JP6549502B2 - Heat dissipation substrate, semiconductor package and semiconductor module using the same - Google Patents

Description

  The present invention relates to a heat dissipation substrate for dissipating heat generated from semiconductor elements such as power semiconductor elements, and a semiconductor package and a semiconductor module using the heat dissipation substrate.

  As described in Patent Document 1, the heat dissipation substrate for radiating the heat generated from the semiconductor chip for power supply alternates between a high thermal conductive layer of copper or copper alloy and a low thermal expansion layer of Fe-Ni based alloy. A high thermal conductivity layer which is formed by laminating a plurality of layers and sandwiches the low thermal expansion layer is continuous through a plurality of through holes formed in the low thermal expansion layer.

Japanese Patent Application Laid-Open No. 10-173109

  In the conventional heat dissipating substrate, due to the difference in thermal expansion coefficient between copper or copper alloy and the Fe-Ni alloy, the heat dissipating substrate may be warped, and the heat dissipation to the outside tends to be deteriorated. .

The heat dissipation substrate of the embodiment of the present invention is
A first metal layer,
A second metal layer joined to the first surface of the first metal layer, wherein the second metal layer is provided with a plurality of first through holes penetrating in the thickness direction;
A third metal layer joined to the second surface opposite to the first surface of the first metal layer, wherein the third metal layer is provided with a plurality of second through holes penetrating in the thickness direction. ,
A fourth metal layer joined to the surface of the second metal layer opposite to the surface joined to the first surface of the first metal layer;
A fifth metal layer joined to the surface of the third metal layer opposite to the surface joined to the second surface of the first metal layer;
The plurality of first through holes and the metal member filled in the plurality of second through holes;
The first metal layer, the fourth metal layer, and the fifth metal layer have a Young's modulus smaller than that of the second metal layer and the third metal layer,
It is characterized in that in plan view, the centers of the plurality of first through holes and the centers of the plurality of second through holes are deviated.

In the semiconductor package according to the embodiment of the present invention, the heat dissipation substrate described above,
A frame made of an insulator fixed to the fourth metal layer of the heat dissipation substrate;
And a power supply terminal attached to the frame.

Further, a semiconductor device according to an embodiment of the present invention includes the above semiconductor package,
And a semiconductor element mounted on the semiconductor package.

According to the heat dissipation board of the embodiment of the present invention, when the heat dissipation board is heated by the heat generated from the semiconductor element, the warpage of the heat dissipation board can be suppressed.

  Further, according to the semiconductor package of the embodiment of the present invention, by providing the above-described heat dissipation substrate, it is possible to suppress a decrease in heat dissipation due to the warpage of the heat dissipation substrate.

  Further, according to the semiconductor device of the embodiment of the present invention, the heat generated from the semiconductor element can be favorably dissipated by providing the above-described semiconductor package, and high reliability can be realized.

It is a perspective view of the heat sink board concerning an embodiment of the present invention. (A) is sectional drawing of the thermal radiation board | substrate in the AA of FIG. 1, (b) is a partial expanded-section perspective view of (a). It is a disassembled perspective view of the thermal radiation board | substrate which concerns on embodiment of this invention. It is a top view which shows one aspect of each metal layer which comprises a thermal radiation board | substrate. It is a top view which shows the other aspect of each metal layer which comprises a thermal radiation board | substrate. 1 is a perspective view showing a semiconductor package according to an embodiment of the present invention. 1 is a perspective view showing a semiconductor device according to an embodiment of the present invention.

  The heat dissipating substrate, the semiconductor package, and the semiconductor device according to the embodiment of the present invention will be described in detail below.

  FIG. 1 is a perspective view of a heat dissipation board according to an embodiment of the present invention. Fig.2 (a) is sectional drawing of the thermal radiation board | substrate in the AA of FIG. 1, FIG.2 (b) is the partial expanded cross-section perspective view of Fig.2 (a). FIG. 3 is an exploded perspective view of the heat dissipation board according to the embodiment of the present invention. FIG. 4 is a plan view of each metal layer constituting the heat dissipation substrate according to the embodiment of the present invention. FIG. 5 is a plan view of metal layers constituting a heat dissipation substrate according to another embodiment of the present invention. FIG. 6 is a perspective view showing a semiconductor package according to an embodiment of the present invention. FIG. 7 is a perspective view showing a semiconductor device according to an embodiment of the present invention.

