JP3176251B2 - Package for storing semiconductor elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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, especially a semiconductor integrated circuit element such as an LSI (Large Scale Integrated Circuit) is generally made of an electrically insulating material such as alumina ceramics. And a plurality of metallized wiring layers made of a refractory metal powder such as tungsten, molybdenum or the like drawn out from the periphery of the recess to the lower surface of the insulating base. And a plurality of connection pads formed on the lower surface of the insulating base and electrically connected to the metallized wiring layer, ball-shaped terminals made of solder attached to the connection pads, and a lid. The semiconductor integrated circuit device is bonded and fixed to the bottom surface of the concave portion of the insulating base via an adhesive made of glass, resin, or the like. The electrode and the metallized wiring layer are electrically connected via a bonding wire, and a lid is bonded to the upper surface of the insulating substrate via a sealing material such as glass or resin, so that the inside of the container including the insulating substrate and the lid is formed. A semiconductor device as a product is obtained by housing the semiconductor integrated circuit element in an airtight manner.

In such a semiconductor device, a ball-shaped terminal made of solder attached to a connection pad on the lower surface of an insulating substrate is placed and contacted on a wiring conductor of an external electric circuit board, and thereafter,
The ball-shaped terminal is heated and melted at a temperature of about 200 to 250 ° C., and is mounted on an external electric circuit board by joining the ball-shaped terminal to a wiring conductor, and is simultaneously housed in a semiconductor element housing package. Each electrode of the semiconductor integrated circuit element is connected to an external electric circuit via a metallized wiring layer and a ball-shaped terminal.

The semiconductor element housing package usually has a thickness of 2 μm to 8 μm on the surface of a connection pad for firmly attaching a ball-shaped terminal made of solder to the connection pad.
About nickel is layered by plating.

[0005]

However, in this conventional package for housing a semiconductor element, the nickel plating layer is flatly attached to the surface of the connection pad, and the heat of the insulating base made of alumina ceramics or the like is not sufficient. The expansion coefficient is about 6.5 × 10 ⁻⁶ / ° C., whereas the external electric circuit board is generally made of glass epoxy resin and has a thermal expansion coefficient of 2 × 10 ⁻⁵ / ° C. to 4 × 10 ⁻⁵ / ° C. When the semiconductor integrated circuit element is housed inside the semiconductor element housing package and then mounted on an external electric circuit board, the heat generated during operation of the semiconductor integrated circuit element causes the heat generated by the semiconductor integrated circuit element and the external When the voltage is repeatedly applied to both of the electric circuit boards, a large difference is caused between the insulating base of the package for housing semiconductor elements and the external electric circuit board due to the difference in thermal expansion coefficient between the two. A the same time thermal stress is generated will by stripping with nickel plating layer are particle course a ball-shaped terminal connection pad surface acts between a connection pad and the ball-shaped terminals of the insulating base lower surface, as a result,
There is a drawback that the electrodes of the semiconductor integrated circuit element housed in the semiconductor element housing package cannot be electrically connected to a predetermined external electric circuit for a long period of time.

[0006]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object the purpose of firmly attaching a ball-shaped terminal made of solder to a connection pad, and connecting each electrode of a semiconductor integrated circuit element housed therein. An object of the present invention is to provide a semiconductor element housing package that can be reliably electrically connected to a predetermined external electric circuit for a long period of time.

[0007]

According to the present invention, there is provided an insulating base made of a ceramic sintered body and having a mounting part on which a semiconductor element is mounted on an upper surface, and a mounting part on which the semiconductor element of the insulating base is mounted. A plurality of metallized wiring layers made of tungsten or molybdenum led out from the periphery to the lower surface, a plurality of connection pads formed on the lower surface of the insulating base, and electrically connected to the metallized wiring layers, And a ball-shaped terminal attached to the connection pad, wherein the package has a thickness of 0.5 mm on the surface of the connection pad to which the ball-shaped terminal is attached.
A tungsten-nickel alloy layer or a molybdenum-nickel alloy layer having a thickness of from 3 μm to 3 μm is deposited.

