JP6909629B2 - Semiconductor device - Google Patents

Description

The present invention relates to a semiconductor device having a package format of QFN.

There are various types of package types in a semiconductor device in which a semiconductor element is mounted on a die pad which is a part of a lead frame which is a base of a plurality of terminals (leads) and the semiconductor elements are covered with a sealing resin. Among these package types, QFN (Quad Flat No-leads) is a type in which a plurality of terminals do not protrude laterally from the sealing resin at all. Since the QFN can reduce the mounting range on the circuit board, it contributes to the miniaturization of electronic devices.

Patent Document 1 discloses an example of a semiconductor device having a package format of QFN. The semiconductor device includes a die pad on which a semiconductor element (semiconductor chip) is mounted, a plurality of terminals (leads) arranged around the die pad, and a sealing resin (sealing body) that covers them. In the semiconductor device, the back surface of the die pad is exposed from the sealing resin, and the area of the die pad in a plan view occupies most of the device area. Therefore, in the semiconductor device, the heat generated from the semiconductor element can be efficiently discharged to the outside from the die pad. However, since the volume of the die pad is relatively large, thermal expansion occurs in the die pad due to the temperature cycle required for using the semiconductor device or the like. Then, the thermal stress caused by the thermal expansion acts on the sealing resin. If the concentration of thermal stress acting on the sealing resin becomes remarkable, cracks may occur in the sealing resin. If moisture or the like enters the crack, there is a concern that a defect may occur in the semiconductor device. For this reason, when the size of the die pad is reduced in order to alleviate the concentration of thermal stress acting on the sealing resin, the surface area of the die pad exposed from the sealing resin is reduced. In this case, a problem is a decrease in heat dissipation due to heat generated from the semiconductor element.

Japanese Unexamined Patent Publication No. 2013-16624

In view of the above circumstances, it is an object of the present invention to provide a semiconductor device capable of ensuring heat dissipation while relaxing the concentration of thermal stress acting on the sealing resin.

The semiconductor device provided by the present invention includes a die pad having a mounting surface and a back surface of a pad facing opposite sides in the thickness direction, and a semiconductor element mounted on the mounting surface and terminals each facing the same direction as the back surface of the pad. It has a back surface, has a plurality of terminals arranged so as to surround the die pad in the thickness direction of the die pad, and conducts to the semiconductor element, and has a resin back surface facing in the same direction as the back surface of the pad, and said. A semiconductor device including a semiconductor element and a sealing resin that covers a portion of each of the die pad and the plurality of terminals, wherein the back surface of the pad and the back surface of the terminal are both exposed from the back surface of the resin, and the said. The die pad is characterized in that a pad recess is formed which is recessed from the back surface of the pad.

In the practice of the present invention, the pad recess is preferably exposed from the back surface of the resin.

In the practice of the present invention, the pad recess is preferably composed of a plurality of annular grooves surrounding the center of the back surface of the pad, and the central positions of the regions surrounded by the annular grooves on the back surface of the pad are the same. Is.

In the practice of the present invention, the pad recess is preferably composed of a plurality of grooves extending along a direction perpendicular to the thickness direction.

In the practice of the present invention, preferably, the die pad further has a pad side surface that intersects the back surface of the pad and faces the plurality of terminals, and the die pad is flush with the mounting surface and said. A pad protruding portion is formed so as to project from the side surface of the pad toward the plurality of terminals.

In the practice of the present invention, the pad recess is preferably filled with the sealing resin, and the back surface of the pad has a pad central portion and a pad outer peripheral portion located around the pad central portion. The central portion of the pad and the outer peripheral portion of the pad are separated from each other by the pad recess in the thickness direction.

In the practice of the present invention, the outer peripheral portion of the pad preferably has a pair of first regions separated from each other in one direction perpendicular to the thickness direction.

In the practice of the present invention, the outer peripheral portion of the pad preferably has a pair of second regions separated from each other in a direction perpendicular to both the thickness direction and the one direction.

In the practice of the present invention, preferably, the edge of the mounting surface is formed with mounting surface recesses that are recessed from the four corners of the mounting surface toward the inside of the die pad in the thickness direction view, and is formed in the thickness direction view. A part of the semiconductor element overlaps the mounting surface recess.

In the practice of the present invention, preferably, a part of the semiconductor element overlaps the outer peripheral portion of the pad in the thickness direction view.

In the practice of the present invention, the position of the outer peripheral portion of the pad is preferably equal to the position of the central portion of the pad in the thickness direction.

Preferably, in the practice of the present invention, the terminal further has a terminal main surface facing in the same direction as the mounting surface, and further includes a wire connecting the semiconductor element and the terminal main surface.

In the practice of the present invention, the die pad and the terminal are preferably provided with an interior plating layer in contact with either the mounting surface or the terminal main surface.

In the practice of the present invention, preferably, the terminal intersects both the main surface of the terminal and the back surface of the terminal, and further has an outer surface of the terminal facing outward, and the sealing resin intersects the back surface of the resin. It further has a resin side surface, and the terminal outer surface is exposed from the resin side surface.

In the practice of the present invention, preferably, the terminal further has an inner side surface of the terminal that intersects the back surface of the terminal and faces the side opposite to the outer surface of the terminal, and the terminal is flush with the main surface of the terminal. A terminal protruding portion is formed so as to project from the inner surface of the terminal toward the die pad.

In the practice of the present invention, preferably, the plurality of the terminals are the plurality of first terminals arranged along the first direction perpendicular to the thickness direction, and the plurality of first terminals in the thickness direction and the first direction. A plurality of second terminals arranged along a second direction perpendicular to both are included, and the outer surface of the terminal is flush with the resin side surface.

According to the semiconductor device according to the present invention, it is possible to secure heat dissipation while relaxing the concentration of thermal stress acting on the sealing resin.

Other features and advantages of the present invention will become more apparent with the detailed description given below based on the accompanying drawings.

