JPH0783068B2 - Method of manufacturing package for semiconductor device - Google Patents

Description

The present invention relates to a method for manufacturing a semiconductor device package,
In particular, the present invention relates to a method for manufacturing a semiconductor device package which has a simplified process and excellent reliability.

[Conventional technology]

In general, a semiconductor device package that houses a semiconductor element or the like is provided with a plurality of metal terminals for input / output or for applying a DC bias voltage. These metal terminals are brazed to a metallized insulating member in order to maintain insulation between the terminals. Further, in a semiconductor device package in which two or more diode elements or a bipolar silicon transistor element are mounted, the insulating property between the metal terminal and the electrode of the semiconductor element is maintained and the semiconductor element is brazed and fixed. The metallized pattern is formed on the insulating member. Further, the package for hermetically sealing the lid member and the like by brazing has a metallizing pattern for sealing which is insulated from the input / output terminals.

In these semiconductor device packages, miniaturization has been advanced in order to increase the packaging density of external devices in which the semiconductor devices are incorporated.

2A to 2H are package cross-sectional views of a manufacturing process for explaining an example of a conventional method for manufacturing a semiconductor device package. First, a raw sheet plate 1 made of alumina porcelain or the like as shown in FIG. 2 (a) is prepared. Next, as shown in FIG. 2B, the through hole 2 is formed. Then, as shown in FIG. 2 (c), metallized patterns 3a and 3b made of tungsten or the like are formed by printing. Here, 3a represents a metallized pattern for brazing metal terminals and connecting with electrodes of semiconductor elements to be mounted,
3b shows a metallized pattern for brazing and fixing a semiconductor element or the like. FIG. 3 shows an example of a top view of the green sheet plate of FIG. 2 (c). As shown in FIG. 3, the respective metallized patterns 3a and 3b are conductively conductive at this stage.

Next, as shown in FIG. 2 (d), the entire substrate is baked at a predetermined temperature, and Ni plating 4 is applied to the metallized patterns 3a, 3b as shown in FIG. 2 (e). At this time, since the metallized patterns 3a and 3b are electrically connected, it is possible to perform plating with a uniform thickness. Ni plating 4 in this case is
It is applied for the purpose of improving the leakage and adhesion of brazing filler metal. The fired substrate thus obtained is then subjected to a dicing method, a mechanical method or the like as shown in FIG.
Cut along the Y direction. By this cutting process, the metallized patterns 3a and 3b are cut and insulated. Then, as shown in FIG. 2 (g), a metal terminal 6 made of Kovar, an iron-Ni alloy or the like is brazed by a brazing material 5 such as a silver-copper alloy. Each metal terminal 6 is electrically connected by a tie bar frame 61 as shown in FIG. 4 which is a top view after brazing. Finally, as shown in FIG. 2 (h), after the metallized pattern 3b for plating is made conductive with the metallizing jig 7 for plating made of copper or the like, the metal terminal 6 and the metallized pattern 3a are electrically connected. , 3b Ni plating and Au plating 8
Are formed by electroplating. Here, the Ni plating is performed for the purpose of preventing discoloration and corrosion of the brazing part due to thermal diffusion of the silver-copper brazing material 5. Au plating, in the metallized pattern 3b, for the purpose of improving the leakability of a brazing material (not shown) such as an Au—Sn alloy for fixing the semiconductor element,
Further, in the metallized pattern 3a, the electrode (not shown) of the mounted element and the metal terminal 6 are improved in the adhesiveness of the Au wire or the like used for connection, and the metal terminal 6 and the external device are connected. It is applied for the purpose of improving the leakability of a brazing material (not shown) such as a lead-tin alloy used for connection.

