JPH06224364A - Terminal pin - Google Patents

Abstract

PURPOSE:To embody a terminal pin having a large mechanical strength and a small resistivity for use in a substrate of semiconductor package or in a connector, etc. CONSTITUTION:A terminal pin used in a substrate of semiconductor package or in a connector, etc., is constituted by a cylindrical body 17 made of kovar and a core material 18 made of copper provided in the cylindrical body 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal pin used for a substrate or a connector of a semiconductor package.

[0002]

2. Description of the Related Art FIG. 3 is a cross-sectional view showing the whole of a semiconductor package. Reference numeral 1 is an insulating substrate made of ceramic or the like, and a large number of terminal pins 2 are implanted therein. The insulating substrate 1 is covered with a cap 3 for hermetic sealing, and the outer circumference 3 of the cap is covered.
A space between the o and the insulating substrate 1 is sealed by the brazing material 4 or welding.

In the cap 3, the semiconductor chip 5 is mounted on the insulating substrate 1, and the space between the semiconductor chip 5 and the conductor pattern 6 of the insulating substrate 1 uses the bumps 7 and the leads 8 in the tab system. Face down bonding is performed in advance by a flip chip method or the like, and each terminal of the semiconductor chip 5 and the terminal pin 2 of the insulating substrate 1 are electrically connected.

A heat radiating member 10 is inserted from the opening 9 of the cap 3 and die-bonded to the back surface of the semiconductor chip 5, and a space between the inner circumference 3i of the cap 3 and the heat radiating member 10 is sealed with a brazing material. There is.

FIG. 4 is a sectional view of the position of the terminal pin 2 on the substrate 1 of FIG. The head 11 of the terminal pin 2 is brazed to the pad 12 of the substrate 1. The inside of the substrate 1 is generally formed by laminating a large number of insulating layers 13 as shown in the drawing, and the conductor patterns 14 and 6 formed on the surfaces of the insulating layers
The space between the two is filled with the through hole of the insulating layer 13
It is configured to be connected by 5.

By the way, in the case of a semiconductor device having pin grid array type terminal pins as shown in the figure, especially for a narrow pin pitch of 0.4 mm to 1.0 mm, the terminal pin 2 made of nickel (Ni) is used. Has been.

[0007]

In terms of conductivity, Ni is
Although copper (Cu) is superior to Cu, Cu is not suitable as a terminal pin because it has low mechanical strength and is easily deformed.
Therefore, Ni-made terminal pins have been used conventionally, but with the recent increase in the density of semiconductor devices and the like, the pitch of the terminal pins has become narrower, and as a result, the outer diameter of the terminal pins has become smaller. There is.

If the terminal pins are miniaturized in this way, Ni
It has become a problem that the strength is insufficient even when manufactured and it is easily deformed, and a terminal pin having high strength and low resistivity is demanded.

A technical problem of the present invention is to realize a terminal pin having a large mechanical strength and a low resistivity by paying attention to such a problem.

[0010]

FIG. 1 is a sectional view for explaining the basic principle of a terminal pin according to the present invention. According to the invention of claim 1, in a terminal pin used for a substrate or a connector of a semiconductor package, the terminal pin 16 is composed of a cylindrical body 17 made of Kovar and copper provided in the cylindrical body 17. It has a core material 18.

[0011]

As described above, in the case of the present invention, the core member 18 made of Cu is inserted into the cylindrical body 17 made of Kovar. Although Cu has a lower resistivity than Ni, it has a lower strength as described above. On the other hand, Kovar has a higher resistivity than Ni, but is stronger.

Therefore, according to the present invention, the electrical continuity is ensured by the inner Cu core 18 and the mechanical strength is ensured by the outer kovar 17, so that the terminal pin as a whole becomes conductive. A terminal pin with excellent mechanical strength can be realized. Moreover, since the outside is a strong kovar, it is not easily damaged during handling. Cu on the inside is easily oxidized, while Kovar on the outside is chemically stable and therefore has excellent durability.

[0013]

EXAMPLES Next, practical examples of how the terminal pin according to the present invention is embodied will be described. FIG. 2 is a sectional view showing an example in which the terminal pin of the present invention is applied to a package of a semiconductor device composed of an integrated circuit, corresponding to FIG.

The terminal pin 16 is made of Kovar (Ni, Co,
Cu core material 18 in a tubular body 17 made of Fe alloy)
The head 19 having an enlarged outer diameter is brazed to the pad 12 on the substrate 1 side.
At this time, it is important that the Cu portion 18 inside is also connected to the pad 12 via the brazing material. In addition, when the semiconductor device is mounted on a printed circuit board or the like, the terminal pin 16
It is essential that the Cu core material 18 is exposed at the terminal pin tips so that the Cu core material 18 at the tip of is connected to the printed circuit board side.

In the embodiment of FIG. 2, when the outer diameter of the cylindrical body 17 made of Kovar is 0.1 mm, the outer diameter of the Cu core material 18 is 0.06 mm, and the total length is 1 mm, the entire terminal pin is obtained. The resistivity is 4.67 (μΩcm), the pin resistance is 59.5 μΩ, and the conductivity is higher than the resistivity 6.8 (μΩcm) and the pin resistance 85.6 μΩ of the terminal pin made of Ni with the same outer dimensions. It is confirmed that the improvement has been made.

Also, for the terminal pin of the same size as described above,
When the pin bending strength and the pin tensile strength were measured, the measured values shown in Tables 1 and 2 were obtained. The pin bending strength is expressed by the load when the bending starts when a load is applied to the intermediate position of the terminal pin.

[0017]

[Table 1]

[0018]

[Table 2]

As is clear from Tables 1 and 2, the conventional N
Compared with the terminal pin made of i, the terminal pin of the present invention made of Cu and Kovar is surely improved in both the pin bending strength and the pin tensile strength. As described above, the mechanical strength is also improved as compared with the conventional Ni-made terminal pin, and it is possible to sufficiently cope with the miniaturization of the terminal pin.

FIG. 2 shows an example implemented in a semiconductor device.
The present invention is effective for, for example, a connector as long as the device has a narrow pin pitch.

[0021]

As described above, according to the present invention, since the Cu core material 18 is inserted into the cylindrical body 17 made of Kovar, the electrical continuity is ensured by the internal Cu material. The mechanical strength can be ensured by the core material 18, and the mechanical strength can be ensured by the Kovar tubular body 17 covering the Cu core material 18. Therefore, the electrical conductivity and the mechanical strength can be surely improved as compared with the conventional Ni-made terminal pins, and the terminal pin pitch of electronic parts can be sufficiently miniaturized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the basic principle of a terminal pin according to the present invention.

FIG. 2 is a sectional view showing an embodiment of a terminal pin of the present invention.

FIG. 3 is a cross-sectional view showing the whole of a semiconductor package.

FIG. 4 is a sectional view showing a conventional terminal pin structure.

Claims (1)

[Claims] 1. A terminal pin used for a substrate of a semiconductor package, a connector, etc., wherein the terminal pin is composed of a cylindrical body (17) made of Kovar and copper provided in the cylindrical body (17). A terminal pin having a core material (18)