JPH10335511A - Semiconductor package - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a semiconductor package excellent in both high frequency characteristics and connection reliability. [Solution] Wiring board on which semiconductor element can be mounted (10)
And a case (20) surrounding the wiring board (10) and a high-frequency terminal (30), a side conductor layer formed on the side face of the wiring board (10) is extended to the surface of the wiring board. Is formed, and the extended conductor layer (43) is electrically and mechanically connected to the frame portion (20a) of the case (20) by the solder (51). . As a result, the surface area of the solder (51) can be made larger than before, so that distortion on the surface is reduced and the reliability of the solder joint is increased. As a result, electric disturbance of the path of the ground current is reduced, and noise generated in the ground current can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency semiconductor package, and more particularly to a semiconductor package excellent in both high-frequency signal characteristics and connection reliability.

[0002]

2. Description of the Related Art First, a conventional semiconductor package will be described with reference to FIGS. In FIG. 4, reference numeral 1
0 is a wiring board, 20 is a metal case, 20a is a frame, 30
Is a high-frequency terminal, 31 is a center conductor, 40 is a wiring conductor, 50
Is solder. FIG. 5 is a partially detailed view of a cross section taken along line BB ′ of FIG.

In FIG. 5, a wiring conductor 40 includes a solder 50
And is electrically connected to the center conductor 31 via. The first conductor layer 11 serving as a ground layer is a side conductor layer 4.
1 and the side conductor layer 41 is solder 5
1, and is electrically connected to the frame portion 20a of the metal case 20.

In such a conventional example, a high-frequency current propagates to the center conductor 31 via the wiring conductor 40 and the solder 50. At the same time, the ground current propagates from the coaxial conductor 33 to the first conductor layer 11 via the frame portion 20a of the metal case 20, the solder 51, and the side conductor layer 41.

In general, the closer the path of the high-frequency current and the ground current is, the smaller the spatial spread of the lines of electric force and lines of magnetic force is, the less the distortion of the waveform is, and the less the influence of external noise is. In this embodiment, since the side surface conductor layer 41 is connected to the frame portion 20a of the metal case 20 by using the solder 51, the path of the ground current is made close to the path of the high frequency current. A semiconductor package having excellent characteristics can be realized.

[0006]

In the above-mentioned conventional example,
Due to the difference in thermal expansion coefficient between the base 20b of the metal case 20 and the wiring board 10, thermal distortion is applied to the solder 51. As a result, as shown in FIG. 6, a crack C is generated inside the solder 51, and electrical conduction cannot be partially obtained. For this reason, disturbance occurs in the path of the ground current, waveform distortion increases, and the circuit is easily affected by external noise.

An object of the present invention is to provide a high-frequency signal semiconductor package which is excellent in both high-frequency characteristics and connection reliability by preventing the above-mentioned solder cracks from being generated or propagated.

[0008]

A semiconductor package according to the present invention is provided with a wiring board on which a semiconductor element can be mounted, a case including a frame and a base surrounding the wiring board, and provided so as to penetrate the frame. A high-frequency terminal made of a conductive material provided, wherein the wiring conductor of the wiring board and the high-frequency terminal are electrically connected, and a side conductor layer and a frame formed on a side surface of the wiring board are provided. In the semiconductor package to be electrically connected, the side conductor layer has an extension conductor layer extending to a surface of the wiring board, and the extension conductor layer is electrically and mechanically connected to the frame. It is characterized by being connected to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 and 2 are a perspective view and a plan view schematically showing a semiconductor package according to the present invention. FIG. 3 is a partially detailed view of a cross section taken along line AA ′ of FIG.

The semiconductor package according to the present invention differs from the conventional example in that it has an extended conductor layer further extending the side conductor layer. That is, on the surface of the wiring substrate 10, the extended conductor layer 43 formed by extending the side conductor layer 41 is formed so as to sandwich the wiring conductor 40. Since the extended conductor layer 43 is made of a metal layer that is easily wetted by solder, like the side conductor layer 41,
As shown in FIG. 3, the solder 51 can spread to the upper surface of the extended conductor layer 43.

The area of the portion exposed on the surface of the solder 51 is larger than that of the conventional example shown in FIG.
Thermal distortion generated on the surface of the solder 51 is lessened than in the conventional example. Even if a crack occurs in the solder 51, as long as the crack does not extend to the gap between the side surface conductor layer 41 and the frame portion 20a, there is no effect that the ground current path is electrically disturbed. By the above effects, a semiconductor package excellent in both connection reliability and high frequency characteristics can be obtained.

