JP2000299400A - Non-lead flat-package type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent short-circuitings between projection terminals or the wiring patterns of a packaging substrate on packaging. SOLUTION: A device 20 is equipped with a number of projection terminals 22, that are used as the terminal for connecting to a packaging substrate and that project extremely short distance outward from the four sides of a nearly square-columnar shaped sealing body 12, where a semiconductor element is sealed inside with resin. The projection terminals 22 orthogonally cross each of four sides of the sealing body 12 on the same surface as the lower surface of the sealing body 12 for projecting. The projection terminals 22 do not retain resin between the projecting terminals 22, and the outer peripheral surface of the projection terminals 22 is exposed from the sealing body 12. In the projection terminal 22, a metal coating where a solder cladding property is increased and at the same time corrosion resistance is superior, is plated. When soldering junctions, since no resin exists between the projection terminals 22, creamy solder creeps into the side surface of the projection terminal, forming a solder bridge by solder to each other, preventing generation of short-circuiting phenomenon, and furthermore, increasing the strength of electrical and mechanical connections with the packaging substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-leaded flat package type semiconductor device, and more particularly, to preventing a short-circuit phenomenon between projecting terminals due to a solder bridge generated between projecting terminals during mounting. And a non-lead flat package type semiconductor device.

[0002]

2. Description of the Related Art With the recent trend of increasing the number of pins, miniaturization and high-density mounting of semiconductor devices, a flat package (F) called a flat lead pin type package type semiconductor device has been developed.
Among the P) type semiconductor devices, a non-lead flat package type semiconductor device has been widely used.

Here, a configuration of a conventional non-lead flat package type semiconductor device will be described with reference to FIG. FIGS. 5A and 5B are plan views of a conventional non-lead flat package type semiconductor device, respectively.
FIG. 6 is a perspective view of a conventional non-lead flat package type semiconductor device, and FIG. 7 is a line II- of FIG.
It is sectional drawing in II. Conventional non-lead flat package type semiconductor device 10 (hereinafter simply referred to as semiconductor device 10)
5 (a), 5 (b) and FIG. 6, a substantially positive terminal in which the internal semiconductor element is sealed with a sealing material such as resin or ceramic as a terminal for connection to a mounting substrate. A large number of protruding terminals 14 protruding outward from four sides of the quadrangular prism-shaped sealing body 12 are provided. Projecting terminal 14
Respectively, on the same surface as the lower surface of the sealing body 14,
4 project perpendicularly to each of the four sides,
As shown in FIG. 5A, FIG. 5B and FIG. 6, the space between the adjacent protruding terminals 14 is filled with the same resin 15 as the sealing body 12.

As shown in FIG. 7, the semiconductor device 10 has a semiconductor chip 17 adhered on a die pad 16 in a sealing body 12 and extends into the electrodes of the semiconductor chip 17 and the sealing body 14. The protruding terminals 14 are connected by bonding wires 18. Thus, the semiconductor chip 17 is connected to the outside via the bonding wires 18 and the protruding terminals 14.

When the semiconductor device 10 is mounted on a mounting board, as shown in FIG. 8, the cream solder 1 on the wiring pattern (not shown) of the mounting board 19 is used.
The protruding terminal 14 is positioned on the solder land on which 9a is attached, and the protruding terminal 14 is soldered to the wiring pattern by a reflow method or the like.

[0006]

However, when the above-described non-lead flat package type semiconductor device is mounted on a mounting board, a short circuit phenomenon occurs between terminals of the semiconductor device or between wiring patterns of the mounting board. There was a problem of doing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a non-lead flat package type semiconductor device which does not cause a short circuit phenomenon between protruding terminals or between wiring patterns of a mounting substrate when mounted on a mounting substrate. It is.

