Semiconductor device

Abstract

To provide a semiconductor device capable of improving the mechanical strength between a mounting portion of a semiconductor chip and a lead and suppressing the occurrence of cracks in a sealing resin.SOLUTION: A semiconductor device 100 includes: a semiconductor chip 110; a die pad 101 on which the semiconductor chip 110 is mounted; a plurality of leads 102 arranged at a distance around the die pad 101 in a plan view; a hanging portion 103 formed integrally with the die pad 101 and arranged so as to overlap the leads 102 in a side view; and a sealing resin 140 which forms an outer shape such that at least part of the plurality of leads 102 are exposed.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In recent years, with the increasing functionality of portable electronic devices such as mobile phones and mobile devices, there has been a growing demand for miniaturization and thinning of semiconductor devices used in such portable electronic devices.

[0003] A general package of a semiconductor device formed by molding with an epoxy resin has a structure in which a semiconductor chip is mounted on a die pad that is a part of a lead frame and covered with an epoxy resin to form an outer shape. One form of a package having such a structure is a DFN (Dual Flat Non-leaded) package. The DFN package is generally manufactured by dicing a lead frame formed with a sealing resin into individual pieces by cutting with a dicing device. As a result, the lead end face of the DFN package has a structure that is exposed on the same plane as the side face of the sealing resin. For this reason, the DFN package can reduce the mounting area of the semiconductor device as compared with a semiconductor device in which the leads protrude from the side face of the sealing resin. A package having the same structure as the DFN package and having external leads exposed in four directions of the sealing resin is a QFN (Quad Flat Non-leaded) package.

[0004] For example, Patent Document 1 describes a semiconductor device of a DFN package in which a notch is formed at the tip of a lead and then diced into individual pieces, and a manufacturing method thereof.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In one aspect of the present invention, an object is to provide a semiconductor device capable of improving the mechanical strength between a die pad and leads and suppressing the occurrence of cracks in a sealing resin.

Means for Solving the Problems

[0007] A semiconductor device according to an embodiment of the present invention includes a semiconductor chip, a die pad on which the semiconductor chip is mounted, a plurality of leads spaced apart around the die pad in a plan view, a suspension portion formed integrally with the die pad and arranged to overlap the leads in a side view, a sealing resin formed with an outer shape such that at least a part of the plurality of leads is exposed, and has.

Effects of the Invention

[0008] According to one aspect of the present invention, it is possible to provide a semiconductor device capable of improving the mechanical strength between a die pad and leads and suppressing the occurrence of cracks in a sealing resin.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described in detail while comparing with the conventional structure with reference to the drawings.

[0011] In the drawings, the same reference numerals are given to the same components, and duplicate explanations may be omitted.

[0012] Also, the X-axis, Y-axis, and Z-axis shown in the drawings are assumed to be perpendicular to each other. The Z-axis direction may be referred to as the "height direction" or the "thickness direction". The surface on the +Z direction side of each member may be referred to as the "front surface" or the "upper surface", and the surface on the -Z direction side may be referred to as the "back surface" or the "lower surface". "Plan view" means looking through each member from the +Z direction side toward the -Z direction side. "Side view" means looking through each member from the +Y direction side toward the -Y direction side.

[0013] Furthermore, the drawings are schematic, and the ratios of width, depth, and thickness are not as shown. The quantity, position, shape, structure, size, etc. of each member are not limited to the embodiments shown below, and can be the preferred quantity, position, shape, structure, size, etc. for carrying out the present invention.

[0014] FIG. 5 is a schematic top view (perspective view) of a conventional semiconductor device. FIG. 6 is a schematic side view (perspective view) of the semiconductor device shown in FIG. 5.

[0015] As shown in FIGS. 5 and 6, in a semiconductor device 900 of a conventional DFN package, electrodes on the surface of a semiconductor chip 910 fixed to a rectangular die pad 901 with a conductive adhesive 920 and a plurality of leads 902 are electrically connected by conductive wires 930 respectively. Further, near the center of the short side of the die pad 901, suspension portions 903 extending in the ±Y directions are integrally formed. The encapsulation resin 940 forms the outer shape of the semiconductor device 900 such that at least a part of the plurality of leads 902 is exposed. The die pad 901 and the plurality of leads 902 are formed of a metal material such as a copper alloy.

[0016] In a semiconductor device 900 of a conventional DFN package as shown in FIGS. 5 and 6, since there is no metal material in regions Y1 and Y2 in the Y direction between the die pad and the leads, it depends only on the rigidity of the encapsulation resin 940, and the mechanical strength is low.