Next, the assembly procedure of the present invention will be described.

First, a metal case 20 having a frame portion 20a and a base 20b is formed by a method such as grinding or precision casting. At this time, a through hole for attaching the high-frequency terminal 30 is also formed in the frame portion 20a. When a ceramic substrate or the like having a small thermal expansion coefficient is used as the wiring board 10, if Kovar having a relatively small thermal expansion coefficient is used as the material of the metal case 20, thermal distortion applied to the solder is reduced, and connection reliability is improved. be able to. next,
In order to ensure the wettability to the solder, a plating layer of nickel or gold is formed on the surface of the metal case 20 (not shown).

A plating layer of nickel or gold is formed on the bottom conductor layer 42, the side conductor layer 41, the wiring conductor 40, and the extension conductor layer 43 of the wiring board 10 in order to ensure wettability to solder. Keep it.

The solder paste is supplied to the upper surface of the base 20b of the metal case in advance, and the wiring board 10 is mounted in the frame portion 20a of the metal case. Extension conductor layer 43
Cream solder is also supplied to the upper surface, and the whole is heated to melt the solder, and cooled to solidify the solder, and then the flux or the like flowing out of the cream solder is washed. Here, if the amount of solder supplied to the upper surface of the extended conductor layer 43 is insufficient and a sufficient solder fillet is not formed, cream solder is supplied again to the upper surface of the extended conductor layer 43 to melt and solidify the solder. Perform

A high-frequency terminal 30 is mounted in a through hole provided in the frame portion 20a. In this embodiment, a spark plug type high-frequency terminal is used, and the frame portion 20 is fitted by screw fitting.
a. As a similar high-frequency terminal, a coaxial conductor 3
A type in which the flange portion of No. 3 is attached to the frame portion 20a using screws may be used. Finally, the center conductor 31 and the wiring conductor 40 are joined by the solder 50 to complete the assembly of the present invention.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.
Various design changes can be made as follows. In the present embodiment, the microstrip line is formed by providing the first conductor layer 11 which is the ground layer immediately below the wiring conductor 40. Here, if a ground layer is also provided immediately above the wiring conductor 40, the wiring structure can be changed to a strip line. In the same plane as the wiring conductor 40, the extension conductor layer 43
The wiring structure can be changed to a coplanar line by providing a ground layer connected to.

[0019]

According to the present invention, since the solder spreads to the upper surface of the extended conductor layer, the surface area of the solder becomes wider than before. For this reason, the strain is alleviated on the surface of the solder, and the generation and propagation of cracks can be prevented. as a result,
Electrical disturbance of the solder joint, which is a path of the ground current, is reduced, and noise generated in the ground current can be reduced.

Therefore, a semiconductor package excellent in both connection reliability and high frequency characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing one embodiment of a semiconductor package according to the present invention.

FIG. 2 is a plan view schematically showing one embodiment of a semiconductor package according to the present invention.

FIG. 3 is a sectional view showing a part of a semiconductor package according to an embodiment of the present invention;

FIG. 4 is a perspective view schematically showing one embodiment of a conventional semiconductor package.

FIG. 5 is a cross-sectional view showing a part of a conventional semiconductor package in detail.

FIG. 6 is a cross-sectional view schematically showing a state where a crack develops in a conventional semiconductor package.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Wiring board, 11 ... First conductor layer, 12 ... Second conductor layer, 20 ... Metal case, 20a ... Frame part, 20b ... Base, 30 ... High frequency terminal, 31 ... Central conductor, 32 ... Dielectric Reference numerals 33, coaxial conductor, 40 wiring conductor, 41 side conductor layer, 42 bottom conductor layer, 43 extended conductor layer, 50, 51
…solder.

Claims (1)

[Claims] A case comprising a wiring board on which a semiconductor element can be mounted, a frame surrounding the wiring board, and a base;
A high-frequency terminal made of a conductor provided so as to penetrate the frame portion, wherein a wiring conductor of the wiring board and the high-frequency terminal are electrically connected to each other and formed on a side surface of the wiring board. In a semiconductor package for electrically connecting a side conductor layer and the frame portion, the side conductor layer has an extension conductor layer extending to a surface of the wiring board, and the extension conductor layer is A semiconductor package electrically and mechanically connected to the frame.