Lead frames and semiconductor devices

Abstract

To provide a lead frame and a semiconductor device, capable of suppressing a mount material from flowing out of a region on which a semiconductor chip is to be mounted.SOLUTION: A lead frame according to the present embodiments includes: a main body portion having a main surface including a mounting region on which a semiconductor chip is to be mounted; a lead portion connected to the main body portion; a groove portion provided in the main surface of the main body portion so as to surround the mounting region and having an inner side surface and an outer side surface; and a protruding portion provided so as to protrude along an inner edge of the groove portion.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] Embodiments of the present invention relate to a lead frame and a semiconductor device.

Background Art

[0002] As a semiconductor device manufactured using a lead frame, there is a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or the like. The semiconductor device has a structure in which a semiconductor chip disposed on a metal plate via a mounting material is coated with a molding resin or the like. When the molding resin absorbs moisture, moisture aggregates between the sealing portion and the metal plate. When the semiconductor device becomes hot in such a state, the sealing portion and the metal plate may be peeled off due to the vapor pressure of the moisture. In order to avoid such a situation, a method of providing a groove portion in the metal plate to suppress peeling between the molding resin and the metal plate is known.

[0003] However, in the manufacture of a semiconductor device, when a semiconductor chip is mounted on a metal plate via a mounting material, the mounting material may flow out from the mounting region. As a result, for example, the mounting material flows into the groove portion, and peeling between the sealing portion and the metal plate is likely to occur.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Embodiments of the present invention provide a lead frame and a semiconductor device that suppress the leakage of mounting material from the mounting area of ​​a semiconductor chip. [Means for solving the problem]

[0006] The lead frame according to this embodiment comprises a main body portion having a main surface including a mounting area on which a semiconductor chip is mounted, a lead portion connected to the main body portion, a groove portion provided on the main surface of the main body portion so as to surround the mounting area and having an inner surface and an outer surface, and a protruding portion projecting along the inner edge of the groove portion. [Brief explanation of the drawing]

[0007] [Figure 1A] (a) is a plan view of the lead frame according to the embodiment. (b) is a side view of the lead frame according to the embodiment. [Figure 1B] This is a cross-sectional view of the lead frame according to the first embodiment, shown by line II in Figure 1A(a). [Figure 2] This is a cross-sectional view corresponding to Figure 1B of the semiconductor device according to the first embodiment. [Figure 3] (a) is a longitudinal cross-sectional view of the groove portion of the lead frame according to the first embodiment. (b) is a longitudinal cross-sectional view of the groove portion of the semiconductor device according to the first embodiment. [Figure 4] (a) is a longitudinal cross-sectional view of the groove portion of the lead frame according to a first modified example of the first embodiment. (b) is a longitudinal cross-sectional view of the groove portion of the lead frame according to a second modified example of the first embodiment. [Figure 5] This is a longitudinal cross-sectional view of the groove portion of a lead frame according to a third modified example of the first embodiment. [Figure 6] This is a perspective view of a jig for forming a groove according to the first embodiment. [Figure 7] This is a diagram illustrating the process of forming a groove according to the first embodiment. [Figure 8] (a) is an SEM image of the side surface of the groove according to the embodiment. (b) is an SEM image of the main surface according to the embodiment. [Figure 9] (a) is a longitudinal cross-sectional view of the groove portion of the lead frame according to the second embodiment. (b) is a longitudinal cross-sectional view of the groove portion of the semiconductor device according to the second embodiment. [Figure 10] This is a diagram illustrating the process of forming a groove according to the second embodiment. [Figure 11] (a) is a longitudinal cross-sectional view of the groove portion of the lead frame according to the third embodiment. (b) is a longitudinal cross-sectional view of the groove portion of the semiconductor device according to the third embodiment. [Figure 12] This is a partially transparent perspective view of a jig for forming a groove according to the third embodiment. [Figure 13] This is a partially transparent front view of a jig for forming a groove according to the third embodiment. [Figure 14] This is a side view of a jig for forming a groove according to the third embodiment. [Figure 15] This is a diagram illustrating the process of forming a groove according to the third embodiment. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings. The drawings are schematic or conceptual, and the proportions of each part may not necessarily be the same as those of actual objects. In the specification and drawings, elements similar to those described above are denoted by the same reference numerals with respect to previously shown drawings, and detailed explanations are omitted as appropriate.

[0009] In this specification, terms such as "orthogonal," "parallel," and "acutely intersecting," as well as dimensions and values ​​of physical properties used to specify shapes, geometric conditions, and physical properties, and their degrees, shall not be strictly interpreted, but shall be interpreted to include a range that allows for the expectation of similar functionality.

[0010] (First Embodiment) Referring to FIGS. 1A and 1B, the lead frame 1 according to the first embodiment will be described. FIG. 1A(a) is a plan view of the lead frame 1 according to the present embodiment, and FIG. 1A(b) is a side view of the lead frame 1 according to the present embodiment. FIG. 1B is a cross-sectional view taken along line I-I in FIG. 1A(a) of the lead frame 1 according to the present embodiment.

[0011] As shown in FIGS. 1A and 1B, the lead frame 1 includes a main body part (mounting part) 2, a plurality of lead parts 4, a groove part 5, a protruding part 6, a protruding part 6A, a tie bar 7, a frame 8, and a through hole 9. The lead frame 1 can be obtained, for example, by punching a metal plate. Note that the material of the lead frame 1 is not particularly limited, and examples thereof include copper, 42% Ni-Fe alloy (42 alloy), etc.

[0012] The main body part 2 has a main surface 2s including a mounting area 3. The mounting area 3 is also called a bed part and is an area where a semiconductor chip 60 described later is mounted.

[0013] In the present embodiment, three lead parts 4 are provided. One of them is directly connected to the main body part 2, and the remaining two are connected to the main body part 2 via the tie bar 7 and the frame 8. The tie bar 7 and the frame 8 are removed in the process of manufacturing a semiconductor device 40 (described later) using the lead frame 1. Note that the number, shape, etc. of the lead parts 4 are arbitrary.

[0014] The groove part 5 is provided on the main surface 2s of the main body part 2 so as to surround the mounting area 3. Note that the groove part 5 may be provided so as to continuously surround the mounting area 3 as shown in FIG. 1A, or may be provided so as to intermittently surround it.

[0015] The protruding portion 6 is provided on the main surface 2s of the main body portion 2 and protrudes along the inner edge of the groove portion 5 (i.e., the side of the groove portion 5 that is on the mounting area 3 side). In other words, the protruding portion 6 is provided so as to surround the mounting area 3. As will be described in detail later, this makes it possible to suppress the outflow of the mounting material 80 from the mounting area 3 when the semiconductor chip 60 is mounted. Preferably, the protruding portion 6 is provided so as to surround the mounting area 3 without any gaps. However, a gap in a part of the protruding portion 6 is acceptable as long as it provides the above effect.

[0016] The protruding portion 6A is provided on the main surface 2s of the main body portion 2 and protrudes along the outer edge of the groove portion 5 (i.e., the side of the groove portion 5 opposite to the mounting area 3). The protruding portion 6A may be provided so as to surround the mounting area 3 without any gaps, or gaps may be provided in the shape of dashed lines. Furthermore, as shown in Figure 5 described later, the protruding portion 6A may not be provided at all.

[0017] The through-hole 9 is provided in the main body portion 2 of the lead frame 1. The through-hole 9 is a hole for inserting screws or the like to fix the semiconductor device 40 to a heat sink or the like. Note that the through-hole 9 is not required.

[0018] Next, with reference to Figure 2, a semiconductor device 40 manufactured using the lead frame 1 will be described. Figure 2 is a cross-sectional view of the semiconductor device 40 according to this embodiment, corresponding to Figure 1B. The semiconductor device 40 is, for example, a MOSFET.

[0019] As shown in Figure 2, the semiconductor device 40 comprises a main body (mounting portion) 2, a groove portion 5, protruding portions 6, 6A, a semiconductor chip 60, a sealing portion 70, and a mounting material 80. Although not shown, the semiconductor device 40 also comprises a plurality of lead portions 4 and through holes 9. Of these, the main body portion 2, lead portions 4, groove portion 5, protruding portions 6, 6A, and through holes 9 are the same as those of the lead frame 1, so their explanation is omitted.

[0020] As shown in Figure 2, the semiconductor chip 60 is mounted on the mounting area 3 of the main body 2 via the mounting material 80. More specifically, the semiconductor chip 60 is mounted on the mounting area 3 of the main body 2, which is surrounded by the groove 5 and the protruding parts 6, 6A, via the mounting material 80. The semiconductor chip 60 may also be electrically connected to the lead part 4 via a cable (not shown). Furthermore, the semiconductor chip 60 may also be electrically connected to the main body 2 via the mounting material 80.

[0021] The position of the semiconductor chip 60 can be arbitrary as long as it is on the mounting area 3. Furthermore, multiple semiconductor chips may be mounted on the mounting area 3.

[0022] The sealing portion 70 is provided to embed the protruding portions 6, 6A, the semiconductor chip 60, and the mounting material 80. The groove portion 5 is also filled with the sealing portion 70. The material of the sealing portion 70 is, for example, epoxy resin.

[0023] The material of the mounting material 80 is, for example, mounting paste, solder, silver sintering agent, etc. As shown in Figure 2, the height of the protruding portion 6 may be higher than the height of the top surface of the mounting material 80. This further suppresses the outflow of the mounting material 80 from the mounting area 3 when the semiconductor chip 60 is mounted on the mounting area 3 via the mounting material 80. Furthermore, having the height of the protruding portion 6 higher than the height of the top surface of the mounting material 80 is advantageous, for example, when the semiconductor chip 60 is mounted near the protruding portion 6 or when multiple semiconductor chips are mounted on the mounting area 3.

[0024] Next, the cross-sectional shape of the groove 5 according to this embodiment will be described in detail with reference to Figure 3. Figure 3(a) is a longitudinal cross-sectional view of the groove 5 of the lead frame 1 according to this embodiment. Figure 3(b) is a longitudinal cross-sectional view of the groove 5 of the semiconductor device 40 according to this embodiment.

[0025] As shown in Figures 3(a) and 3(b), the groove 5 has an inner surface 51, an outer surface 52, and a bottom surface 53. The inner surface 51 is provided perpendicular to the main surface 2s. The outer surface 52 is also provided perpendicular to the main surface 2s and opposite to the inner surface 51. That is, the inner surface 51 and the outer surface 52 are provided opposite each other. The bottom surface 53 is provided to connect the inner surface 51 and the outer surface 52. As shown in Figures 3(a) and 3(b), the bottom surface 53 has an inverted V shape with a raised central portion. More specifically, the bottom surface 53 includes at least a partial surface 53a and a partial surface 53b. Here, the partial surface 53a is connected to the inner surface 51 and intersects the inner surface 51 at an acute angle. The partial surface 53b is connected to the outer surface 52 and intersects the outer surface 52 at an acute angle.

[0026] In this specification, "two surfaces facing each other" means that the two surfaces are substantially parallel. That is, in this embodiment, the inner surface 51 and the outer surface 52 are provided substantially parallel to each other.

[0027] As described above, according to the lead frame 1 and semiconductor device 40 of this embodiment, the protruding portion 6 is provided so as to surround the mounting area 3. This makes it possible to suppress the outflow of the mounting material 80 from the mounting area 3 of the main body 2 when the semiconductor chip 60 is mounted on the main body 2 of the lead frame 1. For example, it is possible to suppress the outflow of the mounting material 80 from the groove portion 5 and the reduction of the bonding area between the groove portion 5 and the sealing portion 70. Furthermore, compared to the case in which the protruding portion 6 is not provided, the bonding area between the main body 2 and the sealing portion 70 is increased, and the peeling of the sealing portion 70 from the main body 2 can be further suppressed. In this embodiment, the protruding portion 6 has a semicircular cross-sectional shape, but it is not limited to this, and may have a rectangular or inverted V-shaped (mountain-shaped) cross-sectional shape.

[0028] Furthermore, in the lead frame 1 and semiconductor device 40 according to this embodiment, the shape of the groove 5 is as described above: the inner surface 51 is perpendicular to the main surface 2s, the outer surface 52 is perpendicular to the main surface 2s and faces the inner surface 51, and the bottom surface 53 connects the inner surface 51 and the outer surface 52. In addition, the bottom surface 53 has a shape that includes a partial surface 53a that intersects the inner surface 51 at an acute angle and a partial surface 53b that intersects the outer surface 52 at an acute angle. That is, the groove 5 has multiple combinations of surfaces that intersect at acute angles. For this reason, in the semiconductor device 40 according to this embodiment, the sealing portion 70 filled in the groove 5 has a shape complementary to the shape of the groove 5. That is, the sealing portion 70 has multiple combinations of surfaces that intersect at acute angles in the portion filled in the groove 5. Therefore, according to this embodiment, peeling of the sealing portion 70 from the main body 2 can be further suppressed.

[0029] The depth of the groove 5 is arbitrary, but a deeper groove is preferable. By increasing the depth of the groove 5, the contact area between the sealing portion 70 and the groove 5 increases. This further suppresses the peeling of the sealing portion 70 from the main body portion 2. The same applies to subsequent embodiments.

[0030] The shape of the base surface 53 is not limited to those described above, and may be as shown in Figures 4(a) and 4(b), for example. In Figure 4(a), the base surface 53A is, so to speak, an inverted W shape. In Figure 4(b), the base surface 53B is an arc shape, so to speak, an inverted U shape. Both the base surface 53A and the base surface 53B intersect the inner surface 51 and the outer surface 52 at an acute angle. Therefore, the same effects as in the above embodiment can be obtained.

[0031] Furthermore, according to the lead frame 1 and semiconductor device 40 of this embodiment, the protruding portion 6A is provided along the outer edge of the groove portion 5. As a result, the bonding area between the main body portion 2 and the sealing portion 70 is increased compared to the case where the protruding portion 6A is not provided, and the peeling of the sealing portion 70 from the main body portion 2 can be further suppressed. Note that, as shown in Figure 5, the protruding portion 6A does not necessarily have to be provided on the outer edge of the groove portion 5. In addition, although the protruding portion 6A has a semicircular cross-sectional shape in this embodiment, it is not limited to this and may have a rectangular or inverted V-shaped (mountain-shaped) cross-sectional shape.

[0032] (Manufacturing method for lead frame according to the first embodiment) Next, an example of a method for manufacturing the lead frame 1 according to the first embodiment will be described with reference to Figures 6 and 7. Figure 6 is a perspective view of the jig 100 used to form the groove 5 according to this embodiment. Figure 7 is a longitudinal cross-sectional view illustrating the process of forming the groove 5 according to this embodiment.

[0033] First, as shown in Figure 6, a jig 100 is prepared for forming the groove 5. The jig 100 comprises a blade 10 and an ultrasonic device 90 connected to the blade 10.

[0034] The blade 10 has a shape complementary to the groove 5. That is, the blade 10 includes a side surface 11, a side surface 12, and a tip surface 13. Here, side surfaces 11 and 12 are parallel to each other. The tip surface 13 includes a partial surface 13a that intersects side surface 11 at an acute angle, and a partial surface 13b that intersects side surface 12 at an acute angle. The material of the blade 10 can be any material as long as it has the hardness necessary to form the groove 5, for example, a cemented carbide.

[0035] The ultrasonic device 90 is an ultrasonic generator that applies ultrasonic vibrations to the blade 10 in the longitudinal and transverse directions. The frequency of the ultrasonic vibrations is, for example, 20 kHz to 100 kHz.

[0036] Next, as shown in Figure 7(1), a lead frame member 1A is prepared. The lead frame member 1A is a lead frame 1 in which the groove portion 5 and protruding portions 6, 6A are not formed. Then, the blade 10 of the jig 100 is brought into perpendicular contact with the main surface 2s of the main body portion 2 of the lead frame member 1A. Note that the lead frame member 1A is not limited to the above, and may be, for example, a metal plate before punching.

[0037] Next, as shown in Figure 7(2), ultrasonic vibrations are applied to the main surface 2s perpendicularly (in the direction of the arrow in the figure) by the ultrasonic device 90. This forms a temporary groove including surfaces corresponding to the inner surface 51, outer surface 52, and bottom surface 53. Here, the inner surface 51 and outer surface 52 are perpendicular to the main surface 2s. The outer surface 52 is opposite the inner surface 51. Furthermore, the bottom surface 53 includes a partial surface 53a that intersects the inner surface 51 at an acute angle and a partial surface 53b that intersects the outer surface 52 at an acute angle.

[0038] Next, as shown in Figure 7(3), ultrasonic vibrations are applied by the ultrasonic device 90 in a direction parallel to the main surface 2s (horizontal direction; direction of the arrow in the figure). This forms the protruding parts 6 and 6A. More specifically, ultrasonic vibrations are applied to the blade 10 in a horizontal direction so that the side surface 11 of the blade 10 abuts against the inner surface 51 of the temporary groove and the side surface 12 of the blade 10 abuts against the outer surface 52 of the temporary groove. This forms the protruding part 6 along the inner edge of the temporary groove and the protruding part 6A along the outer edge of the temporary groove. As a result, the groove 5, the protruding part 6 protruding along the inner edge of the groove 5, and the protruding part 6A protruding along the outer edge of the groove 5 are formed.

