Lead frame and manufacturing method thereof

Abstract

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

Description

[Technical field]

[0001] The present disclosure relates to a leadframe 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. In order to meet such demands, various types of so-called QFN (Quad Flat Non-lead) type semiconductor devices have been proposed, which are configured using a lead frame, a semiconductor element mounted on the mounting surface of the lead frame being sealed with sealing resin, and a portion of the leads being exposed on the back surface.

[0003] Conventionally, however, as the lead frame becomes thinner, it becomes more difficult to maintain the strength of the lead frame, which causes a problem that the lead frame becomes deformed after etching.

[0004] In recent years, there has been a demand to increase the number of leads (number of pins) without changing the chip size. In response to this, the lead width has traditionally been narrowed, but as the lead becomes thinner, it becomes more susceptible to deformation, which makes it difficult to perform stable wire bonding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-184927 A Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a technique for forming a semiconductor chip mounting portion and leads using a non-through groove, sealing the semiconductor chip or the like with resin, and then penetrating the non-through groove to form a semiconductor device. However, if a lead that is thinned from the back side is used, the lead is likely to deform during wire bonding. Also, if a lead that is thinned from the back side is used, the space on the back side of the lead is narrow. For this reason, there is a risk that the sealing resin cannot be sufficiently filled on the back side of the lead.

[0007] The present disclosure provides a lead frame and a manufacturing method thereof that are capable of suppressing deformation of a lead portion during wire bonding. DISCLOSURE OF THEINVENTION

[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 a 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 resin portion is filled in the thinned portion of the lead portion.

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

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

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

[0013] [5] The lead frame described in any one of [1] to [4], wherein the metal connection 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 A 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 connection portion is thinned from the surface side.

[0016] [8] The lead frame described in any one of [1] to [7], wherein the metal connection 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 a 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 a back surface side of the lead frame, wherein a recess is provided on a surface of the metal connecting portion.

[0019]

[11] The lead frame described in

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

[0020]

[12] The lead frame according to

[10] , wherein the recess is formed in a groove shape along the longitudinal direction of the metal connection 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, the long inner lead portions and the short inner lead portions being alternately arranged along the metal connecting portion.

[0022]

[14] The lead frame described in

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

[0023]

[15] A method for manufacturing a lead frame, comprising the steps of: preparing a metal substrate; etching the metal substrate from a back surface side to a portion of 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 back surface recess with the resin portion; and etching the metal substrate from a front surface side to a portion of 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 description of the drawings]

[0025] [Figure 1] FIG. 1 is a plan view showing a lead frame according to a first embodiment. [Diagram 2] FIG. 2 is a bottom view showing the lead frame according to the first embodiment. [Diagram 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 a part IV in FIG. 1). [Diagram 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 showing the semiconductor device according to the first embodiment (a cross-sectional view taken along line VI-VI in FIG. 5). [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 the method for manufacturing the 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] 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] FIG. 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] FIG. 22(A) is a cross-sectional view showing a lead frame according to a fifth embodiment (cross-sectional view taken along line XXIIA-XXIIA in FIG. 21), and FIG. 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 FIG. 21). [Diagram 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. [Diagram 25] FIG. 25 is a plan view showing a lead frame according to a sixth embodiment. [Figure 26] FIG. 26(A) is a cross-sectional view showing a lead frame according to a sixth embodiment (cross-sectional view taken along line XXVIA-XXVIA in FIG. 25), and FIG. 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 FIG. 25). [Figure 27] FIG. 27 is a plan view showing a semiconductor device according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] (First embodiment) Hereinafter, the first embodiment will be described with reference to Figures 1 to 8. In addition, in the following drawings, the same parts are given the same reference numerals, and some detailed descriptions may be omitted.

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

[0028] In this specification, half-etching refers to etching the material to be etched halfway in the 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 limited to the above, 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 of the lead portions 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 portion 12 is thinned from the back surface side. At least a portion of the thinned portion of the lead portion 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 side or the back side. However, this is not limited to the above, and a part of the die pad 11 may be thinned from the front side or the back side by, for example, 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, the suspension leads 14 are connected to the four corners of the die pad 11 via the metal connecting parts 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 side or the back side, and have the same thickness as the metal substrate (metal substrate 31 described later) before processing. However, this is not limited to the above, and the suspension leads 14 may be thinned from the front side or the back side. Since the die pad 11 can be supported by the lead parts 12 and the support leads 13 by the resin part 18, the suspension leads 14 do not need to 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 portion 12 is connected to a semiconductor element 21 via a bonding wire 22. The lead portion 12 is disposed between the die pad 11 and the lead portion 12 via a metal connecting portion 16. The lead portions 12 each extend 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 inner 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 described later. A metal layer that improves adhesion with the bonding wire 22 may be provided on the internal terminal 15. The metal layer may be made of a plating layer such as silver plating.

