Lead frame and manufacturing method thereof

Abstract

To provide a lead frame and a manufacturing method thereof which are capable of suppressing deformation of a lead portion during wire bonding.SOLUTION: A lead frame (10) includes a die pad (11), lead portions (12) arranged around the die pad (11), a metal connecting portion (16) connecting the die pad (11) and the lead portion (12), and resin portions (18) arranged around the die pad (11) and the lead portions (12) on the back side of the lead frame (10). The metal connecting portion (16) is thinned from the front side, and at least a portion of the lead portions (12) is thinned from the back side. The thinned portion of the lead portion (12) is filled with the resin portion (18).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a lead frame and a method for manufacturing the same. [Background technology]

[0002] In recent years, there has been a demand for smaller and thinner semiconductor devices mounted on substrates. To meet this demand, various so-called QFN (Quad Flat Non-lead) type semiconductor devices have been proposed, which use a lead frame, a semiconductor element mounted on the mounting surface of the lead frame is sealed with sealing resin, and a portion of the leads are exposed on the back surface.

[0003] However, conventionally, as the lead frame becomes thinner, it becomes more difficult to maintain the strength of the lead frame, and there is a problem that the lead frame becomes deformed after etching.

[0004] In recent years, there has also been a demand to increase the number of leads (number of pins) without changing the chip size. Conventionally, this has been achieved by narrowing the lead width, but as the lead becomes thinner, it becomes more susceptible to deformation, which creates the problem of making it difficult to perform stable wire bonding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-184927 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a technology for forming a semiconductor chip mounting portion and leads using a non-through groove, sealing the semiconductor chip with resin, and then penetrating the non-through groove to form a semiconductor device. However, if leads that are thinned from the back side are used, the leads are prone to deformation during wire bonding. Furthermore, if leads that are thinned from the back side are used, the space on the back side of the leads is narrow. As a result, there is a risk that the sealing resin cannot be sufficiently filled on the back side of the leads.

[0007] The present disclosure provides a lead frame and a manufacturing method thereof that can suppress deformation of the lead portion during wire bonding. DISCLOSURE OF THE INVENTION

[0008] The embodiments of the present disclosure relate to the following [1] to

[11] .

[0009] [1] A lead frame comprising: a die pad; a lead portion arranged around the die pad; a metal connecting portion connecting the die pad and the lead portion to each other; and a resin portion arranged around the die pad and the lead portion on the back surface side of the lead frame, wherein at least a portion of the lead portion is thinned from the back surface side, and the thinned portion of the lead portion is filled with the resin portion.

[0010] [2] The lead frame according to [1], wherein a portion of the metal connecting portion is located on the back surface side of the lead portion.

[0011] [3] The lead frame according to [2], wherein the width of the portion of the metal connecting portion located on the back surface side of the lead portion is 50 μm or more and 150 μm or less.

[0012] [4] A lead frame described in any one of [1] to [3], wherein the resin portion has a resin surface located on the surface side, and the resin surface is exposed to the outside from between two adjacent lead portions.

[0013] [5] The lead frame according to any one of [1] to [4], wherein the metal connecting portion has an annular or ring-shaped configuration in a planar view.

[0014] [6] The thermal conductivity of the resin part is 1 W m at 25°C. -1 ·K -1 More than 12W m -1 ·K -1 The lead frame according to any one of [1] to [5] below.

[0015] [7] The lead frame according to any one of [1] to [6], wherein the metal connecting portion is thinned from the surface side.

[0016] [8] The lead frame according to any one of [1] to [7], wherein the metal connecting portion is thinned from the back surface side.

[0017] [9] A lead frame comprising: a die pad; a lead portion arranged around the die pad; a plurality of inner lead portions arranged around the die pad; a metal connecting portion connecting the plurality of inner lead portions to each other; and a resin portion arranged around the die pad and the lead portions on the back surface side of the lead frame, wherein the metal connecting portion is thinned from the front surface side, at least a portion of the inner lead portions is thinned from the back surface side, and the resin portion is filled in the thinned portion of the inner lead portions.

[0018]

[10] A lead frame comprising: a die pad; a lead portion arranged around the die pad; a metal connecting portion arranged between the die pad and the lead portion; and a resin portion arranged around the die pad and the lead portion on the back side of the lead frame, wherein a recess is provided on the surface of the metal connecting portion.

[0019]

[11] A lead frame as described in

[10] , wherein a plurality of recesses are provided on the surface of the metal connection portion, the recesses being spaced apart from one another along the longitudinal direction of the metal connection portion, and terminal portions are formed between each recess.

[0020]

[12] The lead frame according to

[10] , wherein the recess is formed in a groove shape along the longitudinal direction of the metal connecting portion.

[0021]

[13] A lead frame described in any one of

[10] to

[12] , wherein a plurality of inner lead portions are supported by the metal connecting portion, the plurality of inner lead portions including long inner lead portions and short inner lead portions, and the long inner lead portions and the short inner lead portions are alternately arranged along the metal connecting portion.

[0022]

[14] A lead frame as described in

[10] , wherein a plurality of recesses are provided on the surface of the metal connection portion, the recesses being spaced apart from one another along the longitudinal direction of the metal connection portion, and thick portions being formed between each recess.

[0023]

[15] A method for manufacturing a lead frame, comprising the steps of: preparing a metal substrate; etching the metal substrate from the back surface side to partway through the thickness direction to form a back surface recess; forming a resin portion on the back surface side of the metal substrate and filling the resin portion in the back surface recess; and etching the metal substrate from the front surface side to partway through the thickness direction to form a die pad, lead portions arranged around the die pad, and metal connecting portions arranged between the die pad and the lead portions.

[0024] According to the present disclosure, deformation of the lead portion during wire bonding can be suppressed. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a plan view showing a lead frame according to a first embodiment. [Figure 2] FIG. 2 is a bottom view showing the lead frame according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the lead frame according to the first embodiment (a cross-sectional view taken along line III-III in FIG. 1). [Figure 4] FIG. 4 is an enlarged perspective view showing a part of the lead frame according to the first embodiment (an enlarged view of part IV in FIG. 1). [Figure 5] FIG. 5 is a plan view showing the semiconductor device according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view (cross-sectional view taken along line VI-VI in FIG. 5) showing the semiconductor device according to the first embodiment. [Figure 7] 7(A) to 7(I) are cross-sectional views showing a method for manufacturing a lead frame according to the first embodiment. [Figure 8] 8(A) to 8(H) are cross-sectional views showing a method for manufacturing a semiconductor device according to the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a lead frame according to a first modified example of the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a lead frame according to a second modified example of the first embodiment. [Figure 11] FIG. 11 is a plan view showing a lead frame according to a second embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing a lead frame according to a second embodiment (a cross-sectional view taken along line XII-XII in FIG. 11). [Figure 13] FIG. 13 is a cross-sectional view showing a semiconductor device according to a second embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing a lead frame according to a modified example of the second embodiment. [Figure 15] FIG. 15 is a cross-sectional view showing a lead frame according to a third embodiment. [Figure 16] FIG. 16 is a cross-sectional view showing a semiconductor device according to a third embodiment. [Figure 17] FIG. 17 is a cross-sectional view showing a lead frame according to a modified example of the third embodiment. [Figure 18] FIG. 18 is a plan view showing a lead frame according to a fourth embodiment. [Figure 19] 19(A) is a cross-sectional view showing a lead frame according to the fourth embodiment (cross-sectional view taken along line XIXA-XIXA in FIG. 18), and FIG. 19(B) is a cross-sectional view showing a lead frame according to the fourth embodiment (cross-sectional view taken along line XIXB-XIXB in FIG. 18). [Figure 20] FIG. 20 is a plan view showing a semiconductor device according to a fourth embodiment. [Figure 21] FIG. 21 is a plan view showing a lead frame according to a fifth embodiment. [Figure 22] Figure 22(A) is a cross-sectional view showing a lead frame according to the fifth embodiment (cross-sectional view taken along line XXIIA-XXIIA in Figure 21), and Figure 22(B) is a cross-sectional view showing a lead frame according to the fifth embodiment (cross-sectional view taken along line XXIIB-XXIIB in Figure 21). [Figure 23] FIG. 23 is a plan view showing a semiconductor device according to a fifth embodiment. [Figure 24] FIG. 24 is a plan view showing a lead frame according to a modified example of the fifth embodiment. [Figure 25] FIG. 25 is a plan view showing a lead frame according to a sixth embodiment. [Figure 26] Figure 26(A) is a cross-sectional view showing a lead frame according to the sixth embodiment (cross-sectional view taken along line XXVIA-XXVIA in Figure 25), and Figure 26(B) is a cross-sectional view showing a lead frame according to the sixth embodiment (cross-sectional view taken along line XXVIB-XXVIB in Figure 25). [Figure 27] FIG. 27 is a plan view showing a semiconductor device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] (First embodiment) The first embodiment will be described below with reference to Figures 1 to 8. In the following figures, the same parts are denoted by the same reference numerals, and some detailed descriptions may be omitted.

[0027] In this specification, the X and Y directions are two directions parallel to each side of the lead frame 10 or the package area 10a, and are perpendicular to each other. The Z direction is perpendicular to both the X and Y directions. The terms "inner" and "inside" refer to the side facing the center of each package area 10a. The terms "outer" and "outside" refer to the side away from the center of each package area 10a. The term "front surface" refers to the surface on the side where the semiconductor element 21 is mounted (the surface on the positive side in the Z direction). The term "rear surface" refers to the surface opposite the "front surface" (the negative side in the Z direction), that is, the surface opposite the surface on which the semiconductor element 21 is mounted.

[0028] In this specification, half-etching refers to etching a material to be etched partway in its thickness direction. The thickness of the material to be etched after half-etching may be, for example, 10% to 90%, or 30% to 70%, or 40% to 60% of the thickness of the material to be etched before half-etching.

