JPS5890748A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain specified brazing strength without deterioration of electrical and mechanical characteristics by providing a metal which is easily wet by brazing material at the brazing area and by providing a means for repelling the brazing material to the brazing-free area. CONSTITUTION:On the occasion of coupling a stad 16 and an insulated wall member 17, for example, with the Silver-Copper eutectic braze 14, the surface of stad 16 is plated by the Ni 15, for example, which is easily wet by the braze 14, the Ni 15 is partly removed exposing the surface of stad 16 which repels the braze and a groove 21 or extrusion 22 is provided therein. Thereby, the fitting area of semiconductor element is not in contact with the brazing material at the wall member fitting area. Accordingly, corrosion of brazing material and deterioration of coupling by chemical reactions based on mixture of them can be prevented and the specified brazing strength can be acquired easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device, and particularly to a semiconductor device having a wax part. With the development of small electronic circuit devices, especially hybrid integrated circuits or high-frequency semiconductor devices, various insulating materials are being used. As is well known, the recent trend toward miniaturization of electronic circuits and demands for electrical properties have placed significant restrictions on the materials and physical structures used, and it has become difficult to achieve the required properties. There are quite difficult problems to be solved in order to satisfy all requirements. One of the most important problems is brazing. When brazing a soldering element that covers a limited space such as an electronic circuit board or a container, in order to ensure the specified brazing strength, it is necessary to balance the characteristics of the constituent materials, metallization technology, and brazing technology. However, in many cases, the problem cannot be solved simply by considering electrical aspects such as crystal frequency characteristics or simply from the aspect of brazing technology. For example, when a metallized layer 2 is applied to the surface of an insulating substrate 1 as shown in FIG. 1, and a flat glue 3 is brazed to the layer 2, Jl! In order to obtain the required brazing strength, the width of the metallized layer, the width of the lead, and the brazing material4
The amount must be selected accordingly. For example, when manufacturing an electronic circuit board that uses ceramic with a low dielectric constant and good heat dissipation as an insulating substrate and has a desired characteristic impedance, it is necessary to give priority to electrical characteristics, so a metallized layer is There are many J11 fists that are difficult to obtain the specified metallization strength and brazing strength due to the plate width of the lead. This effect is particularly noticeable in electronic circuits used in high frequency ranges. To solve this problem, various methods have been proposed up to now.As shown in FIG. Is it possible to alleviate the strain by allowing the brazing filler metal 4 to accumulate in the brazed part?
As shown in Figure 3, there is a metallized layer on a part of the side surface of the insulating substrate 1! There is a method of increasing brazing strength by creating a brazing pool during brazing. Other methods have also been proposed, such as providing a hole in the brazing part of the external lead 3 or creating a shape as shown in FIG. 4 to make it easier for the brazing material 4 to accumulate. However, in the case of FIG. Since the brazing filler metal 4 flows to other parts of the external lead 3, it is difficult to make a solder reservoir with a good yield, and in the case of the structure shown in FIG. It has the disadvantage of increasing the substantial capacitance between the layer 2' and the backside metallization 2', impairing the electrical properties. Also, even if the shape of the external lead is modified, the wax yield may be slightly improved, but no essential solution will be obtained.

On the other hand, when considering the assembly of electronic circuits, lumberjacks may experience problems such as failure to mount or bond the electronic circuit elements due to leakage and mounting or bonding with thin metal wires, etc. Even if bonding is possible, there are disadvantages such as increasing thermal resistance, increasing connection stray capacitance, or even if bonding is possible, bonding strength is weak, and bonding ink strength decreases in long-term time tests. Especially for semiconductors. Insert the element airtight□
No effective method has been proposed for the brazing structure of wall members used in this process.

An object of the present invention is to provide a novel semiconductor device that can easily secure a predetermined brazing strength without deteriorating other electrical and mechanical properties, especially in the brazing structure of a wall member. 0 The present invention provides a semiconductor device in which a wall member and a semiconductor element are mounted on a metal body, in which a brazing material is applied to a portion of the metal body that faces a surface on which the semiconductor element plate is attached and a surface on which the wall member is attached. A metal member that is easily wetted is provided, and a means for repelling the brazing material used for the wall member mounting is provided between the semiconductor element mounting portion and the wall member mounting portion. The brazing part is equipped with a metal member that the brazing material easily wets (easily adapts to), and a means for repelling the brazing material is provided to define the boundary of the area where the brazing material should not flow out, so it is not necessary to attach the element. There is no contact between the brazing material and the wall material used, and corrosion of the brazing material due to chemical reactions caused by internal mixing and deterioration of mounting properties can be prevented. All you have to do is make a groove or a dam to expose the entire surface that is difficult to get wet (especially if you use a metal surface). As a result, it is possible to easily form a wax sump only in the soldering area, and at the same time, it is possible to prevent the above-mentioned problems due to the leakage of the soldering material that occurs in the conventional technique.

