Lead frame and method for manufacturing lead frame

Abstract

Provided are a lead frame capable of easily forming a deeper recess and a method for manufacturing the lead frame. The lead frame includes: an annular frame portion having a first support portion; and a plurality of lead portions extending from the first support portion toward the inside of the frame portion, the frame portion and the lead portions having a first surface; and a second surface located on the opposite side of the first surface, a plurality of first recesses are formed on the first surface of the first support portion, and second recesses are formed on the second surface of each of the lead portions.

Description

Technical Field

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

[0002] Lead frames are used in the manufacture of semiconductor devices such as QFN (quad flat non-leaded package) and a structure called wettable flank is known, in which a recess is formed on the lead in order to improve the wettability of solder in QFN.

[0003] <Prior Art Literature>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-061266

[0006] Patent Document 2: Japanese Patent Application Publication No. 2021-125611 Summary of the invention

[0007] <Problems to be Solved by the Invention>

[0008] In a conventional lead frame for a wettable side surface, it is not easy to form a recessed portion deeply in terms of structure.

[0009] An object of the present disclosure is to provide a lead frame capable of easily forming a deep recess and a method for manufacturing the lead frame.

[0010] <Methods used to solve the problem>

[0011] According to one embodiment of the present disclosure, a lead frame is provided, comprising: an annular frame portion having a first supporting portion; and a plurality of lead portions extending from the first supporting portion toward the inner side of the frame portion, wherein the frame portion and the lead portions have a first surface; and a second surface located on the side opposite to the first surface, wherein a plurality of first recesses are formed on the first surface of the first supporting portion, and a second recess is formed on the second surface of each of the lead portions.

[0012] <Effects of the Invention>

[0013] According to the disclosed technology, the recessed portion can be easily formed to be deep. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram exemplarily showing the outline of the lead frame according to the first embodiment.

[0015] Figure 2FIG. 1 is a plan view exemplarily showing the lead frame according to the first embodiment.

[0016] Figure 3 It is a bottom view exemplarily showing the lead frame according to the first embodiment.

[0017] Figure 4A , Figure 4B 1 is a cross-sectional view schematically showing the lead frame according to the first embodiment.

[0018] Figure 5A , Figure 5B It is a cross-sectional view (part 1) showing the method for manufacturing the lead frame according to the first embodiment.

[0019] Fig. 6A , Figure 6B This is a cross-sectional view (part 2) showing the method for manufacturing the lead frame according to the first embodiment.

[0020] Fig. 7A , Figure 7B It is a cross-sectional view (part 3) showing the method for manufacturing the lead frame according to the first embodiment.

[0021] Fig. 8A , Figure 8B It is a cross-sectional view (part 4) showing the method for manufacturing the lead frame according to the first embodiment.

[0022] Fig.9A , Fig. 9B , Fig. 9C This is a cross-sectional view (part 1) showing a method for manufacturing a semiconductor device using the lead frame according to the first embodiment.

[0023] Fig. 10A , Fig. 10B This is a cross-sectional view (part 2) showing the method for manufacturing a semiconductor device using the lead frame according to the first embodiment.

[0024] Fig.11 It is a cross-sectional view exemplarily showing a usage mode of a semiconductor device.

[0025] Fig.12 FIG. 1 is a plan view exemplarily showing a lead frame according to the second embodiment.

[0026] Fig.13 It is a bottom view exemplarily showing the lead frame according to the second embodiment.

[0027] Fig.14 FIG. 1 is a plan view exemplarily showing a lead frame according to the third embodiment.

[0028] Fig.15It is a bottom view exemplarily showing a lead frame according to the third embodiment.