[0029] (Lead frame configuration) First, an outline of the lead frame according to the present embodiment will be described with reference to Figures 1 to 4. Figures 1 to 4 are diagrams showing the lead frame according to the present embodiment.

[0030] As shown in FIG. 1, the lead frame 10 includes a package area (unit lead frame) 10a. The package areas 10a are arranged in multiple rows and multiple stages (in a matrix) in a plan view within the lead frame 10. However, this is not a limitation, and it is sufficient that there is one or more package areas 10a. Each package area 10a corresponds to a semiconductor device 20 (described later), and is an area located inside the imaginary line in FIG. 1. The imaginary line in FIG. 1 corresponds to the outer periphery of the semiconductor device 20.

[0031] As shown in FIG. 1, the lead frame 10 includes a die pad 11, a plurality of lead portions 12, a metal connecting portion 16, and a resin portion 18. Each of the plurality of lead portions 12 has an elongated shape and is provided around the die pad 11. Each lead portion 12 electrically connects a semiconductor element 21 to an external wiring board (not shown). The metal connecting portion 16 connects the die pad 11 and the lead portions 12 to each other. The resin portion 18 is disposed around the die pad 11 and the lead portions 12 on the back surface side of the lead frame 10. The metal connecting portion 16 is thinned from the front surface side. At least a portion of the lead portions 12 is thinned from the back surface side. At least a portion of the thinned portions of the lead portions 12 is filled with the resin portion 18.

[0032] The multiple package areas 10a are connected to one another via support leads (support members) 13. The support leads 13 support the die pad 11 and the lead portions 12. The support leads 13 extend along the X and Y directions.

[0033] The die pad 11 has a substantially square shape in a plan view. The die pad 11 is not thinned from the front or back side. However, this is not a limitation, and a portion of the die pad 11 may be thinned from the front or back side, for example, by half-etching. The planar shape of the die pad 11 is not limited to a square, and may be a polygon such as a rectangle. Furthermore, suspension leads 14 are connected to the four corners of the die pad 11 via metal connecting portions 16. The die pad 11 is connected and supported to the support leads 13 via the four suspension leads 14. In this embodiment, the suspension leads 14 are not thinned from either the front or back side, and have the same thickness as the metal substrate (metal substrate 31 described later) before processing. However, this is not a limitation, and the suspension leads 14 may be thinned from the front or back side. Because the resin portion 18 can support the die pad 11 with respect to the lead portion 12 and the support leads 13, the suspension leads 14 may not be provided. If the suspension leads 14 are not provided, it is easy to fill the four corners of the die pad 11 with the resin that forms the resin portion 18 .

[0034] A semiconductor element 21, which will be described later, is mounted on the surface of the die pad 11. The front and back surfaces of the die pad 11 are not covered by the resin part 18 and are exposed to the outside from the lead frame 10. The surface of the die pad 11 is located closer to the front surface (positive side in the Z direction) than a resin surface 18a of the resin part 18, which will be described later. In addition, a metal connecting part 16 is connected to the side of the die pad 11 facing the lead part 12. The die pad 11 and the metal connecting part 16 are formed integrally.

[0035] As will be described later, each lead 12 is connected to a semiconductor element 21 via a bonding wire 22. The lead 12 is arranged between the die pad 11 and the lead 12 via a metal connecting portion 16. The lead 12 extends from a support lead 13.

[0036] The multiple lead portions 12 are arranged along the periphery of the die pad 11. Each lead portion 12 has an inner lead 51 and an external terminal 53. The inner lead 51 is located on the inside (the die pad 11 side). The external terminal 53 is located on the outside (the opposite side of the die pad 11, the support lead 13 side). The inner lead 51 is located at the inside end of the lead portion 12, and an internal terminal 15 is formed on its surface side. This internal terminal 15 is an area that is electrically connected to the semiconductor element 21 via a bonding wire 22, as will be described later. A metal layer may be provided on the internal terminal 15 to improve adhesion with the bonding wire 22. The metal layer may be made of a plating layer such as silver plating.

[0037] The inner lead 51 is thinned from the rear surface side by, for example, half etching. The inner lead 51 has the above-mentioned internal terminal 15 and an inner lead back surface 51b. The internal terminal 15 is located on the front surface side of the inner lead 51. The internal terminal 15 is not thinned from the front surface side. The inner lead back surface 51b is located on the back surface side of the inner lead 51. The inner lead back surface 51b is a surface formed by etching. The inner lead back surface 51b is in close contact with the resin part 18. An inner lead side surface 51c is formed on the side of the inner lead 51 facing the die pad 11. A space is formed between the inner lead side surface 51c and the die pad 11.

[0038] The external terminal 53 is located on the support lead 13 side, and its outer end is connected to the support lead 13. The external terminal 53 is not thinned from either the front or back side. The external terminal 53 has an external terminal surface 53a and an external terminal surface 17. The external terminal surface 53a is located on the front side of the external terminal 53 and is exposed to the outside. The external terminal surface 53a is located on the same plane as the internal terminal 15. The external terminal surface 17 is located on the back side of the external terminal 53 and is exposed to the outside. The external terminal surface 17 is not thinned from the back side. Note that the area between the external terminal surface 17 and the support lead 13 may be thinned from the back side to form a connection portion.

[0039] Furthermore, an external terminal inner surface 53d is formed on the external terminal 53 at a position on the back side of the inner lead back surface 51b. The external terminal inner surface 53d extends between the inner lead back surface 51b and the external terminal surface 17. A resin portion 18 is in close contact with the external terminal inner surface 53d.

[0040] The metal connecting portion 16 is arranged to connect the tips of the plurality of lead portions 12. The metal connecting portion 16 is also arranged to surround the die pad 11. This metal connecting portion 16 has a substantially rectangular annular or ring shape in plan view. Each side of the metal connecting portion 16 extends along the X direction or the Y direction. A suspension lead 14 is connected to each of the four corners of the metal connecting portion 16. Note that the metal connecting portion 16 does not necessarily have to have an annular or ring shape. For example, the metal connecting portion 16 may connect the die pad 11 and the tips of the lead portions 12, but may not be provided between adjacent lead portions 12.

[0041] The metal connecting portion 16 is thinned from the front surface side. By thinning the metal connecting portion 16 from the front surface side, the volume of the metal connecting portion 16 is reduced. This makes it easier to remove the metal connecting portion 16 by etching when separating the lead portion 12 and the die pad 11 from each other, as will be described later. The metal connecting portion 16 has a connecting portion front surface 16a, a connecting portion back surface 16b, and a connecting portion outer surface 16c.

[0042] The connecting portion surface 16a is located on the front surface side of the metal connecting portion 16. This connecting portion surface 16a is formed by, for example, half etching. The connecting portion surface 16a is located closer to the back surface (negative side in the Z direction) than the front surface of the die pad 11 and the internal terminals 15. The connecting portion surface 16a may be located on the same plane as the inner lead back surface 51b. A portion of the connecting portion surface 16a located closer to the die pad 11 than the tip of the lead portion 12 is exposed to the outside. A portion of the connecting portion surface 16a located between adjacent lead portions 12 is exposed to the outside (see FIG. 4). On the other hand, a portion of the metal connecting portion 16 located on the back surface side of the inner lead 51 is integrated with the inner lead 51 and is not exposed to the outside. In this embodiment, the metal connecting portion 16 is thinned from the front surface side all around. However, this is not limited to this, and a portion of the metal connecting portion 16 in the circumferential direction may be thinned from the front surface side. For example, the metal connecting portion 16 may be thinned from the front surface side only in the circumferential direction.

[0043] The connecting portion back surface 16b is located on the back surface side of the metal connecting portion 16. This connecting portion back surface 16b is not thinned. The connecting portion back surface 16b is located on the same plane as the back surface of the die pad 11 and the external terminal surface 17. The connecting portion back surface 16b is exposed to the outside in its entirety. Note that a portion of the metal connecting portion 16 may be thinned from the back surface side.

[0044] The connecting portion outer surface 16c is located outside the metal connecting portion 16 (on the support lead 13 side). The connecting portion outer surface 16c extends between the connecting portion front surface 16a and the connecting portion back surface 16b. The resin portion 18 is in close contact with the connecting portion outer surface 16c. As shown in FIG. 4, the connecting portion outer surface 16c is located outside the inner lead side surface 51c (on the support lead 13 side). However, this is not limiting, and the connecting portion outer surface 16c may be located on the same plane as the inner lead side surface 51c between two adjacent lead portions 12.

[0045] The width W1 of the metal connecting portion 16 (see FIG. 3) may be 100 μm or more and 300 μm or less. A part of the metal connecting portion 16 is located on the back surface side of the inner lead 51 of the lead portion 12. The width W2 of the part of the metal connecting portion 16 located on the back surface side of the inner lead 51 of the lead portion 12 (see FIG. 3) may be 50 μm or more and 150 μm or less. The widths W1 and W2 each refer to the distance measured from the die pad 11 side to the lead portion 12 side in a cross section perpendicular to the extension direction of the metal connecting portion 16.

[0046] The resin portion 18 is disposed around the die pad 11 and the lead portions 12. That is, as shown in FIG. 1 , when viewed from the front surface side, the resin portion 18 is located in a region surrounded by the metal connecting portion 16, the two adjacent lead portions 12, and the support lead 13. When viewed from the front surface side, the resin portion 18 is located in a region surrounded by the metal connecting portion 16, the suspension lead 14, the lead portion 12 adjacent to the suspension lead 14, and the support lead 13. When viewed from the back surface side, as shown in FIG. 2 , the resin portion 18 is located in a region surrounded by the metal connecting portion 16, the multiple external terminal surfaces 17, the support lead 13, and the two suspension leads 14. Note that in each drawing, the resin portion 18 is indicated by shading.

