JP2010219095A - Method of manufacturing semiconductor cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor cooling device which can prevent failure in brazing by using a simple jig. <P>SOLUTION: A bottom plate 18, a cooler 16, a thermal conductive member 14, and an insulating substrate 12 are sequentially laminated on a base jig 52, and the laminated components are in contact with positioning jigs 54, 56 to determine positions of the components. Then, the insulating substrate 12 is pressed downward by a pressing member 62 to restrict the positions of the components, and the components are separated from the positioning jigs 54, 56 and respective junction parts of the components are brazed. With this method, the failure in brazing can be prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor cooling device.

  For example, in a power module using an IGBT (Insulated Gate Bipolar Transistor) semiconductor, there is known a semiconductor cooling device that efficiently dissipates heat generated in the semiconductor and keeps the temperature of the semiconductor below a predetermined temperature.

  A schematic configuration of a conventional semiconductor cooling apparatus will be described with reference to FIG. The semiconductor cooling device 110 has a plurality of components. Specifically, an insulating substrate 112 having a front surface 112a on which a semiconductor (not shown) as a heating element is mounted, and a heat conductive member 114 having excellent thermal conductivity are provided on the back surface 112b of the insulating substrate 112. And a bottom plate 118 on which the cooler 116 is disposed. The insulating substrate 112, the heat conducting member 114, the cooler 116, and the bottom plate 118 are joined together by brazing.

  The cooler 116 includes an upper plate 116a that is thermally connected to the heat conducting member 114, and a lower plate 116b that forms a coolant flow path 120 between the upper plate 116a. The upper plate 116a and the lower plate 116b are caulked at an intermediate position of the side wall of the cooler 116, and the caulked portions are joined by brazing.

  Fins 122 are provided in the flow path 120 so as to connect the upper plate 116a and the lower plate 116b. By providing the fins 122, the contact area between the coolant flowing through the flow path 120 and the cooler 116 is increased, so that the heat dissipation performance is improved.

  In the semiconductor cooling device 110 configured as described above, the heat generated in the semiconductor can be efficiently radiated to the coolant flowing through the flow path 120 of the cooler 116 via the insulating substrate 112 and the heat conducting member 114. it can.

  Next, a method for manufacturing the semiconductor cooling device 110 will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing a schematic configuration of a temporary assembly jig 130 for temporarily assembling the semiconductor cooling device 110, and FIG. 6 shows a brazing jig 136 for brazing the temporarily assembled semiconductor cooling device 110. It is sectional drawing which shows schematic structure.

  The temporary assembling jig 130 includes a lower jig 132 and a temporary assembling support post 134 erected on the lower jig 132. The lower jig 132 is formed with a recess 132a into which the insulating substrate 112 and the heat conducting member 114 can be fitted. The semiconductor cooling device 110 is assembled by the temporary assembly jig 130 so that the top and bottom (up and down) are reversed. That is, the insulating substrate 112 and the heat conducting member 114 are sequentially stacked and disposed in the recess 132a. Then, the cooling unit 116 is disposed on the heat conducting member 114 so that the temporarily assembled support column 134 is passed through the through hole 124 formed in the cooling unit 116. At this time, since the surfaces of the heat conducting member 114 and the lower jig 132 coincide with each other, the cooler 116 is placed on the lower jig 132. Then, the bottom plate 118 is disposed on the cooling unit 116 so that the temporarily assembled support column 134 is passed through the through hole 126 formed in the bottom plate 118. By using such a jig, displacement of each component of the semiconductor cooling device 110 on a plane orthogonal to the stacking direction of the semiconductor cooling device 110 is restricted, and the position of each component is determined. Here, an adhesive is applied to the joint portion of each component of the semiconductor cooling device 110 before the temporary assembly. Therefore, the semiconductor cooling device 110 can be integrally taken out from the temporary assembly jig 130 by bonding the joint portions of the respective components with an adhesive.

  The brazing jig 136 includes a brazing jig main body 138, a lower jig 140 that forms the lower surface of the brazing jig main body 138, and an upper jig 142 that forms the upper surface of the brazing jig main body 138. A pressing member 144 is provided on the upper jig 142 via a spring 146. The brazing jig 136 configured as described above accommodates the semiconductor cooling device 110 temporarily assembled by the temporary assembly jig 130. At this time, the pressing member 144 is brought into contact with the insulating substrate 112. The pressing member 144 presses the insulating substrate 112 downward by the restoring force of the spring 146. Thereby, the junction part of each component of the semiconductor cooling device 110 can be reliably stuck. In this state, the semiconductor cooling device 110 is put into a furnace and the inside of the furnace is heated to a high temperature (for example, 650 ° C.), so that the joint portions of the respective components of the semiconductor cooling device 110 are joined by brazing.

