JP2690666B2 - Manufacturing method of semiconductor device storage package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device housing package for housing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element such as an LSI is made of an electrically insulating material such as alumina ceramics, and is used to form a space for housing a semiconductor element in a substantially central portion of an upper surface. A rectangular insulating substrate having a recess and a plurality of metallized wiring layers extending from the periphery of the recess to the outer periphery of the upper surface; external lead terminals electrically connected to the metallized wiring layer; and a lid. The semiconductor element is glass on the bottom surface of the recess of the insulating substrate,
The electrodes are attached and fixed through an adhesive such as resin or solder, and each electrode of the semiconductor element is connected to a metallized wiring layer through a bonding wire. Finally, a lid is attached to the upper surface of the insulating substrate by glass, resin, or solder. A semiconductor device as a final product is obtained by hermetically sealing a semiconductor element inside a container made up of an insulating substrate and a lid by bonding them via a sealing material such as.

In the above-mentioned package for accommodating semiconductor elements, usually, metallized pads electrically connected to the metallized wiring layer are provided on the outer peripheral portion of the upper surface of the insulating substrate in a peripheral shape at a predetermined interval, and the metallized pads are externally provided. The external lead terminals are electrically connected to the metallized wiring layer by joining the lead terminals with a brazing material such as silver solder.

In order to join the external lead terminals to the metallized pad of the insulating substrate via the brazing material, first, a brazing material such as silver brazing is printed in a square ring shape on the metallized pad of the insulating substrate by a screen printing method. The external lead terminals are placed and aligned on the brazing material at positions corresponding to the metallizing pads on the brazing material, and then heated to a temperature of about 900 ° C. to melt the brazing material to form a metallizing pad. This is done by fixing the external lead terminals with brazing.

When the rectangular annular brazing material is heated and melted to fix the external lead terminals to the metallized pad by brazing, the molten brazing material has a force to shrink due to surface tension and the molten brazing material is metalized. Since the wettability with the pad is good and the pulling force on the metallized pad acts, it is possible to selectively transfer between the metallized pad and the external lead terminal, and firmly fix the external lead terminal to the metallized pad with brazing. Is possible.

[0006]

However, recently,
In the package for storing semiconductor elements, the density of the semiconductor elements accommodated in the package is high and the integration is high, and the number of external lead terminals used in the package is extremely large, and the distance between the individual external lead terminals is narrowed. The space between metallized pads is becoming narrower.

Therefore, when the external lead terminal is brazed to each metallized pad by depositing a square annular brazing material on the metallized pad of the insulating substrate and heating and melting the brazing material, the distance between the metallized pads is reduced. Since the metallized pads are narrow, the shrinkage force due to the surface tension of the molten brazing material between the metallized pads becomes weak, and as a result, the molten brazing material is not divided between the metallized pads and is joined between adjacent metallized pads in a connected state. ,
It has a drawback that adjacent metallized pads are electrically short-circuited.

[0008]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object of the present invention is to firmly fix a predetermined external lead terminal to a metallized pad provided on an insulating substrate without causing a short circuit between the metallized pads. Another object of the present invention is to provide a method for manufacturing a package for housing a semiconductor element, which can ensure reliable bonding.

[0009]

A method of manufacturing a package for accommodating a semiconductor element according to the present invention comprises a rectangular insulating container having a cavity for accommodating a semiconductor element inside,
A semiconductor element storage device in which a plurality of metallized pads to which electrodes of a semiconductor element to be housed inside are electrically connected are attached in a peripheral shape, and external lead terminals are brazed to the metallized pads via a brazing material. The package is characterized in that the external lead terminals are brazed to a metallized pad adhered to an insulating container by the following steps (1) to (4).

(1) A step of circumferentially depositing a plurality of metallized pads on the outer surface of the insulating container so that the ends of the metallized pads alternately project to the outside and the inside, and (2) the ends to the outside. The metallized pads protruding from the first
Joining the strip-shaped brazing filler metal of (1) and connecting them in common, (3) joining each metallized pad whose end protrudes inward to the protruding region and jointly connecting the second strip-shaped brazing filler metal, (4) ) A step of placing the tip portions of the external lead terminals on the metallized pads and heating and melting the first and second band-shaped brazing materials to bond the external lead terminals to the metallized pads.