[0008]

The inventor of the present invention has studied in detail the problem that a short circuit phenomenon occurs between terminals of a semiconductor device or between wiring patterns of a mounting board. As shown in FIG. The cream solder 19a is
And the mounting board 19 are crushed and the cream solder 19a
The solder bridges 19b were generated due to the mutual contact, and as a result, it was determined that a short circuit occurred between the protruding terminals 14 of the semiconductor device or between the wiring patterns of the mounting board 19. FIG. 9 is an enlarged view of “A” in FIG. The cause of the occurrence of the solder bridge 19b is that when the semiconductor element is sealed with a resin using a mold, the resin is injected into the mold in a state where the protruding terminals are sandwiched between the molds, and the resin is cured. Therefore, as shown in FIG. 10, the resin 15 is filled between the protruding terminals 14. Therefore, there is no room for excess cream solder to escape, so it spreads sideways,
It was found that solder bridges occurred. In addition, FIG.
FIG. 6 is an enlarged view of “A” in FIG. 5. Therefore, the present inventor has removed the resin 15 between the protruding terminals 14 and provided a space between the protruding terminals 14 to allow excess cream solder to escape, thereby preventing the occurrence of solder bridges and short-circuiting caused by the solder bridges. With the idea of preventing the phenomenon from occurring, the present inventors have completed the present invention through repeated experiments.

In order to achieve the above object, a non-leaded flat package type semiconductor device according to the present invention is characterized in that a semiconductor element is sealed inside with a sealing material such as resin or ceramic. In a non-lead flat package type semiconductor device in which a number of short protruding terminals are protruded outward on the same surface as the lower surface of a sealing body as terminals for connection with a mounting board, the short protruding terminals are connected between the protruding terminals. In addition, the outer peripheral surface of the protruding terminal is exposed from the sealing body without holding a sealing material such as resin or ceramic, and a metal film is provided on the outer peripheral surface of the protruding terminal.

The size of the protruding terminal of the non-lead flat package type semiconductor device according to the present invention is the minimum necessary size that functions as a terminal for connection with the wiring pattern of the mounting board when mounted on the mounting board. It is. The metal film provided on the protruding terminals is formed by sealing the semiconductor element inside with a sealing material, removing the sealing material from between the protruding terminals to expose the outer peripheral surface of the protruding terminals, and then plating the protruding terminals. A metal film formed by deposition, for example, a film that enhances solder adherence at the time of solder joining, a corrosion-resistant metal film, and the like.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment Example This embodiment is an example of an embodiment of a non-leaded flat package type semiconductor device (hereinafter simply referred to as a semiconductor device) according to the present invention, and FIG. FIG. 2 is a plan view, FIG. 2 is a perspective view of the semiconductor device of this embodiment, FIG.
(B) is a cross-sectional view of the protruding terminal. 1 to 3
The same parts as those shown in FIGS. 5 to 7 are denoted by the same reference numerals, and the description thereof will be omitted. Non-lead flat package type semiconductor device 2 of this embodiment
0 (hereinafter simply referred to as a semiconductor device 20) has the same configuration as that of the above-described conventional non-lead flat package type semiconductor device 10 except for the configuration of the protruding terminal 22, as shown in FIG. I have.

As shown in FIG. 1 and FIG. 2, the semiconductor device 20 has a substantially square prism-like sealing shape in which the internal semiconductor element is sealed with a sealing material such as resin or ceramic as a terminal for connection with a mounting substrate. A plurality of protruding terminals 22 that protrude outward from four sides of the stop body 12 extremely short are provided. Projecting terminal 22
Respectively, on the same surface as the lower surface of the sealing body 14,
4 project perpendicularly to each of the four sides. In the semiconductor device 20 of the present embodiment, the protruding terminals 22 correspond to those shown in FIGS.
As shown in FIG. 5, the outer peripheral surface of the protruding terminal 22 is exposed from the sealing body 12 without holding a sealing material such as a resin between the protruding terminals 22. Further, as shown in FIGS. 3A and 3B, a metal film 22b that enhances solder adherence and has excellent corrosion resistance is plated on the terminal base 22a of the protruding terminal 22.

In the semiconductor device 20 of this embodiment, after sealing the semiconductor element with a sealing material such as a resin using a mold, a sealing material such as a resin filled between the protruding terminals 22 is punched. The protrusion terminal 22 is removed from the sealing body 12 by using a mold or the like. Next, the terminal substrate 2 of the exposed protruding terminal 22
A metal film 22b is deposited on 2a by a plating method or the like to complete the semiconductor device 20.

