Semiconductor device and method for manufacturing semiconductor device

Abstract

The present invention provides a semiconductor device comprising a lead frame and a semiconductor component secured at a prescribed position on the lead frame via a bonding material, wherein the lead frame has at least one protruding portion provided to face a lateral peripheral surface of the semiconductor component.

Description

Semiconductor device and method for manufacturing the same

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

[0002] One technology related to a semiconductor device and a method for manufacturing the same is disclosed in Patent Document 1. Patent Document 1 describes that "a recess on the backside of a semiconductor chip is fitted to a protrusion on a die pad of a lead frame with a thermosetting liquid resin having conductive particles dispersed therein, thereby die-bonding the semiconductor chip to the die pad," and that this "makes it possible to accurately mount the semiconductor chip in a predetermined position on the die pad and fix it in place."

[0003] Japanese Patent Application Publication No. 03-284857

[0004] However, the technology of Patent Document 1 mentioned above requires special processing to form recesses, protrusions, etc. on both sides of the lead frame and the semiconductor chip, which increases the number of manufacturing steps and costs.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a semiconductor device in which semiconductor components are accurately aligned and fixed to a lead frame while suppressing increases in the number of manufacturing steps and costs, and to provide a method for manufacturing the same.

[0006] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present application includes multiple means for solving the above problems, but one example is a semiconductor device including a lead frame and a semiconductor component fixed to a predetermined position of the lead frame via a bonding material, wherein the lead frame has at least one protrusion provided facing a side peripheral surface of the semiconductor component.

[0007] According to the present invention, it is possible to provide a semiconductor device in which a semiconductor component is fixed to a lead frame in accurate alignment while suppressing an increase in the number of manufacturing steps and costs, and to provide a method for manufacturing the same.

[0008] 1 is a cross-sectional view showing the configuration of the semiconductor device of the first embodiment; 2 is a plan view showing the configuration of the semiconductor device of the first embodiment; 3 is a perspective view showing an application example of the semiconductor device of the first embodiment; 4 is a plan view showing a modification of the application example of the semiconductor device of the first embodiment; 5 is a process diagram (part 1) showing a method for manufacturing the semiconductor device of the first embodiment; 6 is a process diagram (part 2) showing a method for manufacturing the semiconductor device of the first embodiment; 7 is a cross-sectional view showing a first modification of the semiconductor device of the first embodiment; 8 is a plan view showing a second modification of the semiconductor device of the first embodiment; 9 is a cross-sectional view showing a second example of a protrusion in the semiconductor device of the first embodiment; 10 is a cross-sectional view showing a third example of a protrusion in the semiconductor device of the first embodiment; 11 is a cross-sectional view showing a fourth example of a protrusion in the semiconductor device of the first embodiment; 12 is a cross-sectional view showing a fifth example of a protrusion in the semiconductor device of the first embodiment; 13 is a cross-sectional view showing a sixth example of a protrusion in the semiconductor device of the first embodiment; 14 is a cross-sectional view showing a configuration of the semiconductor device of the second embodiment; 15 is a cross-sectional view showing a configuration of the semiconductor device of the third embodiment; 16 is a cross-sectional view showing a configuration of the semiconductor device of the fourth embodiment.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the embodiments described below, the same components are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0010] First Embodiment Configuration of Semiconductor Device Fig. 1 is a cross-sectional view showing the configuration of a semiconductor device according to a first embodiment. Fig. 2 is a plan view showing the configuration of the semiconductor device according to the first embodiment, and corresponds to a view seen from the direction of the arrow in Fig. 1. The semiconductor device 1 according to the first embodiment shown in Figs. 1 and 2 includes a lead frame 100 and a semiconductor component 300 fixed onto a die pad 100a of the lead frame 100 via a bonding material 200. Note that only a main portion of the lead frame 100 is shown in the drawings.

[0011] The semiconductor component 300 has, for example, a semiconductor chip 301 sealed in a molded resin package 302, and has a lower electrode 303 to which the semiconductor chip 301 is die-bonded, and an upper electrode 304 disposed opposite the lower electrode 303. The lower electrode 303 and the upper electrode 304 form the outer peripheral surface of the package 302, and the lower electrode 303 is bonded to the lead frame 100 by a bonding material 200.