It is a perspective view of the semiconductor device which concerns on 1st Embodiment of this invention. It is a bottom view of the semiconductor device shown in FIG. It is a top view (permeating the sealing resin) of the semiconductor device shown in FIG. It is a front view of the semiconductor device shown in FIG. It is a right side view of the semiconductor device shown in FIG. It is sectional drawing which follows the VI-VI line of FIG. FIG. 3 is a cross-sectional view taken along the line VII-VII of FIG. It is a partially enlarged view of FIG. It is a partially enlarged view of FIG. It is a bottom view of the semiconductor device which concerns on the modification of 1st Embodiment of this invention. It is sectional drawing which follows the XI-XI line of FIG. It is a bottom view of the semiconductor device which concerns on 2nd Embodiment of this invention. It is a bottom view of the semiconductor device shown in FIG. 12 (permeating the sealing resin, omitting the wire). It is a top view (permeating the sealing resin) of the semiconductor device shown in FIG. It is sectional drawing which follows the XV-XV line of FIG. It is a partially enlarged view of FIG. It is a bottom view of the semiconductor device which concerns on 3rd Embodiment of this invention. It is a top view (permeating the sealing resin) of the semiconductor device shown in FIG. It is a front view of the semiconductor device shown in FIG. FIG. 3 is a cross-sectional view taken along the line XX-XX of FIG. It is a partially enlarged view of FIG. It is sectional drawing explaining the manufacturing process of the semiconductor device shown in FIG.

An embodiment for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the accompanying drawings.

[First Embodiment]
The semiconductor device A10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 11. The semiconductor device A10 includes a die pad 1, a semiconductor element 2, a plurality of terminals 3, and a sealing resin 5. In this embodiment, the semiconductor device A10 further includes a wire 4.

FIG. 3 is transparent to the sealing resin 5 for convenience of understanding. The transparent sealing resin 5 in FIG. 3 is shown by an imaginary line (dashed-dotted line). FIG. 8 is an enlargement of the vicinity of the terminal 3 shown in FIG. FIG. 9 is an enlargement of the vicinity of the die pad 1 shown in FIG.

The semiconductor device A10 is surface-mounted on circuit boards of various electronic devices. The package type of the semiconductor device A10 is QFN. As shown in FIG. 1 and the like, the semiconductor device A10 in the thickness direction z-view (hereinafter referred to as “planar view”) of the die pad 1 has a rectangular shape. Here, for convenience of explanation, the direction (horizontal direction in FIG. 2) perpendicular to the thickness direction z of the die pad 1 (hereinafter, simply referred to as “thickness direction z”) is referred to as the first direction x. Further, a direction (vertical direction in FIG. 2) perpendicular to both the thickness direction z and the first direction x of the die pad 1 is referred to as a second direction y.

As shown in FIGS. 3 and 6, the die pad 1 is a member on which the semiconductor element 2 is mounted. The die pad 1 is made of a metal material, and the metal material is, for example, Cu. The die pad 1 is derived from a lead frame obtained by processing the metal material. The die pad 1 has a mounting surface 11, a pad back surface 12, a pad side surface 13, and a pad diagonal member 16.

As shown in FIGS. 6 and 9, the mounting surface 11 faces the thickness direction z. As shown in FIG. 3, the mounting surface 11 has a rectangular shape. The semiconductor element 2 is mounted on the mounting surface 11. The portion of the mounting surface 11 on which the semiconductor element 2 is not mounted is covered with the sealing resin 5.

As shown in FIGS. 6 and 9, the pad back surface 12 faces the side opposite to the mounting surface 11 in the thickness direction z. As shown in FIG. 2, the back surface 12 of the pad has a rectangular shape, and its area is set smaller than that of the mounting surface 11. In this embodiment, the back surface 12 of the pad is exposed from the sealing resin 5.

As shown in FIGS. 3 and 9, the pad side surface 13 intersects the pad back surface 12 and faces the plurality of terminals 3. The pad side surface 13 is composed of four surfaces, and each pad side surface 13 faces either the first direction x or the second direction y. In the thickness direction z, the upper end of the pad side surface 13 located between the mounting surface 11 and the pad back surface 12 is bent toward either the first direction x or the second direction y. The pad side surface 13 is covered with the sealing resin 5.

As shown in FIGS. 2, 6 and 9, the die pad 1 is formed with a pad recess 14 recessed from the back surface 12 of the pad. In the present embodiment, the pad recess 14 is exposed from the sealing resin 5 together with the pad back surface 12. Further, in the present embodiment, the pad recess 14 is composed of a plurality of annular grooves 141 that are recessed from the back surface 12 of the pad and surround the center of the back surface 12 of the pad. As shown in FIG. 2, the center position C of the region surrounded by each annular groove 141 on the back surface 12 of the pad is the same. In the present embodiment, the regions surrounded by the annular grooves 141 are all rectangular, and the center position C points to the intersection of the diagonal lines of the regions. Here, the center of the pad back surface 12 is the same as the center position C. The region surrounded by each annular groove 141 may be circular, for example. The pad recess 14 can be formed in the die pad 1 by etching, for example.

10 and 11 show a semiconductor device A11 which is a modification of the semiconductor device A10. The pad recess 14 may be formed of a plurality of grooves 142 as in the present modification, in addition to the plurality of annular grooves 141 such as the semiconductor device A10. Each groove 142 extends along a direction perpendicular to the thickness direction z. In this modification, the plurality of grooves 142 are recessed from the back surface 12 of the pad and are arranged along the first direction x. Each groove 142 extends along the second direction y. The plurality of grooves 142 may be arranged along the second direction y, and each groove 142 may extend along the first direction x. Further, each groove 142 may be configured to extend along an oblique direction with respect to both the first direction x and the second direction y.

