JP2019047004A - Lead frame, semiconductor device, and method of manufacturing semiconductor device - Google Patents

Abstract

The present invention provides a lead frame, a semiconductor device, and a method of manufacturing a semiconductor device, which can improve the connection reliability between a lead portion having a recess and a wiring board. A lead frame (10) includes a die pad (11) and lead portions (12) provided around the die pad (11). A recess 16 is formed at a position corresponding to at least the outer periphery 20 b of the semiconductor device 20 on the back surface 12 f of the lead portion 12. The width of the lead 12 changes in the longitudinal direction of the lead 12 at least in the region A where the recess 16 is formed. [Selected figure] Figure 1

Description

  The present invention relates to a lead frame, a semiconductor device, and a method of manufacturing the semiconductor device.

  In recent years, there has been a demand for downsizing and thinning of semiconductor devices mounted on a substrate. In order to meet such requirements, a so-called QFN is conventionally configured by sealing a semiconductor element mounted on its mounting surface with a sealing resin using a lead frame and exposing a part of the lead on the back surface side Various semiconductor devices of the (Quad Flat Non-lead) type have been proposed.

  Also, conventionally, a technique is known in which a dimple (concave portion) opening toward a side surface of a semiconductor device is provided in a lead portion of a semiconductor device, and the inside of the dimple is wetted by plating (see, for example, Patent Document 1).

U.S. Pat. No. 6,608,366

  However, in the above-described semiconductor device, when the lead portion is cut to separate the semiconductor device, there is a problem that a burr remains inside the dimple. In this case, the dimples may be partially blocked by the burrs, which may cause connection failure of the plating.

  The present invention has been made in consideration of such points, and provides a lead frame, a semiconductor device, and a method of manufacturing the same, which can improve the connection reliability between a lead portion having a recess and a wiring board. With the goal.

  The present invention is a lead frame for manufacturing a semiconductor device, comprising: a die pad; and a lead portion provided around the die pad, and a position corresponding to at least an outer periphery of the semiconductor device in a back surface of the lead portion. The recess is formed in at least the area where the recess is formed, the width of the lead changes along the longitudinal direction of the lead, or the width of the recess extends along the longitudinal direction of the lead Lead frame.

  The present invention is the lead frame in which the width of the lead portion is widened from the inside to the outside of the lead portion at least in the region where the recess is formed.

  In the present invention, in at least the area where the recess is formed, the width of the back surface of the lead is wider from the inside to the outside of the lead, and the width of the surface of the lead is the lead Lead frame that is uniform from the inside to the outside of the

  The present invention is the lead frame, wherein the width of the recess is wider from the inside to the outside of the lead portion.

  The present invention is the lead frame, wherein the width of the recess is narrowed from the inside to the outside of the lead portion.

  The present invention further includes a connecting bar to which the lead portion is connected, a connecting bar recess is formed on the back surface of the connecting bar, and the recess of the lead portion and the connecting bar recess of the connecting bar are mutually connected. It is a lead frame.

  The present invention relates to a lead frame for manufacturing a semiconductor device, comprising: a die pad; a lead portion provided around the die pad; and a connecting bar to which the lead portion is connected; A recess is formed at least at a position corresponding to the outer periphery of the semiconductor device, a connecting bar recess is formed on the back surface of the connecting bar, and the recess of the lead portion and the connecting bar recess of the connecting bar are mutually connected. It is a lead frame.

  The present invention relates to a semiconductor device, and a connecting member for electrically connecting a die pad, a lead portion provided around the die pad, a semiconductor element mounted on the die pad, the semiconductor element and the lead portion. And the die pad, the lead portion, the semiconductor element, and a sealing resin for sealing the connection member, and a position corresponding to at least the outer periphery of the sealing resin in the back surface of the lead portion. The recess is formed in at least the area where the recess is formed, the width of the lead changes along the longitudinal direction of the lead, or the width of the recess extends along the longitudinal direction of the lead Semiconductor device that changes.

  The present invention relates to a method of manufacturing a semiconductor device, wherein the step of preparing the lead frame, the step of mounting a semiconductor element on the die pad of the lead frame, and the connecting member electrically connect the semiconductor element and the lead portion. And a step of sealing the die pad, the lead portion, the semiconductor element, and the connection member with a sealing resin.

  According to the present invention, the connection reliability between the lead portion having the recess and the wiring board can be enhanced.