When the semiconductor device 20 of this embodiment is mounted on the mounting board 19, the semiconductor device 10
Cream solder 19 on the wiring pattern 9 (not shown)
The protruding terminal 22 is positioned on the solder land on which a is attached, and the protruding terminal 22 is soldered to the wiring pattern by a reflow method or the like.

At the time of solder joining, in the present embodiment, since no resin exists between the protruding terminals 22, the cream solder 19a wraps around the side surface of the protruding terminal 22, as shown in FIG. Therefore, as in the conventional case, the cream solder 19a
A solder bridge is formed between them, and a short circuit phenomenon does not occur, and the strength of electrical and mechanical connection with the wiring pattern of the mounting board 19 can be increased. FIG. 4 is an explanatory diagram showing the relationship between the protruding terminals along line II of FIG. 1 and the solder at the time of soldering when the semiconductor device is mounted on the mounting board. Further, the protruding terminals 22 of the semiconductor device 20 of the present embodiment are plated with a metal film 22b which enhances solder adherence and is excellent in corrosion resistance, so that the protrusions 22 are well adapted to solder and have good resistance to solder. Excellent corrosiveness,
High reliability for long-term use.

[0016]

According to the present invention, as a terminal for connection with a mounting substrate of a non-lead flat package type semiconductor device, a resin or a sealing material such as ceramic is not held between the protruding terminals and the outer periphery of the protruding terminal is maintained. Since the surface is exposed from the sealing body and the protruding terminal having the metal film is provided, the solder goes around the side surface of the protruding terminal at the time of soldering. Therefore, unlike the related art, it is possible to increase the strength of the electrical and mechanical connection between the solder and the wiring pattern of the mounting board without causing a solder bridge to form a short circuit phenomenon. In addition, by providing a metal film with high corrosion resistance and excellent corrosion resistance on the protruding terminals, it has good compatibility with solder, excellent solder jointability and corrosion resistance, and long-term reliability. A high non-lead flat package type semiconductor device can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of a non-leaded flat package type semiconductor device according to the present invention.

FIG. 2 is a perspective view of an embodiment of a non-lead flat package type semiconductor device according to the present invention.

FIG. 3A is a longitudinal sectional view of a protruding terminal, and FIG.
(B) is a cross-sectional view of the protruding terminal.

4 is an explanatory diagram showing a relationship between a protruding terminal and a solder at line II in FIG. 1 at the time of soldering when the semiconductor device of the embodiment is mounted on a mounting board.

FIGS. 5A and 5B are a plan view and a side view, respectively, of a conventional non-lead flat package type semiconductor device.

FIG. 6 is a perspective view of a conventional non-lead flat package type semiconductor device.

FIG. 7 is a cross-sectional view taken along line II-II in FIG.

FIG. 8 is an explanatory diagram showing a relationship between a protruding terminal and solder at the time of soldering when a conventional semiconductor device is mounted on a mounting board.

FIG. 9 is an enlarged view of “A” in FIG. 8;

FIG. 10 is an enlarged view of “B” in FIG. 5;

[Explanation of symbols]

10 ... conventional non-lead flat package type semiconductor device, 12 ... sealing body, 14 ... protruding terminal, 15 ...
Resin between terminals, 16 die pad, 17 semiconductor chip, 18 bonding wire, 19 mounting board,
19a: solder, 20: non-lead of the embodiment example
Flat package type semiconductor device, 22 projecting terminal,
22a ... terminal base, 22b ... metal film.

Claims (2)

[Claims] 1. A large number of short protruding terminals serving as terminals for connection with a mounting substrate are formed on the lower surface of a sealing body from the periphery of the sealing body in which a semiconductor element is sealed with a sealing material such as resin or ceramic. In a non-leaded flat package type semiconductor device, which protrudes outward on the same surface as the above, the short protruding terminal is formed without holding a sealing material such as resin or ceramic between the protruding terminals, and A non-lead flat package type semiconductor device characterized in that a surface is exposed from a sealing body and a metal film is provided on an outer peripheral surface of a protruding terminal. 2. After the metal film seals the semiconductor element inside with the sealing material, the sealing material is removed from between the protruding terminals to expose the outer peripheral surface of the protruding terminal, and then the protruding terminal is plated. 2. The non-lead flat package type semiconductor device according to claim 1, wherein the semiconductor device is a metal film formed by deposition.