JP4390317B2 - Resin-sealed semiconductor package - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a leadless resin-sealed semiconductor package for sealing a semiconductor element with a resin.
[0002]
[Prior art]
With the miniaturization of portable devices, there is a demand for miniaturization of semiconductor packages. Leadless packages are now on the market as one of the satisfying packages.
6A and 6B are views showing a conventional resin-encapsulated semiconductor package, in which FIG. 6A is a side view, FIG. 6B is a bottom view, 1 is a sealing resin, 2 is a lead portion, and 20 is this sealing. A package body including a stop resin 1 and a lead portion 2. This type is a so-called QFN (Quad Flat Non leaded) package, and is a type of package in which the lead portion 2 does not protrude from the package body 20 as shown in FIG.
[0003]
As described above, the package is characterized in that the lead portion 2 does not protrude from the package body 20 and the lead portion 2 mounted on a substrate (not shown) is located on the back surface of the package body 20. However, since there are only four contact surfaces of the lead part 2 with the sealing resin 1, the contact between the lead part 2 and the sealing resin 1 is weak, and the lead part 2 may be dropped.
[0004]
FIG. 7 is a cross-sectional view of the II portion of the package body 20 in FIG. 6. However, since there is a concern about the dropout of the lead portion, many expect high adhesion of the cross-sectional shape peculiar to etching shown in FIG. The place was big.
However, considering the productivity and cost of the lead frame, it is necessary to consider the application of a stamping frame that is punched with a mold. In the stamping frame, the lead is formed by punching with a die, so that the cross-sectional shape of the lead portion 2 is substantially rectangular.
[0005]
[Problems to be solved by the invention]
Since the cross-sectional shape of the conventional resin-encapsulated semiconductor package using the stamping frame as described above is substantially quadrangular, the contact surface between the package body 20 and the lead part 2 is flat with no irregularities, The adhesion of the lead part 2 to the sealing resin is very weak. Further, after mounting on the substrate, due to the difference in thermal expansion coefficient between the semiconductor package and the substrate, stress is applied to the soldered portion of the lead portion 2, and the interface between the sealing resin 1 and the lead portion 2 having weak adhesion due to the force. There was a problem such as peeling off.
[0006]
The present invention has been made to solve such problems, and an object of the present invention is to provide a resin-sealed semiconductor package with high reliability at a low cost even in a frame processed by stamping.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a resin-sealed semiconductor package including a sealing resin and a lead portion bonded to the sealing resin, wherein the mounting surface of the lead portion is exposed. The cross-section of the lead portion is the first side defined by the mounting surface, the second side opposite to the first side, and the first side so as to form an obtuse angle with respect to the first side. A linear third and fourth sides connected to both ends of the first side, and the width of the lead portion in a direction parallel to the first side is from the first side to the second side. The third and fourth sides provide a structure that becomes wider toward the direction of the side, and the sealing resin is in contact with each of the third and fourth sides, and is from the first side. The height of the lead reaches the first width, and the width of the lead portion along the direction of the first side Between the from the height to the second side, is characterized in that it extends while the first width.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
[0013]
Embodiment 1 FIG.
First, Embodiment 1 of the present invention will be described with reference to FIG. 1 and FIG.
1A and 1B are diagrams showing a leadless type resin-encapsulated semiconductor package according to Embodiment 1 of the present invention, where FIG. 1A is a side view and FIG. The lead part 2 does not show its shape but shows its position. Referring to FIG. 1, 1 is a sealing resin, 2 is a lead portion, and 20 is a package body including the sealing resin 1 and the lead portion 2.
[0014]
2 is a bottom view showing the lead portion processed by stamping in Embodiment 1 of the present invention, and is an enlarged view of portion A in FIG. 1 (b). As shown in the shape of FIG. A concave recess 3 is provided in a portion to be bonded to the sealing resin 1. By doing so, the sealing resin 1 enters the recess 3 at the time of transfer molding, and an anchor effect is produced. Further, by doing so, it is effective to prevent the lead 2 from being pulled out by the pulling force from the package body 20 to the outside.
[0015]
Embodiment 2. FIG.
FIG. 3 is a side view showing a lead portion processed by stamping according to Embodiment 2 of the present invention, and is an enlarged view of a portion B in FIG. As described above, in order to prevent the lead portion 2 from coming off in the rear surface direction of the semiconductor package, the taper 4 is provided on the rear surface side of the package body 20 and at the corner of the mounting portion of the lead portion 2.
[0016]
Embodiment 3 FIG.
FIG. 4 is a side view showing a lead portion processed by stamping according to Embodiment 3 of the present invention, and is an enlarged view of portion B in FIG. In the third embodiment, the step 5 is provided at the corner of the mounting surface of the lead portion 2 to reduce the width of the lead portion 2 that protrudes from the back surface of the package body 20, so The lead is prevented from coming off.
[0017]
Embodiment 4 FIG.
FIG. 5 is a bottom view showing a lead portion processed by stamping according to Embodiment 4 of the present invention, and is an enlarged view of portion A in FIG. In the fourth embodiment, the lead width in the side surface direction and the lead width in the inner direction of the package body 20 are changed so as to increase the lead width in the inner direction, and the anchor effect is obtained as in the first embodiment. Can do.
[0018]
Moreover, the effect is further enhanced by using a lead in which a plurality of the first to fourth embodiments are combined.
[0019]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0020]
According to the first to fourth inventions, the adhesion between the lead portion and the sealing resin is enhanced, and the lead portion and the sealing resin are peeled off or dropped even against thermal stress after soldering to the substrate. In addition, a highly reliable resin-encapsulated semiconductor package can be provided.
[0021]
Further, according to the fifth invention, the cost can be reduced as the productivity of the frame is improved.
[Brief description of the drawings]
FIGS. 1A and 1B are a side view and a bottom view showing a resin-encapsulated semiconductor package according to a first embodiment of the present invention.
FIG. 2 is a bottom view showing a lead portion of the resin-encapsulated semiconductor package according to the first embodiment of the present invention.
FIG. 3 is a side view showing a lead portion of a resin-encapsulated semiconductor package in Embodiment 2 of the present invention.
FIG. 4 is a side view showing a lead portion of a resin-encapsulated semiconductor package in Embodiment 3 of the present invention.
FIG. 5 is a bottom view showing a lead portion of a resin-encapsulated semiconductor package according to a fourth embodiment of the present invention.
6A and 6B are a side view and a bottom view showing a conventional resin-encapsulated semiconductor package.
7 is a cross-sectional view taken along line II of the package body in FIG. 6. FIG.
[Explanation of symbols]
1 Sealing resin 2 Lead part 3 Recess 4 Taper 5 Step

Claims (1)

In a resin-encapsulated semiconductor package that includes a sealing resin and a lead portion that is bonded to the sealing resin, and the mounting surface of the lead portion is exposed,
The cross-section of the lead portion includes the first side defined by the mounting surface, the second side opposite to the first side, and the obtuse angle with respect to the first side . Straight third and fourth sides connected to each of the ends of one side ;
The third and fourth sides provide a structure in which the width of the lead portion in the direction parallel to the first side increases toward the second side from the first side,
The sealing resin is in contact with each of the third and fourth sides,
The spread reaches a first width at a certain height from the first side,
The width of the lead portion along the direction of the first side extends with the first width between the height and the second side ,
A resin-encapsulated semiconductor package.

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