FIG. 1 is a plan view showing a lead frame according to a first embodiment. FIG. 2 is a bottom view showing the lead frame according to the first embodiment. FIG. 3 is a cross-sectional view showing a lead frame according to the first embodiment (a cross-sectional view along the line III-III in FIG. 1). FIG. 4 is a plan view showing the semiconductor device according to the first embodiment. FIG. 5 is a cross-sectional view (cross-sectional view along the line V-V in FIG. 4) showing the semiconductor device according to the first embodiment. 6 is a perspective view showing the lead of the semiconductor device according to the first embodiment as viewed from the outside (view in the direction of arrow VI in FIG. 5). 7 (a) to 7 (e) are cross-sectional views showing a method of manufacturing a lead frame according to the first embodiment. 8 (a) to 8 (e) are cross-sectional views showing a method of manufacturing a semiconductor device according to the first embodiment. FIG. 9 is a cross-sectional view showing the semiconductor device according to the first embodiment mounted on a wiring board. 10 (a) and 10 (b) are a plan view and a bottom view showing a lead portion of a lead frame according to a modification (modification 1) of the first embodiment, respectively. FIG. 11 is a plan view showing a lead portion of a lead frame according to a modification (modification 2) of the first embodiment. FIG. 12 is a plan view showing a lead portion of a lead frame according to a modification (Modification 3) of the first embodiment. FIG. 13 is a plan view showing a lead frame according to a second embodiment. FIG. 14 is a plan view showing a lead portion of a lead frame according to a modification of the second embodiment. FIG. 15 is a plan view showing a lead portion of a lead frame according to another modification of the second embodiment. FIG. 16 is a plan view showing a lead frame according to a third embodiment. FIG. 17 is a plan view showing a lead portion of a lead frame according to a modification of the third embodiment. FIG. 18 is a plan view showing a lead portion of a lead frame according to another modification of the third embodiment. FIG. 19 is a plan view showing a lead frame according to a fourth embodiment. FIG. 20 is a plan view showing a lead frame according to a modification of the fourth embodiment.

First Embodiment
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 9. In the following drawings, the same reference numerals are given to the same parts, and a part of the detailed description may be omitted.

Structure of Lead Frame First, an outline of a lead frame for manufacturing a semiconductor device according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a plan view showing a part of the lead frame according to the present embodiment, FIG. 2 is a bottom view showing a part of the lead frame according to the present embodiment, and FIG. 4 is a cross-sectional view showing a lead frame according to FIG.

  The lead frame 10 shown in FIGS. 1 to 3 is used when manufacturing the semiconductor device 20 (FIGS. 4 and 5). Such a lead frame 10 includes a plurality of package areas 10a arranged in multiple rows and multiple stages (in a matrix). In FIGS. 1 and 2, only a part of which is centered on one package area 10a is shown.

  In the present specification, "inside" and "inside" refer to the side of each package area 10a facing the center direction of the die pad 11, and "outside" and "outside" mean the center of the die pad 11 in each package area 10a. It says the side (connecting bar 13 side) which leaves from. Further, the “front surface” means the surface on which the semiconductor element 21 is mounted, and the “back surface” is the surface opposite to the “front surface” and is connected to the external wiring board 80 (see FIG. 9) Say the side to be

  Further, in the present specification, half etching refers to etching a material to be etched halfway to its thickness direction. The thickness of the material to be etched after half etching is, for example, 30% to 70%, preferably 40% to 60%, of the thickness of the material to be etched before half etching. In each of the drawings, the half-etched region is indicated by hatching.

  As shown in FIG. 1 to FIG. 3, the lead frame 10 is provided on a flat rectangular die pad 11 for mounting a semiconductor element 21 (described later), and around the die pad 11. 9) and a plurality of elongated lead portions 12 for connection with each other. The package region 10a is a region corresponding to the semiconductor device 20 (described later), and is a region located inside the imaginary line in FIGS. 1 and 2. Further, in FIG. 1 and FIG. 2, the virtual line corresponds to the outer periphery 20 b (described later) of the semiconductor device 20. In the present embodiment, the lead frame 10 includes the plurality of package areas 10 a, but the present invention is not limited thereto. Only one package area 10 a may be formed in the lead frame 10.

  The plurality of package areas 10 a are connected to one another via a connecting bar (support member) 13. The connecting bar 13 supports the die pad 11 and the lead portion 12 and extends along the X direction and the Y direction. Here, the X direction and the Y direction are two directions parallel to each side of the die pad 11 in the plane of the lead frame 10, and the X direction and the Y direction are orthogonal to each other. Also, the Z direction is a direction perpendicular to both the X direction and the Y direction.

  The die pad 11 has a substantially square planar shape, and a semiconductor element 21 described later is mounted on the surface thereof. The planar shape of the die pad 11 is not limited to a square, and may be a polygon such as a rectangle. Further, suspension leads 14 are respectively connected to four corner portions of the die pad 11, and the die pad 11 is connected to and supported by the connecting bar 13 via the four suspension leads 14. Each suspension lead 14 is formed thin from the back side by half etching over the entire area. However, the present invention is not limited to this, and only a part of the suspension leads 14 may be thinned from the back surface side, and the entire suspension leads 14 may not be thinned.

  Each connecting bar 13 is disposed around the package area 10a and outside the package area 10a. The connecting bar 13 has an elongated bar shape. Further, a plurality of lead portions 12 are connected to the connecting bar 13 at intervals along the longitudinal direction of the connecting bar 13. The connecting bar 13 has the same thickness as a metal substrate (a metal substrate 31 described later) before processing without thinning (half etching).