[0012] Here, the bonding material 200 is assumed to be a bonding material having conductivity, such as solder, metal paste, metal powder, or anisotropic conductive material.

[0013] In the semiconductor device 1 configured as described above, the lead frame 100 has at least one protrusion 101 erected facing the side peripheral surface 300a of the semiconductor component 300. Here, as an example, a configuration is illustrated in which protrusions 101 are provided at two positions sandwiching the semiconductor component 300. Each protrusion 101 is made of a cut-out piece of the lead frame 100 that stands up on the side where the semiconductor component 300 is fixed.

[0014] The protrusion 101 made of such a segment has a shape in which the middle portion in the rising direction of the segment is convex toward the side peripheral surface 300a of the semiconductor component 300. Furthermore, it is preferable that such a protrusion 101 has a shape that is curved along the rising direction of the segment. In such a protrusion 101, the height [H1] to the convex end 101a arranged closest to the semiconductor component 300 is set to a height that reaches the semiconductor component 300, taking into account the thickness of the bonding material 200. This allows the semiconductor component 300 to be aligned with the protrusion 101 more accurately.

[0015] Furthermore, the minimum opening width [W1] between the protrusions 101 arranged on either side of the semiconductor component 300 is set slightly larger than the width [W3] of the semiconductor component 300, so that the semiconductor component 300 can slide up and down freely between the protrusions 101. This allows the semiconductor component 300 to sink into the lead frame 100 when the bonding material 200 is fluidized by heat treatment, for example, when the solder of the bonding material is reflowed, in the manufacture of a semiconductor device, which will be described later.

[0016] Furthermore, the protrusion 101 having such a shape has a shape that moves away from the side peripheral surface 300a of the semiconductor component 300 from the convex end 101a toward the tip side of the protrusion 101. This makes it easier to fit the semiconductor component 300 between the two protrusions 101 in the manufacture of a semiconductor device, which will be described later. Furthermore, even if the lead frame 100 has only one protrusion 101, the shape of the protrusion 101 makes it easier to position the semiconductor component 300 adjacent to the protrusion 101.

[0017] The lead frame 100 also has a hole 100b formed by cutting out a segment. Here, the segment that forms the protrusion 101 is a portion of the lead frame 100 cut out from near the periphery of the semiconductor component 300 in a direction that overlaps the semiconductor component 300 in a planar view. The cutout segment extends outward from the semiconductor component 300 in a direction away from the semiconductor component 300, thereby forming the protrusion 101. Therefore, the hole 100b formed by cutting out the segment is provided at a position that overlaps the peripheral edge of the semiconductor component 300 in a planar view. Such a hole 100b is preferably shaped to overlap the edge of the lower electrode 303 of the semiconductor component 300 in a planar view. This makes it possible to easily check the wetting and spreading properties of the bonding material 200 on the lower electrode 303.

[0018] In consideration of dissipating heat from the semiconductor component 300 through the lead frame 100, it is preferable that the width of the piece that constitutes the protrusion 101 in the direction along the semiconductor component 300 is small.

[0019] 3 is a perspective view showing an application example of the semiconductor device 1 of the first embodiment, and corresponds to an exploded view of the semiconductor device 1. Note that the previously shown FIGS. 1 and 2 also show the main part of the semiconductor device 1 shown in FIG.

[0020] 3, the semiconductor device 1 has a plurality of (e.g., four) electrically independent lead frames 100, with a plurality of semiconductor components 300 fixed to each of some (e.g., two) of the lead frames 100. The semiconductor components 300 are fixed to the lead frames 100 by bonding material 200 (not shown) as described with reference to FIGS. 1 and 2. The lead frame 100 also has protrusions 101 erected on the side surfaces 300a of the semiconductor components 300, with each semiconductor component 300 sandwiched between the protrusions 101.

