JP2017174872A - Package for housing semiconductor element, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package for housing a semiconductor element, which can operate a semiconductor element normally and stably for a long time, and a semiconductor device.SOLUTION: A package 1 for housing a semiconductor element includes: a metal base body 2 on which a semiconductor element is mounted; a plurality of connection terminals 7 that electrically connects between the semiconductor element and an external circuit board; and a frame body 9. The frame body 9 includes a frame main body 10 formed of an insulator, a first metal layer 13 for bonding the base body 2 and the frame main body 10, and a second metal layer 14 for bonding the connection terminal 7 and the frame main body 10. An end face of the first metal layer 13 is positioned on the outer peripheral side of the frame main body 10 relative to the inner peripheral side of the frame main body 10. A first metal layer non-formation region 15 extends along the inner periphery of the frame main body 10. An end face of the second metal layer 14 is positioned on the outer peripheral side of the frame main body 10 relative to the inner peripheral side of the frame main body 10. A second metal layer non-formation region 16 extends along the inner periphery of the frame main body 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a package for housing a semiconductor element for housing a semiconductor element.

  In recent years, high integration and high density of semiconductor elements have rapidly advanced, and the amount of heat generated per unit volume and unit area during operation of the semiconductor elements has increased rapidly. In particular, semiconductor elements that control large power and large current, such as power devices, are required to have high heat dissipation properties, and are thus mounted and fixed on a metal substrate constituted by a heat dissipation substrate to specialize in heat dissipation performance. . In this case, a package for housing a semiconductor element for housing a semiconductor element includes a base and a frame including an insulator, which is erected and attached to the outer periphery of the base so as to surround the semiconductor element mounting portion. The body and the connection terminal for electrically conducting the semiconductor element and the external circuit board are basically configured. At this time, the bonding between the base body and the frame body and the connection terminal and the frame body are performed using a bonding material such as a brazing material via a metal layer. Then, the semiconductor element is mounted and fixed on the mounting portion on the base, the semiconductor element is stored in the semiconductor element storage package, and the electrodes of the semiconductor element and the connection terminals are electrically connected by bonding wires or the like. It becomes a semiconductor device as a product (see, for example, Patent Document 1).

JP-A-8-64714

  However, conventionally, when joining the base body and the frame body and the connection terminal and the frame body via the brazing material, the brazing material protruding from the joint portion sometimes flows into the inner peripheral portion of the frame body. In this case, there is a problem that an electrical short circuit occurs between the base made of metal and the connection terminal, and the semiconductor device cannot be operated normally. Further, when sufficient insulation is not achieved, there is a drawback that the semiconductor element housed in the package cannot be operated normally and stably over a long period of time. Therefore, the present invention has been completed in view of the above-mentioned conventional problems, and its purpose is to improve the insulation between the base and the connection terminal to prevent the occurrence of an electrical short circuit or the deterioration of the insulation performance, An object of the present invention is to provide a highly reliable semiconductor element storage package and a semiconductor device capable of operating a semiconductor element stored in a package normally and stably.

A package for housing a semiconductor element according to one aspect of the present invention includes a metal base having a placement portion on which a semiconductor element is placed on a first surface;
One or a plurality of connection terminals for electrically connecting the semiconductor element mounted on the mounting portion and the external circuit board;
A frame that is attached to an outer peripheral portion of the first surface of the base so as to surround the mounting portion and that is positioned between the base and the connection terminal to insulate the base and the connection terminal Body,
A frame body made of an insulator;
A first metal layer provided on the first surface of the frame body facing the base body of the frame body;
A frame having a second metal layer provided on the frame body second surface opposite to the frame body first surface of the frame body and joined to the connection terminals. ,
In the first metal layer, an end surface on the inner peripheral side of the frame main body is located on the outer peripheral side of the frame main body with respect to the end surface of the frame main body, A first metal layer non-formation region extending along the circumference is provided;
In the second metal layer, an end surface on the inner peripheral side of the frame body is located on an outer peripheral side of the frame body with respect to an end surface of the frame body, and the inner surface is on the second surface of the frame body. A second metal layer non-formation region extending along the circumference is provided.