[0047] The resin portion 18 is disposed on the back surface side of the lead frame 10. That is, the resin portion 18 is located closer to the back surface (negative side in the Z direction) than a midpoint in the thickness direction of the lead frame 10. The resin portion 18 is not located closer to the front surface (positive side in the Z direction) than a midpoint in the thickness direction (Z direction). The midpoint is not limited to the center in the thickness direction of the lead frame 10, but may be located closer to the front surface or back surface than the center in the thickness direction. The midpoint in the thickness direction corresponds to the position in the thickness direction where the inner lead back surface 51b is located. However, the midpoint in the thickness direction may be located closer to the front surface (positive side in the Z direction) than the position where the inner lead back surface 51b is located.

[0048] 3, the resin portion 18 is in close contact with the connecting portion outer surface 16c of the metal connecting portion 16. The resin portion 18 is also disposed on the back surface side of the lead portion 12. Specifically, the resin portion 18 is in close contact with the external terminal inner surface 53d of the lead portion 12 and the inner lead back surface 51b.

[0049] The resin portion 18 has a resin front surface 18a located on the front side and a resin back surface 18b located on the back side. Of these, the resin front surface 18a is exposed to the outside from between two adjacent leads 12 (see FIG. 4). The resin front surface 18a, the inner lead back surface 51b, and the connecting portion surface 16a are located on the same plane. However, this is not limiting, and the resin front surface 18a may be located closer to the front side than the inner lead back surface 51b and the connecting portion surface 16a. The resin back surface 18b is exposed to the outside from the back surface side of the lead frame 10. The back surface of the die pad 11, the resin back surface 18b, and the external terminal surface 17 are located on the same plane.

[0050] The resin portion 18 may be made of a thermosetting resin such as silicone resin or epoxy resin, or a thermoplastic resin such as PPS resin. In order to improve the adhesion between the resin portion 18 and the sealing resin 23 described below, it is preferable to use the same material for the resin portion 18 as for the sealing resin 23. The thermal conductivity of the resin portion 18 is, for example, 1 W·m in an environment of 25°C. -1 ·K -1 It may be more than 3 W m -1 ·K -1 The thermal conductivity of the resin part 18 may be 12 W·m -1 ·K -1 May be less than 10 W m -1 ·K -1 The thermal conductivity of the resin portion 18 is measured by a laser flash method.

[0051] The entire lead frame 10, excluding the resin portion 18, is made of a metal such as copper, a copper alloy, or a 42 alloy (a 42% Ni-Fe alloy). The maximum thickness T1 of the lead frame 10 may be 80 μm or more and 300 μm or less, depending on the configuration of the semiconductor device 20 to be manufactured. In this specification, the maximum thickness of the lead frame 10 refers to the thickness (Z-direction distance) of the thickest portion of the lead frame 10, that is, the thickness of the portion that is not thinned from either the front or back side. The maximum thickness of the lead frame 10 corresponds to the thickness of the metal substrate 31, which will be described later. In this embodiment, the resin portion 18 is provided on the back side of the lead portion 12, making the lead portion 12 less likely to deform due to the force applied during wire bonding. This allows the maximum thickness T1 of the lead frame 10 to be reduced.

[0052] The thickness T2 of the inner lead 51 may be 30% to 60% or 40% to 50% of the maximum thickness T1 of the lead frame 10. The thickness T2 of the inner lead 51 may be 24 μm to 180 μm or 32 μm to 150 μm.

[0053] The thickness T3 of the resin portion 18 may be 30% to 60% or 40% to 50% of the maximum thickness T1 of the lead frame 10. The thickness T3 of the resin portion 18 may be 24 μm to 180 μm or 32 μm to 150 μm.

[0054] (Configuration of semiconductor device) Next, the semiconductor device according to the present embodiment will be described with reference to Figures 5 and 6. Figures 5 and 6 are diagrams showing the semiconductor device according to the present embodiment.

[0055] 5 and 6, a semiconductor device (semiconductor package) 20 includes a die pad 11, a plurality of leads 12, a semiconductor element 21, and a plurality of bonding wires (connecting members) 22. The plurality of leads 12 are arranged around the die pad 11. The semiconductor element 21 is mounted on the die pad 11. Bonding wires 22 electrically connect the lead portions 12 and the semiconductor element 21. A resin portion 18 is disposed around the die pad 11 and the lead portions 12 on the back surface side of the semiconductor device 20. Furthermore, the die pad 11, the lead portions 12, the semiconductor element 21, and the bonding wires 22 are resin-sealed with sealing resin 23.

[0056] The die pad 11, lead portion 12, and resin portion 18 of the semiconductor device 20 are made from the above-mentioned lead frame 10. The configurations of the die pad 11, lead portion 12, and resin portion 18 are the same as those shown in Figures 1 to 4 above, except for the areas not included in the semiconductor device 20, so detailed description will be omitted here.

[0057] On the other hand, the above-mentioned metal connecting portion 16 is removed by etching from the rear surface side after being resin-sealed with sealing resin 23. Therefore, as shown in Figures 5 and 6, the lead portion 12 is separated from the die pad 11 and other lead portions 12 and is electrically independent from each other.

[0058] As a result of removing the metal connecting portion 16 in this way, a recess 27 is formed on the back surface of the sealing resin 23 between the lead portion 12 and the die pad 11. This recess 27 roughly corresponds to the shape of the metal connecting portion 16. The recess 27 has a substantially rectangular annular or ring shape in plan view so as to surround the die pad 11. Note that the recess 27 may be filled with an insulating resin of the same type as or different from the sealing resin 23.

[0059] Various types of semiconductor elements that are commonly used in the past can be used as the semiconductor element 21. For example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, etc. may be used as the semiconductor element 21. The semiconductor element 21 has a plurality of electrodes 21a to which bonding wires 22 are attached. The semiconductor element 21 is fixed to the surface of the die pad 11 by an adhesive 24. For example, die bonding paste or the like may be used as the adhesive 24.

[0060] Each bonding wire 22 is made of a highly conductive material such as gold or copper. One end of each bonding wire 22 is connected to an electrode 21a of the semiconductor element 21. The other end of each bonding wire 22 is connected to an internal terminal 15 of each lead portion 12.

[0061] The sealing resin 23 may be a thermosetting resin such as a silicone resin or an epoxy resin, or a thermoplastic resin such as a PPS resin. The overall thickness of the sealing resin 23 may be approximately 300 μm or more and 1500 μm or less. Furthermore, one side of the sealing resin 23 (one side of the semiconductor device 20) may be, for example, 0.2 mm or more and 16 mm or less. In the space between the die pad 11 and the lead portions 12, the sealing resin 23 is exposed toward the inside of the recess 27. Furthermore, in the portion located between adjacent lead portions 12, the sealing resin 23 is in close contact with the resin surface 18a of the resin portion 18. Note that the sealing resin 23 is not shown in FIG. 5.

[0062] (Lead frame manufacturing method) Next, a method for manufacturing the lead frame 10 shown in FIGS. 1 to 4 will be described with reference to FIGS. 7(A) to 7(I).

[0063] 7(A), a flat metal substrate 31 is prepared. A substrate made of a metal such as copper, a copper alloy, or a 42 alloy (a 42% Ni / Fe alloy) may be used as the metal substrate 31. It is preferable to use a metal substrate 31 that has been subjected to degreasing and cleaning on both sides.

[0064] Next, photosensitive resist is applied to the entire front and back surfaces of the metal substrate 31 and dried. Subsequently, the photosensitive resist on the metal substrate 31 is exposed to light through a photomask and developed. This forms etching resist layers 32 and 33 (FIG. 7(B)). The etching resist layer 33 on the back surface side has openings 33b. The etching resist layer 32 on the front surface side does not have openings, but may have openings. Note that the etching resist layers 32 and 33 may be made of, for example, dry film resist.

[0065] Next, half-etching is performed to thin the metal substrate 31 from its back side to partway along its thickness. In this case, the back side of the metal substrate 31 is etched with an etchant, using the back-side etching resist layer 33 as a corrosion-resistant film (FIG. 7(C)). The front surface of the metal substrate 31 is not etched because it is entirely covered with the etching resist layer 32. This results in a back-side recess 36, which is a non-penetrating recess, being formed on the back side of the metal substrate 31. This back-side recess 36 has a shape corresponding to the resin portion 18. The etchant can be selected appropriately depending on the material of the metal substrate 31 used. For example, when copper is used as the metal substrate 31, a ferric chloride aqueous solution may be used as the etchant. In this case, the ferric chloride aqueous solution may be spray-etched from one or both sides of the metal substrate 31.

[0066] Subsequently, the etching resist layers 32 and 33 are peeled off and removed (FIG. 7(D)).Then, the metal substrate 31 is washed with water and dried.

[0067] Next, a resin portion 18 is formed on the back surface of the metal substrate 31, and the back surface recess 36 is covered with the resin portion 18 (FIG. 7(E)). At this time, a thermosetting resin or a thermoplastic resin may be injection molded or transfer molded onto the back surface of the metal substrate 31. This causes the resin portion 18 to fill the back surface recess 36. At this time, the resin portion 18 is provided so as to cover the entire back surface of the metal substrate 31.

[0068] Next, the resin portion 18 is polished to a predetermined thickness (FIG. 7(F)). Specifically, the resin portion 18 is polished from the back surface side, and polishing of the resin portion 18 is completed after the metal portion that constitutes the metal substrate 31 is exposed. As a result, the back surface of the die pad 11 and the portions of the lead portion 12 that correspond to the external terminal surfaces 17 are exposed on the back surface side. Note that the resin portion 18 can be polished, for example, by buffing.