[0037] The inner lead 51 is thinned from the back 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. In addition, 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 side or the 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] Further, an external terminal inner side surface 53d is formed at a position on the back side of the inner lead back surface 51b of the external terminal 53. The external terminal inner side 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 side surface 53d.

[0040] The metal connection portion 16 is arranged so as to connect the tips of the multiple lead portions 12. The metal connection portion 16 is also arranged so as to surround the die pad 11. This metal connection portion 16 has a substantially rectangular annular or ring shape in a plan view as a whole. Each side of the metal connection portion 16 extends along the X direction or the Y direction. The suspension leads 14 are connected to the four corners of the metal connection portion 16. The metal connection portion 16 does not necessarily have to have an annular or ring shape. For example, the metal connection portion 16 connects the die pad 11 and the tips of the lead portions 12, and does not necessarily have to 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 described below. The metal connecting portion 16 has a connecting portion front surface 16a, a connecting portion back surface 16b, and a connecting portion outer side surface 16c.

[0042] The connecting portion surface 16a is located on the front surface side of the metal connecting portion 16. The connecting portion surface 16a is formed by, for example, half etching. The connecting portion surface 16a is located on the back surface side (negative side in the Z direction) of the front surface of the die pad 11 and the internal terminal 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 on the die pad 11 side from 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 over the entire circumference. Note that 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, a portion of the metal connecting portion 16 excluding the four corners may be thinned from the front surface side.

[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 over 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 side surface 16c is located outside the metal connecting portion 16 (toward the support lead 13). The connecting portion outer side 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 side surface 16c. As shown in FIG. 4, the connecting portion outer side surface 16c is located outside the inner lead side surface 51c (toward the support lead 13). However, this is not limited to the above, and the connecting portion outer side 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 (see FIG. 3) of the metal connecting portion 16 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 (see FIG. 3) 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 may be 50 μm or more and 150 μm or less. Note that 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 portion 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. In each figure, 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 present on the back surface side (negative side in the Z direction) of the lead frame 10 at a midpoint in the thickness direction. The resin portion 18 is not present on the front surface side (positive side in the Z direction) of the midpoint in the thickness direction (Z direction). The midpoint is not limited to the center in the thickness direction of the lead frame 10, and may be located on the front surface side or back surface side of the center in the thickness direction. The midpoint in the thickness direction corresponds to the position where the inner lead back surface 51b is present in the thickness direction. Not limited to this, the midpoint in the thickness direction may be located on the front surface side (positive side in the Z direction) of the position where the inner lead back surface 51b is present.

[0048] 3, the resin portion 18 is in close contact with the connecting portion outer side 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 side 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 lead portions 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 limited to this, 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 a silicone resin or an epoxy resin, or a thermoplastic resin such as a PPS resin. In order to improve the adhesion between the resin portion 18 and a 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 may be more than 3 W m -1 ·K -1 The thermal conductivity of the resin portion 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 lead frame 10, except for the resin portion 18, is generally made of a metal such as copper, a copper alloy, or a 42 alloy (Fe alloy containing 42% Ni). 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 part of the lead frame 10, and refers to the thickness of the part that is not thinned from either the front side or the back side. The maximum thickness of the lead frame 10 corresponds to the plate thickness of the metal substrate 31 described later. In this embodiment, the resin portion 18 is provided on the back side of the lead portion 12, so that the lead portion 12 is 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 thin.

[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] As shown in Fig. 5 and Fig. 6, a semiconductor device (semiconductor package) 20 includes a die pad 11, a plurality of lead portions 12, a semiconductor element 21, and a plurality of bonding wires (connecting members) 22. The plurality of lead portions 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 lead portions 12 and the semiconductor element 21. A resin portion 18 is arranged 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 a 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. Since the configurations of the die pad 11, lead portion 12, and resin portion 18 are similar to those shown in Figures 1 to 4 except for the regions not included in the semiconductor device 20, detailed description thereof will be omitted here.