[0011]

The present invention will now be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a package for housing a semiconductor device to which the manufacturing method of the present invention is applied, 1 is an insulating base, 2 is a lid, and the insulating base 1 and the lid 2 are semiconductors. A container 3 for housing the element 4 is constructed.

The insulating base 1 is made of an electrically insulating material such as alumina ceramics, and a recess 1a for forming a space for accommodating the semiconductor element 4 is formed in a substantially central portion of the upper surface thereof, and the bottom of the recess 1a is formed. The semiconductor element 4 is attached and fixed to the semiconductor element 4 via an adhesive such as glass, resin, or solder.

A metallized wiring layer 5 made of a refractory metal powder such as tungsten or molybdenum is deposited on the insulating substrate 1 from the periphery of the recess 1a to the outer peripheral portion of the upper surface.

The metallized wiring layer 5 serves to electrically connect the semiconductor element 4 housed inside to the outside, and each electrode of the semiconductor element 4 is bonded to a bonding wire around the recess 1a of the metallized wiring layer 5. It is electrically connected via 6.

The metallized wiring layer 5 is formed by depositing a metal such as nickel or gold having a high corrosion resistance and good conductivity on the exposed outer surface by plating to a thickness of 1.0 to 20.0 μm. If so, the metallized wiring layer 5 can be prevented from being oxidized and corroded, and the connection between the metallized wiring layer 5 and the bonding wire 6 can be strengthened. Therefore, in order to prevent the metallized wiring layer 5 from being oxidized and corroded and to make the connection between the metallized wiring layer 5 and the bonding wire 6 strong, nickel, gold or the like must be provided on the exposed outer surface of the metallized wiring layer 5. Excellent corrosion resistance and good conductivity of metal by plating method
It is preferable to coat the layer to a thickness of 20.0 μm to 20.0 μm.

On the outer peripheral surface of the upper surface of the insulating substrate 1, tungsten electrically connected to the metallized wiring layer 5,
A metallized pad 7 made of a refractory metal powder such as molybdenum is adhered and formed, and an external lead terminal 8 is joined to the metallized pad 7 via a brazing material 9 such as silver solder.

The metallized pads 7 act as a base metal for joining the external lead terminals 8 to the insulating base 1, and are arranged in a row along the outer peripheral edge of the insulating base 1 at predetermined intervals. Are alternately projected to the outside and the inside of the insulating base 1.

Since a part of the metallized pad 7 is alternately projected to the outer side and the inner side of the insulating substrate 1, a strip-shaped brazing material is brought into contact with every other metallized pad 7 in the manufacturing method described later. Therefore, it is possible to widen the space between the metallized pads 7 at the portion where the brazing material contacts.

The metallized pad 7 is formed by depositing a metal such as nickel or gold having excellent corrosion resistance and good conductivity on the exposed outer surface by plating to a thickness of 1.0 to 20.0 μm. Thus, the metallized pad 7 can be prevented from being oxidized and corroded, and the metallized pad 7 and the external lead terminal 8 can be joined firmly.
Therefore, the metallized pad 7 is prevented from being oxidized and corroded, and the metallized pad 7 and the external lead terminals 8 are prevented.
In order to form a strong bond with the metallized pad 7, the exposed outer surface of the metallized pad 7 has excellent corrosion resistance against nickel, gold, etc.,
In addition, a metal having good conductivity is used in an amount of 1.0 to 20.
It is preferable to apply a layer to a thickness of 0 μm.

The external lead terminal 8 joined to the metallized pad 7 is 42 alloy (Fe-Ni alloy),
It is a rod-shaped body made of a metal such as Kovar (Fe-Ni-Co alloy) and has a function of electrically connecting the semiconductor element 4 housed inside to an external electric circuit.

Further, 0.1 to 1.0 mm of the inner end portion of the external lead terminal 8 is bent downward at an angle of 45 to 60 °, whereby the tip portion and the metallized pad 7 are connected. A large amount of brazing material pool can be formed between them.

