JPH04277673A - Semiconductor device - Google Patents

Abstract

PURPOSE:To smooth positioning and improve electric reliability while improving an yield. CONSTITUTION:To constitute a semiconductor device A of a mold sealing part 12 mounted on a lead frame die pad 10 and having a built-in semiconductor chip 11, a plurality of leads 13 to be outwardly led out from four peripheral surfaces of a mold sealing part 12 respectively and a suspending lead 14 led out so as to be exposed from the die pad 10 to the outside of the mold seal part 12 while having a positioning reference part 14a whose tip part is recessedly notched. To this positioning reference part, for instance, a positioning pin of a mounting hand to be used for conveynace of the semiconductor device can be positioned only by being engaged so as to be able to perform smooth positioning working. Consequently, it has an effect to improve an yield in each process requiring positioning.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which an IC chip is molded.

0002

[Background Art] In semiconductor device processes, miniaturization and
In order to commercialize molded semiconductor devices that are becoming thinner and have more pins, external leads have been forced to become finer pitched and extremely thin.Furthermore, in the subsequent semiconductor mounting process, surface mounting and Mounting using what is called solder reflow is becoming popular.

Conventionally, this type of semiconductor device includes a flat pack type as shown in FIGS. 7 and 8, for example.

[0004] In the figure, the symbol a indicates a semiconductor device,
This semiconductor device is manufactured by mounting an IC chip on a well-known lead frame, performing wire bonding, and forming a mold part 1 by transfer molding with epoxy resin, and then cutting or etching so that each lead 2 becomes independent. Manufactured with. Also,
In such a semiconductor device, generally, as shown in FIG.
It is fixed by solder reflow.

[0005] Furthermore, in conventional semiconductor devices used for surface mounting, external leads are drawn out from two or all four opposing sides, and the leads are formed and processed into a gull-wing shape, as shown in the example above. In addition, for semiconductor devices of the type that can be pulled out from all four sides, it is known that the molded product has resin protrusions called bumpers at the four corners that have a protective function for the leads. It is being

However, since such semiconductor devices do not have reference parts for positioning, they require high-precision lead processing, high-precision mounting, high-quality soldering without solder bridges, and high reliability. This method had various problems, including the inability to perform high-quality electrical property tests.

[0007] Therefore, as an example of an improved flat package type semiconductor device having a positioning function, there is
A conventional technique described in Japanese Patent No.-13754 is known. This semiconductor device is equipped with a plurality of lead terminals having holes perpendicular to the mounting surface, and when mounting on a printed circuit board, the positioning pins of the mounting hand can be inserted into the holes. , which has a positioning effect.

[0008]

[Problems to be Solved by the Invention] However, in the conventional improved example described above, when the positioning pin of the mounted hand is inserted into the hole formed in the lead terminal and then attempted to be removed, the lead terminal There is a problem in that the opening edge of the hole in the lead terminal gets caught in the positioning pin, making it difficult for the positioning pin to come out.

[0009] Furthermore, with the progress of miniaturization and increase in the number of pins, there has been a problem in that the lead terminals used for positioning and the leads for electrical connection tend to come into contact with each other.

The present invention has been devised by focusing on the problems of the prior art, and includes, for example, a smooth positioning function when handling with a mounted hand, etc., and a reliable function when cutting a lead frame. The object is to obtain a semiconductor device having a positioning function.

[0011]

[Means for Solving the Problems] Accordingly, the present invention provides a method in which a semiconductor element, a die pad on which the semiconductor element is mounted, and an inner lead disposed around the die pad are mold-sealed, and the die pad is suspended. In a semiconductor device in which a tip of a lead is exposed from the mold sealing part,
The solution to this problem is that a positioning reference portion is formed at the tip of the exposed suspension lead in a concave shape notched inward.

0012

[Operation] The positioning reference part is in the shape of a U-shape or a half-moon, for example, with a concave cutout inward at the tip of the exposed hanging lead, so positioning can be performed simply by abutting the positioning pin with the mounted hand. becomes. Therefore, the positioning pin can smoothly come into contact with and leave the positioning pin.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Details of a semiconductor device according to the present invention will be explained below based on embodiments shown in the drawings.

(First Embodiment) FIGS. 1 to 4 show a first embodiment of the present invention. In the figure, A is a semiconductor device, and a mold sealing part 12 houses a semiconductor element (IC chip) 11 mounted on a die pad 10 of a lead frame.
A plurality of leads (outer leads) 13 to 1 are led outward from the four circumferential surfaces of the mold sealing part 12, respectively.
3, which is led out from the die pad 10 so as to be exposed to the outside of the mold sealing part 12, and whose tip is concave (arc-shaped)
The suspension lead 14 has a positioning reference portion 14a cut out in the middle.

