JP6936310B2 - Semiconductor devices and methods for manufacturing semiconductor devices - Google Patents

Description

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

Conventionally, a method for manufacturing a semiconductor device for manufacturing a semiconductor device in which a semiconductor chip and a lead are joined via solder is known (see, for example, Patent Document 1).

As shown in FIG. 12, the conventional semiconductor device 900 described in Patent Document 1 is arranged on a substrate 910 having a semiconductor chip arrangement surface 912 and a semiconductor chip arrangement surface 912, and is arranged on a surface on the substrate 910 side (semiconductor chip arrangement). The collector electrode 922 formed on the surface facing the surface 12) and the emitter formed on the surface opposite to the surface on the substrate 910 side (the surface opposite to the surface facing the semiconductor chip arrangement surface 12). It has a semiconductor chip 920 having a gate electrode 926 formed at a position separated from the electrode 924 (electrode) and the emitter electrode 924, and an electrode connecting piece 923, and the electrode connecting piece 923 is interposed via the emitter electrode 924 and the solder 940. With a joined lead 930

According to the conventional semiconductor device 900, the electrode connection piece 923 is joined to the emitter electrode 924 via the solder 940, that is, the semiconductor chip 920 and the lead 930 are joined only through the solder 940 (intervening member such as a wire). Since it is directly connected (without using), the semiconductor device 900 has a large current capacity and is suitable for an electronic device (for example, a power source) that uses a large current.

JP-A-2010-123686 Japanese Unexamined Patent Publication No. 2017-199809

By the way, it is generally known that it is effective to keep the thickness of the solder at a certain level or higher in order to alleviate the stress (for example, thermal stress) acting on the solder between the semiconductor chip and the lead. (See, for example, Patent Document 2).

However, in the conventional manufacturing process of a semiconductor device, if the paste-like solder material 941 has a certain thickness or more, the solder material 941 is crushed when the leads 930 are arranged on the solder material 941, and excess solder material is generated. There is a problem that the semiconductor device may protrude to an undesired place and the reliability of the semiconductor device may be lowered (see FIG. 13).

Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a semiconductor device whose reliability is unlikely to decrease. Another object of the present invention is to provide a method for manufacturing a semiconductor device for manufacturing such a semiconductor device.

[1] In the semiconductor device of the present invention, a substrate having a semiconductor chip arranging surface and electrodes arranged on the semiconductor chip arranging surface and formed on a surface opposite to the surface facing the semiconductor chip arranging surface are formed. The semiconductor chip includes a lead having an electrode connecting piece joined to the electrode via solder, and the electrode connecting piece has a convex portion protruding toward the semiconductor chip side in a region to be joined to the solder. It is characterized by having a through hole formed on the top of the convex portion and penetrating from a surface on the semiconductor chip side to a surface on the side opposite to the semiconductor chip side.

[2] In the semiconductor device of the present invention, it is preferable that the lead has a shape bent toward the semiconductor chip at the convex portion when viewed in cross section.

[3] In the semiconductor device of the present invention, the side surface shape of the convex portion is preferably a tapered shape in which the semiconductor chip side is narrow.

[4] In the semiconductor device of the present invention, the side surface shape of the convex portion is preferably a rounded shape.

[5] In the semiconductor device of the present invention, the thickness of the solder is preferably 300 μm or more.

[6] The first method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device for manufacturing the semiconductor device according to any one of the above [1] to [5], wherein the semiconductor is mounted on a substrate. The semiconductor chip arranging step of arranging the chips, the convex portion protruding to one surface side, and the convex portion formed on the top of the convex portion, penetrating from the one surface to the other surface on the opposite side to the one surface. A lead having an electrode connecting piece having a through hole formed therein is in a state where the electrode of the semiconductor chip and the electrode connecting piece face each other with a solder material interposed therebetween, and the convex portion protrudes toward the electrode side. An assembly forming step in which the solder material is arranged so as to be in a state to form an assembly, and a joining step in which the electrode and the electrode connecting piece are joined via solder by solidifying after melting the solder material. It is characterized by including.

[7] The second method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device according to any one of the above [1] to [5], wherein the semiconductor is mounted on a substrate. The semiconductor chip arranging step of arranging the chips, the convex portion protruding to one surface side, and the convex portion formed on the top of the convex portion, penetrating from the one surface to the other surface on the opposite side to the one surface. A lead having an electrode connection piece having a through hole and a solder material arranged in a predetermined region including the through hole on the other surface is provided by the electrode of the semiconductor chip and the electrode connection piece. An assembly forming step of forming an assembly by arranging the convex portions so as to face each other at a predetermined interval and projecting the convex portions toward the electrode side, and the penetration of the solder material by melting the solder material. A joining step of joining the electrode and the electrode connecting piece via solder by solidifying the solder material after pouring the solder material between the electrode and the electrode connecting piece through a hole is included. It is characterized by that.

[8] In the method for manufacturing a semiconductor device of the present invention, it is preferable that the solder material is also arranged in a part of the space between the electrode and the electrode connecting piece in the assembly forming step.

[9] In the method for manufacturing a semiconductor device of the present invention, in the assembly forming step, the lead having a shape bent toward the semiconductor chip at the convex portion when viewed in cross section is arranged. Is preferable.

[10] In the method for manufacturing a semiconductor device of the present invention, in the assembly forming step, it is preferable to dispose the lead having a side surface shape of the convex portion having a narrow tapered shape on the semiconductor chip side.

[11] In the method for manufacturing a semiconductor device of the present invention, in the assembly forming step, it is preferable to arrange the leads having a rounded side surface shape of the convex portion.