As shown in FIGS. 3, 6 and 9, the die pad 1 is formed with eaves-shaped pad protrusions 15 that are flush with the mounting surface 11 and project from the pad side surfaces 13 toward the plurality of terminals 3. Has been done. The pad protrusions 15 are formed at four positions on the die pad 1, and each pad protrusion 15 projects in either the first direction x or the second direction y. The pad protrusion 15 has a pad end surface 151 and a pad intermediate surface 152. The pad end face 151 is along the thickness direction z and faces either the first direction x or the second direction y. The pad intermediate surface 152 faces in the same direction as the pad back surface 12 and intersects the pad end surface 151. The pad intermediate surface 152 is connected to the pad side surface 13 inside the die pad 1. In the thickness direction z, the distance from the mounting surface 11 to the pad intermediate surface 152 is about half the distance from the mounting surface 11 to the pad back surface 12. The pad protrusion 15 is covered with the sealing resin 5.

As shown in FIGS. 3 and 7, the pad diagonal member 16 extends obliquely from the intersection of the two pad end faces 151 with respect to both the first direction x and the second direction y. The pad diagonal member 16 is composed of four lumbers and extends radially from the four corners of the die pad 1 in a plan view. The pad slanted lumber 16 has a slanted lumber upper surface 161, a slanted lumber lower surface 162, and a slanted lumber end surface 163. The slanted lumber upper surface 161 faces the same direction as the mounting surface 11 and is flush with the mounting surface 11. The slanted lumber lower surface 162 faces in the same direction as the pad back surface 12. In the direction in which the pad diagonal member 16 extends, one end of the diagonal member lower surface 162 is connected to the pad intermediate surface 152. Further, in the thickness direction z, the distance from the diagonal member upper surface 161 to the diagonal member lower surface 162 is substantially equal to the distance from the mounting surface 11 to the pad intermediate surface 152. The slanted lumber end surface 163 is located at the tip of the pad slanted lumber 16 in the direction in which the pad slanted lumber 16 extends, and intersects both the slanted lumber upper surface 161 and the slanted lumber lower surface 162. The slanted lumber end face 163 has an L shape and is exposed to the outside from the sealing resin 5. In addition, in the pad diagonal member 16, all the portions except the diagonal member end face 163 are covered with the sealing resin 5.

As shown in FIGS. 3 and 6, the semiconductor element 2 is mounted on the mounting surface 11 of the die pad 1. In the present embodiment, the semiconductor element 2 is an integrated circuit (IC) in which a drive circuit for lighting a light source such as an LED is incorporated. The semiconductor element 2 has an element main surface 21 and an element back surface 22.

As shown in FIGS. 6 and 9, the element main surface 21 faces in the same direction as the mounting surface 11 of the die pad 1. A plurality of electrode pads 211 are provided on the element main surface 21. Each electrode pad 211 conducts to a circuit incorporated inside the semiconductor element 2. The electrode pad 211 is made of, for example, Al. In this embodiment, the wire 4 is connected to each electrode pad 211. Further, as shown in FIGS. 6 and 9, the back surface 22 of the element faces the side opposite to the mounting surface 11 in the thickness direction z. The back surface 22 of the element faces the mounting surface 11.

As shown in FIGS. 6 and 9, the bonding layer 29 is interposed between the mounting surface 11 of the die pad 1 and the element back surface 22 of the semiconductor element 2. The bonding layer 29 is composed of, for example, a synthetic resin (so-called Ag paste) containing an epoxy resin containing Ag as a main component. The semiconductor element 2 is mounted on the mounting surface 11 via the bonding layer 29.

As shown in FIG. 3, the plurality of terminals 3 are arranged so as to surround the die pad 1 in a plan view, and are electrically connected to the semiconductor element 2. Each of the plurality of terminals 3 is composed of a lead frame derived from the die pad 1. The plurality of terminals 3 include a plurality of first terminals 3a arranged along the first direction x and a plurality of second terminals 3b arranged along the second direction y. In the present embodiment, seven of the plurality of first terminals 3a are arranged on two sides of the semiconductor device A10 which is separated from each other in the second direction y in a plan view. Further, seven of the plurality of second terminals 3b are arranged on two sides of the semiconductor device A10 which is separated from each other in the first direction x in a plan view. The number of arrays of the plurality of first terminals 3a and second terminals 3b in the semiconductor device A10 is not limited to this embodiment. The plurality of terminals 3 all have the same shape. In the present embodiment, the terminal 3 has a terminal main surface 31, a terminal back surface 32, a terminal outer surface 33, and a terminal inner surface 34.

As shown in FIGS. 3 and 8, the terminal main surface 31 faces in the same direction as the mounting surface 11 of the die pad 1 and has a band shape. The terminal main surface 31 is covered with the sealing resin 5. A wire 4 is connected to the terminal main surface 31, and the terminal 3 is conductive to the semiconductor element 2 via the wire 4.

As shown in FIGS. 2 and 8, the terminal back surface 32 faces in the same direction as the pad back surface 12 of the die pad 1 and is exposed from the sealing resin 5. The terminal back surfaces 32 of the plurality of first terminals 3a and second terminals 3b are all arranged in contact with each side of the semiconductor device A10 in a plan view.

As shown in FIGS. 2 to 6 and 8, the terminal outer surface 33 intersects both the terminal main surface 31 and the terminal back surface 32 and faces outward. In the present embodiment, the terminal outer surface 33 stands up from the terminal back surface 32 toward the terminal main surface 31 along the thickness direction z. The terminal outer surface 33 is exposed from the sealing resin 5 and faces either the first direction x or the second direction y. The terminal outer surface 33 is a flat surface.

As shown in FIGS. 3 and 8, the terminal inner side surface 34 intersects the terminal back surface 32 and faces the side opposite to the terminal outer surface 33. In the thickness direction z, the upper end of the terminal inner side surface 34 located between the terminal main surface 31 and the terminal back surface 32 is bent toward either the first direction x or the second direction y. The inner side surface 34 of the terminal is covered with the sealing resin 5.