  According to another aspect of the present invention, there is provided a semiconductor device including the above-described package for housing a semiconductor element, and a semiconductor element mounted on the mounting portion and electrically connected to the connection terminal. Features.

  According to the package for housing a semiconductor element of one aspect of the present invention, the first surface of the frame body is provided with the first metal layer non-forming region extending along the inner periphery, and the second surface of the frame body. A second metal layer non-formation region is provided extending along the inner periphery. By providing such a non-formation region, when connecting the first surface of the base body and the first frame body main surface using a bonding material such as a brazing material, and the connection terminal and the second frame body main surface. When the bonding material protruding from the bonding portion is accommodated in the first metal layer non-forming region, the bonding material can hardly flow into the inner peripheral portion of the frame body. In addition, it is possible to prevent the connection terminal from being short-circuited or the insulating performance from being deteriorated by the bonding material flowing into the inner peripheral portion of the frame body.

  As a result, it is possible to improve the reliability of the semiconductor element storage package. Thereby, the semiconductor element can be operated normally and stably over a long period of time.

  The semiconductor device of the present invention includes the above-described package for housing a semiconductor element of the present invention and a semiconductor element mounted on the mounting portion and electrically connected to the connection terminal. The semiconductor device housing package of the invention is highly reliable.

It is an external appearance perspective view which shows an example of a structure of the package 1 for semiconductor element accommodation of one Embodiment of this invention. 1 is an exploded perspective view showing an example of a configuration of a semiconductor element housing package 1 according to an embodiment of the present invention, and is an exploded perspective view in a case where a second metal layer 14 and an insulator layer 20 are the same layer. FIG. FIG. 3 is an exploded perspective view showing an example of the configuration of the semiconductor element housing package 1 according to the embodiment of the present invention, and is an exploded perspective view when the second metal layer 14 and the insulator layer 20 are separate layers. It is an external appearance perspective view which shows an example of the structure by the side of the frame main body 1st surface 11 of the frame 9 which the package 1 for semiconductor element accommodation of one Embodiment of this invention comprises. It is a figure including the top view and sectional view which show an example of the composition of semiconductor device storage package 1 of one embodiment of the present invention. It is sectional drawing which shows an example of a structure of the package 1 for semiconductor element accommodation of one Embodiment of this invention, and is sectional drawing to which the A section of FIG. 5 was expanded. It is sectional drawing which shows an example of a structure of the package 1 for semiconductor element accommodation of one Embodiment of this invention, and is sectional drawing to which the B section of FIG. 5 was expanded. It is sectional drawing which shows an example of a structure of the package 1 for semiconductor element accommodation of other embodiment of this invention, and is sectional drawing to which the part corresponded to the B section of FIG. 5 was expanded. It is an external appearance perspective view which shows an example of a structure of the semiconductor device 50 provided with the package 1 for semiconductor element accommodation of one Embodiment of this invention.

Hereinafter, a semiconductor element storage package 1 according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following drawings, the same components will be described using the same reference numerals. FIG. 1 is an external perspective view showing an example of the configuration of a semiconductor element storage package 1 according to an embodiment of the present invention. 2 and 3 are exploded perspective views showing an example of the configuration of the semiconductor element storage package 1 according to the embodiment of the present invention. 2 shows a case where the second metal layer 14 and the insulator layer 20 are the same layer, and FIG. 3 shows a case where the second metal layer 14 and the insulator layer 20 are separate layers. FIG. 4 is an external perspective view showing an example of the configuration of the frame body first surface 11 side of the frame body 9 included in the semiconductor element housing package 1 according to the embodiment of the present invention. FIG. 5 includes a plan view and a cross-sectional view showing an example of the configuration of the semiconductor element storage package 1 according to the embodiment of the present invention. 6 is an enlarged cross-sectional view of part A in FIG. 5, and FIG. 7 is an enlarged cross-sectional view of part B in FIG.

  The semiconductor element housing package 1 includes a base body 2, a frame body 9, and connection terminals 7 as a basic configuration for housing the semiconductor element 51. Examples of the semiconductor element 51 include an element using high power and large current, such as a SiC-based or GaN-based power device.

