Manufacturing method for semiconductor device, and semiconductor device

Abstract

Provided is a manufacturing method for a semiconductor device including: a semiconductor element having an upper surface electrode on one surface and a lower surface electrode on another surface; a first conductor electrically connected to the upper surface electrode; a second conductor electrically connected to the lower surface electrode; and a third conductor electrically connected to the first conductor. The method comprises: forming a sealing body by sealing the first conductor with a sealing member so that a first connection surface of the first conductor connected to the upper surface electrode and a second connection surface of the first conductor connected to the third conductor are exposed at the same surface; supplying a bonding material to the first connection surface and the second connection surface; and sintering the supplied bonding material to bond the first conductor to the upper surface electrode of the semiconductor element and to the third conductor.

Description

Semiconductor device manufacturing method, semiconductor device

[0001] The present invention relates to a method for manufacturing a semiconductor device and a semiconductor device.

[0002] There are further demands for higher heat resistance and heat dissipation in double-sided cooling structures in semiconductor devices. To meet these demands, there is a method of replacing solder bonding with sintering, which has higher thermal conductivity than solder bonding, during the manufacturing process of semiconductor devices. As an example of bonding between components in a semiconductor device, Patent Document 1 listed below discloses a structure in which a bonding material is supplied to the top surface of a semiconductor chip.

[0003] Japanese Patent Application Laid-Open No. 2018-6492

[0004] In the configuration described in Patent Document 1, there is a difference in height between the joining surfaces, which makes it difficult to supply the sintering material, and therefore there is a problem that sintering joining cannot be applied.

[0005] A method for manufacturing a semiconductor device including a semiconductor element having an upper electrode on one side and a lower electrode on the other side, a first conductor electrically connected to the upper electrode, a second conductor electrically connected to the lower electrode, and a third conductor electrically connected to the first conductor, the method comprising: sealing the first conductor with a sealing member to form a sealing body so that a first connection surface of the first conductor connected to the upper electrode and a second connection surface of the first conductor connected to the third conductor are exposed on the same side; supplying a bonding material to the first connection surface and the second connection surface; and sintering the supplied bonding material to bond the first conductor to the upper electrode of the semiconductor element and the third conductor.

[0006] It is possible to provide a semiconductor device and a manufacturing method thereof that realizes high heat resistance, high heat dissipation, and improved productivity.

[0007] 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention; 2 is a cross-sectional view showing a configuration of a first sealing body according to an embodiment of the present invention; 3 is a step of supplying a bonding material to the first sealing body according to an embodiment of the present invention; 4 is a step of drying the applied bonding material according to an embodiment of the present invention; 5 is a manufacturing process of a semiconductor device according to an embodiment of the present invention;

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (FIG. 1) A semiconductor device 1 manufactured by the manufacturing method of the present invention has a double-sided cooling structure to improve heat dissipation. The semiconductor device 1 has a first sealing body 100, a semiconductor element 310, a second conductor 320, and a third conductor 325. In the semiconductor device 1, the first sealing body 100, the semiconductor element 310, the second conductor 320, and the third conductor 325 are sealed with a second sealing member 450, which is an insulating resin member.

[0011] The first sealing body 100 seals the control conductor 110 and the first conductor 120, which are upper leads of the semiconductor element 310, with a sealing member 130, which is an insulating resin member. The sealing member 130 is, for example, an epoxy resin. The first bonding material 400 is a sintering material used for sintering bonding, and is adhered to the connection surfaces of the control conductor 110 and the first conductor 120, respectively.

[0012] The second bonding material 410 is adhered onto the connection surfaces of the second conductor 320 and the third conductor 325, which are lower leads. A portion of the first bonding material 400 and the second bonding material 410 is bonded to the semiconductor element 310, and the other portions of the first bonding material 400 and the second bonding material 410 are directly bonded to each other.

[0013] As shown in the figure, the first bonding material 400 has a flared shape in which the cross-sectional area increases toward the first sealing body 100. Similarly, the second bonding material 410 has a flared shape in which the cross-sectional area increases toward the second conductor 320 and the third conductor 325. This can improve the thermal diffusion of the semiconductor element 310.