As shown in FIGS. 3, 6 and 8, the terminal 3 is formed with an eaves-shaped terminal projecting portion 35 that is flush with the terminal main surface 31 and projects from the terminal inner surface 34 toward the die pad 1. Has been done. The terminal protrusion 35 has a terminal end surface 351 and a terminal intermediate surface 352. The terminal end face 351 is along the thickness direction z and faces either the first direction x or the second direction y. The terminal end surface 351 faces the pad end surface 151 of the pad protrusion 15 of the die pad 1. The terminal intermediate surface 352 faces in the same direction as the terminal back surface 32 and intersects the terminal end surface 351. The terminal intermediate surface 352 is connected to the terminal inner side surface 34 inside the terminal 3. In the thickness direction z, the distance from the terminal main surface 31 to the terminal intermediate surface 352 is about half the distance from the terminal main surface 31 to the terminal back surface 32. The terminal protrusion 35 is covered with the sealing resin 5.

As shown in FIGS. 3, 6, 8 and 9, the wire 4 connects the electrode pad 211 of the semiconductor element 2 and the terminal main surface 31 of the terminal 3. The wires 4 conduct the plurality of terminals 3 to the semiconductor element 2. The wire 4 is made of a metal material such as Au.

As shown in FIG. 6, the sealing resin 5 covers the semiconductor element 2, the die pad 1, and a part of each of the plurality of terminals 3. The sealing resin 5 is a synthetic resin having electrical insulation, for example, a black epoxy resin. The sealing resin 5 has a resin main surface 51, a resin back surface 52, and a resin side surface 53.

As shown in FIG. 6, the resin main surface 51 faces in the same direction as the mounting surface 11 of the die pad 1. The resin main surface 51 is rectangular and flat. As shown in FIG. 6, the resin back surface 52 faces in the same direction as the pad back surface 12 of the die pad 1. Therefore, the resin main surface 51 and the resin back surface 52 face opposite to each other in the thickness direction z. As shown in FIG. 2, the pad back surface 12 and the pad recess 14 of the die pad 1 and the terminal back surface 32 of the terminal 3 are exposed from the resin back surface 52. As shown in FIGS. 4, 5 and 8, the resin side surface 53 intersects both the resin main surface 51 and the resin back surface 52. In the present embodiment, the resin side surface 53 is composed of four surfaces, and each resin side surface 53 faces either the first direction x or the second direction y. From each of the resin side surfaces 53, the diagonal member end surface 163 of the pad diagonal member 16 of the die pad 1 and the terminal outer surface 33 of the terminal 3 are exposed. In this embodiment, the terminal outer surface 33 is flush with the resin side surface 53.

As shown in FIGS. 8 and 9, the interior plating layer 61 is provided so as to cover the mounting surface 11 of the die pad 1 and the terminal main surface 31 of the terminal 3. The interior plating layer 61 is in contact with either the mounting surface 11 or the terminal main surface 31. Further, one end of the bonding layer 29 and the wire 4 is in contact with the interior plating layer 61. The interior plating layer 61 is composed of, for example, Ag.

As shown in FIGS. 8 and 9, the exterior plating layer 62 is provided so as to cover the pad back surface 12 of the die pad 1 and the terminal back surface 32 of the terminal 3. The exterior plating layer 62 is in contact with either the back surface 12 of the pad or the back surface 32 of the terminal. The exterior plating layer 62 is composed of, for example, Sn.

Next, the action and effect of the semiconductor device A10 will be described.

In the semiconductor device A10, the die pad 1 is formed with a pad recess 14 recessed from the back surface 12 of the pad. Both the pad back surface 12 and the pad recess 14 are exposed from the resin back surface 52 of the sealing resin 5. With such a configuration, even when the size of the die pad 1 is reduced in order to alleviate the concentration of thermal stress acting on the sealing resin 5, the pad recess 14 exposes the die pad 1 from the sealing resin 5. A predetermined size can be secured for the surface area of the die pad 1. Therefore, according to the semiconductor device A10, it is possible to secure heat dissipation while relaxing the concentration of thermal stress acting on the sealing resin 5.

The pad recess 14 may be configured to have a plurality of annular grooves 141 such as the semiconductor device A10 or a plurality of grooves 142 such as the semiconductor device A11. The pad recess 14 can be easily formed on the back surface 12 of the pad by etching.

In the semiconductor device A10, the die pad 1 is formed with a pad projecting portion 15 that is flush with the mounting surface 11 and projects from the pad side surface 13 toward the plurality of terminals 3. By adopting such a configuration, both the pad side surface 13 and the pad intermediate surface 152 of the pad protrusion 15 are covered with the sealing resin 5, and the die pad 1 is supported by the sealing resin 5 by the pad protrusion 15. It becomes a state. Therefore, the pad protrusion 15 can prevent the die pad 1 from falling off from the sealing resin 5.

The terminal 3 has a terminal outer surface 33 exposed from the resin side surface 53 of the sealing resin 5. In this embodiment, the terminal outer surface 33 is flush with the resin side surface 53. With such a configuration, when the semiconductor device A10 is mounted on the circuit board, the terminal outer surface 33 promotes the formation of solder fillets, so that the bonding strength of the semiconductor device A10 to the circuit board can be improved.

The terminal 3 is formed with a terminal projecting portion 35 that is flush with the terminal main surface 31 and projects from the terminal inner surface 34 toward the die pad 1. By adopting such a configuration, both the inner side surface 34 of the terminal and the terminal intermediate surface 352 of the terminal protrusion 35 are covered with the sealing resin 5, and the terminal 3 is supported by the sealing resin 5 by the terminal protrusion 35. It will be in a state of being. Therefore, the terminal protrusion 35 can prevent the terminal 3 from falling off from the sealing resin 5.

The die pad 1 and the terminal 3 are provided with an interior plating layer 61 in contact with either the mounting surface 11 or the terminal main surface 31. The interior plating layer 61 can protect the die pad 1 from thermal shock and the like when the semiconductor element 2 is mounted on the die pad 1. In addition to this, when the wire 4 is connected to the terminal 3, the terminal 3 can be protected from thermal shock and the like.

[Second Embodiment]
The semiconductor device A20 according to the second embodiment of the present invention will be described with reference to FIGS. 12 to 16. In these figures, the same or similar elements as the above-mentioned semiconductor device A10 are designated by the same reference numerals, and duplicate description will be omitted.