[0008]

[0009]

According to the semiconductor device housing package of the present invention, a tungsten-nickel alloy layer or a molybdenum-nickel alloy layer is applied to the surface of the connection pad on which the ball-shaped terminal is to be attached. The bonding strength between the nickel alloy layer or the molybdenum-nickel alloy layer, and the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer and the ball-shaped terminal is strengthened. The large thermal stress caused by the difference in the coefficient of thermal expansion of the electric circuit board does not cause the ball-shaped terminals to separate from the connection pads. As a result, the semiconductor integrated circuit element housed inside the semiconductor element housing package is Each electrode is accurately and electrically connected to a predetermined external electrical circuit for a long period of time. Rukoto is possible.

Further, according to the semiconductor device housing package of the present invention, the thickness of the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer on the surface of the connection pad is set to 0.5.
Since the thickness is set to 3 μm to 3 μm, the bonding between the connection pad and the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer, and the bonding between the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer and the ball-shaped terminal become stronger, and the semiconductor integrated circuit element Connection to an external electric circuit becomes more reliable.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2 show an embodiment of a package for housing a semiconductor element according to the present invention, wherein 1 is an insulating base, and 2 is a lid. The insulating base 1 and the lid 2 constitute a container 4 for housing the semiconductor integrated circuit element 3.

The insulating substrate 1 is provided with a concave mounting portion 1a in which a semiconductor integrated circuit device 3 is mounted and accommodated in the center of the upper surface thereof, and the semiconductor integrated circuit device 3 is mounted on the concave mounting portion 1a. It is bonded and fixed via an adhesive such as glass or resin.

The insulating substrate 1 is made of an electrical insulating material such as an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a glass ceramic sintered body, etc. When it is made of an aluminum oxide sintered body, an appropriate organic binder, a solvent, etc. are added to raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide and the like to form a slurry, which is mixed with a conventionally known doctor blade. A ceramic green sheet (ceramic green sheet) is obtained by molding into a sheet by a method such as a calendering method or a calendering roll method. Thereafter, the ceramic green sheet is subjected to an appropriate punching process, and a plurality of the ceramic green sheets are laminated. C).

The insulating substrate 1 has a plurality of metallized wiring layers 5 extending from the periphery of the concave mounting portion 1a on which the semiconductor integrated circuit element 3 is mounted to the lower surface to the lower surface. A plurality of connection pads 6 to which the layer 5 is electrically connected are formed respectively.

The metallized wiring layer 5 and the connection pad 6
Is made of a high melting point metal powder such as tungsten or molybdenum, and a metal paste obtained by adding a suitable organic binder, a plasticizer, and a solvent to the high melting point metal powder such as tungsten is mixed in advance on a ceramic green sheet serving as the insulating substrate 1. By printing and applying a predetermined pattern by a conventionally well-known screen printing method, a predetermined pattern is adhered and formed at a predetermined position of the insulating substrate 1.

The metallized wiring layer 5 serves to electrically connect each electrode of the semiconductor integrated circuit element 3 to a ball-shaped terminal 7 attached to a connection pad 6 to be described later. Each electrode of the semiconductor integrated circuit element 3 is electrically connected to a region located around the mounting portion 1a via a bonding wire 8.

The connection pad 6 electrically connected to the metallized wiring layer 5 functions as a base metal layer when the ball-shaped terminal 7 is attached to the insulating base 1, and the surface of the connection pad 6 is soldered. Is mounted.

The connection pad 6 to which the ball-shaped terminal 7 is attached is also provided on its surface with an alloy layer 9 of tungsten-nickel or molybdenum-nickel as shown in FIG.
The alloy layer 9 is formed by plating nickel on the surface of the connection pad 6 by a plating method.
By heating to a temperature of 50 to 1000 [deg.] C., a predetermined thickness is formed on the surface of the connection pad 6. in this case,
Since the alloy layer 9 made of tungsten-nickel or molybdenum-nickel is formed by alloying the connection pad 6 and the nickel layer by heating, the alloy layer 9 is very firmly adhered to the connection pad 6, for example, the insulating base 1 and the outside. Even if a thermal stress or the like due to a difference in thermal expansion coefficient from the electric circuit board 10 acts, it does not separate from the connection pad 6. The alloy layer 9 made of tungsten-nickel or molybdenum-nickel has extremely good wettability (reactivity) with respect to solder, so that the ball-shaped terminal 7 made of solder is firmly attached to the connection pad 6 via the alloy layer 9. Be worn.

