JPH03280566A - Surface mounting type semiconductor device - Google Patents

Abstract

PURPOSE:To remarkably reduce soldering failure obstacles at the time of automatic mounting, by constituting the tip parts of outer lead terminals as the shape maintaining the same angles to a wiring board. CONSTITUTION:A semiconductor chip with three terminals is hermetically sealed with a sealing member constituted of a paired member of an upper sealing member 1a and a lower sealing member 1b. Each of the tip parts of three outer lead terminals 2 is bent by applying an inclined surface to a guide which surface is formed from the side surface of the lower sealing member 1b to the rear, and has a gentle angle. The tip parts of the outer lead terminals 2 are formed without generating irregularity in the drawing-out shape, by the second bending wherein the inclined surface 3 of the lower sealing member 1b is used as the guide. Hence the irregularity in the drawing-out shape the outer lead terminals which has been apt to be generated can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a surface-mounted semiconductor device, and more particularly to the shape of an external lead terminal. [Prior art l Fig. 4 (al, (b)) and Fig. 5 (a), l
b) shows a plan view and a side view of two different conventional surface mount semiconductor devices, respectively. Usually, the external lead terminal 2 is formed by bending the tip end toward the outside or inside of the lower sealing member 1b. It is pulled out. Here, 1a is an upper sealing member that hermetically seals a semiconductor chip (not shown) in cooperation with lower sealing member 1b. [Problem to be solved by the invention 1] However, these conventional surface-mounted semiconductor devices
Lower sealing member] Since the side surfaces of b are formed in a shape perpendicular to the wiring board,
(If the external lead terminals 2 are bent outward as shown in bl, this is a problem, as shown in Figure 5, which is suitable for high-density mounting.)
In the case of inward molding as in a) and (b), there is a problem that the corner edges of the lower sealing member 1b get in the way and the external lead terminals 2 are likely to have irregularities in the drawer shape and size. In particular, these semiconductor devices are often automatically mounted these days, so irregularities in the shape of external lead terminals are undesirable because they increase the frequency of soldering defects. In view of the above circumstances, an object of the present invention is to provide a surface mount type semiconductor device that improves the structural defects of conventional sealing members, which tend to cause irregularities in the drawer shape when bending and forming external board terminals. It is. 1 Means for Solving the Problems 1 According to the present invention, a surface mount type semiconductor device is provided. A semiconductor chip, a sealing member consisting of a pair of upper and lower members for hermetically sealing the first two semiconductor chips, and a gentle curvature or angular inclination formed from the side surface to the back surface of the lower sealing member of the sealing member. and an external lead terminal of the semiconductor chip, which is molded by drawing the tip end inward along the inclined surface. [Function 1] According to the present invention, the external lead terminal is bent inward using the slope formed from the side surface to the back surface of the lower sealing member as a guide, so that the external lead terminal can be easily pulled out Shape irregularities are resolved. Example 1 Next, the present invention will be described in detail with reference to the drawings. 181 and (b), (cl are respectively a plan view and a side view of a surface-mounted semiconductor device showing one embodiment of the present invention. According to this embodiment, a three-terminal semiconductor chip (not shown) is used. ) is hermetically sealed by a sealing member consisting of a pair of upper sealing member 1a and lower sealing member 1b, and the three external lead terminals 2 are connected to a gentle groove formed from the side surface to the back surface of lower sealing member 1b. Angular slope 3
The tips are bent and formed using the guide as a guide. FIG. 2 (a1 to (cl) are diagrams of the bending and forming process of the external lead terminal of the surface-mounted semiconductor device of the present invention, in which the tip of the external lead terminal 2 is guided by the inclined surface 3 of the lower sealing member lb. Figure 3 1al and (bl are respectively a plan view and a side view of a surface-mounted semiconductor device showing other embodiments of the present invention. In this embodiment, the tips of the two external lead terminals 2 are bent and formed using the inclined surface 3 of the lower sealing member 1b as a guide. The case where the inclined surface 3 is formed linearly at a gentle angle has been described above, but it may also be formed as a circular arc surface with a gentle curvature. [Effect of the invention 1] Detailed explanation above. As described above, according to the present invention, it is possible to obtain a surface mount type semiconductor device in which the tips of the external lead terminals are formed in a shape that maintains the same angle with respect to the wiring board, so that soldering during automatic mounting can be achieved. This has the effect of significantly reducing defects and failures.

[Brief explanation of drawings]

Figures 1 (a) and (b), (cl are respectively a plan view and a side view of a surface mount type semiconductor device showing one embodiment of the present invention, and Figures 2 (a) to (c) are surface mount semiconductor devices according to the present invention. Bending and forming process diagram for external lead terminals of type semiconductor devices,
FIG. 3 (at and (bl are respectively a plan view and a side view of a surface-mounted semiconductor device showing another embodiment of the present invention,
Figure 4 (a), lb) and Figure 5 (at, (
bl is a plan view and a side view of two different conventional surface mount semiconductor devices, respectively. 1a... Upper sealing member, 1b... Lower sealing member, 2... External lead terminal, 3... Inclined surface. Patent applicant NEC Co., Ltd.

Claims (1)

[Claims] A sealing member consisting of a semiconductor chip, a pair of upper and lower members for hermetically sealing the semiconductor chip, and a sloped surface with a gentle curvature or angle formed from a side surface to a back surface of the lower sealing member of the sealing member. and an external lead terminal of the semiconductor chip, which is molded by drawing out a tip end inward along the inclined surface.