[0014] (FIG. 2) The first sealing body 100 has a first surface 140 on one side and a second surface 145 on the other side. The first surface 140 and the second surface 145 are parallel to each other, which allows for the supply of bonding material and sinter bonding in one go, as described below, and contributes to improved productivity. The second surface 145 is the surface that connects to the cooling structure of the semiconductor device 1 (not shown).

[0015] The control conductor 110 is a circuit that replaces conventional wire bonding. The control conductor 110 and the first conductor 120 are sealed with the sealing member 130 to form the first sealing body 100, which eliminates the need for a wire bonding process in the manufacturing process.

[0016] The first connection surface 110a and the first connection surface 120a are surfaces that are bonded to an upper surface electrode provided on one surface of the semiconductor element 310 (FIG. 1). The second connection surface 120b is a surface that is bonded to a third conductor 325 (FIG. 1), which is a lower lead.

[0017] The two connection surfaces 110a of the control conductor 110 are arranged so as to be exposed on the same smooth surface as at least one of the first connection surface 120a and the second connection surface 120b. By forming a smooth surface without any difference in height, the first bonding material 400 (FIG. 1) can be applied to each of the connection surfaces 110a, 120a, and 120b at once, and sinter-bonding can be performed at once, improving productivity.

[0018] (Manufacturing Process) (FIG. 3) First, as described above, the first sealing body 100 is formed so that the connection surfaces 110a, 120a, and 120b are exposed as the same smooth surface on the first surface 140. Next, the first bonding material 400, which is a sintering material, is supplied to the connection surface 110a, the first bonding surface 120a, and the second bonding surface 120b formed on the first surface 140. The first bonding material 400 is a sintered bonding material.

[0019] The first bonding material 400 is applied to a printing mask 600 such as a stencil mask, and is supplied to each connecting surface by a printing method using a printing jig 610 such as a squeegee. The printing mask 600 has a plurality of openings 600a, and the first bonding material 400 is supplied to the connecting surface 110a, the first connecting surface 120a, and the second connecting surface 120b through each of the openings 600a. The first bonding material 400, which is a sintering material, is a paste-like material containing metal particles such as silver or copper.

[0020] (FIG. 4) Fig. 4(a) is a diagram showing the second conductor 320 and the third conductor 325 to which the second bonding material 410 has been supplied, and Fig. 4(b) is a diagram showing the state in which the first bonding material 400 has been supplied to each connection surface of the first sealing body 100 in Fig. 3. The second bonding material 410 is a bonding material similar to the first bonding material 400.

[0021] The second conductor 320 and the third conductor 325 are lead frames having a smooth structure, and when they are arranged side by side, a smooth surface without any height differences can be formed, which is a structure suitable for sintering bonding. The connection surface 320 a of the second conductor 320 and the connection surface 325 a of the third conductor 325 are flush with each other, so the second bonding material 410 can be supplied using the same supply method as the first bonding material 400.

[0022] The first sealing body 100, the second conductor 320 and the third conductor 325 to which the first bonding material 400 and the second bonding material 410 have been supplied are heated and dried at approximately 130 to 150°C to volatilize and dry the solvent contained in the first bonding material 400 and the second bonding material 410.

[0023] The first bonding material 400 and the second bonding material 410 are each formed to have a shape that flares out toward the connection surface to which they are applied. By applying and drying in such a shape, the cross-sectional area gradually increases from the semiconductor element 310 toward the heat dissipation surface, improving heat dissipation by thermal diffusion.

[0024] The second conductor 320 is electrically connected to a bottom electrode provided on the other surface of the semiconductor element 310 ( FIG. 1 ). The third conductor 325 is electrically connected to the second connection surface 120 b of the first conductor 120.

[0025] (FIG. 5) Fig. 5(a) is a diagram showing a state in which a semiconductor element 310 is placed between a heated and dried first sealing body 100 and a second conductor 320 and a third conductor 325. Fig. 5(b) is a diagram showing a state in which the bonding material has been sintered after a mounting process has been carried out in the state shown in Fig. 5(a). Fig. 5(c) is a diagram showing a completed semiconductor device 1 in the state shown in Fig. 5(b) after molding and sealing.