  The heat dissipation substrate 100 includes a first metal layer 1, a second metal layer 2, a third metal layer 3, a fourth metal layer 4, a fifth metal layer 5, and a metal member 6.

  The first metal layer 1 has a first surface 1a and a second surface 1b opposite to the first surface. The second metal layer 2 is bonded to the first surface 1a, and the third metal layer 3 is bonded to the second surface 1b. Furthermore, the fourth metal layer 4 is bonded to the surface of the second metal layer 2 opposite to the surface bonded to the first surface 1 a of the first metal layer 1. Further, the fifth metal layer 5 is bonded to the surface of the third metal layer 3 opposite to the surface bonded to the second surface 1 b of the first metal layer 1. That is, as shown in FIG. 3, the heat dissipation substrate 100 according to the embodiment of the present invention includes the fifth metal layer 5, the third metal layer 3, the first metal layer 1, the second metal layer 2, and the fourth metal layer 4. Have a configuration sequentially stacked.

  Further, the Young's modulus of the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 is smaller than the Young's modulus of the second metal layer 2 and the third metal layer 3. The first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 may have a Young's modulus smaller than the Young's modulus of the second metal layer 2 and the third metal layer 3, and the first metal The layer 1, the fourth metal layer 4 and the fifth metal layer 5 may have the same Young's modulus or may have different Young's modulus. The second metal layer 2 and the third metal layer 3 may have a Young's modulus larger than that of the first metal layer 1, the fourth metal layer 4 and the fifth metal layer 5, and the second metal The layer 2 and the third metal layer 3 may have the same Young's modulus or may have different Young's modulus.

  Furthermore, the thermal conductivity of the first metal layer 1, the fourth metal layer 4, the fifth metal layer 5, and the metal member 6 is higher than the thermal conductivity of the second metal layer 2 and the third metal layer 3. Are used. The thermal expansion coefficients of the first metal layer 1, the fourth metal layer 4, the fifth metal layer 5, and the metal member 6 are larger than the thermal expansion coefficients of the second metal layer 2 and the third metal layer 3.

  Examples of the first metal layer 1, the fourth metal layer 4, the fifth metal layer 5, and the metal member 6 include, for example, metal materials such as copper, silver, aluminum (Al), gold (Au) or the like, or What was formed from an alloy is mentioned. In the present embodiment, the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 are made of copper or an alloy containing copper.

  The second metal layer 2 and the third metal layer 3 are formed of a metal material such as molybdenum (Mo) or tungsten (W), or an alloy thereof (copper-molybdenum sintered body, copper-tungsten sintered body, etc.) It may be done. In the present embodiment, the second metal layer 2 and the third metal layer 3 are made of molybdenum or an alloy containing molybdenum.

  The first metal layer 1, the fourth metal layer 4 and the fifth metal layer 5 may have the same thickness or different thicknesses. Moreover, the 2nd metal layer 2 and the 3rd metal layer 3 may have the same thickness, and may have different thickness. The first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 have the same thickness of the same material, and the second metal layer 2 and the third metal layer 3 have the same thickness of the same material. It is more preferable to do. Thus, warpage or deformation of the heat dissipation substrate 100 that occurs when heat is applied to the heat dissipation substrate 100 is suppressed.

  In the heat dissipation substrate 100 according to the embodiment of the present invention, the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 have a thickness larger than the thicknesses of the second metal layer 2 and the third metal layer 3. And have the same outer shape in plan view. For example, in a plan view, the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 have a long side of 5 mm to 30 mm and a short side of 4 mm to 28 mm. Moreover, thickness is 0.2 mm-2 mm. The second metal layer 2 and the third metal layer 3 have a long side of 5 mm to 30 mm and a short side of 4 mm to 28 mm in plan view. Moreover, thickness is 0.1 mm-1 mm. More specifically, for example, the thickness of the first metal layer 1 is 0.2 mm, the thickness of the fourth metal layer 4 and the fifth metal layer 5 is 0.3 mm, and the thickness of the second metal layer 2 and the third metal layer 3 Should be 0.1 mm.