  The base 2 is constituted by a metal substrate which is a heat dissipation substrate for specializing in heat dissipation performance. That is, the base 2 is made of metal because high heat dissipation is required, and has a mounting portion 5 on which the semiconductor element 51 is mounted on the first surface 3 of the base. The base 2 is formed in a rectangular plate shape, for example. The mounting portion 5 is an area for bonding and fixing the semiconductor element 51 housed in the semiconductor element housing package 1 to the surface of the base 2 through an adhesive such as glass, resin, or brazing material. Further, in order to efficiently dissipate the heat of the semiconductor element 51 to the outside, the semiconductor element 51 is mounted and fixed on the mounting portion 5 in a state where it is mounted on a thermoelectric cooling element (not shown) such as a Peltier element. Also good.

  Specific examples of the metal substrate material include metals such as iron, copper, nickel, chromium, cobalt, molybdenum, and tungsten, or alloys or composites of these metals, such as copper-tungsten alloys and copper-molybdenum alloys. An iron-nickel-cobalt alloy or the like can be used. A metal substrate constituting the base 2 is manufactured by subjecting such a metal material ingot (lumb) to a conventionally known metal processing method such as a cutting method, a die processing method, a rolling method, or a punching method. be able to.

  The connection terminal 7 electrically connects the semiconductor element 51 mounted on the mounting unit 5 and an external circuit board (not shown). The connection terminal 7 is made of, for example, a metal material such as copper, iron, nickel, cobalt, chromium, tungsten, molybdenum and manganese, or an alloy or a composite material of these metals, and a plate material of the metal material is processed into a predetermined shape. Produced. The connection terminal 7 is joined to the second metal layer 14 provided on the surface layer of the insulator constituting the frame body 10 on the second face 12 of the frame body via a joining material such as a brazing material. An electrode of the semiconductor element 51 is electrically connected to one end of the connection terminal 7, and a wiring conductor of an external circuit board (not shown) is electrically connected to the other end of the connection terminal 7 through a conductive adhesive such as solder. Connected to. The connection between the semiconductor element 51 and the connection terminal 7 may be any connection as long as an electric signal can be transmitted, such as connection using a plurality of bonding wires, flip chip connection, connection using an anisotropic conductive film (ACF), or the like. Good.

The frame body 10 included in the frame body 9 is made of an insulator that is an electrically insulating material. The frame body 9 is erected and attached to the outer peripheral portion 6 of the base body first surface 3 so as to surround the mounting portion 5. The frame 9 only needs to surround the placement unit 5. The placement portion 5 may be in the central portion inside the frame body 9 or in other portions. The base body 2 may have substantially the same outer shape as the frame body 9, and the base body first surface 3 is larger than the frame body 9 and the base body 2 extends from the frame body 9 as in this embodiment. There may be a part to perform, and conversely, it may have a part from which the frame body 9 extends from the base 2. A ceramic material may be used as the frame body 10. Further, the frame body 10 may be made of a kind of material, but may have a structure in which a plurality of kinds of materials are laminated. Moreover, the frame main body 10 may be comprised by one insulating board | substrate, and the frame main body 10 may be comprised by laminating | stacking a several insulating board | substrate. Examples of the insulating substrate include an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, a ceramic material such as an aluminum nitride sintered body or a silicon nitride sintered body, or a glass ceramic. A material or a resin material can be used.

  An example of a method for manufacturing the frame body 10 will be described. A mixing member is prepared by mixing a raw material powder containing glass powder and ceramic powder of the above materials, an organic solvent, and a binder. For example, an appropriate organic binder, plasticizer, and solvent are added to and mixed with the raw material powder to produce a mixing member that is a slurry. The mixed member is formed into a sheet by employing, for example, a doctor blade method or a calendar roll method, and a plurality of ceramic green sheets (raw sheets) are produced. A laminated body is produced by laminating a plurality of produced ceramic green sheets, and the laminated body is fired at a temperature of about 1600 degrees to produce the frame body 10.