[Problems to be solved by the invention]

In such a conventional semiconductor device, the color wire 7 and
Ni plating and Au plating 8 are not attached at the contact A portion (FIG. 2 (h)) with the metallized pattern 3b and the metal terminal 6. Therefore, on the metallized pattern 3b, the adhesion strength of the mounted semiconductor element cannot be obtained, or the contact A portion with the terminal 6 is corroded due to the environmental condition in which the semiconductor device is used. Due to the deposition of corrosive substances, there is a drawback that the insulation between the terminals is deteriorated or a short circuit easily occurs. Not only that, but with the miniaturization of semiconductor devices, the outer shape of the package and the area of the metallization pattern 3b have become smaller, which makes it difficult to connect the color wire 7 and requires a lot of man-hours to carry out the metalization. There was a defect that the yield was lowered due to a defect such as the Ni and Au plating 8 not being attached at all on the pattern 3b, and the cost was likely to increase.

The present invention has been made in view of the above drawbacks,
An object of the present invention is to provide a method of manufacturing a package for a semiconductor device in which the plating process is simplified and the production yield is improved due to the reduction of the number of manipulating steps, and the manufacturing cost is reduced.

[Means for solving problems]

The features of the present invention include the step of forming a through hole in a green sheet made of an insulating member such as alumina porcelain, a first metallized pattern for mounting a semiconductor element on the surface of the green sheet, and a step of connecting with an electrode of the semiconductor element. A second metallization pattern and a connection metallization pattern for interconnecting the first and second metallization patterns are formed, and a third metallization pattern for brazing with metal terminals is formed on the back surface of the green sheet. Forming a front and back penetrating metallization pattern interconnecting a third metallization pattern in the through hole; firing the green sheet to form a fired substrate; Exposing the first, second and third metallized patterns and the connection and the front and back penetrating metallized patterns A step of applying a first noble metal plating on the surface, and thereafter, cutting and dividing the fired substrate including cutting of the connection metallization pattern, whereby the first metallization pattern and the second metallization pattern are separated. Obtaining an intermediate product of individual semiconductor device packages in a state of being cut and separated and having the second and third metallization patterns interconnected by the front and back penetrating metallization patterns; and the third metallization of the intermediate product. Brazing a metal terminal to the pattern with a brazing material, and forming a film by the first noble metal plating on the exposed surface of the metal terminal and the brazing material and on other metallized patterns except on the first metallized pattern A step of applying a second precious metal plating on the exposed surface, thereby mounting a semiconductor element. A film formed by the first noble metal plating is formed as a surface film on the first metallized pattern, and the second film is formed on the metal terminal, the brazing material, and the other metallized pattern.
In a method of manufacturing a package for a semiconductor device, which obtains a package in which a film formed by precious metal plating is formed as a surface film. Here, cutting and division of the fired substrate can be performed by a dicing method. Further, it is preferable to perform the second base metal plating after performing the Ni plating as the base plating.

〔Example〕

Next, the present invention will be described with reference to the drawings. 1 (a) to 1 (h) are cross-sectional views of a semiconductor device package, which are shown in the order of steps for explaining an embodiment of the present invention.
First, as shown in FIG. 1 (a), a green sheet plate 1 is prepared as in FIG. 2 (a). Then, as shown in FIG. 1B, the through hole 2 is formed. Next, FIG. 1 (c)
As shown in, Tungsten metallization patterns 3a, 3b
After printing, the substrate is fired to a predetermined temperature as shown in FIG. Then, the fired substrate thus obtained was formed on the metallized patterns 3a and 3b as shown in FIG. 1 (e).
Apply precious metal plating such as gold plating 9. In this case, since the metallized patterns 3a and 3b are electrically connected as shown in FIG. 3, gold plating 9 having a uniform thickness can be obtained. Here, it has been confirmed by the authors that even if the gold plating 9 is directly applied on the tungsten metallization 3a, 3b, there is no problem in the adhesion strength of the plating. However, in the case of molybdenum or metallization of molybdenum, manganese, etc., it has been confirmed that unless Ni is thinly applied (<0.5 μm), sufficient adhesion strength of plating cannot be obtained. further
If the Ni plating is thicker than 0.5 μm, Ni and Au alloy with each other under the brazing temperature conditions described below, making it difficult to connect Au wires, etc. If the Ni thickness is thin, it is easy to connect Au wires. .