[0069] Next, photosensitive resist is applied to the entire front and back surfaces of the metal substrate 31 and dried. Subsequently, the photosensitive resist on the metal substrate 31 is exposed to light through a photomask and developed. This forms etching resist layers 34, 35 (FIG. 7(G)). The etching resist layer 34 on the front surface side has openings 34b. The etching resist layer 35 on the back surface side does not have openings, but may have openings. Note that the etching resist layers 34, 35 may be made of, for example, dry film resist.

[0070] Next, the metal substrate 31 is thinned from the front surface side to the middle of the thickness direction by half etching. In this case, the front surface side of the metal substrate 31 is etched with an etchant, using the etching resist layer 34 on the front surface side as a corrosion-resistant film (FIG. 7(H)). The etchant may be the same as that used when etching the back surface side of the metal substrate 31 (FIG. 7(C)).

[0071] As a result, the surface side of the metal substrate 31 is etched, and the outer shapes of the die pad 11, the lead portions 12, and the support leads 13 are formed. At this time, the surface side of the die pad 11 is thinned by etching. The portions of the metal substrate 31 between the adjacent lead portions 12 are thinned from the surface side, so that the resin surface 18a of the resin portion 18 is exposed to the outside (FIG. 4). Furthermore, the portions of the metal substrate 31 between the die pad 11 and the lead portions 12 are thinned from the surface side, so that the metal connecting portion 16 is formed.

[0072] Next, the etching resist layers 34 and 35 are peeled off and removed (FIG. 7(I)). Then, the metal substrate 31 is washed with water and dried. In this way, the lead frame 10 shown in FIGS. 1 to 4 is obtained.

[0073] (Method of manufacturing a semiconductor device) Next, a method for manufacturing the semiconductor device 20 shown in FIGS. 5 and 6 will be described with reference to FIGS. 8(A) to 8(H).

[0074] First, a lead frame 10 is fabricated (FIG. 8(A)) by, for example, the method shown in FIGS. 7(A)-(I).

[0075] Next, the semiconductor element 21 is mounted on the die pad 11 of the lead frame 10. In this case, the semiconductor element 21 is placed on and fixed to the die pad 11 using an adhesive 24 (die attach process) (FIG. 8(B)). As the adhesive 24, for example, a die bonding paste or the like may be used.

[0076] Next, the electrodes 21a of the semiconductor element 21 and the internal terminals 15 of each lead portion 12 are electrically connected to each other by bonding wires 22 (wire bonding process) (FIG. 8(C)). At this time, the lead frame 10 is placed on a heat block of a wire bonding device (not shown). Next, the inner leads 51 of each lead portion 12 are heated from the back side by the heat block via the metal connecting portions 16 and external terminals 53. At the same time, ultrasonic waves are applied via the capillary 38 of the wire bonding device, and the electrodes 21a of the semiconductor element 21 and the inner leads 51 of each lead portion 12 are connected to each other by bonding wires 22.

[0077] In this embodiment, the die pad 11 and the lead portion 12 are connected to each other by a metal connecting portion 16. Furthermore, a resin portion 18 is filled in the thinned portion on the back surface side of the lead portion 12. Therefore, the back surface side of the inner lead 51 is stably held by the resin portion 18. This prevents the lead portion 12 from being deformed when the bonding wire 22 is joined to the lead portion 12 by the capillary 38. Furthermore, heat from the heat block can be transferred more uniformly than when the heat block is in direct contact with the back surface 51b of the inner lead.

[0078] Next, for example, a thermosetting resin or a thermoplastic resin is injection molded or transfer molded onto the lead frame 10 to form the sealing resin 23 (FIG. 8(D)). In this way, the die pad 11, the leads 12, the semiconductor element 21, and the bonding wires 22 are sealed. The sealing resin 23 also fills the space between the die pad 11 and the leads 12 on the surface side of the metal connecting portion 16.

[0079] Subsequently, an etching resist layer 37 having openings 37b is provided on the rear surfaces of the lead frame 10 and the sealing resin 23 (FIG. 8(E)).

[0080] During this process, first, a photosensitive resist is applied to the entire rear surfaces of the lead frame 10 and the sealing resin 23. Then, the photosensitive resist is exposed through a photomask and developed to form an etching resist layer 37 having openings 37b.

[0081] In this case, the etching resist layer 37 covers the entire back surface of the lead frame 10 and the sealing resin 23 except for the opening 37b. The opening 37b corresponds roughly to the position of the metal connecting portion 16 and has a generally rectangular strip shape in plan view. The connecting portion back surface 16b of the metal connecting portion 16 is exposed through the opening 37b. The etching resist layer 37 may be, for example, a dry film resist.

[0082] Next, the lead frame 10 is etched with an etchant using the etching resist layer 37 as a corrosion-resistant film (FIG. 8(F)). At this time, the etchant entering through the openings 37b dissolves and removes the entire metal connectors 16. By removing the metal connectors 16, recesses 27 are formed at positions corresponding to the metal connectors 16. In this way, the metal connectors 16 are removed, separating the die pad 11 from each lead 12, and separating adjacent leads 12 from each other. The etchant may be the same as that used when etching the back side of the metal substrate 31 (FIG. 7(C)).

[0083] Next, the etching resist layer 37 is peeled off and removed (FIG. 8(G)). After removing the etching resist layer 37, a step of filling the recesses 27 with an insulating resin of the same type as or different from the sealing resin 23 may be provided.

[0084] Thereafter, the sealing resin 23 and the support leads 13 between the semiconductor elements 21 are diced, thereby separating the lead frame 10 into individual semiconductor devices 20. At this time, the sealing resin 23 and the support leads 13 between the semiconductor devices 20 may be cut while rotating a blade containing, for example, artificial diamond.

[0085] In this way, the semiconductor device 20 shown in FIGS. 5 and 6 is obtained (FIG. 8(H)).

[0086] As described above, according to this embodiment, the die pad 11 and the lead portion 12 are connected to each other by the metal connecting portion 16. Furthermore, the resin portion 18 is filled in the thinned portion on the back surface side of the lead portion 12. Therefore, the back surface side of the lead portion 12 is stably held by the resin portion 18. This prevents the lead portion 12 from being deformed when the bonding wire 22 is joined to the lead portion 12 by the capillary 38 during wire bonding (FIG. 8(C)).

[0087] That is, when connecting the bonding wire 22 to the inner lead 51 of the lead portion 12 (see FIG. 8(C)), a pressing force is applied to the lead portion 12 from the front side toward the back side by the capillary 38. According to this embodiment, since the back side of the lead portion 12 is held by the resin portion 18, deformation of the lead portion 12 is suppressed even when such a pressing force is applied by the capillary 38. As a result, the thickness of the lead portion 12 can be reduced, and the overall thickness of the lead frame 10 and the semiconductor device 20 can also be reduced. Since the thickness of the lead portion 12 can be reduced, the width of the lead portion 12 and the spacing between the lead portions 12 can be narrowed, allowing the lead frame 10 and the semiconductor device 20 to have a higher pin count. Furthermore, vibration of the lead portion 12 can be suppressed during wire bonding (FIG. 8(C)). This allows the wire bonding work to be carried out stably. Also, since the length of the lead portion 12 can be increased, the length of the bonding wire 22 can be reduced.

[0088] Furthermore, according to this embodiment, the resin portion 18 is filled in the thinned portion on the back surface of the lead portion 12 before the lead frame 10 is resin-sealed with the sealing resin 23 (FIG. 8(D)). This allows the resin portion 18 to be filled in the thinned portion on the back surface of the lead portion 12 without leaving any gaps. In particular, even if the thickness of the thinned portion on the back surface of the lead portion 12 (thickness T3 in FIG. 3) is small, the resin portion 18 can be filled in this portion without leaving any gaps. This prevents moisture in the air from penetrating the interface between the sealing resin 23 and the lead portion 12 from the back surface of the semiconductor device 20 during use. On the other hand, if the resin portion 18 is not filled in the back surface of the lead portion 12, the sealing resin 23 may not sufficiently reach this portion.

[0089] Furthermore, according to this embodiment, a portion of the metal connecting portion 16 may be located on the back surface side of the inner lead 51 of the lead portion 12. This firmly connects the metal connecting portion 16 and the lead portion 12, and prevents the lead portion 12 from being deformed by the capillary 38 during wire bonding. Furthermore, the width W2 of the portion of the metal connecting portion 16 located on the back surface side of the lead portion 12 may be set to 50 μm or more and 150 μm or less. By setting the width W2 to 50 μm or more, the effect of suppressing deformation of the lead portion 12 described above is more likely to be achieved. Furthermore, by setting the width W2 to 150 μm or less, the recess 27 formed on the back surface of the semiconductor device 20 is prevented from becoming unnecessarily large.

[0090] Furthermore, according to this embodiment, resin portion 18 has resin surface 18a located on the surface side, and resin surface 18a may be exposed to the outside from between two adjacent leads 12. The presence of resin portion 18 between two leads 12 in this manner prevents lateral deformation of lead 12 during wire bonding (FIG. 8(C)).

[0091] Furthermore, according to this embodiment, the metal connecting portion 16 may have an annular or ring shape in plan view, which allows the metal connecting portion 16 to connect a plurality of lead portions 12 together.

[0092] Furthermore, according to this embodiment, the thermal conductivity of the resin portion 18 is 1 W·m -1 ·K -1 More than 12W m -1 ·K -1 As a result, when the inner leads 51 of the lead portion 12 are heated from the back surface side during wire bonding, the heat from the heat block can be uniformly transferred via the resin portion 18, the metal connecting portion 16, and the external terminals 53.

[0093] (First Modification of the First Embodiment) FIG. 9 shows a lead frame 10 according to a first modified example of this embodiment. In the lead frame 10 shown in FIG. 9, the metal connecting portion 16 is thinned from both the front and back sides. The portion of the metal connecting portion 16 thinned from the back side forms a back-side thin portion 16d. The back-side thin portion 16d is located outside (on the support lead 13 side) the inner lead side surface 51c. The back-side thin portion 16d is not filled with the resin portion 18. The width W3 between the back-side thin portion 16d and the inner lead side surface 51c of the metal connecting portion 16 may be 50 μm or more and 250 μm or less.