[0057] On the other hand, the above-mentioned metal connecting portion 16 is removed by etching from the back surface side after being resin-sealed with sealing resin 23. Therefore, as shown in Fig. 5 and Fig. 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 manner, a recess 27 is formed on the rear 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 a plan view so as to surround the die pad 11. Note that the recess 27 may be filled with the same or a different type of insulating resin as 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. This semiconductor element 21 has a plurality of electrodes 21a to which bonding wires 22 are respectively attached. Also, the semiconductor element 21 is fixed to the surface of the die pad 11 by an adhesive 24. For example, a die bonding paste or the like may be used as the adhesive 24.

[0060] Each bonding wire 22 is made of a material with good conductivity, 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 entire thickness of the sealing resin 23 may be about 300 μm or more and 1500 μm or less. Moreover, 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 portion 12, the sealing resin 23 is exposed toward the inside of the recess 27. Moreover, in the portion located between the 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.

[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 the metal substrate 31 after 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 then dried. The photosensitive resist on the metal substrate 31 is then exposed through a photomask and developed. This forms etching resist layers 32, 33 (FIG. 7(B)). The etching resist layer 33 on the back surface side has an opening 33b. The etching resist layer 32 on the front surface side does not have an opening, but may have an opening. The etching resist layers 32, 33 may be, for example, a dry film resist.

[0065] Next, the metal substrate 31 is thinned from the back side of the metal substrate 31 to the middle of the thickness direction by half etching. In this case, the back side of the metal substrate 31 is etched with an etchant, using the etching resist layer 33 on the back side as a corrosion-resistant film (FIG. 7(C)). At this time, the front surface of the metal substrate 31 is not etched because it is entirely covered with the etching resist layer 32. As a result, a back side recess 36, which is a non-penetrating recess, is formed on the back side of the metal substrate 31. This back side recess 36 has a shape corresponding to the resin part 18. The etchant can be appropriately selected according to the material of the metal substrate 31 to be used. For example, when copper is used as the metal substrate 31, an aqueous solution of ferric chloride may be used as the etchant. In this case, the aqueous solution of ferric chloride may be spray-etched from one side 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)). Next, the metal substrate 31 is washed with water and dried.

[0067] Next, the resin part 18 is formed on the back surface of the metal substrate 31, and the back surface recess 36 is covered with the resin part 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. As a result, the resin part 18 is filled into the back surface recess 36. At this time, the resin part 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 stopped after the metal portion constituting the metal substrate 31 appears. As a result, the back surface of the die pad 11 and the portion corresponding to the external terminal surface 17 of the lead portion 12 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 then dried. The photosensitive resist on the metal substrate 31 is then exposed 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 an opening 34b. The etching resist layer 35 on the back surface side does not have an opening, but may have an opening. The etching resist layers 34, 35 may be, for example, a 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 front 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 front 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 front 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 front 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 manner, 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)-(H).

[0074] First, a lead frame 10 is produced (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, each electrode 21a of the semiconductor element 21 and the internal terminal 15 of each lead portion 12 are electrically connected to each other by a bonding wire 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 lead 51 of each lead portion 12 is heated from the back side by the heat block via the metal connecting portion 16 and the external terminal 53. At the same time, while applying ultrasonic waves via the capillary 38 of the wire bonding device, each electrode 21a of the semiconductor element 21 and the inner lead 51 of each lead portion 12 are connected to each other by the bonding wire 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. In addition, 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 makes it possible to prevent 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 directly in contact with the inner lead back surface 51b.

[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 manner, the die pad 11, the lead portion 12, the semiconductor element 21, and the bonding wires 22 are sealed. The sealing resin 23 is also filled between the die pad 11 and the lead portion 12 and on the front surface side of the metal connecting portion 16.

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

[0080] During this process, a photosensitive resist is first applied to the entire back surfaces of the lead frame 10 and the sealing resin 23. The photosensitive resist is then exposed through a photomask and developed to form an etching resist layer 37 having an opening 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 approximately to the position of the metal connecting portion 16 and has a generally rectangular band shape when viewed from above. The connecting portion back surface 16b of the metal connecting portion 16 is exposed from 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 from the opening 37b dissolves and removes the entire metal connection portion 16. By removing the metal connection portion 16, a recess 27 is formed at a position corresponding to the metal connection portion 16. In this manner, the metal connection portion 16 is removed, and the die pad 11 and each lead portion 12 are separated, and adjacent lead portions 12 are separated 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)). Note that after removing the etching resist layer 37, a step of filling the recess 27 with an insulating resin that is the same 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. This separates the lead frame 10 into each semiconductor device 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 manner, the semiconductor device 20 shown in FIGS. 5 and 6 is obtained (FIG. 8(H)).