[0029] Explanation of symbols

[0030] 1, 2, 3 lead frame

[0031] 1A Metal Plate

[0032] 10.10A first side

[0033] 20, 20A second side

[0034] 71Semiconductor components

[0035] 82 solder

[0036] 100 frame

[0037] 110 first supporting portion

[0038] 111, 112, 121, 122, 126, 201, 202, 301, 302, 601, 602 flat surface

[0039] 118, 119, 127, 128, 129, 209, 609 concave parts

[0040] 120 second supporting portion

[0041] 200, 600 lead wire

[0042] 300 wafer pad DETAILED DESCRIPTION

[0043] Hereinafter, the implementation mode will be described in detail with reference to the accompanying drawings. It should be noted that in this specification and the accompanying drawings, for components having substantially the same functional structure, the same symbols are sometimes assigned to omit repeated descriptions. In the following description, the XYZ orthogonal coordinate system is used, and when observed from any point, the +Z side is sometimes referred to as the top, the upper side or the top, and the -Z side is sometimes referred to as the bottom, the lower side or the bottom. In addition, the surface on the lower side is sometimes referred to as one surface or the bottom, and the surface on the upper side is sometimes referred to as the other surface or the top. However, this coordinate system is specified for the purpose of explanation, and there is no limitation on the posture of the lead frame. The lead frame can be used in an upside-down state, or it can be arranged at any angle. In addition, plane observation refers to observing the object from the normal direction of one surface of the lead frame, and the plane shape refers to the shape obtained by observing the object from the normal direction of one surface of the lead frame. In the present disclosure, a flat surface refers to a surface that is not intentionally bent or concave and convex. The arithmetic mean roughness Ra of the flat surface is less than 0.125μm.

[0044] (First embodiment)

[0045] First, a first embodiment will be described. The first embodiment relates to a lead frame. The lead frame according to the first embodiment is a lead frame that has a semiconductor element mounted on its upper surface and is covered with a sealing resin to form a semiconductor device.

[0046] [Lead frame structure]

[0047] The structure of the lead frame according to the first embodiment will be described. Figure 1 It is a diagram exemplarily showing the outline of the lead frame according to the first embodiment. Figure 2 FIG. 1 is a plan view exemplarily showing the lead frame according to the first embodiment. Figure 3 It is a bottom view exemplarily showing the lead frame according to the first embodiment. Figure 4A , Figure 4B 1 is a cross-sectional view schematically showing the lead frame according to the first embodiment. Figure 2 and Figure 3 Shown enlarged Figure 1 part of. Figure 4A Equivalent to along Figure 1 and Figure 2 Cross-sectional view of line IVa-IVa in FIG. Figure 4B Equivalent to along Figure 1 and Figure 2 Cross-sectional view along line IVb-IVb in FIG.

[0048] like Figure 1 As shown in FIG. 1 , the lead frame 1 according to the first embodiment has a plurality of singulation regions 30. For example, the singulation regions 30 have a rectangular planar shape. Between the singulation regions 30, there are cutting regions 40 to be cut during singulation. Figure 2 to Figure 4A , Figure 4B Mainly shown are two singulation regions 30 adjacent to each other in the X-axis direction and the cutting region 40 around them.

[0049] The lead frame 1 has a frame portion 100 in the cutting region 40. The frame portion 100 has a plurality of first support portions 110 extending in the Y-axis direction and a plurality of second support portions 120 extending in the X-axis direction. Each first support portion 110 intersects with the plurality of second support portions 120, and each second support portion 120 intersects with the plurality of first support portions 110. The frame portion 100 has a ring-shaped planar shape formed by two adjacent first support portions 110 and two adjacent second support portions 120.

[0050] The lead frame 1 includes a plurality of lead portions 200 extending from the first support portion 110 to the inside of the annular frame portion 100, a die pad portion 300 provided inside the annular frame portion 100, and a connecting portion 400 connecting the second support portion 120 and the die pad portion 300 in the singulation region 30. The plurality of lead portions 200 are arranged along the Y-axis direction for each first support portion 110.

[0051] The frame portion 100, the lead portion 200, the die pad portion 300, and the connection portion 400 have a first surface 10 (upper surface) on one side and a second surface 20 (lower surface) on the other side opposite to the first surface 10. Figure 2 The first surface 10 is shown in Figure 3 The second face 20 is shown in FIG.

[0052] As a material of the lead frame 1, for example, copper (Cu), Cu alloy, 42 alloy, etc. The thickness of the lead frame 1 can be, for example, approximately 100 μm to 300 μm.

[0053] In the following, the focus is mainly on one singulation region 30 , and the two first supporting portions 110 and the two second supporting portions 120 adjacent to the singulation region 30 are described as being one frame portion 100 .