  As shown in FIG. 2 (b) and FIG. 3, the second metal layer 2 is provided with a plurality of first through holes 2 a penetrating the second metal layer 2 in the thickness direction, and the third metal layer 3 is provided. A plurality of second through holes 3a which penetrate the third metal layer 3 in the thickness direction are provided.

  The first through hole 2a and the second through hole 3a may have, for example, a circular shape, an elliptical shape, an oval shape, a square shape, a rectangular shape, or any other shape. In the heat dissipation substrate 100 according to the embodiment of the present invention, the openings of the first through holes 2a and the second through holes 3a have a circular shape, an elliptical shape, or an oval shape. By forming the first through holes 2a and the second through holes 3a in a circular shape, the stresses generated in the first through holes 2a and the second through holes 3a by the heat applied to the heat dissipation substrate 100 become symmetrical with respect to the central axis, It will be difficult to bias in part.

  The plurality of first through holes 2a may have the same area as each other in plan view, or may have different areas from each other. The plurality of second through holes 3a may also have the same area as each other in plan view, or may have different areas from each other. Assuming that the areas of the plurality of first through holes 2a and the plurality of second through holes 3a are equal to each other in plan view, the heat applied to the heat dissipation substrate 100 causes the first through holes 2a and the second through holes 3a respectively. It is easy for the stress generated in the

  The first through hole 2a has, for example, a circular shape having a diameter of 0.5 mm to 2 mm, or an elliptical shape having a major diameter of 0.5 mm to 2 mm and a minor diameter of 0.4 mm to 1.8 mm, in plan view. The length in the direction is 0.5 mm to 2 mm, and the length in the minor axis direction is an oval of 0.4 mm to 1.8 mm.

  When the opening shape of the first through hole 2a or the second through hole 3a is an elliptical shape or an oval shape, the long side direction of the heat dissipation substrate 100 and the long diameter direction of the first through hole 2a or the second through hole 3a It is preferable to arrange so that and are parallel. In the long side direction, the second metal layer 2 and the third metal layer 3 between the first through hole 2a or the second through hole 3a and the first through hole 2a or the second through hole 3a adjacent thereto are continuous. Will be placed. That is, while the first through hole 2a or the second through hole 3a is continuous without crossing the first through hole 2a or the second through hole 3a in the long side direction, the first through hole 2a or the second through hole 3a is in the short side direction. There are many cases where you cross. For this reason, bending stress in the long side direction becomes strong, and warpage and deformation in the long side direction are suppressed.

  Further, as shown in FIG. 2B and FIG. 3, the metal members 6 are filled in the first through holes 2a and the second through holes 3a. The metal member 6 is preferably made of, for example, a metal excellent in thermal conductivity, such as copper, silver, aluminum (Al), gold (Au), or an alloy thereof.

  The metal member 6 may be formed of the same material as any of the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5, and the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 4 may be formed. It may be formed of a material different from that of the metal layer 5. Moreover, the metal member with which the 1st through-hole 2a is filled, and the metal member with which the 2nd through-hole 3a is filled may be formed from the same material, and may be formed from a different material. In the present embodiment, the metal member filled in the first through hole 2 a and the metal member filled in the second through hole 3 a are the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5. And copper, or an alloy containing copper.

  Further, in the heat dissipation substrate 100 according to the present embodiment, as shown in FIGS. 4 and 5, the plurality of first through holes 2a and the plurality of second through holes 3a are the plurality of first through holes 2a in plan view. It arrange | positions so that each center of gravity and each center of gravity of several 2nd through-holes 3a may shift | deviate. The image center means the position of the center of gravity of the inner flat surface of the first through hole 2a and the second through hole 3a. Hereinafter, the descriptions of the positions of the first through holes 2a and the second through holes 3a are based on the centroid unless otherwise specified.