If the thickness of the alloy layer 9 made of tungsten-nickel or molybdenum-nickel deposited on the surface of the connection pad 6 is less than 0.5 μm, the strength of adhesion to the connection pad 6 is reduced. If the thickness exceeds 3 μm, the alloy layer 9 made of tungsten-nickel or molybdenum-nickel becomes easy to peel.
Are fragile and tend to be broken by an external force and easily peeled off from the connection pad 6. Therefore, the alloy layer 9 made of tungsten-nickel or molybdenum-nickel deposited on the surface of the connection pad 6 has a thickness of 0.1 mm.
The thickness is in the range of 5 μm to 3 μm.

Further, the ball-shaped terminals 7 made of solder attached to the connection pads 6 serve to easily and surely connect the connection pads 6 to the wiring conductors 11 of the external electric circuit board 10. A ball-shaped solder is placed on the surface of the connection pad 6, and then a part of the solder is heated and melted to be attached to the surface of the connection pad 6.

Thus, according to the semiconductor device housing package of the present invention, the semiconductor integrated circuit device 3 is bonded and fixed to the bottom surface of the concave mounting portion 1a of the insulating base 1 with an adhesive, and each of the semiconductor integrated circuit devices 3 The electrodes are electrically connected to the metallized wiring layer 5 via bonding wires 8, and then the lid 2 is joined to the upper surface of the insulating base 1 with a sealing material made of glass, resin, or the like. The semiconductor integrated circuit element 3 is hermetically accommodated inside the container 4 formed of the body 2 to provide a semiconductor device as a product.

In the semiconductor device formed by housing the semiconductor integrated circuit element 3 in the semiconductor element housing package, the ball-shaped terminals 7 on the lower surface of the insulating base 1 are connected to the external electric circuit board 1.
The semiconductor integrated circuit element 3 mounted on the external electric circuit board 10 by being joined to the wiring conductor 11 of the semiconductor integrated circuit 10 and simultaneously housed in the container 4 has the bonding wire 8, the metallized wiring layer 5, and the connection pad. 6 and the wiring conductor 1 of the external electric circuit board 10 via the ball-shaped terminal 7
1 electrically.

Further, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

[0024]

According to the package for housing a semiconductor element of the present invention, a tungsten-nickel alloy layer or a molybdenum-nickel alloy layer is applied to the surface of the connection pad on which the ball-shaped terminal is attached. The bonding strength between the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer, and the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer and the ball-shaped terminal is strengthened, and the connection pad and the ball-shaped terminal are provided on the insulating substrate of the semiconductor element housing package. The large thermal stress caused by the difference in the thermal expansion coefficient of the external electric circuit board and the external electric circuit board does not cause the ball-shaped terminal to peel off from the connection pad. As a result,
The electrodes of the semiconductor integrated circuit device housed in the semiconductor device housing package can be accurately and electrically connected to a predetermined external electric circuit for a long period of time.

According to the package for housing a semiconductor element of the present invention, the thickness of the tungsten-nickel alloy layer or the molybdenum-nickel alloy layer on the surface of the connection pad is set to 0.5.
When the thickness is 3 μm to 3 μm, the connection pad and the tungsten-nickel alloy layer or molybdenum-nickel alloy layer, and the tungsten-nickel alloy layer or molybdenum
The bonding between the nickel alloy layer and the ball-shaped terminal becomes stronger, and the connection of the semiconductor integrated circuit element to the external electric circuit becomes more reliable.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a semiconductor element storage package according to the present invention.

2 is an enlarged cross-sectional view of a main part of the package for housing a semiconductor element shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a ... Concave mounting part on which a semiconductor integrated circuit element is mounted 2 ... Cover 3 ... Semiconductor integrated circuit element 4 ··························································································································· Alloy layer

Claims (1)

(57) [Claims] 1. An insulating base made of a ceramic sintered body and having a mounting portion on which a semiconductor element is mounted on an upper surface, and being led out from the vicinity of the mounting portion on which the semiconductor element is mounted on the insulating base to the lower surface. A plurality of metallized wiring layers made of tungsten or molybdenum, a plurality of connection pads formed on a lower surface of the insulating base, and electrically connected to the metallized wiring layers, and a solder. A tungsten-nickel alloy layer or molybdenum-nickel having a thickness of 0.5 μm to 3 μm on a surface of a connection pad to which the ball-shaped terminal is attached. A package for storing a semiconductor element, wherein an alloy layer is applied.