FIG. 3 shows a lead frame used in the semiconductor device of this embodiment. As shown in the figure,
The hanging lead 14 is connected to the four corners of the square die pad 10.
As shown in FIG. 4, it is bifurcated at a position where the positioning reference portion 14a can be exposed at the four corner portions of the mold sealing portion 12 that will be formed later. The lead frame body 15 is formed so as to be divided into two parts. Further, on the outside of the die pad 10, there is an inner lead 13a that constitutes a part of a plurality of leads 13 arranged facing each of the four sides of the die pad 10, and the inner lead 13a is sealed in the mold sealing part 12. be done. In the figure, 16 is a dam bar that prevents mold resin from flowing out between the leads 13 during molding, and 15a is a feed guide hole of the lead frame 15.

After the mold sealing portion 12 is formed in this manner, the leads 13, dam bars 16, and hanging leads 14 may be cut at desired positions. Note that the cutting position of the suspension lead 14 is the position shown by the broken line in FIG.

With this configuration, positioning can be ensured simply by abutting the positioning pin 17 of the mounting hand against the positioning reference portion 14a, for example, as shown in FIG. Furthermore, as shown in FIG. 2, since the end of the lead 13 bent into a gullwing shape (the part connected to the conductor pattern of the printed circuit board) and the positioning reference part 14a are at different heights, for example, solder bridges may occur. This prevents electrical signals from leaking to the die pad 10 side or the like.

(Second Embodiment) FIGS. 5 and 6 show a second embodiment of the present invention. In the figure, A is a semiconductor device, in which a plurality of leads 13 to 13 are respectively led out from a pair of opposing side surfaces of a mold sealing part 10 having a substantially rectangular parallelepiped shape, and a semiconductor element (not shown) is ) is mounted on the die pad 10 toward a pair of side surfaces other than the pair of side surfaces, and a positioning reference portion 14a is formed in which the tip of the suspension lead 14 is formed in a concave shape facing inward. There is. Note that, as shown in the figure, this positioning reference part is exposed by recessing the side part of the mold sealing part 10. In this embodiment, since the side surface of the mold sealing section 10 where the leads 13 to 13 are provided is different from the side surface of the mold sealing section 10 where the positioning reference section 14a is provided, the electrical connection between the positioning reference section 14a and the lead 13 is different. There is no risk of physical contact.

Also in this embodiment, since the positioning reference portion 14a is formed inwardly in a concave shape, positioning can be performed simply by making contact with the positioning pin of the mounted hand, for example, and the pin can be smoothly engaged and disengaged. There are advantages to doing so.

Although both embodiments have been described above, the present invention is not limited to these embodiments, and various design changes can be made in accordance with the gist of the configuration.

For example, in both of the above embodiments, the positioning reference portion 14a is recessed inwardly in an arc shape (half-moon shape), but it may of course be formed in a U-shape, a V-shape, or the like.

[0022]

As is clear from the above description, according to the present invention, there is an effect of smooth positioning and an effect of improving electrical reliability.

Specifically, it is possible to improve the quality by increasing the positional accuracy of the lead processing, especially the trimming processing of removing the dam bar connecting the external leads to prevent leakage of the mold sealing resin.

Further, according to the present invention, the accuracy of the insertion position into the socket used in the electrical property test is improved.

Further, according to the present invention, it is possible to improve the accuracy of mounting a semiconductor device on a mounting board and the quality of soldering during solder reflow, thereby improving yield.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of essential parts of the first embodiment of the present invention.

FIG. 3 is a plan view of the lead frame.

FIG. 4 is a plan view of a lead frame with mold sealing.

FIG. 5 is a plan view of a second embodiment of the invention.

FIG. 6 is a perspective view of a main part of a second embodiment of the present invention.

FIG. 7 is a perspective view showing a conventional example.

FIG. 8 is a sectional view showing a conventional mounting state.

[Explanation of symbols]

A... Semiconductor device, 10... Die pad, 11... Semiconductor element, 12... Mold sealing part, 13... Inner lead, 13...
Lead, 14... Hanging lead, 15... Lead frame.

Claims (1)

[Claims] 1. A semiconductor element, a die pad on which the semiconductor element is mounted, and an inner lead disposed around the die pad are mold-sealed, and the tips of the hanging leads of the die pad are separated from the mold sealing part. What is claimed is: 1. An exposed semiconductor device, characterized in that a positioning reference portion is formed at the tip of the exposed suspension lead, the positioning reference portion being cut out in a concave shape toward the inside.