[0026] 5A, the semiconductor element 310 is disposed between the first sealing body 100 and the second conductor 320 and third conductor 325. The first connecting surface 120a and the connecting surface 110a, which is closer to the first connecting surface 120a out of the two connecting surfaces 110a, are disposed on one side of the semiconductor element 310 via a first bonding material 400. The second conductor 320 is disposed on the other side of the semiconductor element 310 via a second bonding material 410.

[0027] The semiconductor element 310 is placed on the dried second bonding material 410. At this time, the semiconductor element 310 is temporarily fixed using a temporary bonding agent such as a liquid or high viscosity agent, or a jig. Next, the first sealing body 100 on which the dried first bonding material 400 is placed is placed on the surface opposite to the semiconductor element 310. At this time, the first sealing body 100 is temporarily fixed using a temporary bonding agent such as a liquid or high viscosity agent, or a jig, just like the semiconductor element 310.

[0028] Next, in the mounting process of FIG. 5(b), the first sealing body 100, the semiconductor element 310, the second conductor 320, and the third conductor 325, which are stacked using the first bonding material 400 and the second bonding material 410, are heat-pressed using a semiconductor manufacturing device (not shown) capable of applying heat and pressure.

[0029] When heating and pressurizing are performed by the semiconductor manufacturing equipment, a jig (not shown) is used to adjust the first sealing body 100 so that it is parallel to the second conductor 320 and the third conductor 325. Pressure is also applied so that the first bonding material 400 and the second bonding material 410 are directly or indirectly connected to each other at appropriate positions. This allows for sintering bonding. The heating temperature at this time is, for example, approximately 250 to 300°C. By sintering the supplied bonding material in this manner, the first conductor 120 can be bonded to the upper electrode of the semiconductor element 310 and the third conductor 325.

[0030] 5(c), after the heating and drying step in FIG. 5(b) is completed, the first sealing body 100, the second conductor 320, the third conductor 325, and the semiconductor element 310 are mold-sealed with a second sealing member 450. At this time, the mold-sealing is performed so that the second surface 145, which is the electrode surface and heat dissipation surface of the first conductor 120, and the electrode / heat dissipation surface 320b of the second conductor 320 are exposed.

[0031] This manufacturing method using a printing technique for bonding materials allows the bonding surfaces of the upper and lower leads to be smooth and the bonding materials to be arranged on the same plane, so that the upper and lower leads can be sintered together, realizing a semiconductor device with a double-sided heat dissipation structure that has high heat dissipation and heat resistance.In addition, the wire bonding process can be eliminated, thereby improving productivity.

[0032] (Modification) (FIG. 6) A printed circuit board with embedded leads may be used instead of the first sealing body 100. The printed wiring board 620 includes a signal circuit 650 and a copper inlay 630, which is a cylindrical or rectangular prism-shaped high-current circuit. The copper inlay 630 penetrates the printed wiring board 620 in the thickness direction. The first bonding material 400 is applied to the connection surface of the second conductor 320 and the signal circuit 350 in the printed wiring board 620, and the second bonding material 410 is applied to the connection surface of the second conductor 320 and the third conductor 325. The remaining manufacturing method is the same as described above. This method achieves a semiconductor device with a double-sided heat dissipation structure that exhibits similarly high heat dissipation and heat resistance. Furthermore, the wire bonding process can be eliminated, thereby improving productivity.

[0033] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0034] (1) A method for manufacturing a semiconductor device (1) including a semiconductor element (310) having an upper electrode on one side and a lower electrode on the other side, a first conductor (120) electrically connected to the upper electrode, a second conductor (320) electrically connected to the lower electrode, and a third conductor (325) electrically connected to the first conductor (120), the method comprising: sealing the first conductor (120) with a sealing member (130) so that a first connection surface (120a) of the first conductor (120) connected to the upper electrode and a second connection surface (120b) of the first conductor (120) connected to the third conductor (325) are exposed on the same side; supplying bonding materials (400, 410) to the first connection surface (120a) and the second connection surface (120b); and sintering the supplied bonding materials (400, 410) to bond the first conductor (120) to the upper electrode of the semiconductor element (310) and the third conductor (325). In this way, it is possible to provide a manufacturing method for the semiconductor device 1 that realizes high heat resistance, high heat dissipation, and improved productivity.