[0039] By repeatedly performing the above steps so that the grooves 5 and protrusions 6, 6A surround the mounting area 3, a lead frame 1 having the grooves 5, protrusions 6 and protrusions 6A according to this embodiment can be manufactured.

[0040] Multiple jigs 100 may be used simultaneously. This shortens the process. The same applies to subsequent embodiments.

[0041] More precisely, in the process shown in Figure 7(3), gaps or other features with partially horizontal surfaces may occur at the points where the inner surface 51 and the partial surface 53a intersect, or where the outer surface 52 and the partial surface 53b intersect. The expression "intersects at an acute angle" as used in this specification includes cases where such gaps or features exist.

[0042] Furthermore, in the process shown in Figure 7(3), by ensuring that the side surface 12 of the blade 10 does not come into contact with the outer surface 52 of the temporary groove, a groove 5 without the protruding portion 6A as shown in Figure 5 may be formed. For example, in the process shown in Figure 7(3), by applying a lateral force (leftward direction in the figure) toward the inner surface 51 to the blade 10, a groove 5 without the protruding portion 6A can be formed.

[0043] Referring to Figure 8, the surface roughness of the inner surface 51 and outer surface 52 of the groove 5 of the lead frame 1 according to this embodiment will be described. Figure 8(a) is a scanning electron microscope image (SEM image) of the inner surface 51 ("machined surface" in the figure) according to this embodiment. This figure shows the surface that was machined by ultrasonic vibration in the direction of the arrow from the top in Figure 8. Figure 8(b) is an SEM image of the main surface 2s according to this embodiment.

[0044] The surface roughness of the inner surface 51 (referred to as the "machined surface" in the figure) of the groove 5 according to this embodiment, as shown in Figure 8(a), is rougher than the surface roughness of the main surface 2s, as shown in Figure 8(b). Similarly, the surface roughness of the outer surface 52 of the groove 5 is also rougher than the surface roughness of the main surface 2s. This is because the groove 5 was formed by ultrasonic vibration. The roughness of the inner surface 51 and the outer surface 52 compared to the surface roughness of the main surface 2s enhances the anchoring effect, further suppressing the separation of the sealing portion 70 from the main body portion 2. Surface roughness is evaluated using, for example, the arithmetic mean roughness Ra, maximum height Ry, or ten-point mean roughness Rz as specified in JIS B 0601 (2013).

[0045] As shown in Figure 8(b), in this embodiment, the surface of the main surface 2s is not roughened, but the embodiment is not limited to this, and the surface of the main surface 2s may be roughened.

[0046] As described above, according to the manufacturing method of the lead frame 1 of this embodiment, a lead frame 1 having a groove 5, a protruding portion 6, and a protruding portion 6A having the shapes described above can be manufactured.

[0047] Furthermore, according to the manufacturing method of the lead frame 1 in this embodiment, since the surface roughness of the inner surface 51 and outer surface 52 of the groove 5 is rougher than the surface roughness of the main surface 2s, it is possible to provide a semiconductor device 40 that can further suppress the peeling of the sealing portion 70 from the main body portion 2.

[0048] Furthermore, according to the manufacturing method of the lead frame 1 of this embodiment, the shape and arrangement of the grooves 5 can be easily changed compared to the case in which the grooves 5 are formed by press working using a mold. For example, by changing the settings of the ultrasonic device 90 to change the position, angle, and number of times the blade 10 is applied, grooves 5 of various shapes can be easily formed.

[0049] (Second embodiment) Referring to Figure 9, a lead frame and semiconductor device according to the second embodiment will be described. Figure 9(a) is a longitudinal cross-sectional view of the groove 5A of the lead frame according to this embodiment. Figure 9(b) is a longitudinal cross-sectional view of the groove 5A of the semiconductor device according to this embodiment. The difference between this embodiment and the first embodiment is the shape of the groove. In the following description, the differences from the first embodiment will be the focus, and descriptions of similar parts will be omitted.