[0094] The back-side thin portion 16d may be formed by, for example, half etching. The back-side thin portion 16d may extend along the longitudinal direction of the metal connecting portion 16 in a plan view. The width W4 of the back-side thin portion 16d may be 50 μm or more and 150 μm or less. The metal connecting portion 16 has a metal portion 16e located between the back-side thin portion 16d and the resin portion 18. In this case, the resin portion 18 is not exposed within the back-side thin portion 16d. The metal portion 16e is not thinned from either the front side or the back side. The width W5 of the metal portion 16e may be 25 μm or more and 150 μm or less. Note that the widths W3, W4, and W5 each refer to the distance measured from the die pad 11 side to the lead portion 12 side in a cross section perpendicular to the extension direction of the metal connecting portion 16.

[0095] In FIG. 9, the depth d1 of the rear surface thin portion 16d may be 30% to 60% or 40% to 50% of the maximum thickness T1 of the lead frame 10. The depth d1 of the rear surface thin portion 16d may be 24 μm to 180 μm or 32 μm to 150 μm. In FIG. 9, the depth d1 of the rear surface thin portion 16d is shallower than the thickness T3 of the resin portion 18, but is not limited to this. The depth d1 of the rear surface thin portion 16d may be the same as the thickness T3 of the resin portion 18, or may be deeper than the thickness T3 of the resin portion 18.

[0096] The back-side thin portion 16d may be formed as follows. First, in the step of forming the etching resist layers 34 and 35 described above (FIG. 7(G)), an opening corresponding to the back-side thin portion 16d is formed in the back-side etching resist layer 35. Then, the metal substrate 31 is thinned partway through its thickness from both the front and back sides of the metal substrate 31 by half etching (FIG. 7(H)). At this time, the back-side etching resist layer 35 serves as a corrosion-resistant film, and the back side of the metal substrate 31 is etched with an etchant to form the back-side thin portion 16d.

[0097] Alternatively, the rear surface thin portion 16d may be formed together with the rear surface recess 36 in the step of forming the rear surface recess 36 by half etching on the rear surface of the metal substrate 31 (FIG. 7(C)).

[0098] According to this modification, the volume of the metal connecting portion 16 is further reduced by thinning the metal connecting portion 16 from the back surface side. This makes it easier to remove the metal connecting portion 16 by etching or dicing when separating the lead portion 12 and the die pad 11 from each other (FIG. 8(F)), as described above.

[0099] Other configurations may be the same as those shown in FIGS.

[0100] (Second Modification of the First Embodiment) FIG. 10 shows a lead frame 10 according to a second modified example of this embodiment. In the lead frame 10 shown in FIG. 10, the metal connecting portion 16 is thinned from both the front and back sides. The portion of the metal connecting portion 16 thinned from the back side forms a back side thin portion 16d. The back side thin portion 16d is located outside (toward the support lead 13) the inner lead side surface 51c. The back side thin portion 16d is not filled with the resin portion 18.

[0101] 10, the resin portion 18 is exposed within the rear surface side thin portion 16d. That is, there is no metal portion between the rear surface side thin portion 16d and the resin portion 18.

[0102] According to this modification, the volume of the metal connecting portion 16 is further reduced by thinning the metal connecting portion 16 from the back surface side. This makes it easier to remove the metal connecting portion 16 by etching or dicing when separating the lead portion 12 and the die pad 11 from each other (FIG. 8(F)), as described above.

[0103] Other configurations may be the same as those of the first modified example shown in FIG.

[0104] (Second embodiment) Next, a second embodiment will be described with reference to Figures 11 to 13. Figures 11 to 13 are diagrams showing the second embodiment. In Figures 11 to 13, the same parts as those in the first embodiment shown in Figures 1 to 8 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0105] The lead frame 10A according to this embodiment includes a die pad 11, a plurality of lead portions 12, a plurality of inner lead portions 12A, 12B, and a metal connecting portion 16. The plurality of lead portions 12 and the plurality of inner lead portions 12A, 12B are each arranged around the die pad 11. The metal connecting portion 16 is arranged between the die pad 11 and the lead portions 12. The metal connecting portion 16 also supports the plurality of inner lead portions 12A, 12B.

[0106] Each lead portion 12 has an inner lead 51 and an external terminal 53. The inner lead 51 is thinned from the back surface side by, for example, half etching. An external terminal surface 17 is formed on the back surface of each external terminal 53.

[0107] The metal connecting portion 16 is disposed so as to surround the die pad 11. The metal connecting portion 16 is thinned from the front surface side. This metal connecting portion 16 has a substantially rectangular annular or ring shape in plan view as a whole. Each side of the metal connecting portion 16 extends along the X direction or the Y direction. A suspension lead 14 is connected to each of the four corners of the metal connecting portion 16. The metal connecting portion 16 is supported by the support lead 13 via the four suspension leads 14.

[0108] A plurality of inner lead portions 12A, 12B extend from the metal connecting portion 16, respectively. The multiple inner lead portions 12A, 12B are located between the die pad 11 and the lead portion 12. The inner lead portions 12A, 12B include inner lead portions 12A extending toward the die pad 11 side and inner lead portions 12B extending toward the support lead 13 side.

[0109] Each inner lead portion 12A, 12B has an inner lead 51A, 51B and an external terminal 53A, 53B, respectively. The inner leads 51A, 51B are thinned from the back side by, for example, half etching. External terminal surfaces 17A, 17B are formed on the back sides of the external terminals 53A, 53B, respectively.

[0110] The inner leads 12A, 12B are arranged at intervals along the metal connecting portion 16. When the semiconductor device 20 is fabricated, the inner leads 12A, 12B are individually separated from each other by removing the metal connecting portion 16.

[0111] The resin portion 18 is disposed around the die pad 11 and the lead portions 12. The resin portion 18 is disposed on the back surface side of the lead frame 10A. That is, the resin portion 18 is present on the back surface side (negative side in the Z direction) of the lead frame 10A relative to a midpoint in the thickness direction.

[0112] 12, the resin portion 18 is filled in the thinned portion on the back surface of the lead portion 12 and the thinned portion on the back surface of the inner lead portion 12B. The resin portion 18 is also present between the lead portion 12 and the inner lead portion 12B. The resin portion 18 is also filled in the thinned portion on the back surface of the inner lead portion 12A. The resin portion 18 is also present between the inner lead portion 12A and the die pad 11.

[0113] The lead frame 10A according to this embodiment can be manufactured in substantially the same manner as the lead frame 10 according to the first embodiment (FIGS. 7(A)-(I)).

[0114] FIG. 13 is a diagram showing a semiconductor device 20A according to this embodiment. As shown in FIG. 13, the semiconductor device 20A includes a die pad 11, a plurality of leads 12, a plurality of inner leads 12A and 12B, a semiconductor element 21, and a plurality of bonding wires (connecting members) 22. The plurality of leads 12 are arranged around the die pad 11. The semiconductor element 21 is mounted on the die pad 11. The bonding wires 22 electrically connect the leads 12 and the inner leads 12A and 12B to the semiconductor element 21. A resin portion 18 is arranged around the die pad 11 and the leads 12 on the back surface side of the semiconductor device 20A. Furthermore, the die pad 11, the leads 12, the inner leads 12A and 12B, the semiconductor element 21, and the bonding wires 22 are resin-sealed with a sealing resin 23.

[0115] In this case, the inner lead 12A is separated from the die pad 11, the inner lead 12B, and the other inner leads 12A, and is electrically independent from one another. The inner lead 12B is separated from the die pad 11, the inner lead 12A, and the other inner leads 12B, and is electrically independent from one another. In FIG. 13, by removing the metal connecting portion 16, a recess 27 is formed between the inner lead 12A and the inner lead 12B on the back surface of the semiconductor device 20A. This recess 27 roughly corresponds to the shape of the metal connecting portion 16. The recess 27 has a substantially rectangular annular or ring-like shape in plan view, surrounding the die pad 11. The recess 27 may be filled with an insulating resin of the same or different type as the sealing resin 23.

[0116] The method for manufacturing the semiconductor device 20A according to this embodiment can be performed in substantially the same manner as the method for manufacturing the semiconductor device 20 according to the first embodiment (FIGS. 8(A)-(H)).

[0117] According to this embodiment, when manufacturing the semiconductor device 20A, the inner lead portion 12A and the inner lead portion 12B are individually separated by removing the metal connecting portion 16. Therefore, in addition to the lead portion 12, the inner lead portions 12A and 12B can also be used, and the number of terminal portions (number of pins) connected to an external mounting board can be increased. This allows for a high density of the semiconductor device 20.

[0118] (Modification of the second embodiment) FIG. 14 shows a lead frame 10A according to a modified example of this embodiment. In the lead frame 10A shown in FIG. 14, the metal connecting portion 16 is thinned from both the front surface side and the back surface side. The portion of the metal connecting portion 16 thinned from the front surface side forms a front surface-side thin portion 16f. The portion of the metal connecting portion 16 thinned from the back surface side forms a back surface-side thin portion 16d. The back surface-side thin portion 16d is formed on the inside (die pad 11 side) and outside (support lead 13 side) of the front surface-side thin portion 16f. That is, one back surface-side thin portion 16d is formed on the inside of the front surface-side thin portion 16f, and the other back surface-side thin portion 16d is formed on the outside of the front surface-side thin portion 16f.

[0119] The front-side thin portion 16f and the back-side thin portion 16d may each be formed by, for example, half-etching. The front-side thin portion 16f and the back-side thin portion 16d may each extend along the longitudinal direction of the metal connecting portion 16 in a plan view. External terminals 53A and 53B are respectively present between the back-side thin portion 16d and the resin portion 18. The resin portion 18 is not exposed within the back-side thin portion 16d.