  The following Patent Document 1 discloses an inverter having a ceramic substrate having a front surface on which a semiconductor chip is mounted, and a liquid-cooled heat sink provided on the back surface of the ceramic substrate via a metal substrate having good thermal conductivity. An apparatus is disclosed.

  Patent Document 2 below describes a heat sink manufacturing method in which fins are positioned and temporarily fixed in a state where fins are arranged on a plate substrate by a temporary fixing jig, and then the plate substrate and the fins are brazed. The method of joining by this is disclosed.

JP 2001-286156 A Japanese Patent Laid-Open No. 2001-129661

  In the conventional method of manufacturing the semiconductor cooling device 110, since two types of jigs, the temporary assembling jig 130 and the brazing jig 136, are used, there is a problem that the number of man-hours increases. Even if the semiconductor cooling device 110 is mounted in the temporary assembly jig 130 without using the brazing jig 136, the semiconductor cooling device 110 expands and deforms due to a high temperature. There is a problem that the temporarily assembled support post 134 cannot be removed from the cooler 116 and the bottom plate 118 later.

  Moreover, in the manufacturing method of the conventional semiconductor cooling device 110, an adhesive is applied to the joint portion of each component during temporary assembly. There is a problem that each component moves due to sublimation of the adhesive during brazing. Further, if a part of the adhesive remains without sublimating during brazing, there is a problem that the heat resistance increases and the heat dissipation performance of the semiconductor cooling device 110 is deteriorated.

  The objective of this invention is providing the manufacturing method of the semiconductor cooling device which can prevent generation | occurrence | production of the defect at the time of brazing using a simple jig | tool.

  The present invention provides an insulating substrate having a front surface on which a semiconductor, which is a heating element, is mounted, and a back surface of the insulating substrate via a heat conductive member having excellent heat conductivity, and dissipates heat of the semiconductor. In the manufacturing method of the semiconductor cooling device having the cooler to be placed and the bottom plate on which the cooler is disposed, the bottom plate, the cooler, the heat conducting member, and the insulating substrate are sequentially laminated on the base jig and stacked. A positioning step for determining the position of the component by bringing the component to be brought into contact with the positioning jig, and a position restraining step for restraining the position of the component by pressing the insulating substrate downward by the pressing member; And a brazing step of separating a positioning jig from the component and brazing each joint of the component.

  According to the method for manufacturing a semiconductor cooling device of the present invention, it is possible to prevent the occurrence of defects during brazing using a simple jig.

It is sectional drawing which shows schematic structure of the jig | tool of the manufacturing process which determines the position of the component of the semiconductor cooling device of this embodiment. It is sectional drawing which shows schematic structure of the jig | tool of the manufacturing process which restrains the position of the component of the semiconductor cooling device of this embodiment. It is sectional drawing which shows schematic structure of the jig | tool of the manufacturing process which brazes the semiconductor cooling device of this embodiment. It is sectional drawing which shows schematic structure of the conventional semiconductor cooling device. It is sectional drawing which shows schematic structure of the temporary assembly jig which performs temporary assembly of the conventional semiconductor cooling device. It is sectional drawing which shows schematic structure of the brazing jig | tool which brazes the conventional temporarily assembled semiconductor cooling device.

  Embodiments of a method for manufacturing a semiconductor cooling device according to the present invention will be described below with reference to the drawings. In the present embodiment, as an example, a power module that supplies electric power to a motor that drives an automobile will be described, and a method for manufacturing a semiconductor cooling device that cools the power module will be described.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a jig in a manufacturing process for determining the position of a component of the semiconductor cooling device 10, and FIG. 2 is a manufacturing process for restraining the position of the component of the semiconductor cooling device 10. FIG. 3 is a cross-sectional view showing a schematic configuration of the jig, and FIG. 3 is a cross-sectional view showing a schematic configuration of the jig in the manufacturing process for brazing the semiconductor cooling device 10.

  First, the configuration of the semiconductor cooling device 10 will be described. The semiconductor cooling device 10 includes an insulating substrate 12 on which a semiconductor (not shown) is mounted on the front surface, and a cooler provided on the back surface of the insulating substrate 12 via a heat conductive member 14 having excellent heat conductivity. 16 and a bottom plate 18 on which a cooler is arranged. The insulating substrate 12, the heat conducting member 14, the cooler 16, and the bottom plate 18 are joined together by brazing.

  A semiconductor mounted on the insulating substrate 12 is a switching element used for an inverter or a boost converter, and includes an IGBT, a power transistor, a thyristor, or the like. The switching element generates heat when driven.