[0054] like Figure 2 and Figure 4A , Figure 4B As shown, each lead portion 200 has a flat surface 201 on the first surface 10 . The flat surface 201 is parallel to the XY plane. For example, the entire first surface 10 of the lead portion 200 is the flat surface 201 . The flat surface 201 is connected to the first support portion 110 .

[0055] like Figure 3 and Figure 4A , Figure 4B As shown, each lead portion 200 has a flat surface 202 and a recessed portion 209 on the second surface 20. The flat surface 202 is parallel to the flat surface 201. The recessed portion 209 is recessed from the flat surface 202 toward the flat surface 201. A portion of the flat surface 202 exists on both the +Y side and the -Y side of the recessed portion 209. For example, in a semiconductor device having a wettable side surface structure, the flat surface 202 is a mounting surface for the lead, and the recessed portion 209 is a recessed portion for the lead. The flat surface 202 and the recessed portion 209 are connected to the first supporting portion 110. Each lead portion 200 is supported by the first supporting portion 110. The first supporting portion 110 is sometimes referred to as a cutting strip.

[0056] The depth of the recess 209 is approximately 70% of the distance between the flat surface 201 and the flat surface 202. The flat surface 201 is an example of a fourth flat surface, the flat surface 202 is an example of a second flat surface, and the recess 209 is an example of a second recess.

[0057] like Figure 2 and Figure 4A , Figure 4B As shown, the first support portion 110 has a plurality of recesses 119 and a plurality of flat surfaces 111 on the first surface 10. The flat surface 111 is parallel to the XY plane and is connected to the flat surface 201 of the lead portion 200. The flat surface 111 and the flat surface 201 are flush with each other. The plurality of flat surfaces 111 are arranged along the Y-axis direction. The recess 119 exists between two flat surfaces 111 arranged along the Y-axis direction. The recess 119 also exists between the second support portion 120 and the flat surface 111 closest to the second support portion 120. From another perspective, the flat surface 111 exists between adjacent recesses 119.

[0058] like Figure 3 and Figure 4A , Figure 4B As shown, the first support portion 110 has a plurality of recesses 118 and a plurality of flat surfaces 112 on the second surface 20. The flat surface 112 is parallel to the flat surface 111 and connected to the flat surface 202 of the lead portion 200. The flat surface 112 and the flat surface 202 are flush with each other. The plurality of flat surfaces 112 are arranged along the Y-axis direction. The recess 118 is connected to the recess 209 of the lead portion 200 and exists between two flat surfaces 112 arranged along the Y-axis direction.

[0059] The recess 119 is shallower than the recess 209. The depth of the recess 119 is about 50% of the distance between the flat surface 201 and the flat surface 202, and the depth of the recess 118 is about 70% of the distance between the flat surface 201 and the flat surface 202. The recess 119 is an example of a first recess, the flat surface 111 is an example of a third flat surface, and the flat surface 112 is an example of a first flat surface.

[0060] like Figure 2 As shown, the second support portion 120 has a flat surface 121 on the first surface 10. The flat surface 121 is parallel to the XY plane and is flush with the flat surface 111 and the flat surface 201. For example, the entire first surface 10 of the second support portion 120 is the flat surface 121.

[0061] like Figure 3 As shown, the second support portion 120 has a recess 128 on the second surface 20. The recess 128 exists between two adjacent first support portions 110. The depth of the recess 128 is approximately 70% of the distance between the flat surface 201 and the flat surface 202. The second support portion 120 in the first embodiment is sometimes referred to as a connecting strip.

[0062] like Figure 2 and Figure 4A , Figure 4BAs shown, the wafer pad 300 has a flat surface 301 on the first surface 10. The flat surface 301 is parallel to the XY plane and flush with the flat surface 111 and the flat surface 201. A semiconductor element is mounted on the flat surface 301. The flat surface 301 is an example of a fifth flat surface.

[0063] like Figure 3 and Figure 4A , Figure 4B As shown, the wafer pad 300 has a flat surface 302 on the second surface 20. The flat surface 302 is parallel to the flat surface 301 and is flush with the flat surface 112 and the flat surface 202. The wafer pad 300 may also have a recessed portion surrounding the flat surface 302 on the second surface 20. The flat surface 302 is an example of a sixth flat surface.