  Assuming that the centroids of the first through holes 2a and the second through holes 3a coincide with each other, from one surface to the other surface of the heat dissipation substrate 100 in which the first through holes 2a and the second through holes 3a exist. In the cross section, there is a portion where the second metal layer 2 or the third metal layer 3 is not present. According to the heat dissipation substrate 100 according to the embodiment of the present invention, at least the second metal layer 2 or the third metal layer 3 is disposed in a cross section from one surface to the other surface of the heat dissipation substrate 100. be able to. Accordingly, the warpage and deformation of the heat dissipation substrate 100 can be reduced.

  The heat dissipation substrate 100 is used in a state where the surface of the fifth metal layer 5 opposite to the surface bonded to the third metal layer 3 is in contact with an external heat dissipation body such as an external substrate (not shown). Therefore, when the heat dissipation substrate 100 is warped, the contact area between the heat dissipation substrate 100 and the external substrate is reduced, and the heat dissipation performance is reduced. According to the heat dissipation substrate 100 according to the embodiment of the present invention, the warpage of the heat dissipation substrate 100 can be reduced, and a decrease in heat dissipation can be suppressed. In addition, it is preferable to make the space | interval of 1st adjacent through-hole 2a, and the space | interval of adjacent 2nd through-hole 3a the same. Moreover, it is preferable to arrange the second through hole 3a at the center of the first through holes 2a adjacent to each other in plan view. The heat applied to the heat dissipation substrate 100 can prevent deformation due to stress generated around the first through holes 2 a and the second through holes 3 a from locally increasing.

  The heat dissipation substrate 100 is used, for example, as a semiconductor package 200, with the surface of the fifth metal layer 5 opposite to the surface bonded to the third metal layer 3 in contact with an external substrate (not shown). Therefore, when the heat dissipation substrate 100 is warped or deformed, the contact area between the heat dissipation substrate 100 and the external substrate is reduced, and the heat dissipation of the semiconductor package 200 through the heat dissipation substrate 100 is reduced. According to the heat dissipation substrate 100 according to the embodiment of the present invention, warpage and deformation of the heat dissipation substrate 100 can be reduced, and a decrease in heat dissipation can be suppressed.

  Further, in the heat dissipation substrate 100, the second metal layer 2 and the third metal layer 3 have a Young's modulus larger than that of the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5. The second metal layer 2 is sandwiched between the first metal layer 1 and the fourth metal layer 4, and the third metal layer 3 is sandwiched between the first metal layer 1 and the fifth metal layer 5. Have the following configuration. According to such a configuration, it is possible to effectively suppress the decrease in the rigidity of the heat dissipation substrate 100 and to improve the flatness of the surface of the heat dissipation substrate 100.

  In addition, the second metal layer 2 and the third metal layer 3 having a small thermal expansion coefficient are provided between the first metal layer 1 and the fourth metal layer 4 and between the first metal layer 1 and the fifth metal layer 5 respectively. Since the first metal layer 1, the fourth metal layer 4 and the fifth metal layer 5 are held between the second metal layer 2 and the third metal layer 3, thermal expansion is suppressed. This facilitates the mounting of the semiconductor element 9 having a small thermal expansion coefficient.

  Moreover, it is preferable that the plurality of first through holes 2a and the plurality of second through holes 3a be disposed in a rectangular lattice shape or an orthorhombic lattice shape in a plan view. An example in which the first through holes 2a and the second through holes 3a are arranged in an oblique lattice is shown in FIGS. 4 and 5. FIG. According to such a configuration, the heat radiation path via the second metal layer 2 is dispersedly provided in the second metal layer 2 and the heat radiation path via the third metal layer 3 is dispersedly provided in the third metal layer 3 Therefore, the bias of the heat distribution in the heat dissipation substrate 100 can be reduced, whereby the warpage of the heat dissipation substrate 100 can be effectively suppressed.