The semiconductor device A20 according to the present embodiment is different from the semiconductor device A10 described above in the configuration of the die pad 1. Here, FIGS. 13 and 14 are transparent to the sealing resin 5 for convenience of understanding. The permeated sealing resin 5 in FIGS. 13 and 14 is shown by an imaginary line. Further, in FIG. 13, the wire 4 is omitted for convenience of understanding. FIG. 16 is an enlargement of the vicinity of the die pad 1 shown in FIG.

As shown in FIGS. 12, 13 and 16, in the present embodiment, the pad recess 14 of the die pad 1 is filled with the sealing resin 5. In the present embodiment, the pad recess 14 is composed of a plurality of grooves 142 like the semiconductor device A11 described above. Each groove 142 extends along either the first direction x or the second direction y. Both ends of each groove 142 intersect the other groove 142.

As shown in FIGS. 12 to 16, in the present embodiment, the pad back surface 12 of the die pad 1 has a pad central portion 121 and a pad outer peripheral portion 122. The pad central portion 121 is a rectangular portion located at the center of the semiconductor device A20 in a plan view. A pad recess 14 is formed along the outer edge of the pad central portion 121. The pad outer peripheral portion 122 is a portion located around the pad central portion 121. The pad central portion 121 and the pad outer peripheral portion 122 are separated by a pad recess 14 in a plan view. In the present embodiment, the pad outer peripheral portion 122 has a pair of first regions 122a separated from each other in the first direction x and a pair of second regions 122b separated from each other in the second direction y. The "one direction" described in the claims of the present invention refers to either the first direction x or the second direction y. The pad outer peripheral portion 122 may be configured to include only one of a pair of first regions 122a and a pair of second regions 122b. Each first region 122a has a band shape extending along the second direction y. Each second region 122b has a strip shape extending along the first direction x.

As shown in FIGS. 15 and 16, the position of the pad outer peripheral portion 122 is equal to the position of the pad central portion 121 in the thickness direction z. Further, as shown in FIGS. 13 to 16, in the present embodiment, a part of the semiconductor element 2 overlaps the pad outer peripheral portion 122 in a plan view.

As shown in FIGS. 13 and 14, in the present embodiment, a mounting surface recess 111 is formed on the edge of the mounting surface 11 of the die pad 1. The mounting surface recess 111 is recessed from the four corners of the mounting surface 11 toward the inside of the die pad 1 in a plan view. In the present embodiment, a part of the semiconductor element 2 overlaps the mounting surface recess 111 in a plan view.

As shown in FIG. 16, in the present embodiment, the pad protrusion 15 is not formed on the die pad 1. Further, as shown in FIGS. 13 to 16, in the present embodiment, the pad side surface 13 of the die pad 1 intersects both the mounting surface 11 and the pad back surface 12. In the present embodiment, the pad side surface 13 stands up from the pad back surface 12 toward the mounting surface 11 along the thickness direction z. The pad side surface 13 is a flat surface and faces either the first direction x or the second direction y.

Next, the action and effect of the semiconductor device A20 will be described.

In the semiconductor device A20, the die pad 1 is formed with a pad recess 14 recessed from the back surface 12 of the pad. The pad recess 14 is filled with a sealing resin 5. The pad back surface 12 has a pad central portion 121 and a pad outer peripheral portion 122, which are exposed from the resin back surface 52 of the sealing resin 5. The pad central portion 121 and the pad outer peripheral portion 122 are separated from each other by the pad recess 14. By adopting such a configuration, the region of the die pad 1 from the mounting surface 11 to the pad back surface 12 is divided into a plurality of regions in the thickness direction z. Therefore, the strain of the sealing resin 5 due to the thermal expansion of the die pad 1 is dispersed throughout, and the concentration of thermal stress acting on the sealing resin 5 is relaxed. In this case, a predetermined size can be secured for the surface area of the die pad 1 exposed from the sealing resin 5 by the pad central portion 121 and the pad outer peripheral portion 122. Therefore, the semiconductor device A20 can also secure heat dissipation while relaxing the concentration of thermal stress acting on the sealing resin 5.

In the semiconductor device A20, the pad recess 14 formed in the die pad 1 is filled with the sealing resin 5. By adopting such a configuration, since the die pad 1 is in a state of being supported by the sealing resin 5, it is possible to prevent the die pad 1 from falling off from the sealing resin 5.

In the semiconductor device A20, a mounting surface recess 111 is formed at the edge of the mounting surface 11 of the die pad 1. In a plan view, a part of the semiconductor element 2 overlaps the mounting surface recess 111. Further, in a plan view, a part of the semiconductor element 2 overlaps the outer peripheral portion 122 of the pad. By adopting such a configuration, the area of the semiconductor element 2 can be secured larger than that of the back surface 12 of the pad in a plan view, so that the distance between the electrode pad 211 arranged on the semiconductor element 2 and the terminal 3 is shortened. Therefore, the length of the wire 4 connecting the electrode pad 211 and the terminal 3 can be shortened, which contributes to cost reduction of the semiconductor device A20.

Further, in this case, by making the position of the pad outer peripheral portion 122 equal to the position of the pad central portion 121 in the thickness direction z, the pad central portion 121 and the pad outer peripheral portion 122 become support surfaces for the work table and the like. Therefore, when the semiconductor element 2 is mounted on the die pad 1, when the semiconductor element 2 is pressed against the die pad 1 by a collet (not shown) or the like, the semiconductor element 2 receives a reaction force uniformly from the mounting surface 11. Therefore, the bonding strength of the semiconductor element 2 with respect to the die pad 1 can be ensured.

[Third Embodiment]
The semiconductor device A30 according to the third embodiment of the present invention will be described with reference to FIGS. 17 to 22. In these figures, the same or similar elements as the above-mentioned semiconductor device A10 are designated by the same reference numerals, and duplicate description will be omitted.