[0064] like Figure 2 As shown, the connecting portion 400 has a flat surface on the first surface 10 that is parallel to the XY plane and connected to the flat surface 121 and the flat surface 301. The flat surface of the first surface 10 of the connecting portion 400 is flush with the flat surface 121 and the flat surface 301. Figure 3 As shown, the connecting portion 400 has a recessed portion on the second surface 20 that is connected to the recessed portion 128 and the recessed portion of the wafer pad 300. The depth of the recessed portion of the connecting portion 400 is approximately 70% of the distance between the flat surface 201 and the flat surface 202.

[0065] [Method for manufacturing lead frame]

[0066] Next, a method for manufacturing the lead frame 1 according to the first embodiment will be described. Figure 5A , Figure 5B to Figure 8A , Figure 8B It is a cross-sectional view showing the method for manufacturing the lead frame according to the first embodiment. Figures 5A to 8A Show that Figure 4A The section shown here is the change after rotating 180 degrees around the Y axis. Figure 5B to Figure 8B Will Figure 4B The cross section shown is a change in the section after being rotated 180 degrees about the Y axis.

[0067] First, if Figure 5A and Figure 5B As shown, a metal plate 1A made of metal of a predetermined shape is prepared. The metal plate 1A is a component that is cut at the cutting area 40 and is singulated according to each singulation area 30. As the material of the metal plate 1A, copper, copper alloy, 42 alloy, etc. can be used. The thickness of the metal plate 1A can be, for example, about 100 μm to 300 μm. The metal plate 1A has a first surface 10A on one side and a second surface 20A on the other side located on the opposite side to the first surface 10A.

[0068] Next, a photosensitive resist 510 is formed on the first surface 10A of the metal plate 1A, and a photosensitive resist 520 is formed on the second surface 20A of the metal plate 1A. The resists 510 and 520 can be formed, for example, by applying and drying a resist liquid, or by pasting a resist film. As the resists 510 and 520, for example, a dry film resist such as epoxy resin or acrylic resin, or an electrodeposition resist can be used.

[0069] Then, if Fig. 6A , Figure 6B As shown, by performing exposure and development of the resist 510, a cover pattern 511 and an opening 512 are formed on the resist 510. By performing exposure and development of the resist 520, a cover pattern 521 and an opening 522 are formed on the resist 520. The cover pattern 511 covers a portion of the first surface 10A to be formed in the flat surface included in the first surface 10 of the lead frame 1. The opening 512 is a portion for forming an opening or a recessed portion in the metal plate 1A, and the remaining portion of the first surface 10A is exposed from the opening 512. The cover pattern 521 covers a portion of the second surface 20A to be formed in the flat surface included in the second surface 20 of the lead frame 1. The opening 522 is a portion for forming an opening or a recessed portion in the metal plate 1A, and the remaining portion of the second surface 20A is exposed from the opening 522.

[0070] Then, if Fig. 7A , Figure 7B As shown, the metal plate 1A is half-etched from the first surface 10A side and the second surface 20A side of the metal plate 1A using the resists 510 and 520 as etching masks. In this half-etching, wet etching is performed in which the first surface 10A is directed downward in the vertical direction, the second surface 20A is directed upward in the vertical direction, and an etching liquid is supplied to the first surface 10A and the second surface 20A. For example, spray etching is performed in which an etching liquid is sprayed to the first surface 10A and the second surface 20A. In the case where the metal plate 1A is copper, in the half-etching of the metal plate 1A, as the etching liquid, for example, an aqueous solution of ferric chloride or cupric chloride can be used.

[0071] By orienting the first surface 10A downward in the vertical direction and the second surface 20A upward in the vertical direction, the etching liquid is easily retained on the second surface 20A, and the etching liquid is easily dropped from the first surface 10A. Therefore, the etching rate at the second surface 20A is higher than the etching rate at the first surface 10A. For example, in a state where the etching of the first surface 10A from the vertical lower side has been carried out by about 50% of the thickness of the metal plate 1A, the etching of the second surface 20A from the vertical upper side has been carried out by about 70% of the thickness of the metal plate 1A.

[0072] By such half etching, the recess 119 of the first supporting portion 110 is formed on the first surface 10A, and the recess 209 of the lead portion 200, the recess 118 of the first supporting portion 110, the recess 128 of the second supporting portion 120, and the recesses of the chip pad 300 and the connecting portion 400 are formed on the second surface 20A.