[0086] Thus, according to this embodiment, the die pad 11 and the lead portion 12 are connected to each other by the metal connecting portion 16. Also, the thinned portion on the back side of the lead portion 12 is filled with the resin portion 18. Therefore, the back side of the lead portion 12 is stably held by the resin portion 18. This makes it possible to prevent 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 the bonding wire 22 is connected 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 to 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, even if such a pressing force is applied by the capillary 38, the lead portion 12 is prevented from being deformed. 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 interval between the lead portions 12 can be reduced, and the lead frame 10 and the semiconductor device 20 can have a large number of pins. In addition, the vibration of the lead portion 12 during wire bonding (FIG. 8(C)) can be suppressed. This allows the wire bonding operation to be performed stably. In addition, since the length of the lead portion 12 can be increased, the length of the bonding wire 22 can be reduced.

[0088] According to this embodiment, the resin portion 18 is filled in the thinned portion on the back side of the lead portion 12 before the lead frame 10 is resin-sealed with the sealing resin 23 (FIG. 8(D)). Therefore, the resin portion 18 can be filled in the thinned portion on the back side of the lead portion 12 without any gaps. In particular, even if the thickness of the thinned portion on the back side of the lead portion 12 (thickness T3 in FIG. 3) is thin, the resin portion 18 can be filled in this portion without any gaps. This makes it possible to prevent moisture in the air from penetrating the interface between the sealing resin 23 and the lead portion 12 from the back side of the semiconductor device 20 when the semiconductor device 20 is in use. On the other hand, if the resin portion 18 is not filled in the back side of the lead portion 12, the sealing resin 23 may not sufficiently flow around this portion.

[0089] According to the present embodiment, a part of the metal connection 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 connection portion 16 and the lead portion 12, and prevents the lead portion 12 from being deformed by the capillary 38 during wire bonding. The width W2 of the part of the metal connection 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 the deformation of the lead portion 12 described above is more easily obtained. 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 front side, and resin surface 18a may be exposed to the outside from between two adjacent lead portions 12. The presence of resin portion 18 between two lead portions 12 in this manner makes it possible to prevent lateral deformation of lead portions 12 during wire bonding (FIG. 8(C)).

[0091] Furthermore, according to the present embodiment, the metal connector 16 may have an annular or ring-shaped configuration in plan view, which allows the metal connector 16 to connect a plurality of lead portions 12 together.

[0092] According to the present 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 lead 51 of the lead portion 12 is heated from the back surface side during wire bonding, heat from the heat block can be uniformly transferred via the resin portion 18, the metal connecting portion 16, and the external terminal 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 side and the back side. 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) of 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 connection 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 connection 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 in 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. The widths W3, W4, and W5 each refer to a 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 connection 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 thereto. 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 backside 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 backside thin portion 16d is formed in the etching resist layer 35 on the backside. After that, the metal substrate 31 is thinned from both the front side and the back side of the metal substrate 31 to the middle of the thickness direction by half etching (FIG. 7(H)). At this time, the etching resist layer 35 on the backside serves as a corrosion-resistant film, and the backside of the metal substrate 31 is etched with a corrosive liquid to form the backside 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] The 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 side and the back side. 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) of 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, no metal portion exists 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] The rest of the configuration may be the same as that 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 description thereof will be omitted.

[0105] The lead frame 10A according to the present 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. In addition, the metal connecting portion 16 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. The metal connecting portion 16 has a generally rectangular annular or ring shape in a 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. 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 each extend from the metal connecting portion 16. The plurality of inner lead portions 12A, 12B are located between the die pad 11 and the lead portion 12. The inner lead portions 12A, 12B include the inner lead portion 12A extending toward the die pad 11 side and the inner lead portion 12B extending toward the support lead 13 side.

[0109] Each of the inner lead portions 12A and 12B has an inner lead 51A or 51B and an external terminal 53A or 53B. The inner leads 51A and 51B are thinned from the rear surface side by, for example, half etching. The rear surfaces of the external terminals 53A and 53B are formed with external terminal surfaces 17A and 17B, respectively.