  The die pad 11 has a die pad thick portion 11 a located at the center and a die pad thin portion 11 b formed over the entire periphery of the die pad thick portion 11 a. Among them, the die pad thick portion 11 a is not half-etched and has the same thickness as a metal substrate (a metal substrate 31 described later) before processing. Specifically, the thickness of the die pad thick portion 11 a can be 80 μm or more and 200 μm or less, depending on the configuration of the semiconductor device 20. On the other hand, the die pad thin portion 11b is formed thin from the back surface side by half etching. By providing the die pad thin-walled portion 11 b in this manner, it is possible to make the die pad 11 difficult to separate from the sealing resin 23 (described later).

  Each lead portion 12 is connected to the semiconductor element 21 through a bonding wire 22 as described later, and is disposed between the die pad 11 and a space. The proximal end of each lead 12 is connected to the connecting bar 13. Each lead 12 extends perpendicularly to the longitudinal direction of the connecting bar 13 to which the lead 12 is connected. In this case, the shapes of the plurality of lead portions 12 are all identical to each other, but not limited to this, the shapes of the plurality of lead portions 12 may be different from each other.

  The plurality of lead portions 12 are spaced apart from each other along the longitudinal direction of the connecting bar 13 around the die pad 11 as described above. Adjacent lead portions 12 are shaped so as to be electrically insulated from each other after the manufacture of the semiconductor device 20 (described later). Further, the lead portion 12 is also shaped so as to be electrically insulated from the die pad 11 after the semiconductor device 20 is manufactured.

  The external terminals 17 electrically connected to the wiring substrate 80 are formed on the back surface 12 f of the lead portion 12. Each external terminal 17 is exposed outward from the semiconductor device 20 after the semiconductor device 20 is manufactured. In this case, the external terminals 17 are arranged in one line in plan view along the sides of the die pad 11.

  Further, an internal terminal 15 is formed on the surface 12 d of each lead portion 12. The internal terminal 15 is a region electrically connected to the semiconductor element 21 through the bonding wire 22 as described later. Therefore, a plated portion may be provided on the internal terminal 15 to improve the adhesion to the bonding wire 22.

  In the present embodiment, a recess (dimple) 16 is formed at a position corresponding to at least the outer periphery 20 b (see FIG. 4) of the back surface 12 f of the lead portion 12. That is, a line corresponding to the outer periphery 20 b of the semiconductor device 20 crosses the recess 16. The recess 16 has an elongated racetrack shape in a plan view, and extends along the longitudinal direction of the lead 12. The width W1 of the recess 16 is uniform along the longitudinal direction of the lead 12, except for the substantially semicircular portions located at the both ends 16a and 16b. The planar shape of the recess 16 may be rectangular, circular, elliptical, or the like.

  The recess 16 is formed of a non-penetrating recess which is recessed from the back surface 12 f of the lead portion 12 to the middle of the thickness direction (Z direction). That is, the concave portion 16 is formed by thinning from the back surface 12f side by half etching, and the depth thereof is 30% or more and 70% or less, preferably 40% or more and 60% or less of the thickness of the lead portion 12 is there. The surface side of the recess 16 is not thinned, and is located on the same plane as the surface 12 d of the lead 12.

  The recess 16 extends between the tip of the lead 12 (end on the die pad 11) and the base of the lead 12 (end on the connecting bar 13). That is, the inner end 16 a of the recess 16 is located outside the internal terminal 15 in plan view, and the outer end 16 b of the recess 16 is in contact with the connecting bar 13 or located inside the connecting bar 13 .

  The length L1 of the recess 16 is preferably 35% to 80% of the length L2 of the lead portion 12. The width W1 of the recess 16 is 30% to 80% of the maximum width W2 of the lead portion 12. It is preferable to set it as the following.

  Further, the width of the lead 12 is changed along the longitudinal direction of the lead 12 at least in the region A where the recess 16 is formed (the region overlapping the recess 16 in the longitudinal direction of the lead 12). In this case, the width of the lead 12 is wider from the inside to the outside of the lead 12, and the width W3 of the lead 12 at the inner end 16a of the recess 16 is greater at the outer end 16b of the recess 16. The width W2 of the lead portion 12 is wider. In other words, the width of the lead 12 outside the line (virtual line) corresponding to the outer periphery 20 b is greater than the width of the lead 12 inside the line (virtual line) corresponding to the outer periphery 20 b of the semiconductor device 20 It is getting wider.

  The planar shape of the lead portion 12 is a combination of a substantially semicircular portion located on the inner side and a substantially trapezoidal portion located on the outer side, and as a whole, has a planar substantially rocket shape. In this case, the shape of the outer periphery of the lead portion 12 is the same for the front surface 12 d and the rear surface 12 f. That is, both the front surface 12d and the back surface 12f of the lead portion 12 have a substantially rocket shape in plan view, and the width of the lead portion 12 widens from the inside toward the outside.

  The lead frame 10 described above is made of a metal such as copper, copper alloy, 42 alloy (Fe alloy of 42% of Ni) as a whole. The thickness of the lead frame 10 can be 80 μm or more and 200 μm or less, depending on the configuration of the semiconductor device 20 to be manufactured.