In other words, in the present invention, the brazing material is prevented from spreading by the brazing material repelling means and is rather repelled to the place where it should be brazed by the brazing material repelling means, so that very effective brazing can be achieved. .

Next, in order to clarify the gist of the present invention more specifically, a description will be given based on a 6ζ embodiment with reference to FIGS. 5 and 6.

FIG. 5 is a cross-sectional view of one embodiment of the present invention. In this example, an insulating wall member 17 (e.g. alumina) (e.g. alumina) applied to a stud (heat spreader) 16 (e.g. copper) using conventional multilayer ceramic technology The member 17 is provided with a metallized layer to serve as an electrode of the container and a metallized layer IFI to be brazed to the stud 16, and an external lead 13 is brazed to the wall member to form the container. A semiconductor element 19 (e.g. -jf) is formed inside the mosquito container.
In a semiconductor device, for example, PET, in which a thin metal wire (e.g., gold wire) is mounted and the capacitance of the semiconductor element 19 is electrically connected to the semiconductor container by means of a thin metal wire (e.g., gold wire), the stud 16 and the insulating wall are connected. The member 17 and the brazing material 14
(for example, silver-copper eutectic solder), when brazing the stud 16
A metal layer 15 (for example, N
After applying i) by plating or the like, a part of the solder metal layer 15 is removed to expose the metal layer that is difficult to wet with the brazing material, that is, for example, by cutting etc., #121 is provided, or as shown in FIG. As shown, a protrusion 22 is provided on the stud 16. If these grooves 21 or protrusions η are formed with thick studs wetted with the brazing material, the mounting portion of the semiconductor element and the bonding portion of the metal #1 wire are completely hidden from the brazing material of the wall member.

In addition, to prevent the wax from flowing, apply a wax flow prevention agent, etc.
Alternatively, a method such as partially forming a glass and fogging layer can be considered, but it requires advanced technology to apply and remove the wax flow preventive agent, and installing a glass or oxidized layer requires an oxidizing atmosphere or a reducing atmosphere. This is not a desirable method because it causes material deterioration due to cycles, requires advanced technology for the installation and removal of the layer, and requires a considerable number of man-hours for both techniques.

In addition, in Fig. 5, even if the filler metal 14 gets into the groove, the filler metal that has entered will be thrown out, so this will not have any adverse effects.In addition, the filler metal will shrink to the metal layer 14 around the groove. Therefore, the connection strength can be significantly improved. This effect is
The same can be said for the protrusion in Figure 6, where the brazing material does not creep up at all, making bonding on the protrusion better. Therefore, it is possible to greatly reduce the inductance that affects the high frequency characteristics.

Although the present invention has been described above with respect to its preferred embodiments,
Of course, this is merely an example and does not have a restrictive meaning. Accordingly, the present invention may be practiced with various modifications without departing from the spirit and scope of the invention, but all such modifications are included within the scope of the claims hereinbefore set forth.

[Brief explanation of drawings]

Figure 1 shows the basic factors in brazing technology, Figures 2 to 4 are diagrams for explaining conventional brazing technology, Figure 5 and #! 6
The figure is a sectional view of a semiconductor device according to an embodiment of the present invention. 1... Insulating substrate, 2.12... Metallized layer, 3.13... External lead, 4.1
4...brazing metal, 5.15...metal layer with wet brazing metal, 16...stud, 17...
... Insulating wall member, 18 ... Metallized layer, 19 ... Semiconductor element, Addition ...
・Thin metal wire, 21...Groove, η...Protrusion 1st day 2nd day 5mth 5th figure 6 Oral procedure amendment (side 57.12.29 Patent Director-General of the Agency 1, Indication of the case 1981 Patent Application No. 7694
No. 1, No. 2, Title of the invention: Semiconductor device 3, Relationship to the amended person case Applicant: 5-33-1-4, Shiba 5-chome, Minato-ku, Tokyo, Agent: 5-37-8 Shiba, Minato-ku, Tokyo 108 Resident Mita Building 6 Drawing subject to amendment 7 Contents of amendment Regarding patent application No. 100939/1982, May 7, 1982
I have submitted two divisional applications (Application No. 41 @ No. 57-76941; Japanese Patent Application No. 57-76942) on the same date, but due to a clerical error, I attached the wrong drawings. We have attached the correct drawings in this amendment, so please review them again. -〕・ Knee butterfly 25th $3rd ¥4 bean paste

Claims (1)

[Claims] In a semiconductor device in which a semiconductor element and a wall member that hermetically encapsulates the semiconductor element are brazed onto a metal body, a metal member that is easily wetted by the brazing material is provided on the surface of the metal body in a portion where the wall member and the semiconductor element are brazed. 0, and a means for repelling a brazing material for attaching the wall member toward the wall member is provided between the semiconductor element and the wall member.