[0110] Further, the multiple inner lead portions 12A, 12B are arranged at intervals from each other along the metal connecting portion 16. When the semiconductor device 20 is manufactured, the inner lead portions 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 portion 12. The resin portion 18 is disposed on the back surface side of the lead frame 10A. That is, the resin portion 18 exists 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 the present embodiment can be manufactured in a manner substantially similar to that of 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 the present embodiment. As shown in FIG. 13, the semiconductor device 20A includes a die pad 11, a plurality of lead portions 12, a plurality of inner lead portions 12A and 12B, a semiconductor element 21, and a plurality of bonding wires (connecting members) 22. The plurality of lead portions 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 lead portions 12 and the inner lead portions 12A and 12B to the semiconductor element 21. In addition, a resin portion 18 is arranged around the die pad 11 and the lead portions 12 on the back surface side of the semiconductor device 20A. Furthermore, the die pad 11, the lead portions 12, the inner lead portions 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 portion 12A is separated from the die pad 11, the inner lead portion 12B, and the other inner lead portion 12A, and is electrically independent from each other. The inner lead portion 12B is separated from the die pad 11, the inner lead portion 12A, and the other inner lead portion 12B, and is electrically independent from each other. In FIG. 13, the metal connecting portion 16 is removed, and thus a recess 27 is formed between the inner lead portion 12A and the inner lead portion 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-shaped shape in a plan view so as to surround the die pad 11. The recess 27 may be filled with an insulating resin that is the same as or different from the sealing resin 23.

[0116] The method for manufacturing the semiconductor device 20A according to the present 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 the semiconductor device 20A is manufactured, 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 be used, and the number of terminal portions (number of pins) connected to an external mounting board can be increased. This allows the semiconductor device 20 to be highly dense.

[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 side and the back side. The portion of the metal connecting portion 16 thinned from the front side forms a front side thin portion 16f. 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 formed on the inside (die pad 11 side) and outside (support lead 13 side) of the front side thin portion 16f. That is, one back side thin portion 16d is formed on the inside of the front side thin portion 16f, and the other back side thin portion 16d is formed on the outside of the front 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 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 metal connecting portion 16 is further reduced by thinning metal connecting portion 16 from the back surface side. This makes it easier to remove metal connecting portion 16 by etching or dicing when inner lead portion 12A and inner lead portion 12B are separated from each other in the process of manufacturing semiconductor device 20A.

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

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

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

[0124] 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 thinned from the back surface side forms the back surface side thin portion 16d. The back surface side thin portion 16d is located inside (on the die pad 11 side) of the portion corresponding to the inner lead side surface 51c. The back surface side 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. The metal portion 16e is present between the back side thin portion 16d and the resin portion 18. The resin portion 18 is not exposed in 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 a 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 thereto. The depth d2 of the rear surface thin portion 16d may be shallower than the thickness T3 of the resin portion 18, or may be deeper than the thickness T3 of the resin portion 18.

[0127] The backside 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 backside thin portion 16d is formed in the etching resist layer 35 on the backside. On the other hand, the opening 34b is not formed in the etching resist layer 34 on the frontside. After that, the metal substrate 31 is thinned from the backside of the metal substrate 31 to the middle of the thickness direction by half etching (FIG. 7(H)). At this time, the etching resist layer 35 on the backside is used as a corrosion-resistant film, and the backside thin portion 16d is formed by etching the backside of the metal substrate 31 with a corrosive liquid.

[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 the present 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 the lead portion 12 and the die pad 11 are separated from each other (FIG. 8(F)), as described above.

[0130] FIG. 16 is a diagram showing a semiconductor device 20B according to the present embodiment. As shown in FIG. 16, the semiconductor device 20B includes a plurality of lead portions 12, a semiconductor element 21, and a plurality of bonding wires (connecting members) 22. The plurality of lead portions 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 lead portions 12 and the semiconductor element 21. In addition, a resin portion 18 is arranged around the die pad 11 and the lead portions 12 on the back surface side of the semiconductor device 20B. The die pad 11, the lead portions 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 the other lead portions 12 and are electrically independent from each other.