Next, it is cut in the X and Y directions in FIG. 3 by a dicing method or the like to obtain individual pieces of the ceramic substrate shown in FIG. 1 (f).

At this time, the metallized patterns 3a and 3b are insulated.

Thereafter, as shown in FIG. 1 (g), the metal terminal 6 is brazed to the metallized pattern 3b with the copper-copper brazing material 5. After that, as shown in FIG. 1 (h), electrolytic plating of Ni and Au is performed by electrically connecting only the metal terminals 6 without using a plating jig or the like. At this time, each metal terminal 6
Are connected by a tie bar 61 as in FIG.

Thus, the manufacturing of the package is completed. Tie bar
61 may be cut by a press or the like after completion of assembly including mounting of semiconductor elements or the like, or may be cut before use.

In the above embodiments, the example of the package in which the ceramic layer is a single layer has been described, but it goes without saying that a laminated structure can be similarly applied.

〔The invention's effect〕

As described above, according to the present invention, the metallized pattern that is insulated from the metal terminals is preliminarily plated with the noble metal in the state of the ceramic substrate before division in the finished package, so that the plating process after the brazing of the metal terminals is performed. , There is no need to plate on the insulated metallization. Therefore, the number of man-hours for setting the color-changing jig can be omitted, the plating does not adhere to the contacts of the color-changing jig, the mounting strength and the corrosion resistance are excellent, and the man-hours for the work can be shortened and the yield can be improved. It becomes possible to manufacture.

[Brief description of drawings]

1 (a) to 1 (h) are sectional views of a semiconductor package shown in order of steps for explaining an embodiment of the present invention, and FIGS. 2 (a) to 2 (h) are conventional semiconductor device packages. Sectional views of the semiconductor package shown in order of steps for explaining the manufacturing method, FIG. 3 is a partial top view of the substrate shown in FIG. 1 (c) and FIG. 2 (c), and FIG. 4 is FIG. It is a top view for supplementary explanation of the process of (h). 1 ... Raw sheet plate, 2 ... Through hole, 3a, 3b ... Metallized pattern, 4 ... Ni plating, 5 ... Brazing material, 6
…… Metal terminal, 61 …… Tie bar, 7 …… plating jig, 8 …… Ni plating and Au plating, 9 …… Au plating, X,
Y: Cutting position by dicing.

Claims (3)

[Claims] 1. A step of forming a through hole in a green sheet made of an insulating material such as alumina porcelain, a first metallized pattern for mounting a semiconductor element on the surface of the green sheet, and a second connection for connecting an electrode of the semiconductor element. And a connection metallization pattern for interconnecting the first and second metallization patterns, and a third metallization pattern for brazing with metal terminals on the back surface of the green sheet. Forming a through-hole metallization pattern for interconnecting the metallization patterns of No. 3 in the through hole; baking the green sheet to form a baked substrate; and the first interconnected on the baked substrate. And exposed surfaces of the second and third metallized patterns and the connection and the front and back penetrating metallized patterns A step of applying a first noble metal plating thereon, and thereafter cutting and dividing the fired substrate including cutting of the connection metallization pattern, thereby cutting the first metallization pattern and the second metallization pattern. Obtaining an intermediate product of individual semiconductor device packages in a state in which the second and third metallization patterns are interconnected by the front and back penetrating metallization patterns; and the third metallization pattern of the intermediate product. And brazing the metal terminal with a brazing material, and exposing the film by the first noble metal plating on the exposed surface of the metal terminal and the brazing material and on other metallized patterns except on the first metallized pattern. The step of applying a second precious metal plating on the surface of A film formed by the first noble metal plating is formed as a surface film on the first metallized pattern, and a film formed by the second noble metal plating is formed on the metal terminal, the brazing material, and the other metallized pattern. A method of manufacturing a package for a semiconductor device, which comprises obtaining a package formed as a surface film. 2. A method for manufacturing a semiconductor device package according to claim 1, wherein the firing substrate is cut and divided by a dicing method. 3. A method of manufacturing a package for a semiconductor device according to claim 1, wherein the second noble metal plating is applied after the Ni plating is applied as a base plating.