[0120] According to this modification, the volume of the metal connecting portion 16 is further reduced by thinning the metal connecting portion 16 from the back surface side. This makes it easier to remove the metal connecting portion 16 by etching or dicing when separating the inner lead portion 12A and the inner lead portion 12B from each other in the process of manufacturing the semiconductor device 20A.

[0121] Other configurations may be the same as those shown in FIGS.

[0122] (Third embodiment) Next, a third embodiment will be described with reference to Figures 15 and 16. Figures 15 and 16 are diagrams showing the third embodiment. The third embodiment shown in Figures 15 and 16 differs mainly in that the metal connecting portion 16 is thinned from the back side, not from the front side, and the other configurations are substantially the same as those of the first embodiment described above. In Figures 15 and 16, the same parts as those of the first embodiment shown in Figures 1 to 8 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0123] As shown in FIG. 15, the lead frame 10B according to this embodiment includes a die pad 11, lead portions 12, metal connecting portions 16, and a resin portion 18. The metal connecting portions 16 connect the die pad 11 and the lead portions 12 to each other. The resin portion 18 is disposed around the die pad 11 and the lead portions 12 on the back surface side of the lead frame 10B. The metal connecting portions 16 are thinned from the back surface side. At least a portion of the lead portions 12 are thinned from the back surface side. At least a portion of the thinned portions of the lead portions 12 are filled with the resin portion 18.

[0124] In FIG. 15, the metal connecting portion 16 is thinned from the back surface side. The metal connecting portion 16 is not thinned from the front surface side. The portion of the metal connecting portion 16 that is thinned from the back surface side forms a back surface thin portion 16d. The back surface thin portion 16d is located more inward (closer to the die pad 11) than the portion corresponding to the inner lead side surface 51c. The back surface thin portion 16d is not filled with the resin portion 18.

[0125] The back-side thin portion 16d is formed by, for example, half etching. The back-side thin portion 16d may extend along the longitudinal direction of the metal connecting portion 16 in a plan view. The width W6 of the back-side thin portion 16d may be 25 μm or more and 150 μm or less. A metal portion 16e is present between the back-side thin portion 16d and the resin portion 18. The resin portion 18 is not exposed within the back-side thin portion 16d. The metal portion 16e is not thinned from either the front side or the back side. The width W7 of the metal portion 16e may be 25 μm or more and 100 μm or less. The widths W6 and W7 each refer to the distance measured from the die pad 11 side to the lead portion 12 side in a cross section perpendicular to the extension direction of the metal connecting portion 16.

[0126] In FIG. 15, the depth d2 of the rear surface thin portion 16d may be 30% to 60% or 40% to 50% of the maximum thickness T1 of the lead frame 10. The depth d2 of the rear surface thin portion 16d may be 24 μm to 180 μm or 32 μm to 150 μm. In FIG. 15, the depth d2 of the rear surface thin portion 16d is the same as the thickness T3 of the resin portion 18, but is not limited to this. The depth d2 of the rear surface thin portion 16d may be shallower or deeper than the thickness T3 of the resin portion 18.

[0127] The back-side thin portion 16d may be formed as follows. First, in the step of forming the etching resist layers 34 and 35 described above (FIG. 7(G)), an opening corresponding to the back-side thin portion 16d is formed in the back-side etching resist layer 35. On the other hand, the opening 34b is not formed in the front-side etching resist layer 34. Then, the metal substrate 31 is thinned from the back side of the metal substrate 31 to the middle of its thickness direction by half etching (FIG. 7(H)). At this time, the back-side etching resist layer 35 serves as a corrosion-resistant film, and the back side of the metal substrate 31 is etched with an etchant to form the back-side thin portion 16d.

[0128] Alternatively, the rear surface thin portion 16d may be formed together with the rear surface recess 36 in the step of forming the rear surface recess 36 by half etching on the rear surface of the metal substrate 31 (FIG. 7(C)).

[0129] According to this embodiment, the volume of the metal connecting portion 16 is reduced by thinning the metal connecting portion 16 from the back surface side. This makes it easier to remove the metal connecting portion 16 by etching when separating the lead portion 12 and the die pad 11 from each other (FIG. 8(F)), as described above.

[0130] 16 is a diagram showing a semiconductor device 20B according to this embodiment. As shown in FIG. 16, the semiconductor device 20B includes a plurality of leads 12, a semiconductor element 21, and a plurality of bonding wires (connecting members) 22. The plurality of leads 12 are arranged around a die pad 11. The semiconductor element 21 is mounted on the die pad 11. The bonding wires 22 electrically connect the leads 12 and the semiconductor element 21. A resin portion 18 is arranged around the die pad 11 and the leads 12 on the back surface side of the semiconductor device 20B. The die pad 11, the leads 12, the semiconductor element 21, and the bonding wires 22 are resin-sealed with a sealing resin 23.

[0131] The metal connecting portion 16 is encapsulated with the encapsulating resin 23 and then etched away from the rear surface side. Therefore, the lead portion 12 is separated from the die pad 11 and other lead portions 12, and is electrically isolated from each other.

[0132] As a result of the removal of the metal connecting portion 16, a recess 27 is formed on the back surface of the sealing resin 23 between the lead portion 12 and the die pad 11. This recess 27 roughly corresponds to the shape of the metal connecting portion 16. The recess 27 has a substantially rectangular annular or ring shape in plan view, surrounding the die pad 11. Removal of the metal connecting portion 16 separates the die pad 11 and the lead portion 12 from each other. At this time, an inner lead side surface 51c of the lead portion 12 is formed. The recess 27 is also formed between the die pad 11 and the lead portion 12. At least a portion of the removed metal connecting portion 16 may remain on the side surface of the resin portion 18 that contacts the recess 27. In this case, moisture in the air is prevented from penetrating into the semiconductor element 21 through the interface between the resin portion 18 and the lead portion 12 during use of the semiconductor device 20. The recess 27 may be filled with an insulating resin of the same or different type as the sealing resin 23.

[0133] (Modification of the third embodiment) FIG. 17 shows a lead frame 10B according to a modified example of this embodiment. In the lead frame 10B shown in FIG. 17, the metal connecting portion 16 is thinned from the back surface side, but not from the front surface side. The portion of the metal connecting portion 16 that is thinned from the back surface side forms a back surface thin portion 16d. The back surface thin portion 16d is located more inward (closer to the die pad 11) than the portion corresponding to the inner lead side surface 51c. The back surface thin portion 16d is not filled with the resin portion 18.

[0134] 17, the resin portion 18 is exposed in the rear surface side thin portion 16d. That is, there is no metal portion between the rear surface side thin portion 16d and the resin portion 18.

[0135] According to this modification, the volume of the metal connecting portion 16 is further reduced by thinning the metal connecting portion 16 from the back surface side. This makes it easier to remove the metal connecting portion 16 by etching when separating the lead portion 12 and the die pad 11 from each other (FIG. 8(F)), as described above.

[0136] Other configurations may be the same as those shown in FIGS.

[0137] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Figures 18 to 20. Figures 18 to 20 are diagrams showing the fourth embodiment. In Figures 18 to 20, the same parts as those in the first to third embodiments are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0138] 18 and 19(A)(B) includes a die pad 11, a plurality of elongated peripheral leads 12C, 12D, a metal connecting portion 41, and a resin portion 18. The plurality of peripheral leads 12C, 12D are arranged around the die pad 11. The metal connecting portion 41 is arranged between the die pad 11 and the peripheral leads 12C, 12D, and extends along the periphery of the die pad 11. The resin portion 18 is arranged around the die pad 11 and the peripheral leads 12C, 12D, on the back surface side of the lead frame 10C.

[0139] A plurality of peripheral leads 12C, 12D are provided along the periphery of each package area 10a. The plurality of peripheral leads 12C, 12D include a relatively long peripheral lead 12C and a relatively short peripheral lead 12D. In this specification, the long peripheral lead 12C and the short peripheral lead 12D are collectively referred to as peripheral leads 12C, 12D.

[0140] Each of the peripheral lead portions 12C and 12D has an external terminal 53 and a connection lead 52. The external terminal 53 is located on the inner side (the die pad 11 side). The connection lead 52 is located on the outer side (the opposite side of the die pad 11, the support lead 13 side). The external terminal 53 is located at the inner end of the peripheral lead portions 12C and 12D. An internal terminal 15 is formed on the front side of the external terminal 53. An external terminal surface 17 is formed on the back side of the external terminal 53. The connection lead 52 connects the external terminal 53 and the support lead 13 to each other.

[0141] The metal connecting portion 41 is disposed so as to surround the die pad 11, more inward than the peripheral lead portions 12C and 12D. The metal connecting portion 41 has a generally rectangular shape, with each side extending along the X direction or the Y direction. A suspension lead 14 is connected to each of the four corners of the metal connecting portion 41. The metal connecting portion 41 is supported by the support lead 13 via the four suspension leads 14.

[0142] A plurality of first recesses 41a are formed at intervals on the surface of the metal connecting portion 41. Each first recess 41a is formed by half-etching and has a constant depth without penetrating the entire surface in the thickness direction. Each first recess 41a is formed inside (on the die pad 11 side) the center of the width of the metal connecting portion 41. Each first recess 41a may be formed in the center of the width of the metal connecting portion 41, or may be formed outside (on the opposite side of the die pad 11) the center of the width of the metal connecting portion 41.

[0143] Between adjacent first recesses 41a, inner terminal portions 42 are formed. That is, the first recesses 41a and the inner terminal portions 42 are alternately arranged along the length direction of the metal connecting portion 41. In this case, the inner terminal portions 42 are not half-etched and have the same thickness as the die pad 11 and the support leads 13. A metal layer such as plating may be provided on the surface of each inner terminal portion 42 to improve adhesion with the bonding wire 22.