[0073] Then, if Fig. 8A and Figure 8B As shown, the resists 510 and 520 are removed. The resists 510 and 520 can be removed by using a stripping solution, for example. Thereafter, a plating layer such as silver plating can be formed on the connection portion of the bonding wire of the lead portion 200 by electrolytic plating as needed.

[0074] In this way, the lead frame 1 can be manufactured.

[0075] [Method for manufacturing semiconductor device]

[0076] Next, a method for manufacturing a semiconductor device using the lead frame 1 according to the first embodiment will be described. Fig.9A , Fig. 9B , Figure 9C to Figure 10A , Fig. 10B It is a cross-sectional view showing a method of manufacturing a semiconductor device using the lead frame 1 according to the first embodiment. Fig.9A , Fig. 9B , Figure 9C to Figure 10A , Fig. 10B Equivalent to along Figure 2 Although the lead frame 1 can be used to manufacture a plurality of semiconductor devices, Fig.9A , Fig. 9B , Figure 9C to Figure 10A , Fig. 10B Mainly shows the process of manufacturing a semiconductor device.

[0077] First, if Fig.9A As shown, the lead frame 1 is prepared, and the semiconductor element 71 is mounted on the first surface 10 of the wafer pad 300 in the singulation area 30. At this time, the first surface 10 of the wafer pad 300 and the back surface of the semiconductor element 71 where no electrode is formed are bonded by an adhesive (not shown). As the adhesive, an adhesive film, silver paste, solder, etc. can be used.

[0078] Then, if Fig. 9B As shown, the first surface 10 of the lead portion 200 is electrically connected to an electrode provided on the surface of the semiconductor element by a bonding wire 72. A plating layer may be provided at a portion of the first surface 10 of the lead portion 200 to which the bonding wire 72 is connected.

[0079] Then, if Fig. 9CAs shown, the semiconductor element 71 and the bonding wire 72 are sealed by the sealing resin 73. At this time, the semiconductor element 71 and the bonding wire 72 are sealed by a single sealing resin 73 common to the plurality of singulation regions 30. The upper surface and the side surface of the lead frame 1 are also sealed by the sealing resin 73. As the sealing resin 73, for example, a so-called molding resin containing a filler in an epoxy resin can be used. The sealing resin 73 can be formed by, for example, a transfer molding method or a compression molding method.

[0080] Then, if Fig. 10A As shown, a plating layer 74 is formed by electrolytic plating on the second surface 20 of the lead frame 1. The plating layer 74 is a solder layer containing one or more of tin (Sn), lead (Pb), silver (Ag), etc., for example.

[0081] Then, if Fig. 10B As shown in , the cutting region 40 is cut by a dicing blade, and the singulation region 30 is singulated. Thus, the frame portion 100 is removed, and the semiconductor device 5 is obtained. When the cutting region 40 is cut, since the recess 119 is formed in the first support portion 110 and the recess 128 is formed in the second support portion 120, the frame portion 100 can be easily removed. That is, since the thickness of the frame portion 100 is thinner than when the recesses 119 and 128 are not formed, the frame portion 100 can be removed while reducing the wear of the dicing blade and suppressing the generation of burrs. The semiconductor device 5 has a plurality of lead portions 200, and in the lead portion 200, a recess 209 having a depth of about 70% of the distance between the flat surface 201 and the flat surface 202 is formed.

[0082] The semiconductor device 5 is used by being mounted on, for example, a printed wiring board. Fig.11 2 is a cross-sectional view exemplarily showing a usage form of the semiconductor device 5. Fig.11 As shown, the semiconductor device 5 is mounted on a printed wiring board 81. When mounting the semiconductor device 5, the lead portion 200 is joined to a wiring 83 provided on the printed wiring board 81 by solder 82. The solder 82 contains one or more of Sn, Pb, Ag, etc., for example.

[0083] In the lead frame 1, since the recessed portion 209 is formed in the lead portion 200, a large contact area can be ensured between the solder 82 and the plating layer 74 provided on the lead portion 200. In addition, a fillet can be formed on the solder 82, and the bonding state between the printed wiring board 81 and the semiconductor device 5 can be easily checked. In addition, the bonding strength between the printed wiring board 81 and the semiconductor device 5 can be improved.

