Semiconductor device

Abstract

The invention provides a semiconductor device in which a lead frame can be easily bonded to an element. A semiconductor device 1 is provided with: an element 3; a protective member (5) provided in a frame shape along the surface (31a) of the element (3); and a lead frame 4 provided on the surface 31a of the element 3 and ultrasonically bonded to the surface 31a by being pressed by a bonding tool 9; one end of the lead frame (4) provided on the surface (31a) has an upward extending portion (41). The lead frame (4) is formed in a plate-like structure extending from one end to the other end, the extension portion (41) has a first extension portion (411) along the width direction at one end of the lead frame (4), and a second extension portion (412) and a third extension portion (413) provided along a pair of long sides of the lead frame (4), and the first extension portion, the second extension portion, and the third extension portion are preferably formed in a curved shape.

Description

Technical Field

[0001] The present invention relates to a semiconductor device. Background Art

[0002] Conventionally, when electrically connecting components such as semiconductor chips to other semiconductor chips or substrates, the following techniques are known: for example, one end of a metal component such as a bonding wire or a lead frame is joined to the component, and the other end is joined to another chip or substrate. As one method of joining a metal component to a component, the following technique has been proposed: placing the metal component on the component and pressing it from above with a joining tool that vibrates ultrasonically, thereby performing crimping by ultrasonic bonding (for example, see Patent Document 1).

[0003] [Prior Art Documents]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-56426 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] When ultrasonic bonding is used to bond a component to a lead frame, ultrasonic vibrations are transmitted to the lead frame. Therefore, a resin protection member is provided to protect the surface of the component from the influence of the joining tool. When the lead frame is joined to the component by ultrasonic bonding, there is a concern that the lead frame may interfere with the protection member and affect the surface of the component.

[0008] [Technical Means for Solving the Problems]

[0009] (1) The present invention relates to a semiconductor device (for example, semiconductor device 1), having: a component (for example, component 3); a protection member (for example, protection member 5) provided in a frame shape along the outer periphery of the surface of the aforementioned component (for example, surface 31a); and a lead frame (for example, lead frame 4) provided on the aforementioned surface of the aforementioned component and ultrasonically bonded to the aforementioned surface by being pressed by a joining tool (for example, joining tool 9); one end of the aforementioned lead frame provided on the aforementioned surface has an extension portion (for example, extension portion 41) that avoids the aforementioned protection member and extends upward.

[0010] (2) Preferably, the lead frame is formed in a plate-like structure extending from one end to the other end, and the extending portion has: a first extending portion (for example, the first extending portion 411) along the width direction at one end of the lead frame, and a second extending portion (for example, the second extending portion 412) and a third extending portion (for example, the third extending portion 413) provided along a pair of long sides of the lead frame; the first extending portion, the second extending portion and the third extending portion are formed in a curved shape.

[0011] (3) Preferably, it has a fourth extending portion (for example, the fourth extending portion 414) disposed opposite to the first extending portion and continuous with the other end of the lead frame.

[0012] (Advantages of the Invention)

[0013] According to the above (1), since the extending portion extends upward to avoid the protection component, even if burrs are formed at the end of the lead frame, it is difficult for the lead frame to interfere with the protection component. Since the end of the lead frame does not interfere with the protection component, thus, even when pressing the lead frame with a tool for ultrasonic bonding using ultrasonic vibration, the influence of the vibration will be reduced, and scratches and imprints are not likely to appear on the surface of the component.

[0014] According to the above (2), the first extending portion, the second extending portion and the third extending portion are bent and extended, so that it is easy to form the extending portion in a manner that avoids the protection component.

[0015] According to the above (3), by providing the fourth extending portion on the side where the other end of the lead frame extends, it is also possible to avoid the protection component frame located on the extending side of the lead frame, and it will be more difficult for scratches or imprints to appear on the surface of the component. Description of the Drawings

[0016] Figure 1 is a plan view of a semiconductor module provided with the semiconductor device of the present embodiment.

[0017] Figure 2 is a perspective view of the semiconductor device of the present embodiment.

[0018] Figure 3 is a cross-sectional schematic view of the semiconductor device of the present embodiment. Detailed Embodiments

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As Figures 1 to 3 shown, the semiconductor device 1 is a so-called semiconductor chip having a component 3, a protection component 5, and a lead frame 4. In the semiconductor device 1, the lead frame 4 and the component 3 are joined by an ultrasonic bonding device 90.

[0020] The ultrasonic bonding device 90 includes: a base (not shown) on which an ultrasonic oscillator, a horn extending in an arm shape, and an object to be bonded are placed; and a bonding tool 9 (see Figure 3 ); it is a device that bonds an object to be bonded such as a semiconductor chip by ultrasonic vibration. The horn (not shown) transmits while expanding the vibration amplitude of the ultrasonic wave. The bonding tool 9 is connected to the tip of the horn, and the ultrasonic vibration is transmitted to the bonding tool 9 through the horn. The object to be bonded by the ultrasonic bonding device 90 is not limited to metal components, but in this embodiment, the objects to be bonded are the substrate 2 and the element 3 of the semiconductor chip. The bonding tool 9 ultrasonically bonds the element 3 to the substrate 8 while pressing the element 3.

[0021] The semiconductor device 1 is provided on the substrate 8. As the substrate 8, a direct bond copper (DCB) substrate 8 in which copper is directly bonded to a ceramic plate is used. Additionally, as Figure 1 shown, the substrate 8 is further provided on the copper base 80 with a bonding layer 83 interposed therebetween. The semiconductor device 1 is fixed to the housing 81 in a state where the element 3 and the lead frame 4 are provided on these substrates 8 and the base 80, thereby constituting the semiconductor module 800.

[0022] The element 3 is formed in a layered structure by sandwiching an element body 30 with electrode portions 31. The element body 30 is made of, for example, SiC (silicon carbide). The electrode portions 31 are flat metal plates provided on the upper and lower surfaces of the element body 30. The element 3 is substantially rectangular parallelepiped-shaped.

[0023] The protective member 5 is provided on the surface 31a of the element 3 as Figure 2 shown, and is made of a resin such as polyimide, for example. The protective member 5 is provided to prevent the surface 31a of the element 3 from being damaged or scratched due to the vibration of the bonding tool 9. The protective member 5 is formed in a frame shape along the outer edge of the periphery of the surface 31a of the element 3.

[0024] The lead frame 4 is a plate-shaped member that extends from one end to the other end and is substantially rectangular in plan view, and is provided on the surface 31a of the element 3. The lead frame 4 is made of copper, is pressed by the bonding tool 9, and is ultrasonically bonded to the surface 31a. One end refers to the side that is bonded to the surface 31a, and the other end refers to the side opposite to the one end. The lead frame 4, as Figure 2 shown, includes a main body portion 40 and an extension portion 41.

[0025] The main body portion 40 is formed to be substantially rectangular in plan view and is connected to a conductive component such as the element 3 and other semiconductor elements or substrates. The main body portion 40 has a bonding surface 40a that is bonded to the surface 31a on one end side thereof.

[0026] The extension part 41 is a part that extends upward from one end of the main body part 40 to the outside, that is, in a direction away from the periphery of the main body part 40, and is arranged so as to avoid the protection member 5. The extension part 41 has a first extension part 411, a second extension part 412, a third extension part 413 and a fourth extension part 414.

[0027] The first extension part 411 is arranged along the width direction at one end of the main body part 40. The width direction refers to the short side direction of the main body part 40. The first extension part 411 starts from one end of the main body part 40 and extends toward the opposite side of the other end of the main body part 40, and is formed to bend upward as Figure 3 shown.

[0028] The second extension part 412 and the third extension part 413 are arranged along a pair of long sides of the main body part 40 as Figure 2 shown, and extend along the outside in the width direction of the main body part 40, that is, in a direction away from the long sides, and are formed to bend upward. The second extension part 412 and the third extension part 413 are arranged to face each other.

[0029] The fourth extension part 414 is arranged opposite to the first extension part 411 and is continuous with the other end of the main body part 40. The fourth extension part 414 slopes upward from the other end of the main body part 40 to avoid the protection member 5, bends at a position at a predetermined distance from the joint surface with the surface 31a of the main body part 40, and is continuous with the main body part 40.

[0030] The first extension part 411, the second extension part 412, the third extension part 413 and the fourth extension part 414 are arranged to respectively surround the joint surface 40a of the main body part 40 and extend outward from the four sides of the outer periphery of the joint surface 40a. A gap 415 of about 90 degrees is respectively formed between the first extension part 411 and the second extension part 412, between the first extension part 411 and the third extension part 413, between the second extension part 412 and the fourth extension part 414, and between the third extension part 413 and the fourth extension part 414.

[0031] As Figure 3 shown, when the bonding tool 9 ultrasonically bonds one end of the main body part 40 and the surface 31a of the component 3, if the main body part 40 and the surface 31a are pressed, the main body part 40 is subjected to ultrasonic vibration and generates minute vibration, but the extension part 41 will not interfere with the protection member 5. Since the lead frame 4 is composed of a metal plate-like member, when cutting the metal, a protrusion called a burr may be formed downward in the shearing direction of the plate surface of the lead frame 4. These burrs are irregular and the ends are sharp, and may interfere with the protection material 5. However, if the extension part 41 is formed to extend upward, the position of the outer edge of the lead frame can be set to avoid the protection member 5.

[0032] According to the present embodiment, the following effects can be achieved.

[0033] (1) The semiconductor device 1 includes: an element 3; a protection member 5 disposed in a frame shape along the outer periphery of the surface 31a of the element 3; and a lead frame 4 disposed on the surface 31a of the element 3 and ultrasonically bonded to the surface 31a by being pressed by a bonding tool 9. One end of the lead frame 4 disposed on the surface 31a has an extension portion 41 extending upward. Since the extension portion 41 extends upward and avoids the protection member 5, even if burrs are formed at the end of the lead frame 4, it is difficult for the lead frame 4 to interfere with the protection member 5. Since the end of the lead frame 4 does not interfere with the protection member 5, thus, even when the lead frame is pressed by a tool for ultrasonic bonding using ultrasonic vibration, the influence of the vibration is reduced, and scratches and imprints are not easily formed on the surface of the element.

[0034] (2) According to the present embodiment, the lead frame 4 is formed in a plate-like structure extending from one end to the other end. The extension portion 41 includes: a first extension portion 411 in the width direction at one end of the lead frame 4, and second and third extension portions 412 and 413 disposed along a pair of long sides of the lead frame 4; the first extension portion, the second extension portion, and the third extension portion are formed in a curved shape. Since the first extension portion 411, the second extension portion 412, and the third extension portion 413 are curved and extended, it is easy to form the extension portion 41 in a manner that avoids the protection member 5. In addition, by disposing the first extension portion 411, the second extension portion 412, and the third extension portion 413 around one end of the lead frame 4, the pressing position of the bonding tool 9 can be determined to press one end of the lead frame 4 surrounded by these extension portions by the bonding tool 9.

[0035] (3) According to the present embodiment, it is configured to include a fourth extension portion 414 disposed opposite to the first extension portion 411 and continuous with the other end of the lead frame 4. By disposing the fourth extension portion 414 on the side where the other end of the lead frame 4 extends, it is also possible to avoid the frame of the protection member 5 located on the extension side of the lead frame 4, and it is more difficult for scratches or imprints to appear on the surface 31a of the element 3.

[0036] In addition, the present invention is not limited to the above embodiments, and various changes, improvements, etc. that can achieve the object of the present invention are included in the present invention. In the above embodiment, although the first extension portion 411, the second extension portion 412, and the third extension portion 413 are curved, like the fourth extension portion 414, they can be inclined upward in a straight line shape.

[0037] Reference numerals

[0038] 1 Semiconductor device

[0039] 2 Substrate

[0040] 3 Element

[0041] 4 Lead Frame

[0042] 5 Protection Component

[0043] 9 Joining Tool

[0044] 6 Resin Plate

[0045] 31a Surface

[0046] 41 Extension

[0047] 411 First Extension

[0048] 412 Second Extension

[0049] 413 Third Extension

[0050] 414 Fourth Extension

Claims

1. A semiconductor device having: an element; a protection member disposed in a frame shape along the outer periphery of the surface of the aforementioned element; and a lead frame disposed on the aforementioned surface of the aforementioned element and ultrasonically bonded to the aforementioned surface by being pressed by a bonding tool; one end of the aforementioned lead frame disposed on the aforementioned surface has an extension portion extending upward.

2. The semiconductor device according to claim 1, wherein, The aforementioned lead frame is formed in a plate shape extending from the aforementioned one end to the other end, and the aforementioned extension portion has: a first extension portion along the width direction at the aforementioned one end of the aforementioned lead frame, and a second extension portion and a third extension portion disposed along a pair of long sides of the aforementioned lead frame; the aforementioned first extension portion, the aforementioned second extension portion, and the aforementioned third extension portion are formed in a curved shape.

3. The semiconductor device according to claim 2, wherein There is a fourth extension portion disposed opposite to the aforementioned first extension portion and continuous with the aforementioned other end of the aforementioned lead frame.

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