  In the present embodiment, the lead portion 12 is disposed along all four sides of the die pad 11, but is not limited to this. For example, the lead portion 12 is disposed along only two opposing sides of the die pad 11. May be

Configuration of Semiconductor Device Next, the semiconductor device according to the present embodiment will be described with reference to FIG. 4 and FIG. 4 and 5 are diagrams showing a semiconductor device (QFN type) according to the present embodiment.

  As shown in FIGS. 4 and 5, the semiconductor device (semiconductor package) 20 includes a die pad 11, a plurality of lead portions 12 arranged around the die pad 11, and a semiconductor element 21 mounted on the die pad 11. A plurality of bonding wires (connection members) 22 for electrically connecting the lead portion 12 and the semiconductor element 21 are provided. Further, the die pad 11, the lead portion 12, the semiconductor element 21 and the bonding wire 22 are resin-sealed by a sealing resin 23.

  The die pad 11 and the lead portion 12 are manufactured from the above-described lead frame 10. Among the leads 12, the surface 12 d and the side surface 12 e are covered with the sealing resin 23, and the back surface 12 f is exposed outward from the sealing resin 23.

  Recesses 16 are respectively formed at positions corresponding to the outer periphery 23 b of the sealing resin 23 (the outer periphery 20 b of the semiconductor device 20) on the back surface of each lead portion 12. Each recess 16 has an elongated shape along the longitudinal direction of the lead 12 in plan view. Further, the recess 16 is opened on the back surface 12 f side of the lead portion 12 and is also opened on the outer surface 12 g of the lead portion 12. Therefore, when viewed from the outside of the semiconductor device 20, the outer surface 12g of the lead portion 12 has a reverse concave shape (inverted U shape) (see FIG. 6). The sealing resin 23 is not filled in the recess 16.

  Further, as shown in FIG. 4, the width of the lead portion 12 changes along the longitudinal direction of the lead portion 12 at least in the region A where the concave portion 16 is formed (a region overlapping the recess 16 in the longitudinal direction of the lead portion 12) doing. In this case, the width of the lead 12 is wider from the inside to the outside of the lead 12. That is, the width of the lead 12 at the outer periphery 20 b of the semiconductor device 20 is wider than the width of the lead 12 at the inner end 16 a of the recess 16.

  In addition to the above, the configurations of the die pad 11 and the lead portion 12 are the same as those shown in FIG. 1 to FIG. 3 described above except for the region not included in the semiconductor device 20, and thus detailed description will be omitted here.

  As the semiconductor element 21, various semiconductor elements conventionally used generally can be used, and there is no particular limitation. For example, an integrated circuit, a large scale integrated circuit, a transistor, a thyristor, a diode or the like can be used. The semiconductor element 21 has a plurality of electrodes 21 a to which the bonding wires 22 are attached. The semiconductor element 21 is fixed to the surface of the die pad 11 with an adhesive 24 such as a die bonding paste, for example.

  Each bonding wire 22 is made of, for example, a conductive material such as gold or copper. One end of each bonding wire 22 is connected to the electrode 21 a of the semiconductor element 21, and the other end is connected to the internal terminal 15 of each lead portion 12. The internal terminal 15 may be provided with a plated portion for improving adhesion to the bonding wire 22.

  As the sealing resin 23, thermosetting resin such as silicone resin or epoxy resin, or thermoplastic resin such as PPS resin can be used. The thickness of the entire sealing resin 23 can be about 300 μm or more and 1200 μm or less. The sealing resin 23 is square or rectangular in a plan view, and one side of the outer periphery 23b (one side of the outer periphery 20b of the semiconductor device 20) can be, for example, 6 mm or more and 16 mm or less. In addition, in FIG. 4, the display of the part located in the surface side rather than the die pad 11 and the lead part 12 among sealing resin 23 is abbreviate | omitted.

Method of Manufacturing Lead Frame Next, a method of manufacturing the lead frame 10 shown in FIGS. 1 to 3 will be described with reference to FIGS. 7 (a) to 7 (e). 7 (a) to 7 (e) are cross-sectional views (diagram corresponding to FIG. 3) showing a method of manufacturing the lead frame 10. As shown in FIG.

  First, as shown in FIG. 7A, a flat metal substrate 31 is prepared. As the metal substrate 31, a substrate made of metal such as copper, copper alloy, 42 alloy (Fe alloy of 42% of Ni) can be used. In addition, it is preferable to use what carried out the degreasing etc. with respect to the both surfaces, and the metal substrate 31 wash-processed.

  Next, photosensitive resists 32a and 33a are applied to the entire front and back of the metal substrate 31, respectively, and dried (FIG. 7 (b)). As the photosensitive resists 32a and 33a, conventionally known ones can be used.

  Subsequently, the metal substrate 31 is exposed to light through a photo mask and developed to form etching resist layers 32 and 33 having desired openings 32b and 33b (FIG. 7C).