[0132] As the metal connecting portion 16 is removed, a recess 27 is formed on the back surface of the sealing resin 23 between the lead portion 12 and the die pad 11. The recess 27 generally corresponds to the shape of the metal connecting portion 16. The recess 27 has a substantially rectangular annular or ring shape in a plan view so as to surround the die pad 11. The 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 part 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 entering the semiconductor element 21 side from 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 that is the same as or different from 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 thinned from the back surface side forms a back surface thin portion 16d. The back surface thin portion 16d is located on the inner side (toward the die pad 11) of 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 within the rear surface side thin portion 16d. That is, no metal portion exists 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 the lead portion 12 and the die pad 11 are separated from each other (FIG. 8(F)), as described above.

[0136] The other configuration may be the same as that 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 description thereof will be omitted.

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

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

[0140] Each of the peripheral lead portions 12C, 12D has an external terminal 53 and a connection lead 52. The external terminal 53 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 at the inside end of the peripheral lead portions 12C, 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, on the inside of the peripheral lead portions 12C and 12D. The metal connecting portion 41 has a generally rectangular shape, and each side extends along the X direction or the Y direction. The suspension leads 14 are connected to 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 of the first recesses 41a is formed by half etching and has a certain depth without penetrating in the thickness direction. Each of the first recesses 41a is formed on the inner side (the die pad 11 side) of the width direction center of the metal connecting portion 41. Each of the first recesses 41a may be formed in the width direction center of the metal connecting portion 41, or may be formed on the outer side (the opposite side to the die pad 11) of the width direction center 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 that improves adhesion to the bonding wire 22 may be provided on the surface of each inner terminal portion 42.

[0144] A plurality of second recesses 41b are formed at intervals on the back surface of the metal connection portion 41. Each second recess 41b is formed by half etching and has a certain depth without penetrating in the thickness direction. Each second recess 41b is formed outside the center of the width direction of the metal connection portion 41 (opposite side of the die pad 11). Each second recess 41b may be formed in the center of the width direction of the metal connection portion 41, or may be formed inside the center of the width direction of the metal connection portion 41 (on the die pad 11 side). 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 width direction of the metal connection portion 41 in a plan view. Not limited to this, each first recess 41a and each second recess 41b may be arranged in a staggered manner (alternately) in a plan view.

[0145] In the present embodiment, when the semiconductor device 20C (see FIG. 20) is fabricated, only a portion of the metal connection portion 41 is removed by etching. Specifically, the peripheral regions of each of the first recesses 41a of the metal connection portion 41 are removed. On the other hand, the portions of the metal connection 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] That is, when a part of the metal connection portion 41 is etched away from the back side of the lead frame 10C (see FIG. 8(F)), openings 37a are provided in the etching resist layer 37 in the areas corresponding to the first recesses 41a, the second recesses 41b, and the surrounding areas thereof. Then, the etchant entering through the openings 37a selectively dissolves and removes the peripheral areas of the first recesses 41a and the second recesses 41b of the metal connection portion 41. In this case, the first recesses 41a and the second recesses 41b are provided in the metal connection portion 41. Therefore, the etchant entering through the openings 37a can appropriately remove only the peripheral areas of the first recesses 41a and the second recesses 41b of the metal connection portion 41 without dissolving the inner terminal portion 42 or the peripheral lead portions 12C and 12D more than necessary. In this way, the inner terminal portions 42 remain between the adjacent first recesses 41a of the metal connection portion 41.

[0147] In the present embodiment, the first recess 41a and the second recess 41b are formed at positions corresponding to the tip of the long outer peripheral lead portion 12C, but are not limited thereto, and may be formed at positions corresponding to the tip of the short outer peripheral lead portion 12D. The first recesses 41a and the second recesses 41b are provided over the entire circumferential area of ​​the metal connection portion 41, but are not limited thereto, and may be provided only in a part of the metal connection portion 41. In the present embodiment, the first recess 41a is disposed on the inner side (the die pad 11 side), and the second recess 41b is disposed on the outer side (the opposite side of the die pad 11). However, are not limited thereto, and the first recess 41a may be disposed on the outer side, and the second recess 41b may be disposed on the inner side.

[0148] The semiconductor device 20C shown in Fig. 20 is produced 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 portion 41 of the lead frame 10C, the peripheral regions of each of the first recesses 41a and each of the second recesses 41b are resin-sealed with the sealing resin 23, and then removed by etching from the rear surface side. Therefore, each of the inner terminal portions 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 members. The inner terminal portions 42 are not half-etched, and have the same thickness as the die pad 11. An external terminal surface 17 that is electrically connected to an external mounting board (not shown) is formed on the rear surface of the inner terminal portion 42.