[0021] The semiconductor components 300 fixed to each lead frame 100 and the selected lead frame 100 are connected by conductive clips 400 and sealed in a molded resin package (not shown here). Furthermore, each lead frame 100 has outer leads 100c extending outward from the package, and these outer leads 100c are connected to wiring on a mounting board.

[0022] FIG. 4 is a plan view showing a modified example of the application of the semiconductor device 1′ of the first embodiment. The semiconductor device 1′ shown in this figure differs from the semiconductor device 1 shown in FIG. 3 only in the arrangement of the protrusions 101; otherwise, they are similar. As shown in FIGS. 3 and 4, the direction in which the semiconductor component 300 is clamped by the protrusions 101 is not limited, and an appropriate direction may be selected depending on the layout of each semiconductor device 1, 1′. Note that FIG. 4 does not show the clip 400 shown in FIG. 3, and instead shows a molded resin package 500 that seals multiple lead frames 100.

[0023] 5 and 6 are process diagrams (part 1) and (part 2) showing a method for manufacturing a semiconductor device according to the first embodiment. The method for manufacturing the semiconductor device shown in FIGS. 1 to 4 will be described below in the order shown in FIGS. 5 and 6.

[0024] First, in the first step (1) shown in FIG. 5 , a lead frame material 100′ is prepared, and a bonding material 200 is placed in a region corresponding to the die pad 100a. The bonding material 200 is placed, for example, by coating. Then, in the second step (2), a protrusion 101 is formed on the side of the bonding material 200, for example, at a position that sandwiches the bonding material 200. The protrusion 101 is formed by cutting out a portion of the lead frame material 100′, pushing out the cut-out piece from the opposite side of the bonding material 200 to raise it toward the bonding material 200, and further curving or bending the piece into a desired shape as needed. This completes the preparation of a lead frame 100 having a protrusion 101 on the side of the bonding material 200 provided on the die pad 100a. Note that the step of cutting out the lead frame material 100′ may be performed simultaneously with the step of cutting out the lead frame material 100′ to the outer shape of the lead frame. In addition, the placement of the bonding material 200 on the die pad 100a of the lead frame 100 may be performed after the protrusion portion 101 is formed, and may be performed in a process appropriately selected depending on the material of the bonding material 200.

[0025] In the next third step (3), the semiconductor component 300 is aligned with respect to the lead frame 100. Here, alignment is performed so that the semiconductor component 300 overlaps the bonding material 200 and the side circumferential surface 300a of the semiconductor component 300 abuts against the protrusions 101. At this time, if the protrusions 101 are arranged on both sides of the bonding material 200, the semiconductor component 300 only needs to be positioned between the two protrusions 101, making alignment easy. Furthermore, because the protrusions 101 have a shape that moves away from the side circumferential surface 300a of the semiconductor component 300 toward their tip ends, the semiconductor component 300 can be easily guided between the protrusions 101 without the tip ends of the protrusions 101 getting caught on the semiconductor component 300.

[0026] Next, in the fourth step (4) shown in FIG. 6 , the semiconductor component 300 is placed on the die pad 100a of the lead frame 100 via the bonding material 200. In this state, the semiconductor component 300 is disposed between the protrusions 101. Therefore, for example, by using the protrusions 101 to hold down the semiconductor component 300, it is possible to prevent the semiconductor component 300 from falling off during transportation before being fixed. Furthermore, as shown in the figure, if the shape of the protrusions 101 is such that the middle portion in the rising direction of the piece is convex toward the side surface 300a of the semiconductor component 300, this convex middle portion can hold down the semiconductor component 300, thereby preventing the semiconductor component 300 from being damaged by the tip of the piece.

[0027] After the above steps, the bonding material 200 is heat-treated to fix the semiconductor component 300 to the die pad 100a of the lead frame 100. This results in the semiconductor device 1 shown in FIG. 1 being obtained. During this heat treatment, the bonding material 200 softens or melts and flows, covering the lower electrode 303 of the semiconductor component 300 with the bonding material 200. At this time, if the hole 100b has a shape that overlaps the edge of the lower electrode 303 of the semiconductor component 300 in a planar view, it is easy to confirm that the lower electrode 303 has been covered with the bonding material 200, as described above. On the other hand, if there is a problem with the wetting and spreading property of the bonding material 200 on the lower electrode 303 or if the amount of bonding material 200 is small, it is possible to confirm that the edge of the lower electrode 303 is exposed in the hole 100b.

[0028] Effect of First Embodiment The semiconductor device 1 of the first embodiment described above has a configuration in which the lead frame 100 has the protrusion 101 facing the side peripheral surface 300a of the semiconductor component 300. This makes it possible to provide a semiconductor device 1 in which the semiconductor component 300 is accurately aligned with the lead frame 100, without requiring any special processing on the semiconductor component 300. This also makes it possible to provide the semiconductor device 1 with fewer processes and at lower cost than a semiconductor device in which processing for alignment is also performed on the semiconductor component 300.

[0029] <Modification 1> The semiconductor device 1 of the first embodiment described above can be modified as follows. FIG. 7 is a cross-sectional view showing Modification 1 of the semiconductor device of the first embodiment. In the semiconductor device 1" shown in FIG. 7, the semiconductor component 300' is not packaged in mold resin but is made up of a semiconductor chip. Even with this type of semiconductor device 1", the same effects can be obtained.

[0030] 8 is a plan view showing a second modification of the semiconductor device of the first embodiment. As shown in these figures, the protrusions 101 provided on the lead frame 100 are arranged in various states relative to the side surfaces of the semiconductor component 300. For example, the semiconductor device 1a is an example of the first embodiment described above, and is an example in which the protrusions 101 of the lead frame 100 are arranged so as to sandwich the semiconductor component 300 from two directions.

[0031] Furthermore, semiconductor device 1b is an example in which protrusions 101 of lead frame 100 are arranged so as to sandwich semiconductor component 300 from four directions. With such semiconductor device 1b, semiconductor component 300 can be aligned with lead frame 100 in two planar directions. Furthermore, in manufacturing this semiconductor device 1b, before reflow treatment of bonding material 200 (see FIG. 6 ), it is possible to prevent semiconductor component 300 placed on lead frame 100 via bonding material 200 from falling off in four directions.

[0032] Furthermore, the semiconductor device 1c has a lead frame 100 with multiple protrusions 101 arranged on one side circumferential surface facing one direction of the semiconductor component 300. The illustrated semiconductor device 1c illustrates a configuration in which two protrusions 101 are arranged on one side circumferential surface of the semiconductor component 300, but three or more protrusions 101 may be arranged. In this case, it is preferable to arrange the protrusions 101 at separate positions on one side circumferential surface. This makes it possible to prevent tilting of the semiconductor component 300 in the rotational direction when aligning the semiconductor component 300 with the lead frame 100. Even in this case, it is preferable to arrange the protrusions 101 at positions where the semiconductor component 300 is clamped.

[0033] Furthermore, the semiconductor device 1d has a semiconductor component 300 that is rectangular in plan view. In this case, the protrusions 101 are preferably provided on the shorter sides of the rectangular shape of the semiconductor component 300 at positions that sandwich the semiconductor component 300. This makes it possible to prevent tilting of the semiconductor component 300 in the rotational direction when aligning the semiconductor component 300 with the lead frame 100. Note that each of the above-described second variations can also be applied to the above-described first variation, and the same applies when a semiconductor component 300' made of a semiconductor chip is used.

[0034] 9 to 13 are cross-sectional views showing second to sixth examples of the protrusion in the semiconductor device of the first embodiment. Hereinafter, examples of the shape of the protrusion in the semiconductor device of the first embodiment will be described with reference to FIGS.

[0035] 9 differs from the protrusion 101 shown in Fig. 1 in that the segment that constitutes the protrusion 102 is bent at the middle in the direction rising from the lead frame 100, but the other configurations are the same. Even with this configuration, it is possible to obtain the same effects as in the first embodiment.

[0036] As shown in FIG. 10 , protrusion 103 may be a cutout of lead frame 100 that extends substantially perpendicularly from lead frame 100. Also, as shown in FIG. 11 , protrusion 104 may be a cutout of lead frame 100 that extends at an obtuse angle θ1 relative to lead frame 100. In either of the configurations shown in FIGS. 10 and 11 , when protrusions 103, 1045 are positioned to sandwich semiconductor component 300, the minimum width [W1] between protrusions 103 or 104 is set in consideration of the width [W3] of semiconductor component 300. This allows semiconductor component 300 to be aligned with lead frame 100 without any special processing of semiconductor component 300.

[0037] 12, the protrusions 105 may be formed by cutting out a portion of the lead frame 100 and raising the cut piece at an acute angle θ2 relative to the lead frame 100. In such a configuration, when the protrusions 105 are arranged to sandwich the semiconductor component 300, a minimum width [W1] between the protrusions 105 is set so as not to interfere with the fixation of the lead frame 100 and the semiconductor component 300 via the bonding material 200. Even with protrusions 105 of this shape, the semiconductor component 300 can be aligned with the lead frame 100 without any special processing being performed on the semiconductor component 300.

[0038] 13, the semiconductor component 300 may be disposed between protrusions 101 and 103 of different shapes. The protrusions 101 and 103 of different shapes may be replaced with any of the protrusions 102 to 105 shown in FIGS. 9 to 12. Even with this configuration, the semiconductor component 300 can be aligned with the lead frame 100 without any special processing of the semiconductor component 300. In this case, by using the protrusion 101 (and protrusion 102) having a shape that moves away from the side surface 300a of the semiconductor component 300 toward its tip, it is possible to easily guide the semiconductor component 300 between the protrusions 101 when aligning the semiconductor component 300 with the lead frame 100.

[0039] The above examples of the shape of the protrusions can also be applied to the above-mentioned modified example 1 (FIG. 7) and modified example 2 (FIG. 8).

[0040] 14 is a cross-sectional view showing the configuration of a semiconductor device 2 according to a second embodiment. The semiconductor device 2 shown in this figure differs from the semiconductor device 1 according to the first embodiment in the cutout direction of the piece that constitutes the protrusion 101′ and the position of the resulting hole 100b′, but the other configurations are similar.

[0041] That is, the segment that constitutes the protrusion 101' is a portion obtained by cutting out the lead frame 100 from near the periphery of the semiconductor component 300 in a planar view, toward the outside of the semiconductor component 300. The cutout segment is raised toward the semiconductor component 300, in a direction approaching the semiconductor component 300, and constitutes the protrusion 101'. For this reason, the hole 100b' formed by cutting out the segment does not overlap the semiconductor component 300 in a planar view, and is provided outside the semiconductor component 300.

[0042] The manufacturing method of the semiconductor device 2 of the second embodiment having such a configuration is similar to the manufacturing method of the semiconductor device 1 of the first embodiment.

[0043] The semiconductor device 2 having the above configuration can also achieve the same effects as the semiconductor device 1 of the first embodiment. However, since the hole 100b′ does not overlap with the semiconductor component 300 in a plan view, the wetting and spreading property of the bonding material 200 on the lower electrode 303 cannot be confirmed from the hole 100b′.

[0044] The second embodiment can also be applied to the first modification (FIG. 7) and the second modification (FIG. 8) of the first embodiment, as well as the examples of the shapes of the protrusions (FIGS. 9 to 13).

[0045] Third Embodiment Figure 15 is a cross-sectional view showing the configuration of a semiconductor device 3 according to a third embodiment. The semiconductor device 3 shown in this figure has a configuration that combines the first and second embodiments. That is, the semiconductor device 3 has a protrusion 101 formed by cutting out the lead frame 100 from near the periphery of the semiconductor component 300 in a direction that overlaps with the semiconductor component 300 in a plan view, and a protrusion 101' formed by cutting out the lead frame 100 toward the outside of the semiconductor component 300. The configuration of each of the protrusions 101, 101' is the same as that of the above-described embodiments.

[0046] The manufacturing method of the semiconductor device 3 of the third embodiment having such a configuration is similar to the manufacturing method of the semiconductor device 1 of the first embodiment.