[12] In the method for manufacturing a semiconductor device of the present invention, the solder material is preferably made of a paste-like solder material containing a solvent.

According to the semiconductor device of the present invention, the electrode connection piece is formed on the convex portion protruding toward the semiconductor chip side and the top portion of the convex portion in the region to be joined with the solder, and is formed from the surface on the semiconductor chip side to the semiconductor chip side. Has a through hole that penetrates to the opposite surface, so when the lead is placed on the solder material in the manufacturing process, excess solder material is passed through the through hole to the surface of the lead opposite to the semiconductor chip. Can be made to flow. Therefore, when the thickness of the solder is kept above a certain level, even when the leads are arranged on the solder material (before the joining process), it is possible to prevent the excess solder material from squeezing out to an undesired place. , The reliability of the semiconductor device is less likely to decrease.

Further, according to the semiconductor device of the present invention, since the electrode connection piece has a convex portion protruding toward the semiconductor chip side in the region to be joined with the solder, the contact between the lead and the solder is compared with that of the conventional semiconductor device. The area becomes large.
Further, according to the semiconductor device of the present invention, the electrode connection piece is formed on the top of the convex portion and has a through hole penetrating from the surface on the semiconductor chip side to the surface on the side opposite to the semiconductor chip side. When the lead is arranged on the solder material, the excess solder material can flow through the through hole to the surface of the lead opposite to the semiconductor chip. Therefore, since the solder is also present in the through hole and on the surface of the lead opposite to the semiconductor chip side, the contact area between the lead and the solder becomes larger.
Therefore, the bonding strength between the lead and the solder is increased, and the reliability of the semiconductor device is increased.

According to the first method for manufacturing a semiconductor device of the present invention, in the assembly forming step, a convex portion protruding toward one surface side and a convex portion formed on the top of the convex portion, from one surface to one surface. A lead having an electrode connecting piece having a through hole penetrated to the other surface on the opposite side is in a state where the electrode and the electrode connecting piece face each other with the solder material sandwiched between them, and the convex portion protrudes toward the electrode side. In the joining process, the electrodes and electrode connection pieces are joined via solder by solidifying after melting the solder material, so that the electrodes are joined on the solder material. When the leads are arranged, excess solder material can flow through the through holes toward the surface of the leads opposite to the semiconductor chip. Therefore, when the thickness of the solder is kept above a certain level, even when the leads are arranged on the solder material, it is possible to prevent the excess solder material from squeezing out to an undesired place, and the reliability is lowered. It is possible to manufacture difficult semiconductor devices.

According to the method for manufacturing the second semiconductor device of the present invention, in the assembly forming step, the convex portion protruding toward one surface side and the convex portion formed on the top of the convex portion are formed from one surface to one surface. A lead having an electrode connecting piece having a through hole penetrating to the other surface on the opposite side and having a solder material arranged in a predetermined region including the through hole on the other surface is formed with the electrode and the electrode connecting piece. Are arranged so as to face each other at predetermined intervals and the convex portions are projected toward the electrode side to form an assembly. By solidifying the solder material after pouring the solder material between the electrode connection pieces, the electrodes and the electrode connection pieces are joined via solder, so the solder material before the joining process does not become too thick. There is no need to place the leads on a solder material with a certain thickness or more. Therefore, it is possible to prevent the excess solder material from squeezing out to an undesired place. As a result, it is possible to manufacture a semiconductor device whose reliability is unlikely to decrease.

It is a figure which shows the semiconductor device 1 which concerns on Embodiment 1. FIG. FIG. 1A is a plan view of the semiconductor device 1, and FIG. 1B is a cross-sectional view of the semiconductor device 1. FIG. 5 is an enlarged view of a main part of the semiconductor device 1 according to the first embodiment. FIG. 2A is an enlarged cross-sectional view of a main part of the semiconductor device 1, and FIG. 2B is an enlarged plan view of a main part of the semiconductor device 1. It is a flowchart of the manufacturing method of the semiconductor device which concerns on Embodiment 1. FIG. It is a process drawing of the manufacturing method of the semiconductor device which concerns on Embodiment 1. FIG. FIG. 4A is a diagram showing a substrate preparation process, FIG. 4B is a diagram showing a semiconductor chip arrangement process, and FIG. 4C is a diagram showing a solder material arrangement process. It is a process drawing of the manufacturing method of the semiconductor device which concerns on Embodiment 1. FIG. 5 (a) is a diagram showing a lead frame arrangement process, FIG. 5 (b) is a diagram showing a joining process (reflow process), and FIG. 5 (c) is a diagram showing a wire bonding process. It is a figure which shows for demonstrating the effect of the manufacturing method of the semiconductor device which concerns on Embodiment 1. FIG. 6A is a cross-sectional view of the assembly 50 before arranging the leads (lead frame) on the solder material, and FIG. 6B is a plane view of the assembly 50 before arranging the leads on the solder material. 6 (c) is a cross-sectional view of the assembly 50 after the leads are arranged on the solder material, and FIG. 6 (d) is a plan view of the assembly 50 after the leads are arranged on the solder material. 6 (e) is a cross-sectional view of the assembly 50 after the joining step, and FIG. 6 (f) is a plan view of the assembly 50 after the joining step. It is a figure which shows for demonstrating the effect of the manufacturing method of the semiconductor device which concerns on Embodiment 2. FIG. 7A is a cross-sectional view of the assembly 51 before the joining step (reflow step) is carried out, and FIG. 7B is a plan view of the assembly 51 before the joining step (reflow step) is carried out. (C) is a cross-sectional view of the assembly 51 during the joining step (reflow step), and FIG. 7 (d) is a plan view of the assembly 51 during the joining step (reflow step). It is a figure which shows for demonstrating the effect of the manufacturing method of the semiconductor device which concerns on Embodiment 3. FIG. 8A is a cross-sectional view of the assembly 52 before the joining step (reflow step) is carried out, and FIG. 8B is a plan view of the assembly 52 before the joining step (reflow step) is carried out. (C) is a cross-sectional view of the assembly 52 during the joining step (reflow step), and FIG. 8 (d) is a plan view of the assembly 52 during the joining step (reflow step). FIG. 5 is an enlarged cross-sectional view of a main part showing a convex portion and a through hole of a lead in the semiconductor device according to the modified examples 1 to 4. 9 (a) to 9 (d) are enlarged cross-sectional views of a main part showing the convex portion and the through hole of the lead in the semiconductor device according to the modified examples 1 to 4. It is an enlarged view of the main part in the semiconductor device which concerns on modification 5. FIG. 10A is an enlarged cross-sectional view of a main part of the semiconductor device according to the modified example 5, and FIG. 10B is an enlarged plan view of the main part of the semiconductor device according to the modified example 5. It is a figure which shows the semiconductor device 2 which concerns on modification 6. FIG. 11A is a perspective view of the semiconductor device 2, and FIG. 11B is a cross-sectional view of the semiconductor device 2. It is sectional drawing which shows the conventional semiconductor device 900. In FIG. 12, reference numeral 946 indicates solder, reference numeral 960 and reference numeral 962 indicate terminals, reference numeral 970 indicates wire, and reference numeral 980 indicates resin. It is a figure which shows the problem of the manufacturing method of the conventional semiconductor device. FIG. 13A is a diagram showing a state of the assembly before the lead arrangement, and FIG. 13B is a diagram showing the state of the assembly after the lead arrangement. Reference numerals 941 and 945 indicate a paste-like solder material.