[0144] A plurality of second recesses 41b are formed at intervals on the back surface of the metal connecting portion 41. Each second recess 41b is formed by half-etching and has a constant depth without penetrating the thickness direction. Each second recess 41b is formed outside the widthwise center of the metal connecting portion 41 (on the opposite side from the die pad 11). Each second recess 41b may be formed in the widthwise center of the metal connecting portion 41 or inside the widthwise center of the metal connecting portion 41 (toward the die pad 11). The resin portion 18 is not filled in each second recess 41b. Each first recess 41a and each second recess 41b are arranged side by side in the widthwise direction of the metal connecting portion 41 in a plan view. However, the first recesses 41a and each second recess 41b may also be arranged in a staggered pattern (alternately) in a plan view.

[0145] In this embodiment, when fabricating the semiconductor device 20C (see FIG. 20), only a portion of the metal connecting portion 41 is removed by etching. Specifically, the peripheral regions of each of the first recesses 41a of the metal connecting portion 41 are removed. On the other hand, the portions of the metal connecting portion 41 located between each of the first recesses 41a and each of the second recesses 41b are not removed, but are individually separated to form the inner terminal portions 42.

[0146] Specifically, when etching away a portion of the metal connector 41 from the rear surface of the lead frame 10C (see FIG. 8(F)), openings 37a are formed in the etching resist layer 37 in areas corresponding to the first recesses 41a, the second recesses 41b, and their surroundings. Then, the etchant entering through the openings 37a selectively dissolves and removes the metal connector 41 in the areas surrounding the first recesses 41a and the second recesses 41b. In this case, the metal connector 41 has the first recesses 41a and the second recesses 41b. Therefore, the etchant entering through the openings 37a can appropriately remove only the areas surrounding the first recesses 41a and the second recesses 41b of the metal connector 41 without excessively dissolving the inner terminals 42 or the peripheral leads 12C and 12D. In this way, the inner terminals 42 remain between the adjacent first recesses 41a of the metal connector 41.

[0147] In the present embodiment, the first recesses 41a and the second recesses 41b are formed at positions corresponding to the tips of the long-periphery lead portions 12C, but are not limited to this and may be formed at positions corresponding to the tips of the short-periphery lead portions 12D. The first recesses 41a and the second recesses 41b are provided over the entire circumferential area of ​​the metal connecting portion 41, but are not limited to this and may be provided only in a portion of the metal connecting portion 41. In the present embodiment, the first recesses 41a are arranged on the inner side (the die pad 11 side), and the second recesses 41b are arranged on the outer side (the opposite side of the die pad 11). However, are not limited to this and the first recesses 41a may be arranged on the outer side and the second recesses 41b may be arranged on the inner side.

[0148] The semiconductor device 20C shown in Fig. 20 is fabricated from the lead frame 10C shown in Fig. 18 and Fig. 19(A)(B). In the semiconductor device 20C, the inner terminal portions 42 are arranged at intervals along the four peripheral sides of the die pad 11 (four sides parallel to the X direction or Y direction in Fig. 20).

[0149] Of the metal connecting portions 41 of the lead frame 10C, the peripheral regions of each of the first recesses 41a and each of the second recesses 41b are sealed with the sealing resin 23 and then removed by etching from the rear surface side. Therefore, each inner terminal portion 42 is separated from the die pad 11, the peripheral lead portions 12C and 12D, and the other inner terminal portions 42, and is electrically independent from these components. The inner terminal portions 42 are not half-etched and have the same thickness as the die pad 11. An external terminal surface 17 is formed on the rear surface of the inner terminal portion 42, which is electrically connected to an external mounting board (not shown).

[0150] As a result of removing the metal connecting portion 41 except for the inner terminal portion 42, a recess 27A is formed on the back surface of the sealing resin 23 in the area between the outer lead portions 12C, 12D and the die pad 11, surrounding the die pad 11.

[0151] According to the present embodiment, when the semiconductor device 20C is fabricated, a portion of the metal connecting portion 41 is removed. Furthermore, the remaining portions of the metal connecting portion 41 are individually separated to form the inner terminal portions 42. In this manner, by forming a large number of inner terminal portions 42, the number of terminal portions (the number of pins) connected to an external mounting board can be increased, thereby achieving a further increase in the density of the semiconductor device 20C.

[0152] In this embodiment, some of the inner terminal portions 42 may be formed larger than the other inner terminal portions 42. By connecting multiple bonding wires 22 to inner terminal portions 42 that are larger than the other inner terminal portions 42, they may be used as bus bars for adjusting electrical signals or ground (GND) terminals. This reduces heat generation that accompanies an increase in the number of terminals, and realizes a semiconductor device 20C with higher reliability.

[0153] The manufacturing method of the lead frame 10C and the manufacturing method of the semiconductor device 20C according to this embodiment are substantially the same as the manufacturing method of the lead frame 10 according to the first embodiment (Figures 7(A)-(I)) and the manufacturing method of the semiconductor device 20 (Figures 8(A)-(H)).

[0154] (Fifth embodiment) Next, a fifth embodiment will be described with reference to Figures 21 to 24. Figures 21 to 24 are diagrams showing the fifth embodiment. In Figures 21 to 24, the same parts as those in the first to fourth embodiments are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0155] 21 and 22(A)(B) includes a die pad 11, a plurality of elongated peripheral leads 12C, 12D, a metal connecting portion 43, and a resin portion 18. The plurality of elongated peripheral leads 12C, 12D are arranged around the die pad 11. The metal connecting portion 43 is arranged between the die pad 11 and the peripheral leads 12C, 12D, and extends along the periphery of the die pad 11. The resin portion 18 is arranged around the die pad 11 and the peripheral leads 12C, 12D, on the back surface side of the lead frame 10E.

[0156] In the lead frame 10D shown in FIGS. 21 and 22(A) and 22(B), a recess 43a is formed on the surface of the metal connecting portion 43. The recess 43a is formed as a groove along the longitudinal direction of the metal connecting portion 43. The recess 43a is formed, for example, by half-etching and has a constant depth without penetrating the thickness direction. The recess 43a is formed in the approximate center of the width of the metal connecting portion 43, but may be offset from the approximate center of the width of the metal connecting portion 43. Non-thinned bank portions 43b are formed on both sides of the recess 43a in the width direction. The cross section of the metal connecting portion 43 perpendicular to the longitudinal direction is approximately concave-shaped or approximately U-shaped. Note that in this embodiment, the recess 43a is provided around the entire circumference of the metal connecting portion 43 excluding the four corners. However, this is not limited thereto, and the recess 43a may be provided around the entire circumference of the metal connecting portion 43, including the four corners.

[0157] Providing the recesses 43a in this manner reduces the volume of the metal connecting portions 43. This makes it easier to remove the metal connecting portions 43 by etching when separating the multiple external terminals 56 individually during the manufacture of the semiconductor device 20D (see FIG. 23).

[0158] In this embodiment, a plurality of inner lead portions 12E to 12H are supported by the metal connecting portion 43. The plurality of inner lead portions 12E to 12H include a long inner lead portion 12E, a short inner lead portion 12F, a long inner lead portion 12G, and a short inner lead portion 12H. Each of the inner lead portions 12E to 12H has an external terminal 56 and a connection lead 57. The connection lead 57 is connected to the metal connecting portion 43. The connection lead 57 is thinned from the surface side.

[0159] Of the multiple inner lead portions 12E to 12H, the long inner lead portion 12E and the short inner lead portion 12F each extend outward from the metal connecting portion 43. The long inner lead portion 12E and the short inner lead portion 12F are alternately arranged along the longitudinal direction of the metal connecting portion 43. The long inner lead portion 12G and the short inner lead portion 12H each extend inward from the metal connecting portion 43. The long inner lead portion 12G and the short inner lead portion 12H are alternately arranged along the longitudinal direction of the metal connecting portion 43.

[0160] A long inner lead portion 12G extending inward from the metal connecting portion 43 and a short inner lead portion 12F extending outward from the metal connecting portion 43 are arranged on opposite sides of the metal connecting portion 43. The long inner lead portion 12G and the corresponding short inner lead portion 12F are positioned on a straight line with the metal connecting portion 43 in between.

[0161] The short inner lead portion 12H extending inward from the metal connecting portion 43 and the long inner lead portion 12E extending outward from the metal connecting portion 43 are arranged on opposite sides of the metal connecting portion 43. The short inner lead portion 12H and the corresponding long inner lead portion 12E are located on a straight line with the metal connecting portion 43 in between.

[0162] The short inner lead portion 12F extending outward from the metal connecting portion 43 and the long outer peripheral lead portion 12C face each other, and the long inner lead portion 12E extending outward from the metal connecting portion 43 and the short outer peripheral lead portion 12D face each other.

[0163] Each connection lead 57 of the inner lead portions 12E to 12H is thinned from the front surface side. In this case, the connection leads 57 are exposed on the back surface side, which makes it easy to remove the connection leads 57 together with the metal connecting portions 43. Furthermore, when removing the metal connecting portions 43 by etching (see FIG. 8(E)), it is easy to check from the back surface whether the metal connecting portions 43 and the connection leads 57 have been completely removed. This makes it easy to separate the external terminals 56.

[0164] 22(A)(B). The metal connecting portions 43 of the lead frame 10D are removed by etching from the rear surface side after being resin-sealed with the sealing resin 23. As a result of removing the metal connecting portions 43, recesses 27A are formed on the rear surface of the sealing resin 23 in regions between the inner leads 12E, 12F and the inner leads 12G, 12H.

[0165] 23, the connection leads 57 are removed together with the metal coupling portions 43. However, the present invention is not limited to this, and some or all of the connection leads 57 may remain in the semiconductor device 20D.