[0084] In the lead frame 1 according to the present embodiment, since the recess 209 is formed on the second surface 20 of the lead portion 200 and the recess 119 is formed on the first surface 10 of the first support portion 110, the depths of the recess 209 and the recess 119 can be made different. For example, the recess 209 can be formed deeper to ensure high wettability, and the recess 119 can be formed shallower than the recess 209 to ensure the strength of the first support portion 110. In addition, the recess 209 and the recess 119 can be formed by one half etching. If the recess 119 is formed on the second surface 20 of the first support portion 110, the depths of the recess 209 and the recess 119 cannot be made different by one half etching. Therefore, if the recess 209 is formed deeper to ensure high wettability, the recess 119 will also become deeper, so that the first support portion 110 may be easily deformed.

[0085] It should be noted that the mounting of the semiconductor element on the lead frame is not limited to the connection by bonding wires. For example, a flip-chip connection in which the electrodes of the semiconductor element are connected to the lead portion by soldering bumps may be used. In this case, the chip pad portion may be omitted from the lead frame.

[0086] (Second embodiment)

[0087] Next, a second embodiment will be described. The second embodiment is different from the first embodiment mainly in the configuration of the second support portion. Fig.12 FIG. 1 is a plan view exemplarily showing a lead frame according to the second embodiment. Fig.13 It is a bottom view exemplarily showing the lead frame according to the second embodiment. Fig.12 and Fig.13 Mainly shown are two singulation regions 30 adjacent to each other in the X-axis direction and the cutting region 40 around them.

[0088] like Fig.12 and Fig.13 As shown, in the lead frame 2 according to the second embodiment, the structure of the second supporting portion 120 is different from that of the first embodiment. The second supporting portion 120 in the second embodiment is sometimes referred to as a cutting strip.

[0089] like Fig.12 As shown, the second support portion 120 has a recess 129 on the first surface 10. The recess 129 exists between two adjacent first support portions 110 and is connected to the recess 119 of the first support portion 110. The recess 129 is shallower than the recess 209. The depth of the recess 129 is about 50% of the distance between the flat surface 201 and the flat surface 202. The recess 129 is an example of a third recess.

[0090] like Fig.13As shown, the second support portion 120 has a flat surface 122 on the second surface 20. The flat surface 122 is parallel to the XY plane and connected to the flat surface 112 of the first support portion 110. The flat surface 122 is flush with the flat surface 112 and the flat surface 202. For example, the entire second surface 20 of the second support portion 120 is the flat surface 122.

[0091] The other structures of the second embodiment are the same as those of the first embodiment. The second embodiment can also obtain the same effects as those of the first embodiment. In addition, since the recess 129 is formed on the first surface 10, the depth of the recess 129 can be different from the depth of the recess 209 of the lead portion 200, for example, the depth of the recess 129 can be set to be equal to the depth of the recess 119. Therefore, compared with the first embodiment, the strength of the second support portion 120 can be improved, making the second support portion 120 less likely to deform.

[0092] (Third embodiment)

[0093] Next, a third embodiment will be described. The third embodiment is different from the second embodiment mainly in that a lead portion supported by a second supporting portion is included. Fig.14 FIG. 1 is a plan view exemplarily showing a lead frame according to the third embodiment. Fig.15 It is a bottom view exemplarily showing a lead frame according to the third embodiment. Fig.14 and Fig.15 Mainly shown is one singulation region 30 and its surrounding cutting region 40 .

[0094] like Fig.14 and Fig.15 As shown, the lead frame 3 according to the third embodiment includes the lead portion 600 supported by the second supporting portion 120 in addition to the lead portion 200 supported by the first supporting portion 110 .

[0095] like Fig.14 As shown, each lead portion 600 has a flat surface 601 on the first surface 10. The flat surface 601 is parallel to the XY plane and flush with the flat surface 201 of the lead portion 200. For example, the entire first surface 10 of the lead portion 600 is the flat surface 601. The flat surface 601 is connected to the second support portion 120.

