positional deviation between an external terminal and an electrode pad from occurring easily.
Embodiments will be described below.
First, aspects of the present disclosure will be described by listing. In the following description, the same numerals are used to denote the same or corresponding elements; accordingly, explanation for those elements will not be repeatedly provided.
[1] A semiconductor module according to one aspect of the present disclosure includes: a circuit board; a semiconductor chip having a first electrode pad on a first surface, bonded to the circuit board at a second surface that is opposite to the first surface, and having side surfaces intersecting the first surface and the second surface; an external, terminal electrically connected to the first electrode pad; and an insulating member configured to fix the external terminal, wherein by the Insulating member contacting the side surfaces of the semiconductor chip at a plurality of locations, parallel movement and rotational movement of the semiconductor chip relative to the insulating member in a plane parallel to the first surface are restricted, and wherein the external terminal penetrates the insulating member.
Although further miniaturization of a semiconductor chip that enables a large current to flow is possible, when an external terminal is also miniaturized along with the miniaturization of the semiconductor chip, a current that flows through the external terminal is limited. Accordingly, it is desirable to miniaturize a semiconductor chip while using an external terminal having a size that enables a large current to flow. In this case, due to a positional deviation between the external terminal and an electrode pad, a problem such as a bonding failure and a short circuit may occur. As a result of earnest, consideration, the inventors have found a semiconductor module having a structure that enables a large current to flow and in which a positional deviation between an external terminal and an electrode pad does not easily occur. The present disclosure is based on such consideration made by the inventors.
[2] The first surface of the semiconductor chip is covered by the insulating member, and the external terminal penetrates the insulating member in a direction perpendicular to the first surface. It is easy to stabilize the connection between the external terminal and the first electrode pad.
[3] A surface of the external terminal to be in contact with the first electrode pad has a shape similar to a shape of a surface of the first electrode pad to be in contact with the external terminal. It is possible to increase the cross-sectional area of the external terminal with respect to a direction in which a current flows and it is possible to cause a larger current to flow.
[4] The insulating member is in contact with the side surfaces over an entire periphery of the semiconductor chip. The side surfaces can be protected by the insulating member over the entire periphery.
[5] A planar shape of the semiconductor chip is a quadrilateral, and the insulating member is in contact with at least one location for each of the side surfaces corresponding to respective sides of the quadrilateral. Stability excellent in positional accuracy can be obtained.
[6] The circuit board has a circuit pattern on a surface toward the semiconductor chip, the semiconductor chip has a second electrode pad on the second surface, and the second electrode pad is electrically connected to the circuit pattern. It can be applied to a semiconductor module including a vertical semiconductor chip.
[7] The semiconductor chip is made of a material including SiC. The semiconductor chip using SIC is suitable for miniaturization.
[8] A semiconductor module according to another aspect of the present disclosure includes: a circuit board; a semiconductor chip having a main electrode pad and a control electrode pad on a first surface, bonded to the circuit board at a second surface that is opposite to the first surface, and having side surfaces intersecting the first surface and the second surface; a main terminal electrically connected to the main electrode pad; a control terminal electrically connected to the control, electrode pad; and an insulating member configured to fix the main terminal and the control terminal, wherein the first surface of the semiconductor chip is covered by the insulating member, wherein by the insulating member contacting an entire periphery of the side surfaces of the semiconductor chip, parallel movement and rotational movement of the semiconductor chip relative to the insulating member in a plane parallel to the first surface are restricted, and wherein the main terminal and the control terminal penetrate the insulating member in a direction perpendicular to the first surface.
In the following, embodiments of the present disclosure will be described in detail, but the present embodiments are not limited thereto.
First, a first embodiment will be described.
As illustrated in
The semiconductor chip 110 is made, for example, of Si or SIC. On a first surface 110a that is one surface, a main electrode pad 111 and a control electrode pad 112 are provided, and on a second surface 110b that is the other surface, a main electrode pad 113 is provided. It should be noted that from the viewpoint of size reduction and efficiency, it is preferable that the semiconductor chip 110 is made of SiC. The main electrode pad 111, the control electrode pad 112 and the main electrode pad 113 are made of, for example, aluminum (Al) or the like. The semiconductor chip 110 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), and the main electrode pad 111 is a source electrode pad, the control electrode pad 112 is a gate electrode pad, and the main electrode pad 113 is a drain electrode pad. The semiconductor chip 110 may be an IGBT (Insulated Gate Bipolar Transistor). In a case in which the semiconductor chip 110 is an IGBT, the main electrode pad 111 is an emitter electrode pad, the control electrode pad 112 is a gate electrode pad, and the main electrode pad 113 is a collector electrode pad. The shape of the semiconductor chip 110 is not particularly limited. For example, the semiconductor chip 110 has a planar shape of a square of 3 Hm3 mm, 5 mm*5 mm, or 10 mm*10 mm, and the thickness of the semiconductor chip 110 is 100 μm to 500 μm.