Hereinafter, the method for manufacturing the semiconductor device of the present invention will be described based on the embodiment shown in the figure. It should be noted that each drawing is a schematic view and does not necessarily accurately reflect the actual dimensions.

[Embodiment 1]
1. 1. Configuration of Semiconductor Device 1 in Embodiment 1. As shown in FIGS. 1 and 2, the semiconductor device 1 according to the first embodiment includes a substrate 10, a semiconductor chip 20, leads 30, 62, 64, and solders 40, 46. And the wire 70, and the leads 30, 62, 64 are resin-sealed with the resin 80 except for a part of the external connection terminals and the heat-dissipating metal plate 18.

The substrate 10 is a substrate having a semiconductor chip arranging surface 12. An appropriate substrate (for example, a printed circuit board) can be used as the substrate 10, but in the first embodiment, the insulating substrate 14 and the insulating substrate 14 are formed on one surface, and the semiconductor chip arranging surface 12 is formed. A DCB (Direct Copper Bonding) substrate having a circuit 16 having the circuit 16 and a metal plate 18 for heat dissipation formed on the other surface of the insulating substrate 14 is used. The heat-dissipating metal plate 18 is exposed from the resin 80.

The semiconductor chip 20 is arranged on the semiconductor chip arrangement surface 12, and has a collector electrode 22 formed on one surface (a surface facing the semiconductor chip arrangement surface 12 or a surface on the substrate 10 side), and the other. The emitter electrode 24 (electrode) and the emitter electrode 24 formed on the surface (the surface opposite to the surface facing the semiconductor chip arrangement surface 12 or the surface opposite to the surface on the substrate 10 side) are separated from each other. It is an IGBT (Integrated Gate Bipolar Semiconductor) having a gate electrode 26 formed at the above-mentioned position.

The collector electrode 22 is joined to the semiconductor chip arranging surface 12 of the substrate 10 via the solder 46, and is connected to the outside via the solder 46, the substrate 10 (circuit 16), and the lead 64.
The emitter electrode 24 is joined to the electrode connection piece 32 of the lead 30 via the solder 40, and is connected to the outside via the solder 40 and the lead 30 (external connection terminal 34).

The leads 30, 62, and 64 are flat metal members, and are formed by separating the lead frame. The leads 30, 62, and 64 have a larger cross-sectional area than the wire and can carry a large current.

The lead 30 has an electrode connection piece 32 for connecting to the emitter electrode 24 at one end, and an external connection terminal 34 for connecting to the outside at the other end.

The electrode connection piece 32 is formed on a convex portion 36 protruding toward the semiconductor chip 20 side and a top portion 37 of the convex portion 36 in a region to be joined with the solder 40, and is formed from a surface on the semiconductor chip 20 side to the semiconductor chip 20 side. It has a through hole 38 that penetrates to the opposite surface.

The lead 30 has a shape that is bent toward the semiconductor chip 20 at the portion of the convex portion 36 when viewed in cross section. The convex portion 36 has a shape as if it was punched toward the semiconductor chip 20 side. The side surface shape of the convex portion 36 is a tapered shape narrow on the semiconductor chip 20 side, and the side surface shape (cross-sectional shape of the side surface) of the convex portion is a rounded shape. In other words, the side surface shape of the convex portion 36 has a Mt. Fuji shape in which the semiconductor chip 20 side is the top and a wide base, or a trumpet shape in which the side opposite to the semiconductor chip 20 is wide.

