JP4141789B2 - Power semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power semiconductor device having a power semiconductor element and an electrode of which is insert-molded in a case.
[0002]
[Prior art]
In this type of semiconductor device, an insulating ceramic substrate having a conductive plate material on its upper surface is formed on a known heat sink via solder, and switching is performed on the substrate conductive material via solder. The elements are configured, and each element is connected using a known wire wiring. The inner end of the electrode (output and connection electrode) provided through the case from the outside of the case constituting the semiconductor device is a “pin guide” or “electrode crushing structure” formed on the bottom surface inside the case. Is held by.
[0003]
Moreover, although the electrode located in a case is divided into 2 to a longitudinal direction, a level | step difference is formed in one part, and the electrode is fixed by forming resin in the level | step-difference part (for example, patent document 1). See), and the electrode needs fine processing.
[0004]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-349219 “Power Semiconductor Device” (Embodiment 1, FIG. 3)
[0005]
[Problems to be solved by the invention]
Since the internal electrode is formed with a pin guide structure or an electrode crushing structure when the case is molded, the structure of the case molding die is complicated and expensive. Further, in the pin guide structure, an insulation failure occurs due to air bubbles flowing out from the pin holes remaining after molding. In addition, since the electrode crushing structure cannot hold the electrode sufficiently, a problem has occurred in the wire bond. In addition, since the front surface inside the case and the front surface inside the electrode are configured on the same surface, gap air generated between the bottom surface of the electrode and the case resin is generated as bubbles from the front surface inside the electrode, making it difficult to stabilize the quality. It was.
[0006]
The present invention provides a semiconductor device in which the case-molding mold structure can be simplified, the processing on the electrode surface is eliminated, and air pockets that cause bubbles are eliminated.
[0007]
[Means for Solving the Problems]
In a power semiconductor device in which a case and a semiconductor device mounted thereon are stored in a case, and the inside of the case is filled with a gel resin,
Per the inner leads located inside the case of electrodes provided so as to penetrate the case to the embedded fixed by fixing bed,
The wire bonding surface (2c) of the internal lead is exposed,
Retracting the end face ( 2e ) of the internal lead from the end face ( 7e ) of the fixed bed ; and
A part of the end face ( 2e ) on the wire bonding surface (2c) side is exposed in a notch of the fixing bed formed by partly entering a mold when molding the case .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a plan view of a semiconductor device. A semiconductor element 5 is provided on a circuit board 4 housed in the case 1, and the semiconductor element 5 is connected to other devices by wires 6. The heat radiating plate 3 also serves as the bottom plate of the case 1. FIG. 2 shows an enlarged perspective view of the external electrode 2 portion, and FIG. 3 shows an overall view of the electrode 2. Moreover, the vertical sectional view in the AB direction and CD direction in FIG. 2 is shown in FIG. 4 and FIG.
[0009]
The L-shaped electrode 2 is provided so as to penetrate the case 1, the external lead 2 a is drawn out of the case, and the internal lead 2 b is held by being embedded in the fixing bed 7 in the case. However, the wire bonding surface 2c which is the upper surface portion of the internal lead 2b is flush with the upper surface of the fixing bed 7, and the wire bonding surface 2c is exposed.
[0010]
As shown in FIGS. 2 and 4, the end surface 2 e (FIG. 3) inside the case of the electrode 2 is retracted from the end surface 7 e of the fixing bed 7, and a part of the end surface 2 e is exposed. A notch 7 a is formed in the upper end surface portion of the fixing bed 7.
[0011]
An arrow (→) shown in FIG. 4 indicates a pressing surface by a mold (not shown) when the electrode 2 is embedded in the case 1 and the fixing bed 7. The notch 7a is formed in the fixing bed 7 by the mold entering the portion indicated by the notch 7a. At this time, since the end surface of the mold that has entered the notch 7a comes into contact with the end surface 2e of the electrode 2, the electrode 2 is held at an accurate position during the embedding molding.
[0012]
Since the shape of the mold used here is simple, the mold can be formed at low cost. Further, since no gap is generated between the inner surface of the mold and the case 1 including the electrode 2 and the fixing bed 7 during molding, the generation of bubbles as described above does not occur.
[0013]
Further, as shown in FIG. 3, “sag” 2 d which is plastic deformation at the time of press working is generated around the wire bonding surface 2 c of the electrode 2. When such an electrode 2 is embedded in the fixing bed 7 so that only the wire bonding surface 2c is exposed, as shown in FIG. 4 which is a vertical sectional view in the direction AB in FIG. Since the sagging portion 2d is covered with the resin, the holding strength of the electrode 2 is increased as compared with the case where there is no sagging 2d.
[0014]
【The invention's effect】
In the present invention, when the electrode is molded and fixed to the fixing bed in the case, the end face of the electrode is held by the mold, so the mold shape is simple, and the mold can be formed at low cost. In the molding, since no gap is generated between the inner surface of the mold and the case including the electrode and the fixing bed, the generation of bubbles as described above does not occur.
[Brief description of the drawings]
FIG. 1 is an internal plan view of a power semiconductor device showing an embodiment of the present invention. FIG. 2 is a detailed perspective view of an internal lead portion of an electrode. FIG. 3 is an overall perspective view of an electrode. The figure which showed the vertical cross section in the AB direction of FIG. 5 [FIG. 5] The figure which showed the vertical cross section in the CD direction in FIG.
1 case, 2 electrodes, 2a external lead, 2b internal lead, 2c wire bonding surface, 2d sag, 2e end surface, 3 heat sink, 4 circuit board, 5 semiconductor element, 6 wire, 7 fixing bed, 7a notch

Claims (3)

In a power semiconductor device in which a case and a semiconductor device mounted thereon are stored in a case, and the inside of the case is filled with a gel resin,
Per the inner leads located inside the case of electrodes provided so as to penetrate the case to the embedded fixed by fixing bed,
The wire bonding surface (2c) of the internal lead is exposed,
Retracting the end face ( 2e ) of the internal lead from the end face ( 7e ) of the fixed bed ; and
Electric power characterized in that a part of the end face ( 2e ) on the wire bonding surface (2c) side is exposed in a notch of the fixing bed formed by partly entering a mold during case molding. Semiconductor device.   The power semiconductor device according to claim 1, wherein the wire bonding surface and the upper surface of the fixing bed are the same surface, and the wire bonding surface of the internal lead is exposed.   The power semiconductor device according to claim 2, wherein a portion of a sag at the upper edge of the electrode that is produced when the electrode is pressed is covered with a resin of the fixing bed, thereby increasing the fixing strength of the electrode.

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