  Although not shown in the drawing, the insulating substrate 12 is configured by laminating a first aluminum layer, a ceramic layer, and a second ceramic layer in order.

  An electrical circuit is formed on the first aluminum layer, and a semiconductor is electrically connected to the electrical circuit by soldering. The first aluminum layer is formed of aluminum having excellent conductivity, but may be formed of, for example, copper as long as the material has excellent conductivity. However, it is preferably formed of pure aluminum having high electrical conductivity, high deformability, and good soldering with a semiconductor. The ceramic layer is formed of a ceramic having high insulation performance, high thermal conductivity, and high mechanical strength. The ceramic is, for example, aluminum oxide or aluminum nitrogen. The heat conductive member 14 is joined to the second aluminum layer by brazing. The second aluminum layer is formed of aluminum having excellent thermal conductivity, but may be formed of, for example, copper as long as the material has excellent thermal conductivity. However, it is preferable to be formed of pure aluminum having a high thermal conductivity, a high deformability, and excellent wettability with a molten brazing material.

  The heat conductive member 14 is formed of aluminum having excellent heat conductivity, but may be formed of, for example, copper as long as the material has excellent heat conductivity. However, it is preferable to be formed of pure aluminum having a high thermal conductivity, a high deformability, and excellent wettability with a molten brazing material. The heat conducting member 14 can also have a stress absorbing space. The stress absorption space is a through hole that penetrates the heat conducting member 14 in the stacking direction, and stress can be absorbed by deformation of the through hole.

  The cooler 16 is made of aluminum which is excellent in thermal conductivity and lightweight. The cooler 16 and the bottom plate 18 are formed with through holes 24 and 26 through which a first positioning jig 54 to be described later can pass. The cooler 16 efficiently dissipates heat generated in the semiconductor mounted on the insulating substrate 12 to the coolant flowing through the flow path formed in the cooler 16 via the insulating substrate 12 and the heat conducting member 14. Can do.

  Next, the manufacturing method of the semiconductor cooling device 10 of this embodiment will be specifically described. First, the structure of the manufacturing jig 50 used for manufacturing the semiconductor cooling device 10 will be described with reference to FIGS.

  The manufacturing jig 50 includes a manufacturing jig main body 66, a base jig 52 that forms the lower surface of the manufacturing jig main body 66, and an upper jig 60 that forms the upper surface of the manufacturing jig main body 66.

  A plurality of first positioning jigs 54 are provided extending in the vertical direction so as to connect the upper jig 60 and the base jig 52. The first positioning jig 54 has a cylindrical shape. The first positioning jig 54 is detachably installed on the base jig 52 and supported by the upper jig 60 so as to be slidable in the vertical direction. A plate-like second positioning jig 56 is detachably supported by the first positioning jig 54. In the second positioning jig 56, a through hole 56a penetrating in the vertical direction is formed at a predetermined position. The through-hole 56a is formed so that the insulating substrate 12 and the heat conducting member 14 can be fitted therein.

  A pressing member 62 is provided on the lower surface of the upper jig 60 via a spring 64 that is an elastic member. The pressing member 62 can press the semiconductor cooling device 10 accommodated in the manufacturing jig 50 downward by the restoring force of the spring 64. The pressing member 62 is at the same position as the through hole 56a on the surface orthogonal to the vertical direction, and is formed smaller than the through hole 56a. In addition, in this embodiment, although the case where the spring 64 was connected to the press member 62 was demonstrated, it is not limited to this structure, If it is the structure which can urge | bias the press member 62 below, for example, Other elastic members and solenoids can also be employed.

  Next, a manufacturing process for determining the positions of the components of the semiconductor cooling device 10 will be described with reference to FIG. In this manufacturing process, the first positioning jig 54 is erected on the base jig 52. The bottom plate 18 is disposed on the base jig 52 so that the first positioning jig 54 is passed through the through hole 26 formed in the bottom plate 18. Then, the cooler 16 is disposed on the bottom plate 18 so that the first positioning jig 54 is passed through the through hole 24 formed in the cooler 16. The bottom plate 18 and the cooler 16 are restrained from being displaced in a plane perpendicular to the vertical direction by fitting the first positioning jig 54 into the through holes 24 and 26. That is, the positions of the bottom plate 18 and the cooler 16 are determined by the first positioning jig 54. Next, the second positioning jig 56 is attached to the first positioning jig 54 and disposed on the cooler 16. The heat conductive member 14 is disposed on the cooler 16 so that the heat conductive member 14 is fitted into the through hole 56 a formed in the second positioning jig 56. Then, the insulating substrate 12 is disposed on the heat conducting member 14 so that the insulating substrate 12 is fitted into the through hole 56a formed in the second positioning jig. When the heat conducting member 14 and the insulating substrate 12 are fitted into the through hole 56a of the second positioning jig 56, the positional deviation in the plane perpendicular to the vertical direction is restricted. That is, the positions of the heat conducting member 14 and the insulating substrate 12 are determined by the first positioning jig 56. This manufacturing process can be performed even when the base jig 52 is attached to the manufacturing jig main body 66.