[0050] As shown in Figures 9(a) and 9(b), the groove 5A according to this embodiment has an inner surface 51 and an outer surface 52. The inner surface 51 approaches the mounting area 3 as it deepens. The outer surface 52 also approaches the mounting area 3 as it deepens and intersects the inner surface 51 at an acute angle. That is, in the cross-sections shown in Figures 9(a) and 9(b), the longitudinal cross-sectional shape of the groove 5A is V-shaped due to the inner surface 51 and the outer surface 52. The bottom of the groove 5A (the part where the inner surface 51 and the outer surface 52 intersect) is on the mounting area 3 side of the opening of the groove 5A.

[0051] In this embodiment, as shown in Figures 9(a) and 9(b), the protruding portion 6 is provided along the inner edge of the groove portion 5A. On the other hand, the protruding portion 6A is not provided along the outer edge of the groove portion 5B.

[0052] As shown in Figure 9(b), in the semiconductor device according to this embodiment, the groove 5A is filled with a sealing portion 70. The sealing portion 70 has a shape complementary to the groove 5A.

[0053] As described above, according to the lead frame and semiconductor device of the second embodiment, the protruding portion 6 is provided so as to surround the mounting area 3. This makes it possible to suppress the outflow of the mounting material 80 from the mounting area 3 of the main body portion 2 when the semiconductor chip 60 is mounted on the main body portion 2 of the lead frame. In addition, the bonding area between the main body portion 2 and the sealing portion 70 is increased, and the peeling of the sealing portion 70 from the main body portion 2 can be further suppressed.

[0054] Furthermore, according to the lead frame and semiconductor device of this embodiment, the shape of the groove 5A is such that the inner surface 51 approaches the mounting area 3 as it deepens, and the outer surface 52 intersects the inner surface 51 at an acute angle. This enhances the anchoring effect of the sealing portion 70 filled in the groove 5, and further suppresses the peeling of the sealing portion 70 from the main body 2.

[0055] Furthermore, the sealing portion 70 has a combination of surfaces that intersect at an acute angle in the portion filled in the groove 5. This further suppresses the peeling of the sealing portion 70 from the main body 2.

[0056] (Manufacturing method for lead frame according to the second embodiment) Next, an example of a lead frame manufacturing method according to the second embodiment will be described with reference to Figure 10. Figure 10 is a diagram illustrating the process of forming the groove 5A according to the second embodiment. In the following description, the differences from the lead frame manufacturing method according to the first embodiment will be explained, and similar parts will be omitted.

[0057] First, as shown in Figure 10, a jig for forming the groove 5A is prepared. The jig comprises a blade 20 and an ultrasonic device (not shown) connected to the blade 20. The material of the blade 20 can be any material as long as it has the hardness necessary to form the groove 5A, for example, a cemented carbide. The ultrasonic device can be the same as the ultrasonic device 90 described in the first embodiment.

[0058] Next, a lead frame member is prepared as shown in Figure 10. Then, the blade 20 is brought into contact with the main surface 2s of the main body 2 of the lead frame member at an oblique angle. After that, ultrasonic vibrations are applied to the main surface 2s at an oblique angle (in the direction of the arrow in the figure) using an ultrasonic device. As a result, the groove 5A and the protruding portion 6 shown in Figure 9(a) are formed.

[0059] By repeatedly performing the above steps so that the groove 5A and the protruding portion 6 surround the mounting area 3, a lead frame having the groove 5A and the protruding portion 6 according to this embodiment, as shown in Figure 9(a), can be manufactured.

[0060] Furthermore, in this embodiment, the groove portion 5A and the protruding portion 6 can be manufactured by ultrasonic vibration in one direction (diagonal direction). Therefore, the process can be simplified compared to the manufacturing method of the lead frame according to the first embodiment.

[0061] (Third embodiment) Referring to Figure 11, a lead frame and semiconductor device according to the third embodiment will be described. Figure 11(a) is a longitudinal cross-sectional view of the groove 5B of the lead frame according to this embodiment. Figure 11(b) is a longitudinal cross-sectional view of the groove 5B of the semiconductor device according to this embodiment. The difference between this embodiment and the first and second embodiments is the shape of the groove. In the following description, the differences from the first and second embodiments will be the focus, and descriptions of similar parts will be omitted.