When the electrode connection piece 32 is viewed from the surface opposite to the semiconductor chip 20 side, it seems that there is a concave portion having a shape corresponding to the shape of the convex portion 36. In other words, it seems that there is a recess that becomes narrower toward the semiconductor chip 20 side from the surface opposite to the semiconductor chip 20 side. There is a through hole 38 at the bottom of the recess. The solder that has flowed out from the solder 40 between the emitter electrode 24 and the electrode connection piece 32 has entered the recess, and the solder is the lead 30 from the side of the lead 30 near the through hole 38 opposite to the semiconductor chip 20 side. Is in contact with.

The through hole 38 is formed in the top portion 37 of the convex portion 36, and penetrates from the surface on the semiconductor chip 20 side to the surface on the side opposite to the semiconductor chip 20 side. The through hole 38 is large enough so that the solder material can move back and forth through the through hole 38 when the lead 30 is placed on the solder material before the joining process (that is, the solder material passes through the through hole 38). It is large enough to prevent the solder material from jumping out to an unintended area because it cannot come and go sufficiently).

One end of the lead 62 is connected to the gate electrode 26 via a wire 70, and the other end is a terminal for external connection. One end of the lead 64 is connected to the circuit 16 connected to the collector electrode 22, and the other end is a terminal for external connection.

Solders 40 and 46 are alloys or metals having conductivity and adhesiveness. The solders 40 and 46 are melted and solidified by heating the solder material.
The solder 40 joins the emitter electrode 24 and the electrode connection piece 32. The thickness of the solder 40 (solder thickness) is thicker than the thickness of the solder 46 (solder between the substrate 10 and the semiconductor chip 20), for example, 300 μm or more.
The solder 46 joins the collector electrode 22 and the semiconductor chip arranging surface 12. The solder 46 is formed of a paste-like solder material (so-called cream solder) containing a solvent (specifically, flux), is arranged on the semiconductor chip arrangement surface 12 of the substrate 10 by printing, and reflows. The substrate 10 and the semiconductor chip 20 are joined by heating. Unlike the case of the solder 40, the solder 46 does not have a situation of relaxing the stress acting on the solder (for example, thermal stress), and the thicker the solder 46, the larger the conduction loss. Therefore, it is preferable that the solder 46 is relatively thin.

As the resin 80, an appropriate resin can be used.

2. Manufacturing method of semiconductor device according to the first embodiment As shown in FIG. 3, the manufacturing method of the semiconductor device according to the first embodiment is a bonding of a substrate preparation step S100, a semiconductor chip arranging step S200, and an assembly forming step S300. It includes a step S400, a wire bonding step S500, a resin sealing step S600, and a lead processing step S700.

(1) Substrate preparation step S100
In the substrate preparation step S100, the substrate 10 is prepared (see FIG. 4A). Specifically, the substrate 10 is positioned and arranged on a predetermined jig.

(2) Semiconductor chip placement process S200
In the semiconductor chip arranging step S200, the semiconductor chip 20 is arranged on the semiconductor chip arranging surface 12 of the substrate 10 via the solder material 45 (see FIG. 4B). Specifically, first, a paste-like solder material 45 (for example, so-called cream solder) is printed on the semiconductor chip arrangement surface 12 of the substrate 10. Next, the semiconductor chip 20 is arranged on the semiconductor chip arrangement surface 12 so that the semiconductor chip arrangement surface 12 and the collector electrode 22 of the semiconductor chip 20 face each other with the solder material 45 interposed therebetween.
In the first embodiment, the solder material is supplied by printing the solder material 45, but the solder material is supplied by the dispenser, the solder material is supplied by the thread solder sent out by the solder feeder or the like, and the solder material is melted. The solder material may be supplied by an appropriate method such as supplying the solder material by pouring the solder material.

The cream solder is obtained by adding a flux to the solder powder to form a paste having an appropriate viscosity. Flux is a component that volatilizes at high temperatures (eg, the melting temperature of solder). As the flux, a resin-based flux containing rosin, modified rosin, synthetic resin, etc. as the main component is used, and when a thixotropic agent, a solvent for an activator and an activator, a dispersion stabilizer, etc. are added. There is also.

(3) Assembly forming step S300
The assembly forming step S300 includes a solder material arranging step S310 and a lead frame arranging step S320.

(3-1) Solder material placement process S310
In the solder material arranging step S310, the solder material 41 is arranged on the emitter electrode 24 of the semiconductor chip 20 (see FIG. 4C). As the solder material 41, a paste-like solder material containing a solvent is used. In the first embodiment, as the solvent, a paste-like solder material (specifically, so-called cream solder) containing a solvent (for example, flux) containing a component that volatilizes at a high temperature (for example, the melting temperature of the solder) is used. Use. As the solvent, a paste-like solder material containing a solvent other than the solvent containing a component that volatilizes at a high temperature may be used, or the solder material 41 can move through the through hole 38 in the subsequent lead frame arrangement step. Any other suitable solder material may be used as long as it is a solder material having a certain degree of viscosity.

(3-2) Lead frame arrangement step S320
In the lead frame arranging step, the convex portion 36 projecting to one surface side and the top 37 of the convex portion 36 are formed and penetrated from one surface to the other surface on the opposite side to the other surface. A lead 30 having an electrode connecting piece 32 having a hole 38 (a lead frame to which the lead 30 is connected) is in a state where the emitter electrode 24 and the electrode connecting piece 32 face each other with the solder material 41 in between, and a convex portion. 36 is arranged so as to protrude toward the emitter electrode 24 side (see FIG. 5A). At this time, the leads 62 and 64 in the lead frame 200 are also arranged at predetermined positions.

