JPH0219971Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure of a semiconductor device having a connection plate for connecting a semiconductor element and an external lead wire. This will be explained below with reference to the drawings.

Figures 1a and b are a plan view and a partial sectional view of the conventional device, and Figures 2a and b are explanatory diagrams thereof.In the figures, 1 is the base electrode (plate), 1a is the external mounting hole, 1b and 1c,
Reference numeral 1d denotes external lead wires that are integrated with and separated from the base electrode 1, and are arranged in a height relationship with the base electrode 1, respectively. Reference numeral 2 denotes a semiconductor element (for example, a diode chip), one electrode portion of which is bonded onto the base electrode with solder 2a, and similarly to the base electrode 1, it is disposed in a height relationship with the external lead wires 1b to 1d.
Next, reference numeral 3 denotes a connecting plate which is soldered to the external lead wires (1c, 1d) and the other electrode portion of the semiconductor element 1, respectively, and 3a is a protrusion provided on the adhesive surface with the semiconductor element 1. This apparatus will be explained below with reference to FIG. Figure a shows the assembled state (before soldering) of semiconductor elements, etc., and 4 is solder (sheet-like). In this state, one end of the connection plate 3, that is, the external lead wire 1c
The connecting surfaces of the semiconductor element and the base electrode 1 are parallel to each other, and the semiconductor element is connected to the base electrode 1 via the solder 2a and also to the solder 2b.
These are placed in contact with the protrusions 3a of the connection plate 3 via the respective connection surfaces in areas smaller than those of the connection surfaces. Therefore, the connection plate 3 is held between the external lead wire 1c and the semiconductor element 2 with a height difference at both ends, and the contact surface with the external lead wire is relatively large. The board 3 cannot follow the pattern, in other words, the semiconductor chip 2 is stretched, causing a connection failure in the semiconductor element 2 as shown in FIG. 2b, and the solder 2
a and 2b will not be uniform, leading to poor adhesion or poor thermal fatigue in places where the solder is thin. Furthermore, variations in the bending height between the base electrode 1 and the external lead wire 1c and in the machining accuracy of the connection plate 3 also caused connection failures. The present invention solves the above-mentioned drawbacks, and provides a semiconductor device that improves the ability of the connecting plate to follow the downward movement caused by melting of the solder during soldering, and prevents connection failures of the connecting plate due to variations in the processing accuracy of the parts used. It is something. Figures 3a and 3b are illustrations of the embodiment of the present invention, and figure a is during assembly (before soldering);
Figure b is a cross-sectional view after soldering, Figures 4a and b are perspective views of the connection plate, where 1 is a base electrode, 2 is a semiconductor element, and 5
3 is an external lead wire, 3 is a connection plate, and 6 is a sealing resin. As shown in FIG. 4, the connection plate 3 has a connection portion with the external lead wire 5 in a convex shape (Figure a) or a V-shape (Figure B). That is, even in the state before soldering as shown in FIG. 3a, the connection plate 3 has a degree of freedom, and therefore, in the state where the solders 2a, 2b, and 4 are melted, the semiconductor element 2 is in the position of the connection part as shown in FIG. 3b. A proper connection can be obtained without being affected by the surface tension of the solder.
Similarly, even if there is a variation in the bending height of the base electrode or the connection plate, it can be easily absorbed by the presence of the protrusion. In the above embodiment, there are projections 3 on the connection part of the connection plate 3.
Although the figure is shown in which a similar protrusion is provided at the connection portion of the external lead wire 5, the same effect can be obtained.
As is clear from the above explanation, according to the present invention, by providing the protrusion on the connection part, the connection between the semiconductor element and the connection plate during soldering can be easily made without being affected by the accuracy of the parts, and the connection plate can be easily connected. It has great practical effects, such as being easily applicable to other semiconductor devices.

[Brief explanation of the drawing]

Figures 1 and 2 are conventional structural diagrams and their explanatory diagrams,
3 and 4 are structural diagrams of an embodiment of the present invention. In the figure, 1 is a base electrode (plate), 1a is a mounting hole, 1b, 1c, 1d are external lead wires, 2 is a semiconductor element, 2a, 2b are solder, 3 is a connection plate, 3a,
3b is a projection, 4 is solder, 5 is an external lead wire, 6
is mold resin.

Claims (1)

[Scope of utility model registration request] a base electrode, a semiconductor element with one electrode part bonded on the base electrode, an external lead wire arranged in a height relationship with the semiconductor element, and the other electrode part of the semiconductor element and the external lead wire. What is claimed is: 1. A semiconductor device comprising a connection plate for connecting two points by solder, wherein a protrusion is provided on a connection surface of the connection plate with a semiconductor element and a connection surface with an external lead wire.