  Next, the metal substrate 31 is etched with an etching solution using the etching resist layers 32 and 33 as a corrosion resistant film (FIG. 7 (d)). Thereby, the outer shape of the die pad 11 and the lead portion 12 is formed. At this time, the concave portion 16 is formed on the back surface 12 f of the lead portion 12 by being half-etched from the back surface 12 f of the lead portion 12. The corrosion liquid can be appropriately selected according to the material of the metal substrate 31 to be used. For example, when using copper as the metal substrate 31, usually, an aqueous solution of ferric chloride is used, and both surfaces of the metal substrate 31 are used. Can perform spray etching.

  Thereafter, the etching resist layers 32 and 33 are peeled and removed to obtain the lead frame 10 shown in FIGS. 1 to 3. (FIG. 7 (e)).

Method of Manufacturing Semiconductor Device Next, a method of manufacturing the semiconductor device 20 shown in FIGS. 4 and 5 will be described with reference to FIGS. 8 (a) to 8 (e).

  First, for example, the lead frame 10 is manufactured by the method shown in FIGS. 7 (a) to 7 (e) (FIG. 8 (a)).

  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 and fixed on the die pad 11 by using an adhesive 24 such as a die bonding paste, for example (die attach process) (FIG. 8B).

  Next, the electrodes 21a of the semiconductor element 21 and the internal terminals 15 of the leads 12 are electrically connected to each other by bonding wires (connecting members) 22 (wire bonding step) (FIG. 8C). .

  Next, a sealing resin 23 is formed by injection molding or transfer molding a thermosetting resin or a thermoplastic resin on the lead frame 10 (resin sealing step) (FIG. 8 (d)). Thus, the die pad 11, the lead 12, the semiconductor element 21 and the bonding wire 22 are sealed. At this time, the surface 12 d and the side surface 12 e of the lead portion 12 are covered with the sealing resin 23, and the back surface 12 f is exposed outward from the sealing resin 23. Further, the concave portion 16 of the lead portion 12 opens on the back surface 12 f side without being filled with the sealing resin 23.

  After the resin sealing step, a solder plating layer may be formed on the back surface 12 f of the lead portion 12 and the recess 16 by performing electrolytic plating.

  Next, the lead frame 10 is separated into the semiconductor devices 20 by dicing the sealing resin 23 between the semiconductor elements 21. At this time, the lead frame 10 and the sealing resin 23 between the semiconductor devices 20 may be cut while rotating a blade (not shown) made of, for example, a diamond grindstone.

  Thus, the lead frame 10 is separated for each semiconductor device 20, and the semiconductor device 20 shown in FIG. 4 and FIG. 5 is obtained (FIG. 8 (e)).

  Thereafter, the semiconductor device 20 is connected to the wiring substrate 80 (see FIG. 9). At this time, solder plating provided on the back surface 12 f, the outer surface 12 g, and the recess 16 of the lead portion 12 forms a solder fillet 39. In the present embodiment, since the width of the lead 12 is wider from the inside to the outside of the lead 12, the area of the back surface 12f and the outer surface 12g of the lead 12 is secured wide. Therefore, the solder fillet 39 can be stably formed. Thus, the lead portions 12 and the wiring substrate 80 can be stably connected, and the connection reliability of the semiconductor device 20 can be improved. In addition, since the solder fillet 39 is filled in the inside of the concave portion 16, it can be easily confirmed that the lead portion 12 and the wiring substrate 80 are connected at the time of the appearance inspection.

  As described above, according to the present embodiment, in the back surface 12f of the lead portion 12, the recess 16 is formed at a position corresponding to at least the outer periphery 20b of the semiconductor device 20, and the region A in which the recess 16 is formed. , The width of the lead 12 changes along the longitudinal direction of the lead 12. In particular, the width of the lead 12 is wider from the inside to the outside of the lead 12. Thus, when the semiconductor device 20 is mounted on the wiring substrate 80, the lead portion 12 and the wiring substrate 80 can be joined in a wide range, and the connection reliability between the lead portion 12 and the wiring substrate 80 can be enhanced. it can.

  In addition, if the lead 12 is cut to separate the semiconductor device 20 (FIG. 8E), even if burrs remain inside the recess 16, the lead 12 and the wiring substrate 80 are made wider. It can be joined in the range. For this reason, it can suppress that the connection defect of plating arises by the burr | flash in the recessed part 16. In FIG.

Modifications Next, each modification of the lead frame 10 according to the present embodiment will be described with reference to FIGS. 10 to 12. The modified example shown in FIGS. 10 to 12 is different in the configuration of the lead portion 12, and the other configuration is substantially the same as the embodiment shown in FIGS. 1 to 9. In FIG. 10 to FIG. 12, the same parts as in FIG. 1 to FIG. 9 are assigned the same reference numerals and detailed explanations thereof will be omitted.