  When the first through holes 2a and the second through holes 3a are arranged in an oblique lattice, warpage or bending in the long side direction or the short side direction of the heat dissipation substrate 100 can be prevented.

  The plurality of first through holes 2a and the plurality of second through holes 3a may be disposed so as not to overlap each other in plan view. That is, the plurality of first through holes 2a and the plurality of second through holes 3a may be disposed so that there is no overlapping portion in plan view. According to such a configuration, the warpage of the heat dissipation substrate 100 can be further effectively reduced.

  Each of the plurality of first through holes 2a may be disposed so as to overlap at least one of the plurality of second through holes 3a when viewed in plan. That is, each of the plurality of first through holes 2a may be disposed so as to partially overlap at least one of the plurality of second through holes 3a. According to such a configuration, it is possible to reduce the deviation of the heat distribution in the heat dissipation substrate 100 and to enable efficient heat conduction in the thickness direction of the heat dissipation substrate 100 via the metal member 6.

  Further, in plan view, the areas of the plurality of first through holes 2a are equal to each other, the areas of the plurality of second through holes 3a are equal to each other, and the area of the second through holes 3a is more than the area of the first through holes 2a. You may make it large. Thereby, the thermal conductivity in the direction from the fourth metal layer 4 to the fifth metal layer 5 of the heat dissipation substrate 100 can be improved.

  The heat dissipation substrate 100 according to the embodiment of the present invention is manufactured as follows.

  First, the first metal layer 1, the fourth metal layer 4 and the fifth metal layer 5 made of copper or an alloy containing copper are prepared by punching and cutting using a mold, and the mold is prepared. A second metal layer 2 in which a plurality of first through holes 2a made of molybdenum or an alloy containing molybdenum is formed by performing punching and cutting as used, and a plurality of second through holes 3a are formed 3 Prepare the metal layer 3

  Next, the first metal layer 1, the second metal layer 2, the third metal layer 3, the fourth metal layer 4, and the fifth metal layer 5 are stacked in a predetermined order, and then subjected to a rolling pressure bonding process. A heat dissipation substrate 100 is obtained in which the metal members 6 constituting the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 are filled in the first through holes 2a and the second through holes 3a.

  The heat dissipation substrate 100 according to the embodiment of the present invention may be manufactured as follows. First, as described above, the first metal layer 1, the fourth metal layer 4, and the fifth metal layer 5 are prepared. Furthermore, the second metal layer 2 in which the first through hole 2a is filled in advance with the metal member 6 and the third metal layer 3 in which the second through hole 3a is filled in advance with the metal member 6 are prepared. Then, between the first metal layer 1 and the second metal layer 2, between the first metal layer 1 and the third metal layer 3, between the second metal layer 2 and the fourth metal layer 4, and the third Between the metal layer 3 and the fifth metal layer 5, a preform of a brazing material such as a silver-copper solder is sandwiched. In this state, the heat dissipation substrate 100 is put into a high temperature furnace (for example, about 800 ° C. in the case of using silver-copper solder) to melt the preform of the brazing material and then taken out from the high temperature furnace and cooled. can get.

  The semiconductor package 200 according to the embodiment of the present invention includes the heat dissipation substrate 100 having the above configuration, the frame 7 made of an insulator, and the power supply terminal 8, and the fourth metal layer 4 of the heat dissipation substrate 100. Then, the frame 7 made of an insulator is attached, and the power supply terminal 8 is attached to the frame 7.

The frame 7 may be made of any insulating material, and may be made of, for example, a resin or ceramic. In the semiconductor package 200 according to an embodiment of the present invention, the frame body 7, for example, made of _Al 2 _{O 3} quality ceramic, AlN _ceramics, 3Al ₂ O 3 · 2SiO insulator such ₂ quality ceramics.

  According to the semiconductor package 200, by including the heat dissipation substrate 100, it is possible to suppress a decrease in the heat dissipation to the external heat dissipation member due to the warpage or deformation of the heat dissipation substrate 100. Moreover, since the warpage of the heat dissipation substrate 100 is small, it is possible to reduce the possibility of the frame 7 attached to the heat dissipation substrate 100 peeling off or causing a crack due to bending stress. The semiconductor package 200 is particularly suitable for use in mounting the semiconductor element 9 for high power applications and other high heat generating electronic components.

