JPH0362562A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To prevent fracture of a package main body and the thermal destruction of a circuit part when bonding solder is fixed on the wiring of a printed board, by a method wherein, when outer leads for substrate connection use are manufactured, notches or through holes are formed in the tips of said leads, and these tip sides are made to protrude from the side surface of the package main body. CONSTITUTION:A notch 3 is formed at the tip part of an outer lead 2a protruding from the side surface of a package main body 1 constituting an IC. When the lead is mounted on a printed board 5, the area larger than the solder 7 preliminarily soldered on a wiring 6 can be irradiated with infrared rays or a light beam for heating, so that the bonding is enabled by the reflow of solder 7a without unnecessarily heating the outer lead 2a. Further fused solder flows into the notch, so that the mechanical strength increases and the bonding of the outer lead 2a and the wiring 6 becomes sure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit device, and particularly to a semiconductor integrated circuit device having an external lead for connecting a substrate.

[Conventional technology]

FIG. 4 is a perspective view showing an example of a conventional semiconductor integrated circuit device mounted on a printed circuit board.

When mounting this type of conventional semiconductor integrated circuit device on a printed circuit board, as shown in FIG.
The external lead 2 protruding from the side surface of the board was welded to the corresponding wiring 6 of the printed circuit board 5 using solder.

[Problem to be solved by the invention]

The conventional semiconductor integrated circuit device described above uses solder to join the wiring external leads of the printed circuit board, but during this joining, infrared rays, laser 6, etc. are used to heat the board terminals by heat conduction. Since the solder is melted on the top, the temperature of the external leads becomes high before the solder is heated, which may cause the sealing resin in the package body near the external leads to fluff or damage the circuit inside the package body. The disadvantage is that it causes thermal damage to the parts. Furthermore, if the temperature at the time of bonding is lowered or the heating time is shortened in order to prevent this from happening, there is a drawback that the melting of the solder becomes poor and the yield of bonding decreases.

An object of the present invention is to provide a semiconductor integrated circuit device that eliminates such drawbacks.

[Means to solve the problem]

The semiconductor integrated circuit device of the present invention has an external lead that protrudes from the side surface of the package body and has a cut at its tip or a through hole formed at its tip.

〔Example〕

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

FIG. 1 is a perspective view of a semiconductor integrated circuit device showing one embodiment of the present invention. In this semiconductor integrated circuit, as shown in the figure, a notch 3 is formed at the end of an external lead 2a protruding from the side surface of a package body 1.

Other than that, it is the same as the conventional example.

FIG. 2 is a partially enlarged perspective view showing the semiconductor integrated circuit device shown in FIG. 1 mounted on a printed circuit board. By providing the notch 3 at the tip of the external lead 2, for example, as shown in FIG.
If the solder 7 is pre-soldered on the wiring 6,
It is possible to irradiate a larger area with infrared rays or a light beam, and the solder 7a can be reflowed and bonded without unnecessarily heating the external leads 2a. The bonding area of the external lead 2a is increased by providing the notch 3, and the melted solder enters there, thereby increasing the mechanical strength, and the external lead 2a and the wiring 6 are reliably bonded.

FIG. 3 is a perspective view of a semiconductor integrated circuit device showing another embodiment. Moreover, the same effect can be obtained by providing a through hole 3a, for example, as shown in FIG. 3, in place of the notch in the external lead of the above-described embodiment.

〔Effect of the invention〕

As explained above, the present invention allows a heat source such as an infrared laser beam to be applied to the solder for joining wiring on a printed circuit board by providing a cut or a through hole in the tip of the external lead that protrudes from the package body. It is possible to heat and melt solder without heating more than necessary.

Therefore, it is possible to obtain a semiconductor integrated circuit device that does not cause thermal damage to the flatness of the package body near the external leads or to the circuit portion within the package body.

[Brief explanation of drawings]

1 and 3 are perspective views of a semiconductor integrated circuit device showing an embodiment of the present invention, and FIG. 2 is a partially enlarged perspective view showing the semiconductor integrated circuit device shown in FIG. 1 mounted on a printed circuit board. FIG. 4 is a partially enlarged perspective view showing an example of a conventional semiconductor integrated circuit mounted on a printed circuit board. DESCRIPTION OF SYMBOLS 1... Package body, 2.2a, 2b... External leads, 3... Notch, 3a... Through hole, 5... Printed circuit board, 6... Wiring, 7... Solder.

Claims (1)

[Claims] A semiconductor integrated circuit device characterized by having an external lead that protrudes from a side surface of a package body and has a cut at its tip or a through hole formed at its tip.