[0062] As shown in Figures 11(a) and 11(b), the groove 5B of the lead frame according to this embodiment has an inner surface 51, an outer surface 52, and a bottom surface 53. The groove 5B is, so to speak, roughly dovetail-shaped. That is, the inner surface 51 is provided such that it approaches the mounting area 3 as it gets deeper, and the outer surface 52 is provided such that it moves away from the mounting area 3 as it gets deeper. The bottom surface 53 is provided so as to connect the inner surface 51 and the outer surface 52. As shown in Figures 11(a) and 11(b), the bottom surface 53 has an inverted V-shape with a raised central portion. More specifically, the bottom surface 53 includes a partial surface 53a and a partial surface 53b. Here, the partial surface 53a is connected to the inner surface 51 and intersects the inner surface 51 at an acute angle. The partial surface 53b is connected to the outer surface 52 and intersects the outer surface 52 at an acute angle.

[0063] In this embodiment, as shown in Figures 11(a) and 11(b), a protruding portion 6 is provided along the inner edge of the groove portion 5B. In addition, a protruding portion 6A is provided along the outer edge of the groove portion 5B.

[0064] As shown in Figure 11(b), the groove 5B of the semiconductor device according to this embodiment is filled with a sealing portion 70. The portion of the sealing portion 70 that fills the groove 5B has a shape complementary to the groove 5B.

[0065] As described above, according to the lead frame and semiconductor device of the third embodiment, the protruding portion 6 is provided so as to surround the mounting area 3. This makes it possible to suppress the outflow of the mounting material 80 from the mounting area 3 of the main body portion 2 when the semiconductor chip 60 is mounted on the main body portion 2 of the lead frame. In addition, the bonding area between the main body portion 2 and the sealing portion 70 is increased, and the peeling of the sealing portion 70 from the main body portion 2 can be further suppressed.

[0066] Furthermore, according to the lead frame and semiconductor device of this embodiment, the shape of the groove 5B is as described above: the inner surface 51 approaches the mounting area 3 as it deepens, the outer surface 52 moves away from the mounting area 3 as it deepens, and the bottom surface 53 connects the inner surface 51 and the outer surface 52 and includes a partial surface 53a and a partial surface 53b that intersects with the partial surface 53a, with the partial surface 53a intersecting the inner surface 51 at an acute angle and the partial surface 53b intersecting the outer surface 52 at an acute angle. In other words, the groove 5B has multiple combinations of surfaces that intersect at acute angles. In the semiconductor device of this embodiment, the sealing portion 70 having a shape complementary to the groove 5B has multiple combinations of surfaces that intersect at acute angles in the portion filled in the groove 5B. This makes it possible to further suppress the peeling of the sealing portion 70 from the main body 2. Furthermore, compared to the second embodiment, the anchoring effect of the sealing portion 70 filled in the groove 5 is further enhanced, and the peeling of the sealing portion 70 from the main body 2 can be further suppressed.

[0067] Furthermore, according to the lead frame and semiconductor device of this embodiment, the protruding portion 6A is provided along the outer edge of the groove portion 5B. This increases the bonding area between the main body portion 2 and the sealing portion 70, and further suppresses the peeling of the sealing portion 70 from the main body portion 2.

[0068] (Manufacturing method for lead frame according to the third embodiment) An example of a lead frame manufacturing method according to the third embodiment will be described with reference to Figures 12 to 15. Figure 12 is a partially transparent perspective view of the jig 300 for forming the groove 5B according to this embodiment. Figure 13 is a partially transparent front view of the jig 300, and Figure 14 is a side view of the jig 300. Figure 15 is a diagram illustrating the process of forming the groove 5B according to this embodiment. In Figures 12, 13, and 15, the fixing plate 32 on the front side (front side) of the jig 300 is shown transparently to make the structure of the jig 300 easier to understand. In the following description, the differences from the lead frame manufacturing methods according to the first and second embodiments will be explained, and similar parts will be omitted.

[0069] First, a jig 300 for forming the groove 5B according to this embodiment is prepared. As shown in Figures 12 to 14, the jig 300 comprises an ultrasonic device 90, a jig body 30, a plurality of spring fixing parts 30a protruding from the front and back of the jig body 30, a plurality of springs 31 with one end connected to each spring fixing part 30a, two fixing plates 32 connected to the other end of each spring 31, two fixing pins 33 connecting the two fixing plates 32 to each other, two cutter blades 34 through which each fixing pin 33 is inserted into the center and pivotally supported by each fixing pin 33, spring fixing parts 34a provided on the front and back of each cutter blade 34, and a plurality of springs 35 with both ends connected to the plurality of spring fixing parts 34a, connecting the two cutter blades 34 to each other via the spring fixing parts 34a. The two cutter blades 34 are closed so that their tips 34b meet by the restoring force of the springs 35. The material of the two cutter blades 34 can be any material as long as it has the hardness necessary to form the groove 5B, for example, a cemented carbide.