[0047] Even with the semiconductor device 3 configured as above, it is possible to obtain the same effects as the semiconductor device 1 of the first embodiment.

[0048] The third embodiment can also be applied to the first modification (FIG. 7), the second modification (FIG. 8) and the examples of the shapes of the protrusions (FIGS. 9 to 13) of the first embodiment.

[0049] 16 is a cross-sectional view showing the configuration of a semiconductor device 4 of a fourth embodiment. The semiconductor device 4 shown in this figure differs from the semiconductor device 1 of the first embodiment in that the protrusions 110 are formed by partial deformation of the lead frame 100, and the lead frame 100 does not have holes associated with the formation of the protrusions 110. As with the other embodiments, the protrusions 110 are provided facing the side peripheral surface of the semiconductor component 300.

[0050] The manufacturing method of the semiconductor device 4 of the fourth embodiment having such a configuration is the same as the manufacturing method of the semiconductor device 1 of the first embodiment except for the step of forming the protrusion 110 .

[0051] Even with the semiconductor device 4 having such a configuration, the semiconductor component 300 can be aligned with the lead frame 100 without any special processing being performed on the semiconductor component 300 .

[0052] In the fourth embodiment, the protrusion 110 is configured by partially deforming the lead frame 100. However, the protrusion 110 may be fixed on the lead frame 100. The fourth embodiment is also applicable to the above-described first modification (FIG. 7) and second modification (FIG. 8) of the first embodiment, and to each of the examples of the shape of the protrusion (FIGS. 9 to 13).

[0053] Furthermore, the present invention is not limited to the above-described embodiments and modifications, and includes various other modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0054] DESCRIPTION OF SYMBOLS 1, 1', 1'', 1a to 1d, 2 to 4... Semiconductor device 100... Lead frame 100a... Die pad 100b, 100b'... Hole portion 101, 101', 102 to 105... Projection portion (piece) 110... Projection portion 200... Bonding material 300, 300'... Semiconductor component 300a... Side peripheral surface 303... Lower electrode

Claims

1. A semiconductor device comprising a lead frame and a semiconductor component fixed to a predetermined position on the lead frame via a bonding material, wherein the lead frame has at least one protrusion facing the side surface of the semiconductor component.

2. The semiconductor device according to claim 1, wherein the protrusion is formed by cutting out a part of the lead frame and raising the cut piece toward the side where the semiconductor component is fixed.

3. The semiconductor device according to claim 2, wherein the protruding portion has a shape in which the middle portion in the rising direction of the segment is convex toward the side peripheral surface of the semiconductor component.

4. The semiconductor device according to claim 2, wherein the segment is raised toward the outside of the semiconductor component, and the lead frame has a hole formed by cutting out the segment at a position that overlaps the semiconductor component in a plan view.

5. The semiconductor device according to claim 4, wherein the semiconductor component has an electrode on a surface facing the lead frame, and an edge of the electrode is arranged to overlap the hole in a plan view.

6. The semiconductor device according to claim 1, wherein the protrusions are provided at positions that sandwich the semiconductor component.

7. The semiconductor device according to claim 1, wherein the protrusion has a shape that moves away from the side surface of the semiconductor component toward the tip.

8. The semiconductor device according to claim 1, wherein the semiconductor component has a rectangular shape in a plan view, and the protrusions are provided on the short sides of the rectangular shape of the semiconductor component at positions that sandwich the semiconductor component.

9. The semiconductor device according to claim 1, wherein a plurality of the semiconductor components are fixed onto the lead frame via the bonding material, and the protrusions are provided facing the side surfaces of the plurality of semiconductor components, respectively.

10. A method for manufacturing a semiconductor device, comprising: preparing a lead frame having a protrusion on the side of a bonding material provided on a die pad; aligning the semiconductor component with the lead frame so that the semiconductor component overlaps the bonding material and the side surface of the semiconductor component abuts against the protrusion; placing the semiconductor component on the lead frame via the bonding material; and fixing the semiconductor component to the lead frame by heat treating the bonding material.

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