The circuit board 120 includes an insulator substrate 121 made of an insulator, a metal layer 122 that is a wiring layer formed on the first surface 120a that is one surface, and a metal layer 123 that is a heat dissipation layer formed on the second surface 120b that is the other surface. The metal layer 122 has a circuit pattern, and to the metal layer 122, the main electrode pad 113 of the semiconductor chip 110 is electrically connected by a bonding material 124, such as solder.
For example, the insulator substrate 121 is made of an insulator material such as ceramics, and the metal layers 122 and 123 are made of Cu (copper) or the like.
The external terminal 140 includes, for example, a main terminal 141 and a control terminal 142 that are, for example, cylindrical. The main terminal 141 is fixed to the insulating member 130 by penetrating the main terminal through hole 131 and is electrically connected to the main electrode pad 111 by unillustrated solder or the like. The control terminal 142 is fix to the insulating member 130 by penetrating the control terminal through hole 132 and is electrically connected to the control electrode pad 112 by unillustrated solder or the like.
The stoppers 138 may, for example, have a height such that the sum of the height of the stoppers 138 and the height of the semiconductor chip 110 is greater than or equal to the depth of the opening portion 136. Accordingly, the second surface 110b of the semiconductor chip 110 is flush with the end surface 130a of the guide portion 137 that, is on the circuit board 120 side, or is on the circuit board 120 side with respect to the end surface 130a. The height by which the semiconductor chip 110 protrudes from the base portion 135 is, for example, less than or equal to ½ of the thickness of semiconductor chip 110. In a case in which the semiconductor chip 110 protrudes from base portion 135, there is a gap 126 between the end surface 130a and the circuit board 120.
For example, the insulating member 130 is made of ceramics such as alumina or an organic resin such as polyphenylene sulfide (PPS), and the external terminal 140 is made of Cu (copper) or the like.
(Method of Manufacturing Semiconductor Module)
Next, a method of manufacturing the semiconductor module 100 will be described.
First, the semiconductor chip 110, the circuit board 120, the insulating member 130, and the external terminal 140 are prepared. Then, as illustrated i.n FIG. 4A, the main terminal 141 is fitted into the main terminal through hole 131 and the control terminal 142 is fitted into the control terminal through hole 132. At this time, the sum of the height by which the main terminal 141 and the control terminal 142 protrude front the bottom surface of the opening 1 portion 36 within the opening portion 136 and the height of the main electrode pad 111 or the control electrode pad 112 is greater than the height of the stoppers 133. The insulating member 130 and the external terminals 140 may be integrally formed rather than individually prepared. Next, the semiconductor chip 110 is positioned above the base portion 135 such that the main electrode pad 111 faces the main terminal through hole 131 and the main terminal 141 and the control electrode pad 112 faces the control terminal through hole 132 and the control terminal 142. Also, unillustrated solder or the like is provided on the main terminal 141 or the main electrode pad 111, and unillustrated solder or the like is provided on the control terminal 142 or the control electrode pad 112. Examples of solder materials include Sn alloys such as SnSb and SnCu. This state corresponds to the state that is illustrated in
The semiconductor chip 110 is then fitted into the opening portion 136 as illustrated in
Then, as illustrated in
Then, as illustrated in
In this manner, the semiconductor module 100 according to the first embodiment can be manufactured.
In the first embodiment as described above, the semiconductor chip 110 is guided by the guide portion 137 of the insulating member 130 to which the main terminal 141 and the control terminal 142 are fixed, the main electrode pad 111 contacts the main terminal 141 and the control electrode pad 112 contacts the control terminal 142. Accordingly, the position of the main terminal 141 can be adjusted with respect to the main electrode pad 111 with high accuracy and the position of the control terminal 142 can be adjusted with respect to the control electrode pad 11.2 with high accuracy. In particular, because the planar shape of the semiconductor chip 110 is a quadrilateral, and the insulating member 130 is in contact with the respective side surfaces 110c, stability excellent in positional accuracy is obtained.
Also, because the insulating member 130 is in contact with the side surfaces 110c of the semiconductor chip 110, the side surfaces 110c, where high voltage is particularly likely to occur, can be insulation-protected. In sealing using resin, air bubbles or voids may occur in the resin. Therefore, the insulating member 130 can be used for a more reliable insulation protection. Further, at the time of fitting the semiconductor chip 110 into the opening portion 136, by applying a flowable insulating material, such as silicone rubber, to the side surfaces 110c of the semiconductor chip 110 or the Inside surface of the guide portion 137, it is possible to further firmly protect the side surfaces 110c. It should be noted that even though there is a gap 126 between the end surface 130a and the circuit board 120, this gap 126 is small and can also be embedded by using an insulating material such as a sealing resin.
Also, because the main electrode pad 113 is electrically connected to the metal layer 122 having a circuit pattern, the present embodiment is suitable for the semiconductor module 100 having the semiconductor chip 110 having a vertical structure.