[0017] Since the mechanical strength is low in regions Y1 and Y2, warping and twisting may occur against external impacts, vibrations, stresses, etc., and there is a risk of cracks in the semiconductor device, poor mounting on the mounting substrate, and characteristic variations in the semiconductor element. For this reason, it may be difficult to handle the semiconductor device itself. The same applies to other packages such as QFN packages where there are regions without metal material.

[0018] Therefore, the semiconductor device in an embodiment of the present invention has a shape such that the suspension portion overlaps the lead in a side view. As a result, a metal material exists in regions Y1 and Y2 between the die pad and the lead, the mechanical strength between the die pad and the lead can be improved, and the occurrence of cracks in the encapsulation resin can be suppressed.

[0019] (An example of the embodiment) FIG. 1 is a schematic top view (perspective view) of a semiconductor device in an embodiment of the present invention.

[0020] As shown in FIG. 1, the semiconductor device 100 in the embodiment of the present invention includes a semiconductor chip 110, a die pad 101, a plurality of leads 102, a suspension portion 103, and a sealing resin 140.

[0021] The die pad 101 is a mounting portion of the semiconductor chip 110 and is rectangular in plan view. In plan view, the tip portions 102a of the plurality of leads 102 are arranged at a certain distance from two opposite sides of the die pad 101 in the +X direction and the -X direction.

[0022] The suspension portion 103 extends from the four corners of two sides of the die pad 101 in the +Y direction and the -Y direction. The suspension portion 103 includes a suspension portion member 103a that is exposed on the side surface of the sealing resin 140, and a suspension portion member 103b that is orthogonal to the suspension portion member and extends in the +X direction and the -X direction along the side surface of the sealing resin 140 to the corner portion 140a of the sealing resin 140. Here, the suspension portion member 103b extends to the side of the corner portion 140a rather than the position of the tip portion 102a of the lead 102 that extends in the same direction as the suspension portion member 103b in the +X direction and the -X direction. As a result, in the Y-direction regions Y1 and Y2 between the die pad 101 and the lead 102 in plan view, the suspension portion member 103b exists, so that the mechanical strength of the semiconductor device 100 can be improved.

[0023] In this embodiment, the suspension portion 103 can be provided with the suspension portion member 103a and the suspension portion member 103b by performing etching processing with a chemical solution or press processing for shearing so as to have a predetermined shape.

[0024] Note that the die pad 101, the plurality of leads 102, and the suspension portion 103 are formed of a copper alloy of the same material in this embodiment and have an integrated lead frame structure. FIG. 1 shows one combination for forming one semiconductor device. Finally, it is divided into individual semiconductor devices.

[0025] The semiconductor chip 110 is a semiconductor chip for operating the semiconductor device 100 and is mounted on the upper surface of the die pad 101. The conductive wire 130 electrically connects a plurality of electrode pads (not shown) formed on the upper surface of the semiconductor chip 110 and the plurality of leads 102. In the present embodiment, the conductive wire 130 is a gold wire.

[0026] FIG. 2 is a schematic cross-sectional view taken along line II-II shown in FIG. 1.

[0027] As shown in FIG. 2, the lower surface of the die pad 101 is exposed from the encapsulating resin 140 in terms of improving the heat dissipation property of the semiconductor chip 110. The suspension member 103a constituting the suspension portion 103 extends from the die pad 101 in the +Y direction and the -Y direction and is exposed on the side surface of the encapsulating resin 140. The upper surface of the suspension member 103a is flush with the upper surface of the die pad, and the thickness of the suspension member 103a is formed thinner than the thickness of the die pad 101. As a result, the encapsulating resin 140 enters under the suspension member 103a, and the die pad 101 can be prevented from falling off from the encapsulating resin 140.

[0028] In a semiconductor device of a conventional DFN package in which the lower surface of the die pad is exposed from the encapsulating resin, it is common to form a reduced thickness around the lower surface of the die pad so that the encapsulating resin enters the lower part around the die pad and the die pad does not fall off from the encapsulating resin. In such a structure, there is a risk that the load and ultrasonic waves during the formation of the conductive wire may not be sufficiently transmitted to the semiconductor chip at the portion where the thickness of the die pad is thin. Therefore, it is necessary to avoid the portion where the thickness of the die pad is thin and arrange the electrode pads of the semiconductor chip at the thick portion. In the present embodiment, since the suspension portion 103 has a function of preventing the die pad from falling off, the entire die pad can be made to have the same thickness. For this reason, compared with the die pad of the semiconductor device of the above-described conventional DFN package, the electrode pads can be arranged more on the outer peripheral side of the semiconductor chip, and the distance between the electrode pads of the semiconductor chip and the leads can be shortened. As a result, it is possible to reduce the amount of the conductive wire made of gold or the like used, and the manufacturing cost of the semiconductor device can be suppressed.