[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 part of the metal connecting portion 41 is removed. Furthermore, the parts of the metal connecting portion 41 that are not removed are individually separated to become the inner terminal portions 42. In this manner, by forming a large number of the inner terminal portions 42, the number of terminal portions (the number of pins) connected to an external mounting board can be increased, and further high density of the semiconductor device 20C can be realized.

[0152] In this embodiment, some of the inner terminal portions 42 may be formed larger than the other inner terminal portions 42. By connecting a plurality of bonding wires 22 to the 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 similar to the manufacturing method of the lead frame 10 (FIGS. 7(A)-(I)) and the manufacturing method of the semiconductor device 20 (FIGS. 8(A)-(H)) according to the first embodiment.

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

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

[0156] In the lead frame 10D shown in FIG. 21 and FIG. 22(A)(B), a recess 43a is formed on the surface of the metal connection part 43. The recess 43a is formed in a groove shape along the longitudinal direction of the metal connection part 43. The recess 43a is formed by, for example, half etching, and has a certain depth without penetrating in the thickness direction. The recess 43a is formed in the approximate center of the width direction of the metal connection part 43, but may be shifted from the approximate center of the width direction of the metal connection part 43. On both sides of the width direction of the recess 43a, a bank part 43b that is not thinned is formed. The cross section perpendicular to the longitudinal direction of the metal connection part 43 is approximately concave-shaped or approximately U-shaped. In the present embodiment, the recess 43a is provided on the entire circumference of the metal connection part 43 except for the four corners, but is not limited thereto, and may be provided on the entire circumference including the four corners of the metal connection part 43, for example.

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

[0158] In this embodiment, a plurality of inner lead portions 12E-12H are supported by the metal connecting portion 43. The plurality of inner lead portions 12E-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-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 front 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] The long inner lead portion 12G extending inward from the metal connecting portion 43 and the short inner lead portion 12F extending outward from the metal connecting portion 43 are disposed 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 disposed on opposite sides of the metal connecting portion 43. The short inner lead portion 12H and the corresponding long inner lead portion 12E are positioned 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 faces each other, and the long outer peripheral lead portion 12C faces each other, and the long inner lead portion 12E extending outward from the metal connecting portion 43 faces each other, and the short outer peripheral lead portion 12D faces 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, so that the work of removing the connection leads 57 together with the metal connecting portions 43 can be easily performed. Furthermore, when removing the metal connecting portions 43 by etching (see FIG. 8(E)), it can be easily confirmed from the back surface side whether or not the metal connecting portions 43 and the connection leads 57 have been completely removed. This facilitates the work of isolating the external terminals 56.

[0164] The semiconductor device 20D shown in Fig. 23 is produced from the lead frame 10D shown in Fig. 21 and Fig. 22(A)(B). The metal connecting portion 43 of the lead frame 10D is 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 portion 43, a recess 27A is formed in the back surface of the sealing resin 23 in the region between the inner lead portions 12E, 12F and the inner lead portions 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 a part of the connection leads 57 may be left in the semiconductor device 20D, or the entire connection leads 57 may be left 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 portion 12H extends to the inside of the metal connecting portion 43, and the long inner lead portion 12G does not extend. 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 secured relative to the size of the semiconductor device 20D.

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

[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 intervals 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 parts (number of pins) can be increased to 308 pins. Also, 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 parts (number of pins) can be increased to 280 pins. In this way, according to this embodiment, a semiconductor device capable of mounting a highly functional 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 parts (number of pins) can be increased to 208 pins to 216 pins. This number of pins (208 pins to 216 pins) corresponds to the same number of pins as a conventional 28 mm square QFP (Quad Flat Package).

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

[0171] 25 and 26(A)(B) includes a die pad 11, a plurality of elongated peripheral lead portions 12J, 12K, a metal connecting portion 44, and a resin portion 18. The plurality of peripheral lead portions 12J, 12K are arranged around the die pad 11. The metal connecting portion 44 is arranged between the die pad 11 and the peripheral lead portions 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 lead portions 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 (the peripheral edge portion on the support lead 13 side) of the metal connecting portion 44. 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, 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 certain depth without penetrating in the thickness direction. Each recess 44a is formed in the approximate center of the metal connecting portion 44 in the width direction, but may be formed inside or outside of the approximate center of the metal connecting portion 44 in the width direction.