Also, because the second surface 110b of the semiconductor chip 110 is flush with the end surface 130a of the guide portion 137 or is on the circuit board 120 side with respect to the end surface 130a, the bonding material 124 can be reliably in contact with the metal layer 122 and the main electrode pad 113. That is, reliability excellent with regard to bonding can be obtained.
Next, a second embodiment will, be described. The second embodiment differs from the first embodiment in the configuration of the main terminal and the control terminal.
The semiconductor module according to the second embodiment includes an external terminal 240 instead of the external terminal 140, and the external terminal 240 includes a main terminal 241 and a control terminal 242 that have a prism shape, as illustrated in
The cross-sectional area of the main terminal 241 with respect to the direction in which a current flows can be larger than that of the main terminal 141, and the cross-sectional area of the control terminal 242 with respect to the direction in which a current flows can be larger than that of the control terminal 142. Therefore, according to the second embodiment, it is possible to cause a larger current to flow than in the first embodiment. Also, even when the cross-sectional area of the main terminal 241 and the control terminal 242 is increased, the position of the main terminal 241 can be adjusted with respect to the main electrode pad 111 with high accuracy, and the position of the control terminal. 242 can be adjusted with respect to the control electrode pad 112 with high accuracy.
Next, a third embodiment will be described. The third embodiment differs from the first embodiment in the configuration of the main electrode pad and the main terminal.
The semiconductor module according to the second embodiment includes a main electrode pad 311 instead of the main electrode pad ill, and includes an external terminal 340 instead of the external terminal 140, and the external terminal 340 includes a main terminal 341 and a control terminal 242, as illustrated in
The cross-sectional area of the main terminal 341 with respect to the direction in which a current flows can be larger than that of the main terminal 241. Therefore, according to the third embodiment., it is possible to cause a larger current to flow than in the second embodiment. Also, even when the cross-sectional area of the main terminal 341 is increased, the position of the main terminal 341 can be adjusted with respect to the main electrode pad 311 with high accuracy.
It should be noted that “similar” in the second and third embodiments does not mean “similar” in a strict sense. It is sufficient to be similar to the extent that it can be regarded as being similar in terms of social belief, and an effect of enabling a large current to flow can be obtained even when it is not similar in a strict sense. For example, a slight difference may tee present in the ratio of side lengths.
Next, a fourth embodiment will be described. The fourth embodiment differs from the first embodiment in the configuration of the insulating member.
As illustrated in
In the fourth embodiment as described above, the semiconductor chip 110 is guided by guide portions 437 of the insulating member 430 to which the main terminal 141 and the control terminal 142 are fixed, the main electrode pad 111 contacts the main terminal 141 and the control electrode pad 112 contacts the control terminal 142. Therefore, similarly to the first embodiment, the position of the main terminal 141 can be adjusted with respect to the main electrode pad 111 with high accuracy and the position of the control terminal 142 can be adjusted with respect to the control electrode pad 112 with high accuracy.
Also, because the insulating member 430 is in contact with the side surfaces 110c of the semiconductor chip 110, the side surfaces 110c, where high voltage is particularly likely to occur, can be insulation-protected. Although the portions of the side surfaces 110c are exposed from the insulating member 430, these portions can be insulation-protected by resin sealing.
Next, a fifth embodiment will be described. The fifth embodiment differs from the first embodiment in the configuration of the insulating member.
As illustrated in
In the fifth embodiment as described above, the semiconductor chip 110 is guided by the guide portions 537 of the insulating member 530 to which the main terminal 141 and the control terminal 142 are fixed, the main electrode pad 111 contacts the main terminal 141 and the control electrode pad 112 contacts the control terminal 142. Accordingly, similarly to the first embodiment, the position of the main terminal 141 can be adjusted with respect to the main electrode pad 111 with high accuracy and the position of the control terminal 142 can be adjusted with respect to the control electrode pad 112 with high accuracy.
Also, because the insulating member 530 is in contact with the side surfaces 110c of the semi conductor chip 110, the side surfaces 110c, where high voltage is particularly likely to occur, can be insulation-protected. Although the portions of. the side surfaces 110c are exposed from the insulating member 530, these portions can be insulation-protected by resin sealing.
Next, a sixth embodiment will be described. The sixth embodiment differs from the first embodiment in that a support member is added.
The semiconductor module according to the sixth embodiment includes a support member 600 that is provided on the side of the insulating member that is opposite to the circuit board 120 and supports the insulating member 130, as illustrated in
For example, the support member 600 can be made of a material that is the same as the insulating member 130. That is, the support member 600 is made of ceramics such as alumina or an organic resin such as PPS.
in any of the first to sixth embodiments, the opening portion 136 may be filled with an insulating material, such as a resin.
Although the embodiments have been described in detail above, it is not limited to a specific embodiment Various. modifications and changes can be made within a scope set forth in the claims.
Number | Date | Country | Kind |
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2018-042050 | Mar 2018 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2019/001793 | 1/22/2019 | WO | 00 |