The semiconductor device 300 according to the embodiment of the present invention is configured to include the semiconductor package 200 and the semiconductor element 9 configured as described above, mounts the semiconductor element 9 on the semiconductor package 200, and the power supply terminal 8 and the semiconductor element 9. Are electrically connected by a bonding wire 10. The semiconductor element 9 is mounted on the area of the fourth metal layer 4 inside the frame 7.
Thereafter, the semiconductor element 9 is sealed with potting resin, or a lid is attached to the upper surface of the frame 7 to seal and protect the semiconductor element 9, and the semiconductor device 300 is completed.

  According to the semiconductor device 300, by including the semiconductor package 200, warpage and deformation of the heat dissipation substrate 100 can be suppressed, heat generated from the semiconductor element 9 can be properly dissipated, and the sealing performance is excellent. Thus, a semiconductor device with improved reliability can be provided.

DESCRIPTION OF SYMBOLS 1 1st metal layer 1a 1st surface 1b 2nd surface 2 2nd metal layer 2a 1st through-hole 3 3rd metal layer 3a 2nd through-hole 4 4th metal layer 5 5th metal layer 6 metal member 7 frame 8 Power supply terminal 9 semiconductor element 10 bonding wire 100 heat dissipation substrate 200 semiconductor package 300 semiconductor device

Claims (10)

A first metal layer,
A second metal layer joined to the first surface of the first metal layer, wherein the second metal layer is provided with a plurality of first through holes penetrating in the thickness direction;
A third metal layer joined to the second surface opposite to the first surface of the first metal layer, wherein the third metal layer is provided with a plurality of second through holes penetrating in the thickness direction. ,
A fourth metal layer joined to the surface of the second metal layer opposite to the surface joined to the first surface of the first metal layer;
A fifth metal layer joined to the surface of the third metal layer opposite to the surface joined to the second surface of the first metal layer;
The plurality of first through holes and the metal member filled in the plurality of second through holes;
The first metal layer, the fourth metal layer, and the fifth metal layer have a Young's modulus smaller than that of the second metal layer and the third metal layer,
A heat dissipation board characterized in that the respective centers of the plurality of first through holes and the respective centers of the plurality of second through holes are deviated in plan view.   The first metal layer, the fourth metal layer, the fifth metal layer, and the metal member are made of copper or an alloy containing copper, and the second metal layer and the third metal layer are made of molybdenum or molybdenum. The heat dissipation substrate according to claim 1, wherein the heat dissipation substrate is made of an alloy containing   The first metal layer, the fourth metal layer, and the fifth metal layer have a thickness larger than the thicknesses of the second metal layer and the third metal layer. The heat dissipation board as described in.   4. The flat display device according to claim 1, wherein the plurality of first through holes and the plurality of second through holes are arranged in a rectangular lattice shape or an oblique lattice shape. The heat dissipation board described in the item.   The heat dissipation substrate according to any one of claims 1 to 4, wherein the plurality of first through holes and the plurality of second through holes do not overlap in a plan view.   5. The device according to claim 1, wherein each of the plurality of first through holes overlaps at least one of the plurality of second through holes in a plan view. Heat dissipation board as described.   In plan view, the areas of the plurality of first through holes are equal to one another, the areas of the plurality of second through holes are equal to one another, and the areas of the plurality of second through holes are of the plurality of first through holes. The heat dissipation substrate according to any one of claims 1 to 6, which is larger than the area.   Each of the plurality of first through holes and the plurality of second through holes have an oval shape or an oval shape in a plan view. The heat dissipation board as described in. The heat dissipation substrate according to any one of claims 1 to 8.
A frame made of an insulator fixed to the fourth metal layer of the heat dissipation substrate;
A power supply terminal attached to the frame;
Semiconductor package. A semiconductor package according to claim 9;
A semiconductor element mounted on the semiconductor package;
Semiconductor devices.

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