The semiconductor device A30 according to the present embodiment is different from the semiconductor device A10 described above in the configurations of the plurality of terminals 3 and the sealing resin 5. Further, the semiconductor device A30 includes an outer wire 41 and an inner wire 42 instead of the wire 4. Here, FIG. 18 is transparent to the sealing resin 5 for convenience of understanding. In FIG. 18, the permeated sealing resin 5 is shown by an imaginary line. FIG. 21 is an enlargement of the vicinity of the terminal 3 shown in FIG. The cross-sectional position of FIG. 22 is the same as the cross-sectional position of FIG.

As shown in FIGS. 17 and 19 to 21, in the present embodiment, the sealing resin 5 is formed with a groove portion 54 recessed from the resin back surface 52 and penetrating each terminal 3. In the present embodiment, the groove portions 54 are formed at four positions, and each of the groove portions 54 is along either the first direction x or the second direction y.

As shown in FIGS. 17 and 20, in the present embodiment, each terminal 3 has an external terminal 301 located outside the groove 54 and an inside (die pad 1 side) located inside the groove 54. Includes terminal 302. The external terminal 301 and the internal terminal 302 are separated from each other by a groove 54. The external terminal 301 and the internal terminal 302 constitute the first terminal 3a and the second terminal 3b, respectively.

As shown in FIGS. 17 to 21, the external terminal 301 has a terminal first main surface 311 and a terminal first back surface 321, an external terminal outer surface 331, and an external terminal inner side surface 341.

As shown in FIGS. 18, 20, and 21, the terminal first main surface 311 faces the same direction as the mounting surface 11 of the die pad 1. An external wire 41 is connected to the terminal first main surface 311. The external wire 41 connects the electrode pad 211 of the semiconductor element 2 and the terminal first main surface 311. The outer wire 41 is made of a metal material such as Au. Further, the terminal first main surface 311 is provided with an interior plating layer 61 in contact with the terminal first main surface 311. The outer wire 41 is in contact with the interior plating layer 61.

As shown in FIGS. 17, 20, and 21, the terminal first back surface 321 faces in the same direction as the pad back surface 12 of the die pad 1 and is exposed from the sealing resin 5. The terminal first back surface 321 of the plurality of first terminals 3a and the second terminal 3b are all arranged in contact with each side of the semiconductor device A10 in a plan view. Further, the terminal first back surface 321 is provided with an exterior plating layer 62 in contact with the terminal first back surface 321.

As shown in FIGS. 14 and 19-21, the outer terminal outer surface 331 intersects both the terminal first main surface 311 and the terminal first back surface 321. In the present embodiment, the outer terminal outer surface 331 stands up from the terminal first back surface 321 toward the terminal first main surface 311 along the thickness direction z. The outer terminal outer surface 331 is exposed from the resin side surface 53 of the sealing resin 5 and faces either the first direction x or the second direction y. The outer terminal outer surface 331 is a flat surface and is flush with the resin side surface 53.

As shown in FIG. 21, the outer terminal inner side surface 341 intersects the terminal first back surface 321 and faces the side opposite to the outer terminal outer surface 331. In the thickness direction z, the upper end of the outer terminal inner surface 341 located between the terminal first main surface 311 and the terminal first back surface 321 is bent toward either the first direction x or the second direction y. is doing. The inner side surface 341 of the outer terminal is covered with the sealing resin 5.

As shown in FIG. 21, the external terminal 301 is flush with the first main surface of the terminal 311 and protrudes from the inner side surface 341 of the external terminal toward the groove 54 of the sealing resin 5. The portion 36 is formed. The external terminal protrusion 36 has an external terminal end surface 361 and an external terminal intermediate surface 362. The external terminal end surface 361 is along the thickness direction z and faces either the first direction x or the second direction y. The external terminal end surface 361 is exposed from the groove portion 54. The external terminal intermediate surface 362 faces in the same direction as the terminal first back surface 321 and intersects the external terminal end surface 361. The external terminal intermediate surface 362 is connected to the external terminal inner side surface 341 inside the external terminal 301. In the thickness direction z, the distance from the terminal first main surface 311 to the external terminal intermediate surface 362 is about half the distance from the terminal first main surface 311 to the terminal first back surface 321. The external terminal protrusion 36 is covered with the sealing resin 5 except for the external terminal end surface 361.

As shown in FIG. 18, in a plurality of external terminals 301 forming a part of a plurality of first terminals 3a arranged on one side of the semiconductor device A10 in a plan view, an external terminal protrusion of the external terminal 301 located at the center thereof. 36 is formed in a state along the second direction y. The external terminal protrusions 36 of the external terminals 301 arranged apart from the external terminal 301 located at the center in the first direction x are formed in a state of being inclined with respect to the second direction y. The external terminal protrusion 36 of the external terminal 301 is set so that the inclination with respect to the second direction y increases as the distance from the centrally located external terminal 301 in the first direction x increases. Further, as shown in FIG. 18, in the plurality of external terminals 301 forming a part of the plurality of second terminals 3b arranged on one side of the semiconductor device A10 in a plan view, the external terminals of the external terminals 301 located at the center thereof. The protruding portion 36 is formed in a state along the first direction x. The external terminal protrusions 36 of the external terminals 301 arranged apart from the external terminal 301 located at the center in the second direction y are formed in a state of being inclined with respect to the first direction x. The external terminal protrusion 36 of the external terminal 301 is set so that the inclination with respect to the first direction x increases as the distance from the centrally located external terminal 301 in the second direction y increases.

As shown in FIGS. 17, 18, 20, and 21, the internal terminal 302 has a terminal second main surface 312, a terminal second back surface 322, and an internal terminal inner side surface 342.

As shown in FIGS. 18, 20, and 21, the terminal second main surface 312 faces in the same direction as the mounting surface 11 of the die pad 1. An internal wire 42 is connected to the terminal second main surface 312. The internal wire 42 connects the electrode pad 211 of the semiconductor element 2 and the terminal second main surface 312. The inner wire 42 is made of a metal material such as Au. Further, the terminal second main surface 312 is provided with an interior plating layer 61 in contact with the terminal second main surface 312. The internal wire 42 is in contact with the interior plating layer 61.