  The first metal layer 13 included in the frame body 9 is provided on the frame body first surface 11 facing the base body 2. The first metal layer 13 is provided on the outer peripheral portion 6 of the base body 2 to join the base body first surface 3 of the base body 2 and the frame body first surface 11. For this reason, the first metal layer 13 is provided around the first surface of the frame body. The second metal layer 14 included in the frame body 9 is provided on the frame body main body second surface 12 opposite to the frame body main body first surface 11. The second metal layer 14 is provided to join the connection terminal 7 and the frame body second surface 12.

  The first metal layer 13 and the second metal layer 14 are made of a refractory metal powder such as tungsten, molybdenum, or manganese. The first metal layer 13 and the second metal layer 14 are formed as follows. For example, a frame body first surface 11 and a frame body second surface 12 of a green sheet to be a frame body 10 made of a metal paste obtained by adding and mixing a suitable organic binder and solvent to a metal powder such as tungsten. In addition, a predetermined pattern is printed and applied in advance by a conventionally known screen printing method. Then, the first metal layer 13 and the second metal layer 14 are fired simultaneously with the ceramic green sheet at a temperature of about 1600 degrees, so that the frame body first surface 11 and the frame body second surface of the frame body 10 are formed. 12 are provided in a predetermined pattern. Note that a Ni plating layer is preferably deposited on the surfaces of the first metal layer 13 and the second metal layer 14.

  The first metal layer 13 functions as a base metal layer when the frame body first surface 11 is bonded to the base first surface 3. The second metal layer 14 functions as a base metal layer when the connection terminal 7 is joined to the frame body second surface 12. When the base body 2 or the connection terminal 7 is joined, it is brazed via a brazing material such as silver (Ag) -copper (Cu) brazing. Moreover, you may join via solder etc.

  The first metal layer end face 18 of the first metal layer 13 is positioned on the outer peripheral side of the frame body 10 with respect to the frame body end face 17 on the inner peripheral side of the frame body 10. Therefore, a first metal layer non-formation region 15 extending along the inner periphery of the frame body 10 is provided on the frame body first surface 11. In addition, in the inner peripheral part of the frame main body 10, the distance which the 1st metal layer end surface 18 is retracted to the outer peripheral side of the frame main body 10 rather than the frame main body end surface 17 is, for example, the inner periphery of the frame main body 10 and It is set to 2% or more and 20% or less of the width dimension between the outer periphery.

  Further, the second metal layer end surface 19 of the second metal layer 14 is located on the outer peripheral side of the frame main body 10 with respect to the frame main body end surface 17 on the inner peripheral side of the frame main body 10. Therefore, a second metal layer non-formation region 16 extending along the inner periphery of the frame body 10 is provided on the frame body second surface 12. In addition, in the inner peripheral part of the frame main body 10, the distance by which the 2nd metal layer end surface 19 is set back to the outer peripheral side of the frame main body 10 rather than the frame main body end surface 17 is the inner periphery of the frame main body 10, for example. It is set to 2% or more and 20% or less of the width dimension between the outer periphery.

  By providing such a non-formation region, when the base body first surface 3 and the frame body first surface 11 are bonded using a bonding material such as a brazing material, the connection terminal 7 and the frame body main body When the two surfaces 12 are bonded, the bonding material that protrudes from the bonding portion can be accommodated in the non-forming region. As a result, the bonding material can be prevented from flowing out from the inner peripheral portion of the frame body 10. As a result, the insulation of the connection terminal 7 is improved, and an electrical short circuit between the connection terminal 7 and the base 2 due to the bonding material or deterioration of the insulation performance can be prevented, and the reliability can be improved. It becomes possible.

  In the present embodiment, the first metal layer end face 18 and the second metal layer end face 19 recede from the frame body end face 17 to the outer periphery side of the frame body 10 at the inner periphery of the frame body 10. The distances are substantially the same, and the first metal layer end face 18 and the second metal layer end face 19 are in the same position so as to overlap each other in plan perspective. Stress is caused between the first metal layer end face 18 and the second metal layer end face 19 and the frame body 10 due to the difference in thermal expansion coefficient between the frame body 10 and the first metal layer 13 and the second metal layer 14. Arise. However, warpage generated in the frame body 10 due to this stress is reduced, and cracks and cracks generated in the vicinity of the inner peripheral portion of the frame body 10 can be suppressed.

