JPS6351541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device such as a semiconductor rectifier for an automobile.

The conventional rectifying element for an automobile alternator shown in FIG.
At the same time, the internal lead wire 3 is glued, and the lid 4 is fixed.
is fixed to the container 1, and the internal lead wire 3 is connected to the external lead wire 5 integrated with the lid 4. This type of can-sealed rectifier is excellent in terms of reliability and electrical characteristics, but it is difficult to reduce weight and cost, so recently molded rectifiers as shown in Figure 2 have been used. rectifying elements came into use. In the rectifying element shown in FIG. 2, a diode chip 8 is fixed with solder between a concave metal base 6 and a lead wire 7, and a thin inner coating layer 9 of junction coating resin (JCR) such as silicone varnish is provided. After that, an outer coating layer 10 of silicone rubber or the like is provided. Therefore, there is no need for anything equivalent to the lid 4 in FIG. 1, making it possible to reduce weight and cost.

However, since the tip of the lead wire 7 is a round bar, it has been difficult to make a connection with high adhesive strength and low electrical resistance. In order to solve this kind of problem, it is conceivable to use a lead wire 7 whose tip is pressed flat like the external lead wire 5 shown in FIG. 1. However, if a flat portion is provided at the tip of the lead wire 7 shown in FIG. 2, handling of the lead wire becomes troublesome and the shape of the jig becomes complicated.
Assembling workability deteriorates. Also, as shown in Figure 2, after assembling the rectifier, the lead wire 7
It is conceivable to press the tip of the chip, but if it is simply pressed after assembly, unnecessary force will be applied to the outer coating layer 10, the chip 8, etc., and there is a risk that the characteristics will deteriorate.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a semiconductor device that allows external connections to be made reliably and easily, with good workability, and while preventing deterioration of characteristics.

To achieve the above object, the present invention provides a lead wire having a header portion, a first rod-like portion, a first plate-like portion, and a second rod-like portion in this order, and the header portion of the lead wire. a step of adhering a semiconductor chip between the first plate-shaped portion and a metal substrate; and a step of covering a portion of the semiconductor chip and the lead wire with an insulating material so that more than half of the first plate-shaped portion is exposed to the outside. and, thereafter, pressing a portion of the second bar-shaped portion where an external connection terminal is to be formed to form a second plate-shaped portion. It is related.

According to the above invention, the following effects can be obtained.

(a) Since the part of the lead wire that should form the external connection terminal is kept in a rod shape until the final stage of assembly, the lead wire is easy to handle and workability is good.

(b) Since more than half of the first plate-like part is exposed from the covering insulator, this first plate-like part exerts a shock-reducing effect when the second plate-like part is formed by pressing, and the chip This prevents impact from being applied to the area and its surroundings. Therefore, characteristic deterioration can be prevented.

Next, embodiments of the present invention will be described with reference to FIGS. 3 to 11.

First, as shown in FIGS. 3 and 4, a header portion 11, a first rod-shaped portion 12, and a first plate-shaped portion 1
A lead wire 15 made of a Cu material coated with Ni plating and having a second rod-shaped portion 14 is prepared. The rod-shaped parts 12 and 14 of this lead wire 15 are round bars with a circular cross section of 1.5 mm in diameter, and the plate-shaped part 13 is pressed to a thickness of 0.2 mm and bent into a U-shape so that the main surfaces face each other. This is the part that was

Next, as shown in FIG. 5, a lower solder piece 17, a diode chip 18, and an upper solder piece 1 are placed on a concave metal case or metal base 16 made of Ni-plated Cu material.
The sixth
As shown in the figure, a chip 18 is soldered and bonded between the header portion 11 and the metal base 16. When assembling and soldering, a jig 20, only a part of which is shown in FIG.
and the lead wire 15 in a predetermined positional relationship.

Next, as shown in FIG. 7, a silicone varnish or the like is applied as JCR to the surface of the chip 18 to form an inner coating layer 21, and a silicone rubber material is further filled to form an outer coating layer 22 made of an insulating material. do. The outer coating layer 22 covers at least a portion of the inner coating layer 21, the header portion 11, and the first rod-shaped portion 12, but is provided so that more than half of the first plate-shaped portion 13 is exposed.

Next, by pressing the tip of the first rod-shaped portion 14 in the same direction as the first plate-shaped portion 13, the thickness is 0.3 mm as shown in the front view of FIG. 8 and the side view of FIG. A second plate-shaped portion 23 is formed, followed by punching with a press to form a U-shaped notch 24 as shown in FIG. 10, and the second plate-shaped portion 23 is immersed in a molten solder bath or a tin bath. to form a surface film. This second plate-shaped portion 23 has increased hardness through work hardening, and has sufficient strength as a terminal even with a thickness of about 0.3 mm. Note that it is desirable to press so that the surface area of the second plate-like portion 23 is 1.2 times or more, more preferably 1.5 times or more, the surface area of the rod-like portion 14 of the same length.