As shown in FIGS. 17, 20, and 21, the terminal second back surface 322 faces the same direction as the pad back surface 12 of the die pad 1 like the terminal first back surface 321 and is exposed from the sealing resin 5. The terminal second back surface 322 at each terminal 3 is located between the terminal first back surface 321 and the pad back surface 12 in a plan view. Further, in the plurality of first terminals 3a and the second terminal 3b, the distance between the adjacent terminal second back surfaces 322 is set shorter than the distance between the adjacent terminal first back surfaces 321.

As shown in FIG. 21, the inner terminal inner side surface 342 intersects the terminal second back surface 322 and faces the outer terminal inner side surface 341. In the thickness direction z, the upper end of the inner terminal inner surface 342 located between the terminal second main surface 312 and the terminal second back surface 322 is bent toward either the first direction x or the second direction y. is doing. The inner side surface 342 of the internal terminal is covered with the sealing resin 5.

As shown in FIG. 21, the internal terminal 302 has an eaves-shaped internal terminal protrusion that is flush with the second main surface 312 of the terminal and protrudes from the inner side surface 342 of the internal terminal toward the groove 54 of the sealing resin 5. The portion 37 is formed. The internal terminal protrusion 37 has an internal terminal end surface 371 and an internal terminal intermediate surface 372. The internal terminal end surface 371 is along the thickness direction z and faces either the first direction x or the second direction y. The internal terminal end surface 371 is exposed from the groove 54 and faces the external terminal end surface 361 of the external terminal protrusion 36. The internal terminal intermediate surface 372 faces in the same direction as the terminal second back surface 322 and intersects the internal terminal end surface 371. The internal terminal intermediate surface 372 is connected to the internal terminal inner side surface 342 inside the internal terminal 302. In the thickness direction z, the distance from the terminal second main surface 312 to the internal terminal intermediate surface 372 is half the distance from the terminal second main surface 312 to the terminal second back surface 322. The internal terminal protrusion 37 is covered with the sealing resin 5 except for the internal terminal end surface 371.

As shown in FIG. 18, in the plurality of internal terminals 302 forming a part of the plurality of first terminals 3a arranged on one side of the semiconductor device A10 in a plan view, the internal terminal protrusions of the internal terminals 302 located at the center thereof. 37 is formed in a state along the second direction y. The internal terminal protrusions 37 of the internal terminals 302 arranged apart from the centrally located internal terminal 302 in the first direction x are formed in a state of being inclined with respect to the second direction y. The internal terminal protrusion 37 of the internal terminal 302 is set so that the inclination with respect to the second direction y increases as the distance from the centrally located internal terminal 302 in the first direction x increases. Further, as shown in FIG. 18, in the plurality of internal terminals 302 forming a part of the plurality of second terminals 3b arranged on one side of the semiconductor device A10 in a plan view, the internal terminals of the internal terminals 302 located at the center thereof. The protruding portion 37 is formed in a state along the first direction x. The internal terminal protrusions 37 of the internal terminals 302 arranged so as to be separated from the central internal terminal 302 in the second direction y are formed in a state of being inclined with respect to the first direction x. The internal terminal protrusion 37 of the internal terminal 302 is set so that the inclination with respect to the first direction x increases as the distance from the centrally located internal terminal 302 in the second direction y increases.

As shown in FIGS. 19 to 21, the groove portion 54 of the sealing resin 5 has an insulator 55 interposed between the external terminal end surface 361 of the external terminal protrusion 36 and the internal terminal end surface 371 of the internal terminal protrusion 37. Has been injected. The insulator 55 is composed of a fluid synthetic resin used for underfilling, for example.

As shown in FIG. 22, the semiconductor device A30 can simultaneously form the groove portion 54, the external terminal 301, and the internal terminal 302 by inserting the blade 81 from the resin back surface 52 after forming the sealing resin 5. can.

Next, the action and effect of the semiconductor device A30 will be described.

In the semiconductor device A30, similarly to the semiconductor device A10 described above, the die pad 1 is formed with a pad recess 14 recessed from the back surface 12 of the pad. Both the pad back surface 12 and the pad recess 14 are exposed from the resin back surface 52 of the sealing resin 5. Therefore, the semiconductor device A30 can also secure heat dissipation while relaxing the concentration of thermal stress acting on the sealing resin 5.

In the semiconductor device A30, the sealing resin 5 is formed with a groove portion 54 that is recessed from the resin back surface 52 and penetrates each terminal 3. Further, each terminal 3 is located outside the groove 54 and has the terminal first back surface 321 and is located inside the groove 54 and has the terminal second back surface 322. Includes terminal 302. By adopting such a configuration, the external terminal 301 and the internal terminal 302 are in a state of being electrically insulated, and each of them can be an independent terminal 3. The external terminal 301 has a terminal first main surface 311 and an external wire 41 is connected to the terminal first main surface 311. The internal terminal 302 has a terminal second main surface 312, and an internal wire 42 is connected to the terminal second main surface 312. Different electric signals can be passed through the outer wire 41 and the inner wire 42. Therefore, in the semiconductor device A20, the number of terminals 3 can be increased, and the semiconductor element 2 in which a denser circuit is integrated can be provided.

The external terminal 301 has an external terminal outer surface 331 exposed from the resin side surface 53 of the sealing resin 5. In the present embodiment, the outer terminal outer surface 331 is flush with the resin side surface 53. With such a configuration, when the semiconductor device A30 is mounted on the circuit board, the outer terminal outer surface 331 promotes the formation of solder fillets, so that the bonding strength of the semiconductor device A30 to the circuit board can be improved.

The external terminal 301 is formed with an external terminal protruding portion 36 that is flush with the first main surface of the terminal 311 and projects from the inner side surface 341 of the external terminal toward the groove 54 of the sealing resin 5. By adopting such a configuration, both the outer terminal inner surface 341 and the outer terminal intermediate surface 362 of the outer terminal protrusion 36 are covered with the sealing resin 5, and the outer terminal 301 is sealed by the outer terminal protrusion 36. It is in a state of being supported by the resin 5. Therefore, the external terminal protrusion 36 can prevent the external terminal 301 from falling off from the sealing resin 5.