[0166] Fig. 24 shows a lead frame 10E according to a modified example of this embodiment. In Fig. 24, only the short inner lead portions 12H extend inside the metal connecting portion 43, and the long inner lead portions 12G do not. Therefore, the external terminals 53, 56 are arranged in five rows around the die pad 11. In this case, a large area of ​​the die pad 11 can be ensured relative to the size of the semiconductor device 20D.

[0167] The manufacturing methods of the lead frames 10D and 10E and the semiconductor device 20D according to this embodiment are substantially the same as the manufacturing methods of the lead frame 10 according to the first embodiment (FIGS. 7(A)-(I)) and the manufacturing methods of the semiconductor device 20 (FIGS. 8(A)-(H)).

[0168] In this embodiment, in both the lead frame 10D shown in Fig. 21 (six rows of external terminals 53, 56) and the lead frame 10E shown in Fig. 24 (five rows of external terminals 53, 56), all of the external terminals 53, 56 can be arranged in a staggered pattern with equal spacing between the external terminals 53, 56. This makes it possible to suppress the occurrence of solder bridges when mounting on a board, thereby improving mounting reliability.

[0169] According to this embodiment, for example, in the case of a 12 mm square package, if the lead frame 10D (external terminals 53, 56 in six rows) shown in FIG. 21 is used, the number of terminal portions (number of pins) can be increased to 308. Furthermore, for example, in the case of a 12 mm square package, if the lead frame 10D (external terminals 53, 56 in five rows) shown in FIG. 21 is used, the number of terminal portions (number of pins) can be increased to 280. Thus, according to this embodiment, a semiconductor device capable of mounting a high-performance LSI can be manufactured at low cost. Furthermore, for example, in the case of a 10 mm square package, if the lead frame 10D (external terminals 53, 56 in five rows) shown in FIG. 21 is used, the number of terminal portions (number of pins) can be increased to 208 to 216. This number of pins (208 to 216) corresponds to the number of pins of a conventional 28 mm square QFP (Quad Flat Package).

[0170] (Sixth embodiment) Next, a sixth embodiment will be described with reference to Figures 25 to 27. Figures 25 to 27 are diagrams showing the sixth embodiment. In Figures 25 to 27, the same parts as those in the first to fifth embodiments are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0171] 25 and 26(A)(B) includes a die pad 11, a plurality of elongated peripheral leads 12J, 12K, a metal connecting portion 44, and a resin portion 18. The plurality of peripheral leads 12J, 12K are arranged around the die pad 11. The metal connecting portion 44 is arranged between the die pad 11 and the peripheral leads 12J, 12K, and extends along the periphery of the die pad 11. The resin portion 18 is arranged around the die pad 11 and the peripheral leads 12J, 12K on the back surface side of the lead frame 10F.

[0172] The peripheral lead portions 12J, 12K have an inner lead 51, a connection lead 52, and an external terminal 53. The inner lead 51 is located on the inside (the die pad 11 side). The connection lead 52 is located on the outside (the opposite side of the die pad 11, the support lead 13 side). The external terminal 53 is located between the inner lead 51 and the connection lead 52. The inner lead 51 and the connection lead 52 are thinned from the back surface side. The external terminal 53 is not thinned. The connection lead 52 is connected to the support lead 13.

[0173] 25 and 26(A) and (B), the metal connecting portion 44 is provided at the tip of the inner lead 51 of the peripheral lead portions 12J and 12K. The metal connecting portion 44 is arranged so as to surround the die pad 11. The inner leads 51 of the peripheral lead portions 12J and 12K are connected to the outer peripheral edge portion of the metal connecting portion 44 (the peripheral edge portion on the support lead 13 side). A connecting bar 45 extends from the metal connecting portion 44 toward the inside (the die pad 11 side). In this case, the metal connecting portion 44 is connected to and supported by all the inner leads 51. However, this is not limiting, and the metal connecting portion 44 may be connected to only some of the inner leads 51.

[0174] A recess 44a is formed on the surface of the metal connecting portion 44 near the tip of each inner lead 51. Each recess 44a is formed by half-etching and has a constant depth without penetrating the entire thickness. Each recess 44a is formed at approximately the center of the metal connecting portion 44 in the width direction, but may be formed inside or outside of the approximately center of the metal connecting portion 44 in the width direction.

[0175] The recesses 44a are spaced apart from one another along the longitudinal direction of the metal connecting portion 44. Thick portions 44b are formed between adjacent recesses 44a. The recesses 44a and thick portions 44b are alternately arranged along the longitudinal direction of the metal connecting portion 44. The thick portions 44b are not half-etched and have the same thickness as the die pad 11 and the support leads 13. Two connecting bars 45 are connected to each of the four sides of the die pad 11. The die pad 11 is supported by the metal connecting portions 44 and the connecting bars 45. Hanging leads 14 are provided at the four corners of the die pad 11. Note that the resin portion 18 can support the die pad 11 relative to the peripheral leads 12J and 12K and the support leads 13, so the hanging leads 14 are not necessary. If the hanging leads 14 are not provided, it is easier to fill the four corners of the die pad 11 with resin that forms the resin portion 18.

[0176] In this embodiment, when fabricating the semiconductor device 20F (see FIG. 27), the periphery of each recess 44a of the metal connecting portion 44 and the thick portion 44b of the metal connecting portion 44 begin to be etched simultaneously. However, it takes more time to remove the thick portion 44b than to remove the area of ​​each recess 44a. This makes it possible to adjust the progress of etching of the metal connecting portion 44 itself.

[0177] In this embodiment, when etching and removing the metal connecting portion 44 from the back surface side of the lead frame 10F (see FIG. 8(E)), openings 37b are formed in the etching resist layer 37 on the back surface of the sealing resin 23 at positions corresponding to the metal connecting portion 44. Then, the etchant entering through the openings 37b appropriately dissolves and removes the recesses 44a and thick portions 44b of the metal connecting portion 44. In this case, because the recesses 44a are formed in the surface of the metal connecting portion 44, the etchant entering through the openings 37b can appropriately remove the entire metal connecting portion 44 without dissolving the peripheral leads 12J, 12K more than necessary.

[0178] In this embodiment, the recesses 44a are provided near the tips of all the inner leads 51. However, the present invention is not limited to this, and the recesses 44a may be provided only near the tips of some of the inner leads 51.

[0179] In this way, by providing recesses 44a in a dot pattern at regular intervals along the metal connecting portion 44 and forming thick portions 44b between each recess 44a, it is possible to appropriately adjust the penetration and dissolution of the etching solution when removing the metal connecting portion 44 by etching.

[0180] 27 is produced from the lead frame 10F shown in Fig. 25 and Fig. 26(A)(B). The metal connecting portions 44 of the lead frame 10F are removed by etching from the back surface side after being resin-sealed with the sealing resin 23. As a result of removing the metal connecting portions 44, a recess 27B is formed on the back surface of the sealing resin 23 in the region between the peripheral leads 12J, 12K and the die pad 11 so as to surround the die pad 11.

[0181] The manufacturing method of the lead frame 10F and the manufacturing method of the semiconductor device 20F according to this embodiment are substantially the same as the manufacturing method of the lead frame 10 according to the first embodiment (FIGS. 7(A)-(I)) and the manufacturing method of the semiconductor device 20 (FIGS. 8(A)-(H)).

[0182] It is also possible to combine the multiple components disclosed in the above embodiments and modifications as needed, or to delete some of the components disclosed in the above embodiments and modifications.

Claims

1. A semiconductor device, A die pad; a lead portion disposed around the die pad; a resin portion disposed on a back surface side of the semiconductor device around the die pad and the lead portion; a semiconductor element mounted on the die pad; a connecting member that electrically connects the lead portion and the semiconductor element; a sealing resin that seals the die pad, the lead portion, the semiconductor element, and the connection member; At least a part of the lead portion is thinned from the back surface side, and the resin portion is filled in the thinned part of the lead portion, a recess formed on the rear surface of the sealing resin between the die pad and the lead portion;

2. The resin portion has a resin surface located on the surface side, The semiconductor device according to claim 1 , wherein the sealing resin is in close contact with the resin surface of the resin portion.

3. A semiconductor device as described in Claim 1, wherein the resin portion is exposed toward the recess.

4. The lead portion has an inner lead and an external terminal, an inner lead side surface is formed on a side of the inner lead facing the die pad; 2. The semiconductor device according to claim 1, wherein the inner lead side surface is exposed toward the inside of the recess.

5. A metal connecting portion connecting the die pad and the lead portion to each other, The semiconductor device according to claim 1 , wherein at least a portion of the removed metal connecting portion remains on a side surface of the resin portion that contacts the recess.

6. A semiconductor device, A die pad; a plurality of leads arranged around the die pad; a resin portion disposed on a back surface side of the semiconductor device around the die pad and the lead portion; a semiconductor element mounted on the die pad; a connecting member that electrically connects the lead portion and the semiconductor element; a sealing resin that seals the die pad, the lead portion, the semiconductor element, and the connection member; the lead portion includes a first lead portion extending toward the die pad and a second lead portion extending toward an outside of the semiconductor device; At least a portion of the first lead portion is thinned from the back surface side, and the thinned portion of the first lead portion is filled with the resin portion; A semiconductor device, wherein a recess is formed on a rear surface of the semiconductor device between the first lead portion and the second lead portion.

7. A semiconductor device as described in claim 1 or 6, wherein the recess has an approximately rectangular annular or ring shape in a planar view so as to surround the die pad.

8. A semiconductor device as described in claim 1 or 6, wherein the recess is filled with an insulating resin of the same or different type as the sealing resin.

9. The semiconductor device according to claim 1, wherein the thermal conductivity of the resin portion is equal to or greater than 1 W·m −1 ·K −1 and equal to or less than 12 W·m −1 ·K −1 in a 25° C. environment.

Images