Specifically, the convex portion 36 is arranged on the solder material 41 so as to face the emitter electrode 24 side (see FIGS. 6A and 6B). At this time, the surplus solder material 41 moves through the through hole toward the side of the lead 30 opposite to the semiconductor chip 20 side (see FIGS. 6 (c) and 6 (d)). Therefore, the solder material 41 does not flow out to an unintended region (for example, a region where the emitter electrode is not formed when viewed in a plane). Even if the solder material flows out on the surface of the lead 30 opposite to the semiconductor chip 20 side, there are no electrodes having different potentials around it, so that a problem is unlikely to occur.

As a result, the convex portion 36 protruding toward one surface side and the through hole 38 formed at the top 37 of the convex portion 36 and penetrating from one surface to the other surface on the opposite side to the other surface are formed. The lead 30 having the electrode connecting piece 32 is in a state where the emitter electrode 24 and the electrode connecting piece 32 face each other with the solder material 41 interposed therebetween, and the convex portion 36 projects toward the emitter electrode 24 side. The assembly 50 can be formed by arranging in (see FIG. 5 (a)).

(4) Joining process (reflow process) S400
In the joining step (reflow step) S400, the assembly 50 is placed in a reflow furnace (not shown) and heated to melt the solder materials 41 and 45, and then the solder materials 41 and 45 are solidified to solidify the solder 40. , 46 (see FIG. 5 (b)). At this time, the excess solder material moves to the surface of the lead 30 opposite to the semiconductor chip 20 side through the through hole 38 (see FIGS. 6 (e) and 6 (f)). At this time, a gas such as flux is discharged to the outside through the through hole 38. As a result, the semiconductor chip arranging surface 12 of the substrate 10 and the emitter electrode 24 of the semiconductor chip 20 are joined via the solder 46, and the collector electrode 22 of the semiconductor chip 20 and the electrode connection piece 32 of the lead 30 are soldered 40. Join through.

(5) Wire bonding step S500
Next, the gate electrode 26 and the lead 62 (see FIG. 1) are connected by using a wire 70 (see FIG. 5 (c)). Any wire 70 can be used as appropriate.

(6) Resin sealing step S600 and lead processing step S700
Next, the external terminals of the leads 30, 62, 64 and the metal plate 18 for heat dissipation are removed, and the resin is sealed with the resin 80 (resin sealing step S600, not shown). Next, the leads 30, 62, The 64 is separated from the lead frame, and processing such as bending of a predetermined portion is performed (lead processing step S700, not shown).
In this way, the semiconductor device 1 according to the first embodiment can be manufactured.

3. 3. Effect of the method for manufacturing a semiconductor device according to the first embodiment According to the semiconductor device 1 according to the first embodiment, the electrode connection piece 32 has a convex portion 36 protruding toward the semiconductor chip 20 in a region to be joined with the solder 40. Since it has a through hole 38 formed on the top 37 of the convex portion 36 and penetrating from the surface on the semiconductor chip 20 side to the surface on the side opposite to the semiconductor chip 20 side, it leads on the solder material 41 in the manufacturing process. When the 30 is arranged, the excess solder material can flow through the through hole 38 to the surface of the lead 30 opposite to the semiconductor chip 20. Therefore, when the thickness of the solder 40 is kept to a certain thickness or more, even when 30 leads are arranged on the solder material 41 (before the joining process), the excess solder material 41 does not protrude to an undesired place. This can be prevented, and the reliability of the semiconductor device is less likely to decrease.

Further, according to the semiconductor device 1 according to the first embodiment, since the electrode connection piece 32 has a convex portion 36 protruding toward the semiconductor chip 20 in the region where the solder 40 is joined, the electrode connection piece 32 is compared with the conventional semiconductor device. , The contact area between the lead 30 and the solder 40 becomes large.
Further, according to the semiconductor device 1 according to the first embodiment, the electrode connection piece 32 is formed on the top 37 of the convex portion 36 and penetrates from the surface on the semiconductor chip 20 side to the surface on the side opposite to the semiconductor chip 20 side. Since the lead 30 is provided with the through hole 38, when the lead 30 is arranged on the solder material 41, the surplus solder material 41 can flow through the through hole 38 to the surface of the lead 30 opposite to the semiconductor chip 20. can. Therefore, since the solder 40 is also present in the through hole 38 and on the surface of the lead 30 opposite to the semiconductor chip 20 side, the contact area between the lead 30 and the solder 40 becomes larger.
Therefore, the bonding strength between the lead 30 and the solder 40 is increased, and the reliability of the semiconductor device is increased.

According to the semiconductor device 1 and the method for manufacturing the semiconductor device according to the first embodiment, the lead 30 has a shape that is bent toward the semiconductor chip 20 at the convex portion 36 when viewed in cross section, and thus is a joining step. In the above, the surplus solder material 41 that has passed through the through hole 38 can be wrapped around the back side of the surface of the lead 30 on the semiconductor chip side. Therefore, the portion of the lead 30 near the opening of the through hole 38 comes into contact with the solder 40 on both the semiconductor chip 20 side and the side opposite to the semiconductor chip 20. Therefore, the joint strength between the lead 30 and the solder 40 is further increased, and the reliability of the semiconductor device is less likely to be lowered.

Further, according to the semiconductor device 1 and the method for manufacturing the semiconductor device according to the first embodiment, the side surface shape of the convex portion 36 is a tapered shape in which the semiconductor chip 20 side is narrow, so that the side surface of the convex portion 36 is relative to the semiconductor chip. The contact area between the lead 30 and the solder 40 is larger than that in the case of being vertical. Therefore, the bonding strength between the lead 30 and the solder 40 is further increased, and the reliability of the semiconductor device is increased.