Further, the internal terminal 302 is formed with an internal terminal protruding portion 37 that is flush with the second main surface 312 of the terminal and protrudes from the inner side surface 342 of the internal terminal toward the groove portion 54 of the sealing resin 5. By adopting such a configuration, both the inner terminal inner surface 342 and the inner terminal intermediate surface 372 of the inner terminal protrusion 37 are covered with the sealing resin 5, and the inner terminal 302 is sealed by the inner terminal protrusion 37. It is in a state of being supported by the resin 5. Therefore, the internal terminal protrusion 37 can prevent the internal terminal 302 from falling off from the sealing resin 5.

Both the external terminal end surface 361 of the external terminal protrusion 36 and the internal terminal end surface 371 of the internal terminal protrusion 37 are exposed from the groove 54 of the sealing resin 5. An insulator 55 interposed between the outer terminal end surface 361 and the inner terminal end surface 371 is injected into the groove portion 54. By adopting such a configuration, it is possible to appropriately secure the electrical insulation between the external terminal 301 and the internal terminal 302.

The present invention is not limited to the embodiments described above. The specific configuration of each part of the present invention can be freely redesigned.

A10, A11, A20, A30: Semiconductor device 1: Die pad 11: Mounting surface 111: Mounting surface recess 12: Pad back surface 121: Pad central part 122: Pad outer peripheral part 122a: First area 122b: Second area 13: Pad side surface 14: Pad recess 141: Circular groove 142: Groove 15: Pad protrusion 151: Pad end face 152: Pad intermediate surface 16: Pad diagonal member 161: Slanting material upper surface 162: Slanting material lower surface 163: Slanting material end surface 2: Semiconductor element 21 : Element main surface 211: Electrode pad 22: Element back surface 29: Bonding layer 3: Terminal 3a: First terminal 3b: Second terminal 301: External terminal 302: Internal terminal 31: Terminal main surface 311: Terminal first main surface 312 : Terminal 2nd main surface 32: Terminal back surface 321: Terminal 1st back surface 322: Terminal 2nd back surface 33: Terminal outer surface 331: External terminal outer surface 34: Terminal inner surface 341: External terminal inner surface 342: Internal terminal inner surface 35: Terminal protrusion 351: Terminal end surface 352: Terminal intermediate surface 36: External terminal protrusion 361: External terminal end surface 362: External terminal intermediate surface 37: Internal terminal protrusion 371: Internal terminal end surface 372: Internal terminal intermediate surface 4: Wire 41: External wire 42: Internal wire 5: Encapsulating resin 51: Resin main surface 52: Resin back surface 53: Resin side surface 54: Groove 55: Insulator 61: Interior plating layer 62: Exterior plating layer 81: Blade C: Center Position z: Thickness direction x: First direction y: Second direction

Claims (12)

A die pad having a mounting surface and a pad back surface that face each other in the thickness direction,
The semiconductor element mounted on the mounting surface and
Each has a terminal back surface facing in the same direction as the pad back surface, and a plurality of terminals arranged so as to surround the die pad in the thickness direction of the die pad and conducting conduction to the semiconductor element.
A semiconductor device having a resin back surface facing in the same direction as the pad back surface, and comprising the semiconductor element and a sealing resin that covers a part of each of the die pad and the plurality of terminals.
Both the back surface of the pad and the back surface of the terminal are exposed from the back surface of the resin.
The die pad is formed with a pad recess that is recessed from the back surface of the pad .
A semiconductor device in which the pad recess is filled with the sealing resin. The back surface of the pad has a pad central portion and a pad outer peripheral portion located around the pad central portion.
The semiconductor device according to claim 1, wherein the central portion of the pad and the outer peripheral portion of the pad are separated from each other by the pad recess in the thickness direction. The semiconductor device according to claim 2 , wherein the outer peripheral portion of the pad has a pair of first regions separated from each other in one direction perpendicular to the thickness direction. Prior Symbol pad peripheral portion, a pair of second regions spaced apart from each other in a direction which is perpendicular to both the thickness direction and the one direction, the semiconductor device according to claim 3. The edge of the mounting surface is formed with recesses on the mounting surface that are recessed from the four corners of the mounting surface toward the inside of the die pad in the thickness direction.
The semiconductor device according to any one of claims 2 to 4, wherein a part of the semiconductor element overlaps the mounting surface recess in the thickness direction. The semiconductor device according to claim 5 , wherein a part of the semiconductor element overlaps the outer peripheral portion of the pad in the thickness direction. The semiconductor device according to claim 6 , wherein the position of the outer peripheral portion of the pad is equal to the position of the central portion of the pad in the thickness direction. The terminal further has a terminal main surface that faces in the same direction as the mounting surface.
The semiconductor device according to any one of claims 1 to 7, further comprising a wire connecting the semiconductor element and the terminal main surface . The semiconductor device according to claim 8 , wherein the die pad and the terminal are provided with an interior plating layer in contact with either the mounting surface or the terminal main surface. The terminal further has a terminal outer surface that intersects both the terminal main surface and the terminal back surface and faces outward.
The sealing resin further has a resin side surface that intersects the resin back surface.
The semiconductor device according to claim 8 or 9 , wherein the terminal outer surface is exposed from the resin side surface. The terminal further has a terminal inner surface that intersects the terminal back surface and faces the side opposite to the terminal outer surface.
The semiconductor device according to claim 10, wherein the terminal is formed with a terminal protruding portion that is flush with the main surface of the terminal and projects from the inner surface of the terminal toward the die pad. The plurality of terminals are a plurality of first terminals arranged along a first direction that is perpendicular to the thickness direction, and a first terminal that is perpendicular to both the thickness direction and the first direction. Includes a plurality of second terminals arranged along two directions,
The semiconductor device according to claim 10 or 11 , wherein the terminal outer surface is flush with the resin side surface.

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