The external lead terminal 8 is formed by depositing a metal having excellent corrosion resistance such as nickel and gold and having good conductivity on the exposed outer surface by plating to a thickness of 1.0 to 20.0 μm. If this is done, the external lead terminals 8 can be prevented from being oxidized and corroded, and the connection between the external lead terminals 8 and the external electric circuit can be made firm. Therefore, in order to prevent the external lead terminals 8 from being oxidized and corroded and to strengthen the connection between the external lead terminals 8 and the external electric circuit, nickel, gold or the like is formed on the exposed outer surface of the external lead terminals 8. It is preferable to deposit a metal having excellent corrosion resistance and good conductivity in a thickness of 1.0 to 20.0 μm by a plating method.

Thus, according to the package for accommodating the semiconductor element of the present invention, the semiconductor element 4 is attached and fixed to the bottom surface of the recess 1a of the insulating substrate 1 via an adhesive such as glass, resin, solder, and the like. Each electrode is electrically connected to the metallized wiring layer 5 via the bonding wire 6, and then the lid 2 is joined to the upper surface of the insulating substrate 1 via a sealing material such as glass, resin or solder, The semiconductor element 4 is hermetically sealed inside the container 3 composed of the insulating base 1 and the lid 2.

Next, a method of manufacturing the semiconductor element housing package of the present invention will be described with reference to FIGS.

First, as shown in FIG. 3, a rectangular insulating substrate 1 having a recess for accommodating a semiconductor element and an external lead terminal 8 are prepared.

The insulating substrate 1 is alumina (Al ₂ O ₃ )
Ceramics are prepared by adding and mixing an appropriate binder and an organic solvent to raw material powders such as silica (SiO ₂ ), calcia (CaO) and magnesia (MgO) to form a sludge and adopting the conventionally known doctor blade method. A green sheet (ceramic green sheet) is obtained, and thereafter, the ceramic green sheet is subjected to appropriate punching processing, and a plurality of the green sheets are laminated to obtain a high temperature (about 160
It is manufactured by firing at a temperature of 0 ° C.

The outer lead terminal 8 is bent at its inner end downward by adopting a metal working method such as rolling, etching or pressing of an ingot (lump) of metal such as 42 alloy or Kovar. It is formed into a rod shape, and its outer ends are connected by the connecting member 10 at predetermined intervals.

The connecting member 10 is an external lead terminal 8
Is held at a predetermined interval, and the external lead terminals 8 are connected to the metallized pads 7 of the insulating substrate 1 and then cut and removed.

The insulating substrate 1 is also formed with a plurality of metallized wiring layers 5 extending from the periphery of the recess to the outer peripheral edge and metallized pads 7 electrically connected to the metallized wiring layers 5. The metallized pad 7 is formed so that its ends alternately project outward and inward.

The metallized wiring layer 5 and the metallized pad 7 are made of a refractory metal powder such as tungsten (W), molybdenum (Mo), and manganese (Mn), and a suitable organic solvent is added and mixed to the metal powder such as tungsten. The metal paste obtained by the above is applied to the surface of the ceramic green sheet to be the insulating substrate 1 in advance by printing and coating using a thick film method such as the well-known screen printing method, so that the insulating paste is formed on the insulating substrate 1. .

Next, as shown in FIG. 4, among the metallized pads 7 formed on the insulating substrate, the metallized pads 7a whose ends project outward are joined to the projecting regions by the first band-shaped brazing material 11a. Then, the metallized pads 7b whose ends are protruded inward are connected to each other by connecting the second strip-shaped brazing material 11b to the protruding regions. The first strip-shaped brazing material 11a and the second strip-shaped brazing material 11b
Is, for example, 72% by weight of silver and 28% by weight of copper, and a brazing material paste obtained by adding and mixing an appropriate binder and solvent to the brazing material powder is used to form a first strip by applying a conventionally known screen printing method. The brazing material 11a is provided with the metallized pads 7a whose ends project outwardly,
1b is annularly arranged on the insulating base 1 so as to commonly connect the respective metallized pads 7b protruding inside the end portion.

Next, the tip of the external lead terminal 8 is placed on each of the metallized pads, and the first and second band-shaped brazing materials 11a and 11b are heated and melted at a temperature of about 900.degree. By transferring the brazing materials 11a and 11b between the metallized pads and the external lead terminals 8, the external lead terminals 8 are brazed to the metallized pads to complete a semiconductor element housing package as a product.