(Modification 1)
10A and 10B, unlike the embodiment shown in FIGS. 1 to 9, the shape of the lead portion 12 is different between the front surface 12d and the back surface 12f. That is, as shown in FIG. 10B, the width of the back surface 12f of the lead 12 gradually widens from the inside to the outside of the lead 12 in at least the region A where the recess 16 is formed. On the other hand, as shown in FIG. 10A, the width of the surface 12 d of the lead 12 is uniform from the inside to the outside of the lead 12 at least in the region A where the recess 16 is formed. In this case, the side surface 12e of the lead portion 12 is scraped from the surface 12d side by half etching. Therefore, the cross section of the lead portion 12 at least at the peripheral edge of the package region 10a (the phantom line in FIGS. 10A and 10B) gradually increases in width from the surface 12d to the back surface 12f.

  10A and 10B, since the width of the back surface 12f of the lead portion 12 is wider from the inside to the outside of the lead portion 12, the area of the back surface 12f of the lead portion 12 can be increased. . Thereby, the solder fillet 39 (see FIG. 9) can be stably formed. On the other hand, since the width of the front surface 12d of the lead portion 12 is narrower than the width of the back surface 12f at least at the periphery of the package region 10a, the amount of burrs generated from the lead portion 12 during dicing can be suppressed.

(Modification 2)
In FIG. 11, unlike the embodiment shown in FIGS. 1-9, the recess 16 of the lead 12 extends across the connecting bar 13 to the corresponding lead 12 of the adjacent package area 10a. That is, the recess 16 extends across the pair of opposing lead portions 12 and the connecting bar 13 connecting the pair of lead portions 12. The recess 16 has an elongated shape in plan view, and extends along a direction orthogonal to the longitudinal direction of the connecting bar 13.

  In FIG. 11, since the recess 16 of the lead portion 12 extends to the connecting bar 13, the amount of burr generated from the lead portion 12 at the time of dicing can be suppressed. In addition, the amount of metal to be diced can be reduced, and blade wear can be suppressed.

(Modification 3)
In FIG. 12, in addition to the recess 16 shown in FIG. 11, a plurality of additional recesses 16 c are formed along the connecting bar 13. The additional recess 16 c is formed on the back side of the connecting bar 13. The additional recesses 16 c each have an elongated racetrack shape in a plan view and extend along the longitudinal direction of the connecting bar 13. Also, the plurality of additional recesses 16 c are spaced apart from one another along the longitudinal direction of the connecting bar 13. The additional recess 16 c is spaced apart from each recess 16, and the recess 16 passes between the pair of additional recesses 16 c adjacent to each other.

  By providing the additional recessed part 16c in the connecting bar 13 in FIG. 12, the quantity of the burr | flash generate | occur | produced from the lead part 12 at the time of dicing can be restrained. In addition, the amount of metal to be diced can be reduced, and blade wear can be suppressed.

  In FIGS. 11 and 12 as well as FIGS. 10A and 10B, the shape of the lead 12 may be different between the front surface 12d and the back surface 12f. That is, the width of the back surface 12f of the lead portion 12 may be gradually expanded from the inside to the outside, and the width of the surface 12d of the lead portion 12 may be uniform from the inside to the outside.

Second Embodiment
Next, a second embodiment will be described with reference to FIG. FIG. 13 is a plan view showing a lead frame 10A according to the second embodiment. The second embodiment shown in FIG. 13 is different in the shape of the lead portion 12, and the other configuration is substantially the same as that of the first embodiment described above. In FIG. 13, the same parts as those of the first embodiment shown in FIGS. 1 to 9 are designated by the same reference numerals and their detailed description will be omitted.

  In the lead frame 10A shown in FIG. 13, a recess 16A is formed in the back surface 12f of each lead portion 12. The recess 16A has a substantially triangular shape in a plan view. The width of the recess 16A gradually widens from the inside to the outside of the lead portion 12.

  The recess 16A is formed of a non-penetrating recess which is recessed from the back surface 12f of the lead portion 12 halfway in the thickness direction (Z direction). The concave portion 16A is formed by thinning from the back surface 12f side by half etching, and the depth thereof is 30% or more and 70% or less, preferably 40% or more and 60% or less of the thickness of the lead portion 12 is there. The length L3 of the recess 16A is preferably 30% to 80% of the length L2 of the lead 12. The maximum width W4 of the recess 16A is 50% to 80% of the maximum width W5 of the lead 12. It is preferable to set it as% or less.

  In the present embodiment, the width of the lead 12 is constant at least in the region A where the recess 16A is formed (the region overlapping the recess 16A in the longitudinal direction of the lead 12). In this case, the planar shape of the lead portion 12 is a combination of a substantially semicircular portion located inside and a substantially rectangular portion located outside. That is, the width of the lead portion 12 is uniform except for the substantially semicircular portion. Further, the shape of the outer periphery of the lead portion 12 is the same for the front surface 12 d and the rear surface 12 f.

  According to the present embodiment, the recess 16A is formed at least at a position corresponding to the outer periphery 20b of the semiconductor device 20 on the back surface 12f of the lead portion 12, and the width of the recess 16A in the region A in which the recess 16A is formed. Changes along the longitudinal direction of the lead 12. Specifically, the width of the recess 16A is wider from the inside to the outside of the lead portion 12. As a result, the solder plating can easily flow from the inside to the outside of the lead portion 12 through the recess 16A, and the solder fillet 39 (see FIG. 9) can be stably formed. As a result, the connection reliability between the lead portion 12 and the wiring substrate 80 can be enhanced.