When forming a full-wave rectifier circuit using the rectifying element 25 shown in FIG. 10, as shown in FIG.
One polarity rectifying element 25 on one metal base 26
At the same time, a rectifying element 25a having a polarity opposite to that of the rectifying element 25 is fixed to the other metal base 27, and the pair of rectifying elements 25a are made to face each other. to fix it.

According to this embodiment, the following effects can be obtained.

(a) Since the tip of the lead wire 15 is kept in a rod shape except at the final stage of assembly, the lead wire 15
Easy to handle. Furthermore, when positioning the lead wire 15 using the jig 20, the jig 20 does not have a complicated shape and is easy to assemble. Therefore, the rectifying element can be manufactured with good workability.

(b) Since more than half of the first plate-shaped portion 13 is exposed from the outer coating layer 10, the first plate-shaped portion 13 exerts a shock-reducing effect when forming the second plate-shaped portion 23 by pressing. However, the impact on the chip 18 etc. is reduced and characteristic deterioration is prevented. At this time, since the second plate-like portion 23 is pressed so that its thickness direction coincides with the thickness direction of the first plate-like portion 13, the relaxation effect occurs more effectively.

(c) Since the thickness direction of the second plate-like portion 23 coincides with the thickness direction of the first plate-like portion 13, the first plate-like portion 23
As shown in Figure 1, a pair of rectifying elements 25, 25
Since the second plate-like portions 23 of each of the second plate-shaped portions 23a are loosely connected, the respective lead wires 15 can be easily bent, and unnecessary external force can be prevented from being applied to the chip 18. Also, the 11th
Even when connecting the lead wires 15 to each other or to an external circuit by keeping them vertical without bending them as shown in the figure, force may not be applied in the thickness direction of the second plate-shaped portion 23. Therefore, this external force can be alleviated by the first plate-shaped portion 13.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified. For example, the outer covering layer 22 may be provided so that the entire first plate-like portion 13 is exposed.

Further, the outer covering layer 22 may be provided up to nearly half of the first plate-shaped portion 13. However, if more than half of the first plate-shaped portion 13 is covered, the impact-reducing effect decreases, which is not preferable.

Further, if the first plate-shaped portion 13 is bent into a U-shape, V-shape, S-shape, etc., the impact-reducing effect is increased, but in some cases, such a bending portion may not be provided.

Furthermore, depending on the pressing method used when forming the second plate-like portion 23, the first plate-like portion 13 and the second plate-like portion
It is not necessary to align the plate-shaped portions 23 in the same direction.

Further, although the outer covering layer 22 is preferably made of a rubber-like insulating material, it is also possible to use a non-elastic material.

Further, in the embodiment, the U-shaped notch 24 was provided in consideration of screw fixation, etc., but it is not necessary when fixing by soldering only. It is also applicable to semiconductor elements other than rectifying elements.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing a conventional rectifier, FIGS. 3 to 11 are for explaining a rectifier according to an embodiment of the present invention, and FIG. A perspective view, FIG. 4 is a side view of the lead wire,
Fig. 5 is a partially cutaway exploded front view showing the state in which the rectifying element is assembled, Fig. 6 is a sectional view showing the state after soldering, Fig. 7 is a sectional view showing the state in which the outer coating layer is provided, and Fig. 6 is a sectional view showing the state after soldering. Figure 8 is a front view showing the state in which the second plate-like part is formed, Figure 9 is a right side view of Figure 8, and Figure 9 is a right side view of Figure 8.
Figure 0 is a side view showing a state in which a U-shaped notch is provided.
FIG. 11 is a front view showing a state in which a rectifier circuit is formed. In addition, in the symbols used in the drawings, 11 is the header part, 12 is the first rod-shaped part, and 13 is the first
14 is a second rod-shaped portion, 15 is a lead wire, 16 is a metal base, 18 is a diode chip, 21 is an inner coating layer, 22 is an outer coating layer, 23
is the second plate-like portion.

Claims (1)

[Scope of Claims] 1. A header portion, a first rod-shaped portion, a first plate-shaped portion, and a second rod-shaped portion are sequentially provided, the header portion being provided at one end side, and the second rod-shaped portion a step of preparing a lead wire in which a portion is provided on the other end side, and bonding a semiconductor chip between the header portion of the lead wire and a metal base; a step of covering the semiconductor chip and a part of the lead wire with an insulating material so as to be exposed to the semiconductor chip; and then pressing a portion of the second rod-shaped portion where an external connection terminal is to be formed. 2. A method for manufacturing a semiconductor device, comprising the step of forming a second plate-like portion. 2. The step of pressing the second bar-shaped portion to form the second plate-shaped portion is performed so that the thickness direction of the second plate-shaped portion is in the same direction as the thickness direction of the first plate-shaped portion. 2. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of pressing said second rod-shaped portion so that the second bar-shaped portion is pressed. 3. Claims in which the first plate-shaped part is a part bent in a U-shape from the first and second rod-shaped parts located on the same straight line so that the main surfaces of the plates face each other. A method for manufacturing a semiconductor device according to item 1 or 2.