When the convex portion 36 has a shape in which the lead 30 is bent toward the semiconductor chip 20 when viewed in cross section, and the side surface shape of the convex portion 36 is a tapered shape in which the semiconductor chip 20 side is narrow. When the lead 30 is viewed from the side opposite to the semiconductor chip 20 side, the side surface is formed with a concave portion having a tapered shape. The solder material 41 that has flowed to the opposite side tends to stay in the vicinity of the through hole 38, and when such a solder material 41 solidifies, it becomes solder having a shape like a screw head (a shape like a conical shape with the semiconductor chip side at the apex). .. Therefore, there is also an effect that the lead 30 and the solder 40 are more difficult to peel off, and the bonding strength between the lead 30 and the solder 40 can be further increased.

Further, according to the semiconductor device 1 and the method for manufacturing the semiconductor device according to the first embodiment, since the side surface shape of the convex portion 36 is a rounded shape, the lead 30 (lead frame) is placed on the solder material 41. When the above is placed, the excess solder material is easy to move, and it is difficult for air to accumulate in the solder material. Therefore, it is possible to manufacture a semiconductor device whose reliability is less likely to decrease.

Further, according to the semiconductor device 1 according to the first embodiment, according to the method for manufacturing the semiconductor device according to the first embodiment, the thickness of the solder 40 is 300 μm or more, and therefore, between the semiconductor chip 20 and the lead 30. The stress acting on the solder 40 (for example, thermal stress) can be relaxed, and problems such as cracks in the solder 40 are less likely to occur. As a result, it is possible to manufacture a semiconductor device whose reliability is unlikely to decrease. From this point of view, in order to make the above-mentioned defects less likely to occur, the thickness of the solder 40 is preferably 400 μm or more, and the thickness of the solder 40 is even more preferably 500 μm or more.

According to the method for manufacturing a semiconductor device according to the first embodiment, in the assembly forming step, a convex portion 36 protruding toward one surface side and a top 37 of the convex portion 36 are formed, and one surface is formed from one surface. A lead 30 having an electrode connecting piece 32 having a through hole 38 penetrating to the other surface on the opposite side of the lead 30 is in a state where the emitter electrode 24 and the electrode connecting piece 32 face each other with the solder material 41 in between. The convex portion 36 is arranged so as to protrude toward the emitter electrode 24 side to form the assembly 50, and in the joining step, the solder material 41 is melted and then solidified to form the emitter electrode 24 and the electrode. Since the connection piece 32 is joined via the solder 40, when the lead 30 is arranged on the solder material 41, the surplus solder material 41 is passed through the through hole 38 to the surface of the lead 30 opposite to the semiconductor chip 20. It can flow toward. Therefore, when the thickness of the solder 40 is kept to a certain thickness or more, even when the leads 30 are arranged on the solder material 41 before the joining process, it is possible to prevent the excess solder material 41 from protruding to an undesired place. It is possible to manufacture a semiconductor device whose reliability is unlikely to decrease.

According to the method for manufacturing a semiconductor device according to the first embodiment, the solder material 41 is made of a paste-like solder material containing a solvent, and since such a solder material has fluidity, the lead 30 is placed on the solder material 41. When the above is arranged, the surplus solder material 41 can flow through the through hole 38 toward the surface of the lead 30 opposite to the semiconductor chip 20.

[Embodiment 2]
The semiconductor device manufacturing method according to the second embodiment basically has the same steps as the semiconductor device manufacturing method according to the first embodiment, but the position where the solder material is arranged is the manufacturing of the semiconductor device according to the first embodiment. Different from the method. In the method for manufacturing a semiconductor device according to the second embodiment, in the assembly forming step (lead frame arranging step), the solder material 41 is not arranged between the emitter electrode 24 and the electrode connecting piece 32, and the electrode connecting piece 32 is used. The solder material 42 is arranged in a predetermined region including the through hole 38 on the surface opposite to the surface on the emitter electrode 24 side (the surface opposite to the surface on which the convex portion is formed) (FIG. 7 (a). )reference.). That is, the lead 30 in which the solder material 42 is arranged in a predetermined region including the through hole 38 on the surface of the electrode connection piece 32 opposite to the surface on the emitter electrode 24 side is connected to the emitter electrode 24 and the electrode connection piece 32. The assembly 51 is formed by arranging the solders so as to face each other at predetermined intervals and the convex portions 36 to protrude toward the emitter electrode 24 side.

In the assembly forming step (lead frame arranging step), a predetermined portion (preferably a plurality of portions) of the leads 30 (lead frame) is sandwiched and fixed by a predetermined jig from above and below to fix the emitter electrode. The 24 and the electrode connecting piece 32 are separated from each other at a predetermined interval.

In the joining step, the solder material 42 arranged in a predetermined region including the through hole 38 on the surface of the electrode connection piece 32 opposite to the surface on the emitter electrode 24 side is melted and passed through the through hole 38 to the emitter electrode 24. It is poured between the electrode connection piece 32 and the electrode connection piece 32 (see FIG. 7B). Then, the solder material 42 is solidified when the solder material 41 is filled between the emitter electrode 24 and the electrode connection piece 32. As a result, the emitter electrode 24 and the electrode connection piece 32 can be joined via the solder 40.