  In the present embodiment, as in the embodiment shown in FIGS. 1 to 9, even in the region A where at least the recess 16A is formed, the width of the lead portion 12 is widened from the inside to the outside. Good (see Figure 14).

  Further, in the present embodiment, as in the embodiment shown in FIGS. 10A and 10B, the width of the back surface 12f of the lead portion 12 is gradually expanded from the inside to the outside, and the surface of the lead portion 12 is The width 12d may be uniform from the inside to the outside (see FIG. 15).

Third Embodiment
Next, a third embodiment will be described with reference to FIG. FIG. 16 is a plan view showing a lead frame 10B according to the third embodiment. The third embodiment shown in FIG. 16 is different in the shape of the lead portion 12, and the other configuration is substantially the same as that of the first embodiment described above. In FIG. 16, the same parts as those of the first embodiment shown in FIGS. 1 to 9 are designated by the same reference numerals and their detailed description will be omitted.

  In the lead frame 10B shown in FIG. 16, a recess 16B is formed on the back surface 12f of the lead portion 12. The recess 16B has a substantially triangular shape in a plan view. The width of the recess 16 B gradually widens from the outside to the inside of the lead 12.

  The recessed portion 16B is configured by a non-penetrating recessed portion that is recessed from the back surface 12f of the lead portion 12 to the middle in the thickness direction (the Z direction). The concave portion 16B is formed by thinning from the back surface 12f side by half etching, and the depth thereof is 30% or more and 70% or less, preferably 40% or more and 60% or less of the thickness of the lead portion 12 is there. The length L4 of the recess 16B is preferably 30% or more and 80% or less of the length L2 of the lead 12. The maximum width W6 of the recess 16B is 50% or more 80 of the maximum width W5 of the lead 12. It is preferable to set it as% or less.

  In the present embodiment, the planar shape of the lead portion 12 is the same as that of the second embodiment shown in FIG. That is, the width of the lead 12 is constant at least in the region A where the recess 16B is formed (the region overlapping the recess 16B in the longitudinal direction of the lead 12).

  According to the present embodiment, recessed portion 16B is formed at a position corresponding to at least outer periphery 20b of semiconductor device 20 on back surface 12f of lead portion 12, and the width of recessed portion 16B is from the outside to the inside of lead portion 12 It is getting wider. Thereby, the area of the outer surface 12 g (see FIG. 9) of the lead portion 12 can be secured widely, and the solder fillet 39 can be stably formed. As a result, the connection reliability between the lead portion 12 and the wiring substrate 80 can be enhanced.

  In the present embodiment, as in the embodiment shown in FIGS. 1 to 9, even in the region A where at least the recess 16B is formed, the width of the lead portion 12 is widened from the inside to the outside. Good (see Figure 17).

  Further, in the present embodiment, as in the embodiment shown in FIGS. 10A and 10B, the width of the back surface 12f of the lead portion 12 is gradually expanded from the inside to the outside, and the surface of the lead portion 12 is The width 12d may be uniform from the inside to the outside (see FIG. 18).

Fourth Embodiment
Next, a fourth embodiment will be described with reference to FIG. FIG. 19 is a plan view showing a lead frame 10C according to the fourth embodiment. In the fourth embodiment shown in FIG. 19, the shape of the lead portion 12 is different, and the other configuration is substantially the same as that of the first embodiment described above. In FIG. 19, the same parts as those of the first embodiment shown in FIGS. 1 to 9 are designated by the same reference numerals and their detailed description will be omitted.

  In the lead frame 10C shown in FIG. 19, the recess 16C is formed at a position corresponding to at least the outer periphery 20b (virtual line) of the semiconductor device 20 on the back surface 12f of the lead portion 12. That is, a line corresponding to the outer periphery 20b of the semiconductor device 20 crosses the recess 16C. The recess 16 </ b> C has an elongated rectangular shape in plan view, and extends along the longitudinal direction of the lead 12. The width of the recess 16 C is uniform along the longitudinal direction of the lead 12.

  The recess 16C is formed of a non-penetrating recess which is recessed from the back surface 12f of the lead portion 12 halfway in the thickness direction (Z direction). That is, the concave portion 16C is formed by thinning from the back surface 12f side by half etching, and the depth thereof is 30% or more and 70% or less, preferably 40% or more and 60% or less of the thickness of the lead portion 12 is there.

  The recess 16C extends from a position outside the tip of the lead portion 12 (the end on the die pad 11 side) in plan view to a position in contact with the connecting bar 13. The recess 16 </ b> C is located at a substantially central portion in the width direction of the lead portion 12.

  In FIG. 19, a connecting bar recess 13 a is formed on the back surface of the connecting bar 13. The connecting bar recess 13 a has an elongated rectangular shape in a plan view, and extends over the entire length of the connecting bar 13 along the longitudinal direction. The connecting bar recess 13 a is formed of a non-penetrating recess which is recessed from the back surface of the connecting bar 13 halfway in the thickness direction (Z direction). That is, the recess 16C is formed by thinning from the back surface 12f side by half etching, and the depth thereof is substantially the same as the depth of the recess 16C. The connecting bar recess 13 a is located at a substantially central portion in the width direction of the connecting bar 13.

  In the present embodiment, the recess 16 </ b> C of the lead portion 12 and the connecting bar recess 13 a of the connecting bar 13 are connected to each other. That is, a plurality of recesses 16C are connected to one connecting bar recess 13a.

  In the present embodiment, the width of the lead 12 is constant at least in the region A where the recess 16C is formed (the region overlapping the recess 16C in the longitudinal direction of the lead 12). The planar shape of the lead portion 12 is rectangular.

  According to the present embodiment, the recess 16C of the lead portion 12 and the connecting bar recess 13a of the connecting bar 13 are connected to each other. As a result, when the lead frame 10C is manufactured by etching (see FIG. 7D), it is possible to easily flow the etching solution to the recess 16C of each lead 12 via the connecting bar recess 13a. Thereby, the substitutability of the etching liquid in the recessed part 16C can be improved, and the shape of the recessed part 16C can be formed stably.

  In addition, in the above, although the connecting bar recessed part 13a is formed over the longitudinal direction whole area of the connecting bar 13, it is not restricted to this. For example, as shown in FIG. 20, the connecting bar recess 13a may be provided only in the region of the connecting bar 13 to which the lead portion 12 is connected. In this case, it is possible to maintain the strength of the connecting bar 13 while improving the replaceability of the etching solution in the recess 16C.

  Further, in the present embodiment, as in the embodiment shown in FIGS. 1 to 9, even in the region A where at least the recess 16C is formed, the width of the lead portion 12 becomes wider from the inside to the outside. good.

  Further, in the present embodiment, as in the embodiment shown in FIGS. 10A and 10B, the width of the back surface 12f of the lead portion 12 is gradually expanded from the inside to the outside, and the surface of the lead portion 12 is The width 12d may be uniform from the inside to the outside.

  It is also possible to appropriately combine a plurality of components disclosed in the above-described embodiments and modifications as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiments and modifications.

DESCRIPTION OF SYMBOLS 10 lead frame 10a package area 11 die pad 12 lead part 13 connecting bar 14 suspension lead 15 internal terminal 16 recessed part 17 external terminal 20 semiconductor device 21 semiconductor element 22 bonding wire 23 sealing resin

Claims (9)

In a lead frame for manufacturing a semiconductor device,
With die pad,
And a lead portion provided around the die pad,
A recess is formed at a position corresponding to at least the outer periphery of the semiconductor device on the back surface of the lead portion,
A lead frame in which the width of the lead portion changes along the longitudinal direction of the lead portion or the width of the recess changes along the longitudinal direction of the lead portion at least in a region where the recess is formed. .   The lead frame according to claim 1, wherein a width of the lead portion widens from the inside to the outside of the lead portion at least in a region where the recess is formed.   At least in the region where the recess is formed, the width of the back surface of the lead portion is wider from the inside to the outside of the lead portion, and the width of the surface of the lead portion is outside the inside of the lead portion The lead frame of claim 1 wherein the lead frame is uniform.   The lead frame according to any one of claims 1 to 3, wherein the width of the recess is wider from the inside to the outside of the lead portion.   The lead frame according to any one of claims 1 to 3, wherein the width of the recess narrows from the inside to the outside of the lead portion.   The apparatus further comprises a connecting bar connected to the lead portion, wherein a connecting bar recess is formed on a back surface of the connecting bar, and the recess of the lead portion and the connecting bar recess of the connecting bar are connected to each other. The lead frame according to any one of 1 to 5. In a lead frame for manufacturing a semiconductor device,
With die pad,
Lead portions provided around the die pad;
And a connecting bar connected to the leads.
A recess is formed at a position corresponding to at least the outer periphery of the semiconductor device on the back surface of the lead portion,
A connecting bar recess is formed on the back of the connecting bar,
A lead frame in which the recess of the lead portion and the connecting bar recess of the connecting bar are connected to each other. In semiconductor devices,
With die pad,
Lead portions provided around the die pad;
A semiconductor element mounted on the die pad;
A connecting member for electrically connecting the semiconductor element and the lead portion;
And a sealing resin that seals the die pad, the lead portion, the semiconductor element, and the connection member.
A recess is formed at a position corresponding to at least the outer periphery of the sealing resin on the back surface of the lead portion,
A semiconductor device, wherein the width of the lead portion changes along the longitudinal direction of the lead portion or the width of the recess portion changes along the longitudinal direction of the lead portion at least in a region where the recess is formed. . In a method of manufacturing a semiconductor device,
Preparing a lead frame according to any one of claims 1 to 7;
Mounting a semiconductor element on the die pad of the lead frame;
Electrically connecting the semiconductor element and the lead portion by a connecting member;
A method of manufacturing a semiconductor device, comprising: sealing the die pad, the lead portion, the semiconductor element, and the connection member with a sealing resin.

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