[0070] Furthermore, the jig body 30 is provided with a recess 36 that accommodates a portion of the cutter blade 34. The shape of the recess 36 is formed such that the width of the tips of the two cutter blades 34 widens when the cutter blade 34 rotates around the fixing pin 33.

[0071] After preparing the jig 300 as described above, the jig 300 is brought into contact perpendicularly with the main surface 2s of the lead frame member, as shown in Figure 15(1). That is, the tip 34b of the cutter blade 34 of the jig 300 is brought into contact with the main surface 2s, as shown in Figure 15(1).

[0072] Next, as shown in Figure 15(2), the ultrasonic device 90 is driven to apply ultrasonic vibrations perpendicular to the main surface 2s (in the direction of the arrow in the figure). As the excavation of the groove progresses, the tip 34b of the cutter blade 34 receives an upward force from the main surface 2s as a reaction, causing the fixing plate 32 to rise relative to the jig body 30 against the restoring force of the spring 31. As a result, the base end 34c of the cutter blade 34 moves along the surface of the recess 36 of the jig body 30, causing the tip 34b of each cutter blade to move outward against the restoring force of the spring 35, and widening the gap between the tips 34b. As a result, the groove 5B and protrusions 6, 6A with the shape shown in Figure 15(2) are formed.

[0073] By repeatedly performing the above steps so that the groove 5B and protrusions 6, 6A surround the mounting area 3, a lead frame having the groove 5B and protrusions 6, 6A according to this embodiment can be manufactured.

[0074] The groove 5B may also be formed by ultrasonic machining from two oblique directions using the jig of the second embodiment. Preferably, the jig 300 of this embodiment is used. This allows manufacturing by ultrasonic vibration in one direction (vertical direction), shortening the process. In addition, the shape of the groove 5B can be formed more stably.

[0075] While several embodiments of the present invention have been described, these embodiments and examples are presented as examples only and are not intended to limit the scope of the invention. These embodiments and examples can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and examples and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0076] 1 Lead frame 1A Lead frame member 2 Main body 2s main surface 3 Loading area 4 Lead section 5,5A,5B Groove 6,6A Protruding section 7 Tie Bar 8 frames 9 Through hole 10 blades 11,12 Side view 13 Tip surface 20 blades 30 Jig body 30a, 34a Spring fixing part 31,35 springs 32 Fixing plate 33 Fixing pins 34 cutter blades 34b Tip 34c proximal end 36 recesses 40 Semiconductor Equipment 51 Inner surface 52 External surface 53 Bottom 60 semiconductor chips 70 Sealing section 80 Mounting material 90 Ultrasonic device 100,300 jigs

Claims

1. A mounting portion having a main surface including a mounting area, comprising a groove portion having an inner surface and an outer surface, provided on the main surface so as to surround the mounting area, and a protruding portion projecting along the inner edge of the groove portion, A semiconductor chip mounted in the mounting area of ​​the aforementioned mounting portion via a mounting material, A sealing portion is provided to embed the semiconductor chip and is filled in the groove, Equipped with, The inner surface of the groove approaches the mounting area as it deepens, and the outer surface of the groove moves away from the mounting area as it deepens. The groove portion is a bottom surface connecting the inner surface and the outer surface, and further comprises a bottom surface including a first partial surface and a second partial surface intersecting the first partial surface. A semiconductor device in which the first partial surface intersects the inner surface at an acute angle, and the second partial surface intersects the outer surface at an acute angle.

2. The semiconductor device according to claim 1, wherein the surface roughness of the inner surface of the groove is rougher than the surface roughness of the main surface.

3. The semiconductor device according to claim 1 or 2, further comprising a protruding portion, separate from the protruding portion, provided along the outer edge of the groove.

4. The semiconductor device according to claim 1 or 2, wherein the height of the protruding portion is higher than the height of the upper surface of the mounting material.

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