As described above, in the method for manufacturing the semiconductor device according to the second embodiment, the position where the solder material is arranged is different from the case of the method for manufacturing the semiconductor device according to the first embodiment, but in the assembly forming step, one surface side. It has an electrode connection piece 32 having a convex portion 36 protruding from the surface and a through hole 38 formed in the top portion 37 of the convex portion 36 and penetrating from one surface to the other surface on the opposite side to the other surface. Then, on the other surface, the lead 30 in which the solder material 42 is arranged in a predetermined region including the through hole 38 is in a state where the emitter electrode 24 and the electrode connecting piece 32 face each other at a predetermined interval, and the convex portion 36. Is arranged so as to protrude toward the emitter electrode 24 side to form the assembly 51, and in the joining step, the solder material 42 is melted and passed through the through hole 38 to form the emitter electrode 24 and the electrode connecting piece 32. By solidifying the solder material 42 after pouring the solder material 42 between them, the emitter electrode 24 and the electrode connection piece 32 are joined via the solder 40, so that the thickness is a certain thickness or more (before the joining process). ) The leads 30 are not arranged on the solder material, and it is possible to prevent the excess solder material from protruding to an undesired place. As a result, it is possible to manufacture a semiconductor device whose reliability is unlikely to decrease.

Further, according to the method for manufacturing a semiconductor device according to the second embodiment, since the solder material 42 is made of a paste-like solder material, the solder material is easily melted in the joining step, and when the solder material 41 is melted, the solder material 41 is melted. It becomes easy to flow the solder material 41 between the emitter electrode 24 and the electrode connection piece 32 through the through hole 38 through the solder material 42.

Further, according to the method for manufacturing a semiconductor device according to the second embodiment, in the assembly forming step, the emitter electrode 24 is arranged because the lead 30 whose side surface shape of the convex portion 36 has a narrow tapered shape on the semiconductor chip 20 side is arranged. The solder material 41 supplied between the and the electrode connection piece 32 is unlikely to flow back from the through hole 38, and the solder material 41 can be efficiently supplied between the emitter electrode 24 and the electrode connection piece 32.

Further, according to the method for manufacturing a semiconductor device according to the second embodiment, since the side surface shape of the convex portion 36 has a rounded shape, the solder material 42 can easily move, and the emitter electrode 24 and the electrode connection piece can be easily moved. The solder material 41 can be efficiently supplied between the 32 and the 32.

Since the semiconductor device manufacturing method according to the second embodiment has the same configuration as the semiconductor device manufacturing method according to the first embodiment except for the position where the solder material is arranged, the semiconductor device according to the first embodiment has the same configuration. It has the corresponding effect among the effects of the manufacturing method of.

[Embodiment 3]
The method for manufacturing a semiconductor device according to the third embodiment basically has the same steps as the method for manufacturing a semiconductor device according to the second embodiment, but a solder material is also provided between the emitter electrode 24 and the electrode connecting piece 32. The point of arrangement is different from the case of the method for manufacturing the semiconductor device according to the second embodiment. That is, in the method for manufacturing a semiconductor device according to the third embodiment, in the assembly forming step, only a predetermined region including the through hole 38 is formed on the surface of the electrode connection piece 32 opposite to the surface on the emitter electrode 24 side. The solder material 43 is also arranged in a part of the space between the emitter electrode 24 and the electrode connection piece 32 (see FIGS. 8A and 8B). In the joining step, the solder material supplied between the emitter electrode 24 and the electrode connecting piece 32 through the through hole 38 and the solder material previously arranged between the emitter electrode 24 and the electrode connecting piece 32 are formed. The mixture is mixed and the space between the emitter electrode 24 and the electrode connecting piece 32 is filled with a solder material and solidified (see FIGS. 8 (c) and 8 (d)).

As described above, in the method of manufacturing the semiconductor device according to the third embodiment, the point that the solder material is also arranged between the emitter electrode 24 and the electrode connecting piece 32 is the case of the method of manufacturing the semiconductor device according to the second embodiment. However, as in the case of the method for manufacturing the semiconductor device according to the second embodiment, in the assembly forming step, the convex portion 36 projecting to one surface side and the convex portion 36 are formed on the top 37 of the convex portion 36. The electrode connection piece 32 has an electrode connection piece 32 having a through hole 38 penetrating from one surface to the other surface on the opposite side to the other surface, and the solder material 42 is formed in a predetermined region including the through hole 38 on the other surface. Are arranged so that the emitter electrode 24 and the electrode connection piece 32 face each other at a predetermined interval, and the convex portion 36 projects toward the emitter electrode 24 side. By forming the solid 51, and in the joining process, the solder material 42 is melted, the solder material 42 is poured between the emitter electrode 24 and the electrode connection piece 32 through the through hole 38, and then the solder material 42 is solidified. Since the emitter electrode 24 and the electrode connection piece 32 are joined via the solder 40, the leads 30 are not arranged on the solder material (before the joining process) having a certain thickness or more, and excess solder is used. It is possible to prevent the material from sticking out to an undesired place. As a result, it is possible to manufacture a semiconductor device whose reliability is unlikely to decrease.

Further, according to the method for manufacturing a semiconductor device according to the third embodiment, in the assembly forming step, the solder material 43 is also arranged in a part of the space between the emitter electrode 24 and the electrode connection piece 32. The space between the emitter electrode 24 and the electrode connecting piece 32 can be filled with the solder material in a short time, and the semiconductor device can be efficiently manufactured.

The method for manufacturing the semiconductor device according to the third embodiment is the method for manufacturing the semiconductor device according to the second embodiment, except that the solder material is also arranged between the emitter electrode 24 and the electrode connecting piece 32. Since it has the same configuration as that of the above, it has the corresponding effect among the effects of the method for manufacturing the semiconductor device according to the second embodiment.

Although the present invention has been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment. It can be carried out in various aspects within a range that does not deviate from the purpose, and for example, the following modifications are also possible.