[0035] (2) The control conductor 110 electrically connected to the upper surface electrode is sealed together with the first conductor 120 by the sealing member 130. This can improve productivity.

[0036] (3) The connection surface 110a of the control conductor 110 is exposed from the sealing member 130, and is arranged on the same plane as at least one of the first connection surface 120a and the second connection surface 120b. This improves productivity.

[0037] (4) In sealing body 100, first surface 140 on which first connecting surface 120a and second connecting surface 120b are formed and second surface 145, which is the surface opposite first surface 140, are parallel to each other. This allows for simultaneous sinter-bonding, thereby improving productivity.

[0038] (5) The semiconductor device 1 includes a semiconductor element 310 having an upper electrode on one side and a lower electrode on the other side, a first conductor 120 electrically connected to the upper electrode, a second conductor 320 electrically connected to the lower electrode, a third conductor 325 electrically connected to the first conductor 120, a sealing member 130 sealing the first conductor 120 while exposing a first connection surface 120a of the first conductor 120 connected to the upper electrode and a second connection surface 120b of the first conductor 120 connected to the third conductor 325 on the same side, and sintered bonding materials 400, 410 bonding the first connection surface 120a to the upper electrode and the second connection surface 120b to the third conductor 325, respectively. This configuration makes it possible to provide a semiconductor device 1 that achieves high heat resistance, high heat dissipation, and improved productivity.

[0039] (6) The sintered bonding materials 400, 410 have a shape that widens toward the sealing member 130, increasing the cross-sectional area. This configuration improves the thermal diffusion.

[0040] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0041] 1 semiconductor device 100 sealing body 110 control conductor 110a connection surface 120 first conductor 120a first connection surface 120b second connection surface 130 sealing member 140 first surface 145 second surface 310 semiconductor element 320 second conductor 320a connection surface 320b electrode / heat dissipation surface 325 third conductor 325a connection surface 400 first bonding material 410 second bonding material 450 second sealing member 600 printing mask 600a opening 610 printing jig 620 printed wiring board 630 copper inlay 640 upper lead 650 signal circuit

Claims

1. A method for manufacturing a semiconductor device including: a semiconductor element having an upper electrode on one side and a lower electrode on the other side; a first conductor electrically connected to the upper electrode; a second conductor electrically connected to the lower electrode; and a third conductor electrically connected to the first conductor, the method comprising: sealing the first conductor with a sealing member to form a sealing body so that a first connection surface of the first conductor connected to the upper electrode and a second connection surface of the first conductor connected to the third conductor are exposed on the same side; supplying a bonding material to the first connection surface and the second connection surface; and sintering the supplied bonding material to bond the first conductor to the upper electrode of the semiconductor element and the third conductor.

2. A method for manufacturing a semiconductor device according to claim 1, wherein a control conductor electrically connected to said upper surface electrode is sealed together with said first conductor by said sealing member.

3. A method for manufacturing a semiconductor device as described in claim 2, wherein the connection surface of the control conductor is exposed from the sealing member and is arranged on the same plane as at least one of the first connection surface and the second connection surface.

4. A method for manufacturing a semiconductor device as described in claim 1, wherein in the sealing body, a first surface on which the first connection surface and the second connection surface are formed and a second surface opposite to the first surface are parallel to each other.

5. A semiconductor device comprising: a semiconductor element having an upper electrode on one side and a lower electrode on the other side; a first conductor electrically connected to the upper electrode; a second conductor electrically connected to the lower electrode; a third conductor electrically connected to the first conductor; a sealing member that seals the first conductor while leaving a first connection surface of the first conductor connected to the upper electrode and a second connection surface of the first conductor connected to the third conductor exposed on the same side; and a sintered bonding material that bonds the first connection surface and the upper electrode, and the second connection surface and the third conductor, respectively.

6. A semiconductor device according to claim 5, wherein the sintered bonding material has a shape that widens toward the sealing member, increasing the cross-sectional area.

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