In this case, when the first and second band-shaped brazing materials 11a and 11b are heated and melted, the molten brazing materials 11a and 11b are contracted by the surface tension, and at the same time, the molten brazing materials act. Due to the good wettability between the metallized pads 11a, 11b and the metallized pads 7a, 7b, they are selectively transferred onto the metallized pads 7a, 7b, and the external lead terminals 8 and the metallized pads 7a, 7b are firmly brazed. To do.

The strip-shaped brazing material 11a, 11b has the metallized pad 7b between the adjacent metallized pads 7a, 7a and the metallized pad 7a between the adjacent metallized pads 7b, 7b. 7a, between 7a and metallized pad 7b,
The distance between 7b becomes long, and as a result, each brazing material 11a,
When the external lead terminals 8 are brazed to the metallized pads 7 by heating and melting 11b, the shrinkage force due to the surface tension of the molten brazing material between the metallized pads becomes strong, and each molten brazing material is separated between the metallized pads. The metallization pads are surely separated by, and no electrical short circuit occurs between the adjacent metallized pads.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above-mentioned embodiments, the band-shaped brazing material 11a, Although the paste-like brazing material is used as 11b, a plate-like or rod-like brazing material may be used.

Further, in the above-mentioned embodiment, the band-shaped brazing material 1 is used.
Although silver solder is used as 1a and 11b, solder or other brazing material may be used.

Further, in the above embodiment, the metallized pad 7
The width of the portion protruding from the insulating base 1 to the outside and the inside of the insulating base 1 was formed to be the same as the width of the central portion of the metallized pad 7. However, the width of the protruding portion is the width of the central portion of the metallized pad 7. It may be formed to be about 1.0 to 1.5 times wider.

[0038]

According to the method for manufacturing a package for accommodating semiconductor elements of the present invention, a plurality of metallized pads are arranged in a peripheral shape on the outer surface of the insulating container so that their ends alternately project outward and inward. The metallized pads that are attached to the outer surface of the metallized pad and have their ends protruding outward are commonly connected by bonding a first band-shaped brazing material to the protruding region, and the metallized pads whose end portions protrude inward are Since the second band-shaped brazing material is commonly connected by joining the band-shaped brazing material to each other, the interval between the metallized pads to which the respective band-shaped brazing materials are connected becomes wide. When brazing the external lead terminals, each molten brazing material has a large shrinkage force due to its surface tension and is reliably divided, causing a short circuit between adjacent metallized pads. Not Rukoto, robust external lead terminals to a predetermined metallization pad, it is possible to reliably brazed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a semiconductor element housing package manufactured by a manufacturing method of the present invention.

FIG. 2 is a plan view of an insulating base of the package shown in FIG.

FIG. 3 is an exploded perspective view for explaining the method for manufacturing the semiconductor element housing package of the present invention.

FIG. 4 is an enlarged plan view of a main part of FIG. 3;

[Explanation of symbols]

 1 ... Insulating substrate 2 ... Lid 3 ... Container 4 ... Semiconductor element 5 ... Metallized wiring layer 7 ... Metallized pad 8 ... External lead terminal 11a ... 1st strip brazing material 11b ... 2nd strip brazing material

Claims (1)

(57) [Claims] 1. A plurality of metallized pads, to which electrodes of a semiconductor element to be housed inside are electrically connected, are formed on an outer surface of a rectangular insulating container having a space for housing a semiconductor element therein. A semiconductor element housing package, which is formed by depositing in rows and brazing external lead terminals to the metallized pads via a brazing material, wherein the external lead terminals are insulated by the following steps (1) to (4). A method of manufacturing a package for accommodating a semiconductor device, comprising brazing to a metallized pad adhered to a container. (1) A step of circumferentially depositing a plurality of metallized pads on the outer surface of the insulating container so that the ends thereof alternately project outward and inward, (2) the ends project outward. A step of joining the metallized pads to the projecting regions by connecting them to a first strip-shaped brazing material, and (3) connecting the metallized pads whose ends project inwardly to the projecting regions with a second strip-shaped brazing material. (4) External leads are placed on each metallized pad by placing the tips of the external lead terminals on each of the metallized pads and heating and melting the first and second band-shaped brazing materials. Step of joining terminals.