(1) The materials, shapes, positions, sizes, etc. described in the above embodiments are examples, and can be changed as long as the effects of the present invention are not impaired.

(2) In each of the above embodiments, the convex portion 36 has a tapered shape whose side surface is curved, but the present invention is not limited to this. For example, the convex portion may have a tapered shape on the side surface (see FIG. 9A), or the convex portion has a flat portion at the top and a through hole is formed in a part thereof. This may be done (see FIG. 9B). Further, the convex portion may have a shape in which the lead 30 is bent more gently toward the semiconductor chip side (see FIG. 9C).

(3) In each of the above embodiments, the convex portion is a convex portion having a shape in which the lead 30 is bent toward the semiconductor chip 20 when viewed in cross section, but the present invention is limited thereto. is not it. For example, the thickness of the lead in the vicinity of the through hole may be increased to form a convex portion (see FIG. 9D).

(4) In each of the above embodiments, as the semiconductor chip, a semiconductor chip in which the emitter electrode is divided into a plurality of electrodes may be used. In this case, a lead having a convex portion and a through hole formed at a position corresponding to each of the divided electrodes (a position corresponding to a position where the solder material is arranged) may be used (Modification Example 5, see FIG. 10). .).

(5) In each of the above embodiments, the semiconductor device is a semiconductor device including one semiconductor chip, but the present invention is not limited thereto. For example, the semiconductor device may be a semiconductor device having two semiconductor chips (see FIG. 11) or a semiconductor device having three or more semiconductor chips.

As a semiconductor device including two semiconductor chips, for example, the following semiconductor device in which two semiconductor chips are cascode-connected (semiconductor device 2 in Modification 6, see FIG. 11) can be considered. In the semiconductor device 2 of the sixth modification, the emitter electrode 24f of the semiconductor chip 20f is electrically connected to the lead 30f, and the collector electrode 22f of the semiconductor chip 20f is connected to the lead 30g via the circuit 16f of the substrate 10f. At the same time, the emitter electrode 24g of the semiconductor chip 20g is electrically connected via the lead 30g, and the collector electrode 22g of the semiconductor chip 20g is connected to the lead 66 via the circuit 16g, although not shown. Even in a semiconductor device having such a configuration, convex portions and through holes may be formed in the leads 30f and 30g.

(6) In each of the above embodiments, a lead having one convex portion and one through hole is used, but the present invention is not limited thereto. Leads having two or more protrusions and through holes may be used.

(7) In each of the above embodiments, the semiconductor chip 20 is a 3-terminal IGBT, but the present invention is not limited thereto. The semiconductor chip 20 may be another three-terminal semiconductor element (for example, MOSFET), the semiconductor chip 20 may be a two-terminal semiconductor element (for example, a diode), and the semiconductor chip 20 may be a semiconductor element with four or more terminals (4). The terminal may be, for example, a thyristor).

(8) In each of the above embodiments, the semiconductor device is a so-called vertical semiconductor device having a collector electrode on one surface of the semiconductor chip and an emitter electrode and a gate electrode on the other surface. Is not limited to this. For example, the semiconductor device may be a so-called horizontal semiconductor device having all electrodes on the surface opposite to the substrate side.

1 ... Semiconductor device, 10, 10a, 10b ... Substrate, 12, 12a, 12b ... Chip arrangement surface, 14, 14a, 14b ... Insulating substrate, 16, 16a, 16b ... Circuit, 18, 18a, 18b ... For heat dissipation Metal plate, 20, 20a, 20b ... Chip, 22, 22a, 22b ... Collector electrode, 24, 24a, 24b ... Emitter electrode (electrode), 26 ... Gate electrode, 30, 30a, 30b, 30c, 30d, 30e, 30f , 30g, 62, 64, 66 ... Leads, 32, 32a, 32b, 32c, 32d, 32e, 32f, 32g, ... Electrode connection pieces, 34 ... External connection terminals, 36, 36a, 36b, 36c, 36d, 36f, 36g ... Convex, 37, 37a, 37b, 37c, 37d, 36f, 36g ... Top of convex, 38, 38a, 38b, 38c, 38d, 38f, 38g ... Through hole, 40, 46 ... Solder, 41, 42, 43, 45 ... Solder material, 50, 51, 52 ... Assembly, 70 ... Wire, 80 ... Resin

Claims (1)

A semiconductor chip arranging step of arranging a semiconductor chip having electrodes formed on a surface opposite to the surface facing the semiconductor chip arranging surface on the semiconductor chip arranging surface of the substrate.
A through hole penetrating from a surface on the semiconductor chip side to a surface on the side opposite to the semiconductor chip side, a convex portion having a shape in which a portion around the through hole is bent toward the semiconductor chip side in a curved shape, and the above. It has an electrode joint having a concave portion formed on the surface opposite to the semiconductor chip side corresponding to the convex portion, and the solder material is arranged on the surface of the electrode joint portion opposite to the semiconductor chip. The lead terminals are arranged so that the electrodes of the semiconductor chip and the electrode joints face each other at a predetermined distance, and the convex portions project toward the electrodes. Assembly forming process to form the assembly
By melting the solder material, pouring the solder material between the electrode and the electrode joint portion through the through hole, and then solidifying the solder material, the electrode and the electrode joint portion are soldered. joined through the wood, saw including a bonding step of bonding the solder material to the electrode junction remote from the electrode bonded part and the convex portions of the periphery of the convex portion as well as joined to the convex portion,
A method for manufacturing a semiconductor device, characterized in that, in the assembly forming step, a solder material is also arranged in a part of the space between the electrode and the electrode joint.

Images