[0096] like Fig.15As shown, each lead portion 600 has a flat surface 602 and a recess 609 on the second surface 20. The flat surface 602 is parallel to the flat surface 601 and is flush with the flat surface 202 of the lead portion 200. The recess 609 is recessed from the flat surface 602 toward the flat surface 601. A portion of the flat surface 602 exists on both the +X side and the -X side of the recess 609. For example, in a semiconductor device having a wettable side surface structure, the flat surface 602 is a mounting surface of the lead, and the recess 609 is a recess of the lead. The flat surface 602 and the recess 609 are connected to the second support portion 120. Each lead portion 600 is supported by the second support portion 120. The depth of the recess 609 is about 70% of the distance between the flat surface 601 and the flat surface 602, that is, the distance between the flat surface 201 and the flat surface 202.

[0097] like Fig.14 As shown, the second support portion 120 has a plurality of flat surfaces 126 on the first surface 10 in addition to the recess 129. The flat surface 126 is parallel to the XY plane and is connected to the flat surface 601 of the lead portion 600. The flat surface 126 and the flat surface 601 are flush with each other. The plurality of flat surfaces 126 are arranged along the X-axis direction. The recess 129 exists between two flat surfaces 126 arranged along the X-axis direction. The recess 129 also exists between the first support portion 110 and the flat surface 126 closest to the first support portion 110. From another perspective, the flat surface 126 exists between adjacent recesses 129.

[0098] like Fig.15 As shown, the second support portion 120 has a plurality of recesses 127 in addition to the flat surface 122 on the second surface 20. The recess 127 is connected to the recess 609 of the lead portion 600 and exists between two flat surfaces 122 arranged along the X-axis direction. The depth of the recess 127 is approximately 70% of the distance between the flat surface 201 and the flat surface 202.

[0099] The other structures of the third embodiment are the same as those of the second embodiment. The third embodiment can also achieve the same effects as those of the second embodiment.

[0100] Although preferred embodiments and the like have been described in detail above, the present disclosure is not limited to the above embodiments and the like, and various modifications and substitutions may be made to the above embodiments and the like without departing from the scope described in the claims.

Claims

1. A lead frame, comprising: The annular frame has a first supporting portion; and A plurality of lead portions extending from the first support portion toward the inner side of the frame portion, The frame portion and the lead portion have: Side 1; and a second side, located on the opposite side to the first side, A plurality of first recesses are formed on the first surface of the first support portion. A second recess is formed on the second surface of each of the lead portions.

2. The lead frame according to claim 1, wherein: The first recess is shallower than the second recess.

3. The lead frame according to claim 1 or 2, wherein: The first support portion has a first flat surface on the second surface, Each of the lead portions has a second flat surface on the second surface, which is connected to the first flat surface and flush with the first flat surface.

4. The lead frame according to claim 3, wherein: The first support portion has a third flat surface parallel to the first flat surface between adjacent first recessed portions. Each of the lead portions has a fourth flat surface on the first surface, which is connected to the third flat surface and flush with the third flat surface.

5. The lead frame according to claim 1 or 2, comprising: The wafer pad is arranged inside the frame.

6. The lead frame according to claim 4, comprising: A wafer pad is arranged inside the frame, The wafer pad has: a fifth flat surface, flush with the third flat surface; and The sixth flat surface is flush with the first flat surface.

7. The lead frame according to claim 1 or 2, wherein: The first supporting portion extends along a first direction, The frame portion has a second supporting portion extending in a second direction perpendicular to the first direction, A third recess is formed on the first surface of the second support portion.

8. A method for manufacturing a lead frame, comprising: A process of wet-etching a metal plate having a first surface and a second surface located on the opposite side of the first surface to form an annular frame having a first support portion and a plurality of lead portions extending from the first support portion to the inside of the frame portion, During the wet etching, the first surface is directed downward in the vertical direction, and the second surface is directed upward in the vertical direction, and etching liquid is supplied to the first surface and the second surface to form a plurality of first recesses on the first surface of the first supporting portion, and to form second recesses on the second surface of each of the lead portions.

9. The method for manufacturing a lead frame according to claim 8, wherein: The first recess is formed shallower than the second recess.

10. The method for manufacturing a lead frame according to claim 8 or 9, wherein: The first supporting portion extends along a first direction, The frame portion has a second supporting portion extending in a second direction perpendicular to the first direction, In the wet etching, a third recessed portion is formed on the first surface of the second supporting portion.

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