[0175] The recesses 44a are arranged at intervals along the longitudinal direction of the metal connecting portion 44. A thick portion 44b is formed between adjacent recesses 44a. The recesses 44a and the thick portion 44b are alternately arranged along the longitudinal direction of the metal connecting portion 44. The thick portion 44b is not half-etched and has the same thickness as the die pad 11 and the support lead 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 portion 44 and the connecting bar 45. The suspension leads 14 are provided at the four corners of the die pad 11. Since the resin portion 18 can support the die pad 11 with respect to the peripheral lead portions 12J and 12K and the support lead 13, the suspension leads 14 do not need to be provided. When 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.

[0176] In this embodiment, when the semiconductor device 20F (see FIG. 27) is fabricated, the periphery of each recess 44a of the metal connecting portion 44 and the thick portion 44b of the metal connecting portion 44 start to be etched at the same time. On the other hand, it takes more time to remove the thick portion 44b than to remove the region 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 the metal connecting portion 44 is etched and removed from the back surface side of the lead frame 10F (see FIG. 8(E)), an opening 37b is provided in the etching resist layer 37 on the back surface of the sealing resin 23 at a position corresponding to the metal connecting portion 44. Then, the etchant entering from the opening 37b appropriately dissolves and removes each of the recesses 44a and the thick portion 44b of the metal connecting portion 44. In this case, since the recesses 44a are provided on the surface of the metal connecting portion 44, the etchant entering from the opening 37b can appropriately remove the entire metal connecting portion 44 without dissolving the peripheral lead portions 12J, 12K more than necessary.

[0178] In the present 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, the penetration and dissolution of the etching solution can be appropriately adjusted when removing the metal connecting portion 44 by etching.

[0180] The semiconductor device 20F shown in Fig. 27 is produced from the lead frame 10F shown in Fig. 25 and Fig. 26(A)(B). The metal connecting portion 44 of the lead frame 10F is 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 portion 44, a recess 27B is formed in the back surface of the sealing resin 23 in the region between the peripheral lead portions 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 similar to the manufacturing method of the lead frame 10 (FIGS. 7(A)-(I)) and the manufacturing method of the semiconductor device 20 (FIGS. 8(A)-(H)) according to the first embodiment.

[0182] It is also possible to combine the multiple components disclosed in the above embodiments and modifications as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiments and modifications.

Claims

1. In the lead frame, A die pad; A plurality of lead portions arranged along a side of the die pad; a metal connection portion arranged to connect the ends of the plurality of leads on the die pad side; a resin portion disposed around the lead portion on a rear surface side of the lead frame, A lead frame, wherein at least a portion of the lead portion is thinned from a rear surface side, and the resin portion is filled in the thinned portion of the lead portion.

2. The lead frame according to claim 1 , wherein a portion of the metal connecting portion is located on a rear surface side of the lead portion.

3. In the lead frame, A plurality of leads; A metal connection portion arranged to connect a plurality of the lead portions; a resin portion disposed around the lead portion on a rear surface side of the lead frame, At least a portion of the lead portion is thinned from a back surface side, and the resin portion is filled in the thinned portion of the lead portion; A lead frame, wherein a portion of the metal connecting portion is located on a rear surface side of the lead portion.

4. 4. The lead frame according to claim 2, wherein a width of the portion of the metal connecting portion located on the back surface side of the lead portion is 50 [mu]m or more and 150 [mu]m or less.

5. 4. The lead frame according to claim 1, wherein the resin portion has a resin surface located on a front side, the resin surface being exposed to the outside between two adjacent lead portions.

6. The lead frame according to claim 1 , wherein the metal connecting portion has an annular or ring-shaped configuration in a plan view.

7. The thermal conductivity of the resin portion is 1 W·m －１ K －１ More than 12W・m －１ K －１ 4. The lead frame according to claim 1 or 3, wherein:

8. The lead frame according to claim 1 , wherein the metal connecting portion is thinned from a front surface side.

9. The lead frame according to claim 1 , wherein the metal connecting portion is thinned from a rear surface side.

10. The lead frame according to claim 9 , wherein a part of the metal connecting portion is present between the portion thinned from the rear surface side of the metal connecting portion and the resin portion.

11. The lead frame according to claim 9 , wherein the resin portion is exposed within a portion that is thinned from the rear surface side of the metal connecting portion.

Images