[0029] FIG. 3 is a schematic side view (perspective view) of the semiconductor device shown in FIG. 1.

[0030] As shown in FIG. 3, the suspension member 103b is orthogonal to the suspension member 103a and extends along the side surface of the encapsulating resin 140 in the direction of the corner portion 140a of the encapsulating resin 140. The suspension member 103b extends to a position overlapping the lead 102 extending in the same direction as the suspension member 103b in a side view. The lower surface and the end surface of the lead 102 are exposed from the encapsulating resin 140 and function as outer leads.

[0031] Thus, the semiconductor device 100 can improve the mechanical strength of the semiconductor device by arranging the suspension member 103b, which is a metal material, between the die pad 101 and the lead 102.

[0032] The upper surface of the suspension member 103b is formed flush with the upper surfaces of the suspension member 103a and the die pad 101. Also, the thickness of the suspension member 103b is the same as that of the suspension member 103a and is formed thinner than the thickness of the die pad 101. As a result, a structure is formed in which the sealing resin 140 enters the lower surfaces of the suspension member 103a and the suspension member 103b that constitute the suspension portion 103, and the die pad 101 can be prevented from falling off from the sealing resin 140.

[0033] In this embodiment, the suspension portion 103 is formed by etching with a chemical solution or press working so that the thicknesses of the suspension member 103a and the suspension member 103b become a predetermined thickness with respect to the upper surface of the die pad 101.

[0034] Here, a method for manufacturing the semiconductor device 100 will be described with reference to FIG. 3.

[0035] As shown in FIG. 3, the semiconductor chip 110 is fixed to the upper surface of the die pad 101 with the conductive adhesive 120. Next, a plurality of electrode pads (not shown) formed on the upper surface of the semiconductor chip 110 and the upper surfaces of the plurality of leads 102 are electrically connected with the conductive wires 130. Then, it is clamped with a mold (not shown), a sealing resin is injected into the mold and solidified to seal, and then it is divided into individual pieces by cutting with a dicing device, and the semiconductor device 100 as shown in FIG. 3 is manufactured.

[0036] As a result, in the semiconductor device 100, in a side view from the Y direction, by arranging the suspension member 103b, which is a metal material, between the die pad 101 and the lead 102, the mechanical strength can be improved and the occurrence of cracks in the sealing resin can be suppressed.

[0037] (Modification of the embodiment) FIG. 4 is a schematic top view (perspective view) of a semiconductor device according to a modification of the embodiment of the present invention.

[0038] In a modified example of the embodiment of the present invention, the semiconductor device 200 has suspension portions 203 extending from two corners that are symmetric with respect to the center of the die pad 101. The rest is the same as the semiconductor device 100.

[0039] Thereby, in the semiconductor device 200, when viewed from the side in the Y direction, by disposing a suspension portion member 203b made of a metal material between the die pad 101 and the lead 102, the mechanical strength can be improved, and the occurrence of cracks in the encapsulating resin can be suppressed.

[0040] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and designs and the like within the scope without departing from the gist of the present invention are also included.

[0041] For example, in the present embodiment, the package of the leadless type semiconductor device is a DFN package, but it is not limited to this, and other packages may be used. Further, although the lower surface of the die pad is exposed from the encapsulating resin, the die pad may be embedded inside the encapsulating resin. The materials of the die pad, the suspension portion, and the lead are copper alloys, but it is not limited to this, and other metal materials may be used.

Description of Reference Numerals

[0042] 100, 200 Semiconductor device 101 Die pad (mounting portion for semiconductor chip) 102 Lead 102a Tip portion 103, 203 Suspension portion 103a, 203a Suspension portion member 103b, 203b Suspension portion member 110 Semiconductor chip 120 Conductive adhesive 130 Conductive wire 140 Encapsulating resin 140a Corner portion Y1, Y2 Regions

Claims

1. A semiconductor chip, a die pad on which the semiconductor chip is mounted, a plurality of leads spaced apart around the die pad in a plan view, a suspension portion formed integrally with the die pad and arranged to overlap the leads in a side view, a sealing resin forming an outer shape such that at least a part of the plurality of leads is exposed, and a semiconductor device characterized by having the above.

2. The semiconductor device according to claim 1, wherein an upper surface of the suspension portion is flush with an upper surface of the die pad, and a thickness of the suspension portion is formed thinner than a thickness of the die pad.

3. The semiconductor device according to claim 1 or 2, wherein the suspension portion is formed at four corners of the die pad.

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