JPH033354A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a device capable of sure surface mounting by making outer leads protruding from a package sealing a semiconductor chip and the like protrude on the same plane as the bottom surface of the package and in parallel to the bottom surface. CONSTITUTION:In a surface mounting type semiconductor device wherein a semiconductor chip 3 is mounted on a lead frame 1 and sealed in a package 6, from which outer leads 7 are made to protrude, the outer leads 7 are made to protrude on the same plane as the bottom surface of the package 6 and in parallel to the bottom surface. For example, inner leads 5 are bent step-wise in the vicinity of an element mounting part 2; the semiconductor chip 3 is mounted on the element mounting part 2 of the lead frame 1 wherein the outer leads 7 are arranged in parallel to the element mounting parts 2; the chip 3 is electrically connected with the inner leads 5 by using bonding wires 4. These are sealed with resin, thereby constituting the package 6. From the lower side peripheral part of the package 6, the outer leads 7 are made to protrude on the same plane as the bottom surface of the package 6 and in parallel to the bottom surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device that is surface mounted on a mounting board.

[Conventional technology]

Conventionally, in this type of semiconductor device, as shown in FIG. 6, a semiconductor element chip 23 is mounted on an element mounting portion 22 of a lead frame 21 and electrically connected to an inner lead 25 by a bonding wire 24. After these are sealed with a package 26 made of resin or the like, outer leads 2.7 are formed into a desired shape.

This semiconductor device is surface-mounted by bonding the bottom surface of the package 26 to the mounting board 11 with the adhesive 12 and connecting the outer leads 27 to the circuit pattern with the solder 13.

[Problem to be solved by the invention]

In the conventional semiconductor device described above, the outer leads 27 are bent outside the package 26, so variations in the processing accuracy tend to cause variations in the height position of the outer leads 27 with respect to the bottom surface of the package 26. There is a problem that suitable surface mounting cannot be performed.

That is, when the outer lead 27 is bent to a position higher than the bottom surface of the package 26, when the bottom surface of the package 26 is bonded to the mounting board 11 with the adhesive 12, the gap between the outer lead 27 and the circuit pattern of the mounting board 11 becomes large. If it becomes too much, it will not be possible to connect with solder, etc.

On the other hand, when the outer leads 27 are bent to a position lower than the bottom surface of the package 26, when the outer leads 27 come into contact with the circuit pattern of the mounting board 11, the gap between the bottom surface of the package 26 and the mounting board 11 increases. It becomes too large and temporary attachment with adhesive 12 becomes impossible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device configured so that surface mounting can be performed reliably.

[Means for Solving the Problems] In the semiconductor device of the present invention, an outer lead protruding from a package in which a semiconductor element chip or the like is sealed is made to protrude on the same plane as and parallel to the bottom surface of the package.

[Effect]

With this configuration, the bottom surface of the package and the outer leads can be disposed on the same surface of the mounting board, and the bonding of the package and the soldering of the outer leads can be respectively performed reliably.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

In the figure, a semiconductor element chip 3 is mounted on an element mounting portion 2 of a lead frame l, and is electrically connected to inner leads 5 by bonding wires 4.

These are sealed with resin to form a package 6, and an outer lead 7 is formed to protrude from the lower peripheral edge of the package 6, flush with and parallel to the bottom surface of the package 6.

FIG. 2 is a perspective view of the lead frame 1 used to form the semiconductor device of FIG. The outer lead 7 is oriented parallel to the element mounting section 2.

After mounting the semiconductor element chip 3 on the element mounting portion 2 of this lead frame 1, as shown in FIG. By clamping the outer lead 7 at B and performing resin sealing using these molds A and B, the first
The package 6 shown in the figure can be formed, and the bottom surface of the package 6 and the outer leads 7 can be formed on the same surface.

According to the semiconductor device with this configuration, as shown in FIG.
When mounting the semiconductor device on the mounting board 11, the bottom surface of the package 6 is bonded with an adhesive 12. Then, since the bottom surface of the package 6 and the outer leads 7 are on the same plane, a gap with a size corresponding to the thickness of the adhesive 12 is always formed between the outer leads 7 and the mounting board 11. Actually, since the outer lead 7 is located on the wiring pattern, the gap therebetween is extremely small. This makes it possible to reliably connect the outer leads 7 with the solder 13.

FIG. 5 is a sectional view of another embodiment of the invention.

This embodiment differs from the previous embodiments in that a reversely concave groove 6a is provided in the approximate center of the bottom surface of the package 6.

By providing the groove 6a in the reverse concave shape in this way, the adhesive 12 can be applied thickly when bonding the semiconductor device to the mounting board, so there is an advantage that the amount of adhesive applied can be easily controlled.

[Effects of the Invention] As explained above, in the present invention, the outer leads protruding from the package are made to protrude on the same plane and parallel to the bottom surface of the package, so that the relative position between the bottom surface of the package and the outer leads is This has the effect that the bottom surface of the package and the outer leads can be disposed on the same surface of the mounting board during mounting, and that the bonding of the package and the soldering of the outer leads can be performed reliably.

Further, the process of bending the outer leads after packaging is not necessary, which has the effect of making it possible to manufacture semiconductor devices at low cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a perspective view of a lead frame, FIG. 3 is a sectional view showing a package manufacturing method, FIG. 4 is a sectional view showing a mounting state, and FIG. This figure is a cross-sectional view of another embodiment of the present invention, and FIG. 6 is a cross-sectional view showing a mounting state of a conventional semiconductor device. ■10. Lead frame, 2... Element mounting section, 3...
・Semiconductor element chip, 4... Bonding wire, 5
...Inner lead, 6...Package, 6a...
Groove, 7... Outer lead, 11... Mounting board, 12
...Adhesive, 13...Solder, 21...Lead frame, 22...Element mounting portion, 23...Semiconductor element chip, 24...Bonding wire, 25...Inner lead, 26 ...Package, 27...Outer lead.

Claims (1)

[Claims] 1. In a surface-mounted semiconductor device in which a semiconductor element chip is mounted on a lead frame and sealed in a package, and outer leads protrude from the package, the outer leads protrude on the same plane as and parallel to the bottom surface of the package. A semiconductor device characterized by: