JPH04253349A - Internal connection structure of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an internal connection structure for enabling an improved soldering to be made between an upper electrode and a lower electrode of a semiconductor chip for a semiconductor device such as a diode module. CONSTITUTION:Side wall portions 4c and 4d which rise at right angle toward an upper direction from left and right side edges of the upper side 4a for an upper electrode 4 in U shape which is mounted on a semiconductor chip 3 are subjected to bending machining for forming a U-character shaped groove 4e at an area in reference to the upper surface, a connection electrode is placed between the above left and right side-wall portions 4c and 4d when soldering connection electrodes 6 and 7 to the upper electrode 4, and then an area between the upper electrode 4 and the connection electrode 7 is soldered in this state, thus enabling the melted solder to be retained within the groove portion 4 for performing soldering properly and preventing squeeze-out of solder due to excessive amount of solder, and sagging and dropping to the semiconductor chip.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to a plurality of diodes,
The present invention relates to an internal connection structure of a semiconductor device, which is a semiconductor module composed of a thyristor or the like.

0002

[Prior Art] First, the configuration of a conventional semiconductor device is shown in FIGS. 3 to 5, taking the above-mentioned diode module as an example.
This is shown and explained below. In the figure, 1 is a heat dissipation base plate, 2
3 is an insulating substrate, 3 is a semiconductor chip (diode) mounted side by side on the insulating substrate 2, 4 is a U-shaped upper electrode bonded on the semiconductor chip 3, 5, 6, 7 is a connection terminal, and 8 is a It is an outer case. Note that the upper electrode 4 and each of the connection terminals 5, 6, and 7 are made of a material such as a copper plate and formed into a predetermined shape by press working. Further, among the connection terminals 5, 6, and 7, the connection terminal 5 also serves as a mounting base for the semiconductor chip 3 on the right side, and the connection terminal 6 is connected to the semiconductor chips 3 arranged on the left side via the upper electrode 4,
The connection terminal 7 is internally wired so as to serve as a mounting base for the semiconductor chip 3 on the left side and a connection conductor for connecting the left and right semiconductor chips in series, and each connection terminal 5, 6, 7 is connected to the outer case 8. It passes through and becomes an external lead terminal. Incidentally, an equivalent circuit of the diode module having the above configuration is shown in FIG.

The above diode module is assembled as follows. First, the semiconductor chip 3 is individually soldered and mounted on the connection terminals 5 and 7, and then the upper electrode 4 is soldered onto the semiconductor chip 3 to assemble a single unit. Next, each of the above-mentioned units is lined up and bonded at a predetermined position on the insulating substrate 2 bonded to the heat dissipation base 1, and
The tip of the connection terminal 7 on which the semiconductor chip 3 on the left is mounted is overlapped with the top surface of the upper electrode 4 of the semiconductor chip 3 on the right, and soldered between them, and then the top of the upper electrode 4 of the semiconductor chip 3 on the left is placed on the top surface of the upper electrode 4 of the semiconductor chip 3 on the left. Solder the connection terminal 6. Thereafter, an outer case 8 is placed on the module, and the inside of the case is filled with a sealing resin (for example, silicone gel) to complete the module assembly.

0004

However, in the internal connection structure of the semiconductor device described above, there remains a problem in soldering between the upper electrode 4 and the connection terminal, especially in the solderability between the connection terminal 7. . That is, in order to ensure a good solder joint state when soldering between the upper electrode 4 and the connecting terminal 7 using the above-mentioned module assembly method, the left and right semiconductor chips 3 are placed side by side on the insulating substrate 2. It is necessary that the conductor piece of the connecting terminal 7 and the upper surface of the upper electrode 4 overlap each other so as to be in close contact with each other in the assembled state. However, parts such as upper electrodes and connection terminals that are bent and formed by press working etc. have variations in size and shape, and deformation may occur when the parts are handled after being formed.

Therefore, as shown in FIG.
When soldering between the upper electrode 4 and the upper electrode 4, if there is variation or deformation in the height dimension h of the upper electrode 4 (either the upper side 4a or the lower side 4b of the U-shaped upper electrode 4 is inclined), the upper Parallelism cannot be obtained between the upper surface of the electrode 4 and the surface of the connection terminal 7, and a gap is created between the two on the soldering surface. For this reason, in the soldered state, the solder layer 9 takes the form shown in the figure, resulting in poor soldering, and when thermal or mechanical stress is applied, the solder joints peel off, reducing the reliability of the product. significantly reduced. Furthermore, if the amount of solder is increased to fill the gap on the soldering surface, there is a risk that the solder will drip onto the semiconductor chip 3 due to the gap, causing defective chip characteristics.

The present invention has been made in consideration of the above points, and even if there are variations or deformations in the dimensions and shapes of each component when soldering between the upper electrode and the connection terminal, these dimensions can be fixed. It is an object of the present invention to provide an internal connection structure for a semiconductor device that can compensate for errors and deformation and ensure a good soldering condition.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the present invention targets the above-mentioned diode module, etc., and provides a groove portion into which a connecting terminal fits into the upper surface side of the upper electrode of the semiconductor chip. A connection terminal is inserted into this groove and soldered.

Furthermore, the groove in the above structure is formed between the upper surface of the upper electrode and the side wall portions rising upward from the left and right edges of the upper surface, and the side wall portions are formed by bending. be able to.

[0009]

[Function] With the above configuration, when stacking the connecting terminal on top of the upper electrode and soldering between them, even if there is some dimensional variation or deformation of each part, the connecting terminal will fit into the groove and Since it faces the electrode, if the amount of solder is sufficient, the solder held in the groove will normally solder connect the two. Moreover, since the groove functions to prevent the molten solder from spilling out or dripping, even if the amount of solder is increased somewhat, there is no risk of excess solder dripping onto the semiconductor chip.

0010

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention which is applied to the diode module shown in FIG. 3, and the same members corresponding to FIGS. There is. That is, the U-shaped upper electrode 4 mounted on the semiconductor chip 3 has side wall portions 4c and 4d that rise upward at right angles from the left and right edges of the upper side 4a, and are bent. A U-shaped groove 4e is formed between the electrode 4d and the upper surface of the electrode 4. Moreover, this groove portion 4
The groove width e is selected in accordance with the dimensions (width of the electrode conductor piece) of the mating connection electrode 7 that is soldered to the upper electrode 4. When soldering the connection electrodes 6 and 7 to the upper electrode 4, the connection electrodes are attached to the left and right side walls 4c and 4d.
In this state, the upper electrode 4 and the connecting electrode 7 are soldered together.

[0011]

[Effects of the Invention] As described above, according to the internal connection structure of the present invention, when the connection terminal is stacked on the upper electrode and the two are soldered, there is no possibility of slight dimensional variation or deformation of each component. Even if there is, if the amount of solder is sufficient, the solder held in the groove can successfully solder connect the two. Furthermore, the groove prevents the molten solder from protruding or dripping, so even if the amount of solder is increased, there is no risk of excess solder dripping onto the semiconductor chip, thereby improving soldering workability. .

[Brief explanation of the drawing]

[Fig. 1] An exploded perspective view of the main structure showing the internal connection structure of the embodiment of the present invention.

[Figure 2] Assembly diagram of a semiconductor device adopting the internal connection structure shown in Figure 1

[Figure 3] Assembly configuration diagram of a conventional semiconductor device

[Figure 4]
Equivalent circuit diagram of Figure 3

[Figure 5] Exploded perspective view of the main structure in Figure 3

[Figure 6] Diagram showing the soldered state in Figure 5

[Explanation of symbols]

3 Semiconductor chip 4 Upper electrode 4a Top side 4c Side wall part 4d Side wall part 4e Groove 6 Connection terminal 7 Connection terminal

Claims (3)

[Claims] Claim 1: A semiconductor device in which a U-shaped upper electrode is mounted and bonded on a semiconductor chip, and a connecting terminal is overlaid and soldered on the upper surface of the upper electrode, wherein the connecting terminal is fitted onto the upper surface of the upper electrode. An internal connection structure for a semiconductor device, characterized by forming a groove into which the semiconductor device fits. 2. The internal connection structure according to claim 1,
1. An internal connection structure for a semiconductor device, wherein a groove portion is formed between an upper surface of an upper electrode and side wall portions rising upward from both left and right edges of the upper surface. 3. The internal connection structure according to claim 2,
An internal connection structure for a semiconductor device, characterized in that a side wall portion is formed by bending.