  As shown in FIGS. 1 to 5, in the present embodiment, the semiconductor element housing package 1 includes four connection terminals 7. For this reason, on the second frame body main surface 12, the second metal layer 14 is divided into four regions separated from each other at positions corresponding to the four connection terminals 7. Then, each of the four connection terminals 7 is joined to each of the four regions of the second metal layer 14. The number of connection terminals 7 included in the semiconductor element storage package 1 may be 1 to 3, or 5 or more.

  The second metal layer 14 is made of the same metal material as the first metal layer 13 and is provided at least on each side of the frame body second surface 12 and has the same thickness as the first metal layer 13. Good. The frame body 10 having a different thermal expansion coefficient is sandwiched between the first metal layer 13 and the second metal layer 14 provided on each side of the frame body second surface 12 having the same thermal expansion coefficient and thickness. As a result, warpage and distortion generated in the frame body 9 can be suppressed.

  Furthermore, when the frame main body second surface 12 is viewed in plan, the insulator layer 20 is provided in a region other than the four regions of the second metal layer 14 in the region of the outer peripheral portion 6. Thereby, the thickness of the frame 9 in the portion where the second metal layer 14 is not provided can be prevented from being thinner than the thickness of the frame 9 in the portion where the second metal layer 14 is provided. As a result, in the frame body second surface 12, the frame body 9 is prevented from being warped or distorted due to thermal expansion or contraction of the second metal layer 14 provided by being divided into four regions separated from each other. be able to. As a result, when the frame body 9 is bonded to the base body 2 with a bonding material such as a brazing material via the first metal layer 13, the warpage of the frame body 9 is corrected by the base body 2. It can prevent that a crack arises. Note that the thickness t2 of the insulator layer 20 may be larger than the thickness t1 of the second metal layer 14, thereby further improving the mechanical strength of the frame body 9 and suppressing the warp of the frame body 9. Thus, cracks occurring in the frame body 9 can be prevented.

Further, the outer peripheral shape of the frame body 10 is substantially rectangular when viewed from above, and is an insulator over at least the corners of the rectangular frame body second surface 12 and the long side of the frame body 9 to the adjacent short side. A layer 20 is provided. As a result, the thickness of the corner frame 9 can be increased, and cracks can be prevented from occurring even in corners where external forces and stresses tend to concentrate. Moreover, the deformation | transformation and distortion of the frame 9 from the corner | angular part can be suppressed. Note that only the thickness of the insulating layer 20 at the corner portion may be particularly increased as compared with the thickness of the insulating layer 20 at the portion other than the corner portion. Furthermore, as shown in FIG. 7, the insulator layer 20 may be provided separately from each of the four regions of the second metal layer 14. In other words, a gap may be provided between the insulator layer end face 23 and the second metal layer 14. Thereby, even when the second metal layer 14 is thermally expanded at a high temperature, there is a gap between the second metal layer 14 and the insulator layer 20, so that the second metal layer 14 and the insulator layer 20 have a gap. It becomes possible to relieve the stress generated therebetween.

  Next, a semiconductor element storage package 1 according to another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view showing an example of the configuration of the semiconductor element housing package 1 according to another embodiment of the present invention, and is an enlarged cross-sectional view corresponding to a portion B in FIG. As shown in FIG. 8, the insulator layer 20 includes an insulator layer second surface 22 on the opposite side of the insulator layer first surface 21 facing the frame body 10, and insulation adjacent to the second metal layer 14. A curved portion 25 is provided at the ridge corner 24 with the body layer end face 23. The curved portion 25 may be an inclined surface. As a result, it is possible to alleviate stress concentration that occurs at the ridge corner 24 where stress is particularly likely to concentrate.

  FIG. 9 is a perspective view showing an example of the configuration of the semiconductor device 50 including the semiconductor element storage package 1 according to the embodiment of the present invention as an example. When assembling the semiconductor device 50, the semiconductor element 51 is mounted on the mounting portion 5 of the base 2 and is bonded and fixed to the base 2 via an adhesive or the like, and the semiconductor element 51 and the connection terminal 7 are connected via a bonding wire or the like. Connect them electrically. In this manner, the semiconductor device 50 as a product for storing the semiconductor element 51 using the semiconductor element storage package 1 including the base body 2, the frame body 9 and the connection terminal 7 is completed. It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Semiconductor device storage package 2 Base | substrate 3 Base | substrate 1st surface 5 Mounting part 6 Outer peripheral part 7 Connection terminal 9 Frame body 10 Frame body main body 11 Frame body main body 1st surface 12 Frame body main body 2nd surface 13 1st metal layer 14 Second metal layer 15 First metal layer non-formation region 16 Second metal layer non-formation region 17 End surface 18 of frame body First metal layer end surface 19 Second metal layer end surface 20 Insulator layer 21 Insulator layer first surface 22 Insulator layer second surface 23 Insulator layer end surface 24 Edge corner portion 25 Bending portion 50 Semiconductor device 51 Semiconductor element t1 Second metal layer thickness t2 Insulator layer thickness

Claims (10)

A metal base having a mounting portion on which the semiconductor element is mounted on the first surface;
One or a plurality of connection terminals for electrically connecting the semiconductor element mounted on the mounting portion and the external circuit board;
A frame that is attached to an outer peripheral portion of the first surface of the base so as to surround the mounting portion and that is positioned between the base and the connection terminal to insulate the base and the connection terminal Body,
A frame body made of an insulator;
A first metal layer provided on the first surface of the frame body facing the base body of the frame body;
A frame having a second metal layer provided on the frame body second surface opposite to the frame body first surface of the frame body and joined to the connection terminals. ,
In the first metal layer, an end surface on the inner peripheral side of the frame main body is located on the outer peripheral side of the frame main body with respect to the end surface of the frame main body, A first metal layer non-formation region extending along the circumference is provided;
In the second metal layer, an end surface on the inner peripheral side of the frame body is located on an outer peripheral side of the frame body with respect to an end surface of the frame body, and the inner surface is on the second surface of the frame body. A package for housing a semiconductor element, characterized in that a second metal layer non-formation region extending along the periphery is provided.   2. The semiconductor element housing according to claim 1, wherein an end surface of the second metal layer and an end surface of the first metal layer are in the same position in a plan view in the inner peripheral portion of the frame body. For package. A plurality of the connection terminals,
In the second surface of the frame body, the second metal layer is divided into a plurality of regions that are spaced apart from each other, corresponding to each of the plurality of connection terminals,
3. The semiconductor according to claim 1, wherein each of the plurality of connection terminals is joined to the second surface of the frame body by each of the plurality of regions of the second metal layer. Package for element storage.   4. The package for housing a semiconductor element according to claim 3, wherein an insulator layer is provided in a region other than the plurality of regions of the second metal layer on the second surface of the frame body. 5.   5. The package for housing a semiconductor element according to claim 4, wherein the outer peripheral shape of the frame body is substantially rectangular when viewed from above, and the insulator layer is provided at corners of the rectangle.   6. The package for housing a semiconductor element according to claim 4, wherein the insulator layer is provided apart from each of the plurality of regions of the second metal layer.   The insulating layer is provided with an inclined portion or a curved portion at a ridge angle portion between a surface opposite to a surface facing the frame body and a surface close to the second metal layer. The package for housing a semiconductor device according to any one of claims 4 to 6.   8. The package for housing a semiconductor element according to claim 4, wherein a thickness of the insulator layer is the same as a thickness of the second metal layer. 9.   8. The package for housing a semiconductor element according to claim 4, wherein a thickness of the insulator layer is larger than a thickness of the second metal layer. 9. A package for housing a semiconductor element according to any one of claims 1 to 9, and a semiconductor element mounted on the mounting portion and electrically connected to the connection terminal. A featured semiconductor device.

Images