  Next, a manufacturing process for restricting the positions of the components of the semiconductor cooling device 10 will be described with reference to FIG. The base jig 52 and the upper jig 60 are attached to the manufacturing jig main body 66. At this time, the first positioning jig 54 is slidably supported on the upper jig 60, and the pressing member 62 provided on the upper jig 60 is brought into contact with the insulating substrate 12. The pressing member 62 presses the insulating substrate 12 downward by the restoring force of the spring 64. Thereby, the position of the semiconductor cooling device 10 is restrained. Moreover, the junction part which each component of the semiconductor cooling device 10 contacts can be made to contact | adhere reliably.

  And the manufacturing process which brazes the semiconductor cooling device 10 is demonstrated using FIG. The upper jig 60 slides the first positioning jig 54 upward. Accordingly, the second positioning jig 56 supported by the first positioning jig 54 also moves upward. By this operation, the first positioning jig 54 that has passed through the through-hole 24 of the cooler 16 and the through-hole 26 of the bottom plate 18 is detached from these through-holes 24, 26, and the second positioning jig 56 passes therethrough. It leaves | separates from the insulated substrate 12 and the heat conductive member 14 which were fitted in the hole 56a. As a result, the restriction on the positional deviation of the semiconductor cooling device 10 in the plane perpendicular to the vertical direction by the first and second positioning jigs 54 and 56 is released. However, since the position of the semiconductor cooling device 10 is restrained by the pressing member 62, the position of the positioned semiconductor cooling device 10 does not shift. Thereafter, in this state, the semiconductor cooling device 10 is put into a furnace and the inside of the furnace is heated to a high temperature (for example, 650 ° C.), so that the joint portions of the respective components of the semiconductor cooling device 10 are joined by brazing.

  According to the manufacturing method of the semiconductor cooling device 10 of the present embodiment, one simple jig is used without using two kinds of jigs, a temporary assembling jig and a brazing jig, unlike the conventional manufacturing method. Since it is only used, man-hours can be reduced. Further, according to the method for manufacturing the semiconductor cooling device 10 of the present embodiment, the semiconductor cooling device 10 is not in contact with the jig for regulating displacement in the furnace, so that the semiconductor cooling device 10 expands and deforms at a high temperature. Can also prevent the occurrence of defects. Moreover, according to the manufacturing method of the semiconductor cooling device 10 of the present embodiment, since the adhesive is not applied to the joint portion of each component of the semiconductor cooling device 10 as in the conventional manufacturing method, at the time of brazing Each component does not move, and it is possible to prevent a decrease in the heat dissipation performance of the semiconductor cooling device 10 due to an increase in the thermal resistance of the joint.

  In the present embodiment, the case where the positions of the cooler 16 and the bottom plate 18 are determined by the first positioning jig 54 passing through the through hole 24 of the cooler 16 and the through hole 26 of the bottom plate 18 has been described. The configuration is not limited to this. For example, the first positioning jig 54 is a wall-like member, and the positions of the cooler 16 and the bottom plate 18 can be determined by contacting the cooler 16 and a part of the outer periphery of the bottom plate 18.

  10,110 Semiconductor cooling device, 12,112 Insulating substrate, 14,114 Heat conduction member, 16,116 Cooler, 18, 118 Bottom plate, 24, 26, 124, 126 Through hole, 50 Manufacturing jig, 52 Base jig 54 First positioning jig 56 Second positioning jig 60 Upper jig 62 Pressing member 64 Spring

Claims (1)

An insulating substrate having a front surface on which a semiconductor as a heating element is mounted;
A cooler for dissipating heat of the semiconductor, provided on the back surface of the insulating substrate via a heat conductive member having excellent heat conductivity;
A bottom plate on which a cooler is placed;
In the manufacturing method of the semiconductor cooling device having
Positioning that determines the position of the component by placing the base plate, the cooler, the heat conduction member, and the insulating substrate in order on the base jig and bringing the laminated component into contact with the positioning jig. Steps,
A position restraining step of restraining the position of the component by pressing the insulating substrate downward by a pressing member;
A brazing step of separating a positioning jig from the component and brazing each joint of the component;
A method for manufacturing a semiconductor cooling device, comprising:

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