JP3350269B2 - Semiconductor device - 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 used for an information processing device such as a computer.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device used for an information processing apparatus such as a computer includes a semiconductor element, a die pad on which the semiconductor element is mounted, a large number of external lead terminals extending at predetermined intervals from the periphery of the die pad, and the semiconductor device. element,
A die pad and a mold resin that covers a part of the external lead terminals are provided, and a lead frame in which the die pad and a large number of external lead terminals are integrally connected to each other through a frame-shaped connection band is prepared. A semiconductor element is mounted and fixed on the upper surface of the die pad of the lead frame. Next, each electrode of the semiconductor element is electrically connected to an external lead terminal via a bonding wire, and one of the semiconductor element, the die pad and the external lead terminal is connected. It is manufactured by covering the part with a mold resin.

The lead frame is made of a metal containing copper or iron as a main component, and a thin plate of the metal containing copper or iron as a main component is subjected to conventionally known metal working such as punching or etching. Produced by

In such a conventional semiconductor device, after a semiconductor element and a part of an external lead terminal are covered with a mold resin, the external lead terminal is cut and separated from a frame-shaped connecting band.
By making each external lead terminal electrically independent and connecting each external lead terminal to an external electric circuit, the internal semiconductor element is electrically connected to the external electric circuit.

[0005]

However, recently,
Semiconductor devices have rapidly increased in density and integration, and the number of electrodes has increased significantly. With this, the external lead terminals connecting each electrode of the semiconductor device to an external electric circuit have a line width of 0.3 mm. The distance between adjacent external lead terminals has become extremely narrow, not more than 0.3 mm.
Therefore, this conventional semiconductor device is easily deformed by an external force when an external force is applied to the external lead terminal, for example, when the external lead terminal is connected to an external electric circuit,
Adjacent external lead terminals may touch and cause a short circuit,
There is a disadvantage that the external lead terminals cannot be accurately and firmly electrically connected to a predetermined external electric circuit.

In order to solve the above-mentioned drawbacks, an insulating base having a mounting portion on which a semiconductor element is mounted at the center of the upper surface and a plurality of wiring layers extending in a fan shape from the periphery of the mounting portion to the outer periphery is provided. A semiconductor element mounted on the mounting portion of the base body and having an electrode connected to one end of the wiring layer;
A semiconductor comprising a plurality of external lead terminals attached to the other end of the wiring layer and connecting the semiconductor element to an external electric circuit, and a molding resin covering a part of the insulating base, the semiconductor element and the external lead terminals A device, or a metal base having a mounting portion on which a semiconductor element is mounted in the center of the upper surface, and a plurality of wiring layers attached to the outer periphery of the upper surface of the metal base and led out in a fan shape from the inner periphery to the outer periphery. An insulating frame body, a semiconductor element mounted on the mounting portion of the metal base, and an electrode connected to one end of the wiring layer, and attached to the other end of the wiring layer, and the semiconductor element is connected to an external electric circuit. A semiconductor device comprising a plurality of external lead terminals to be connected and a mold resin covering a part of the metal base, the insulating frame, the semiconductor element and the external lead terminals has been proposed or considered.

According to such a semiconductor device, since the external lead terminals are attached to the wiring layer which spreads in a fan shape, the line widths and adjacent intervals of the external lead terminals are increased to effectively prevent deformation of the external lead terminals. Electrical insulation between adjacent external lead terminals can be maintained.

However, in these semiconductor devices, an insulating base on which a semiconductor element and external lead terminals are mounted or mounted on an upper surface, or a metal base on which a semiconductor element, an insulating frame and external lead terminals are disposed on an upper surface, is provided. When set in a jig, a liquid resin such as epoxy is dropped into the jig, and then the injected resin is cooled to a temperature of about 180 ° C. and 100 K
The insulating base and the semiconductor element are coated with a mold resin by applying a pressure of gf / mm ² and thermally cured, and the insulating base and the metal base generally have a center line average roughness (Ra) of Ra.
When the liquid resin such as epoxy is dropped and injected into a jig on which the insulating base and the metal base are set, the flowability of the liquid resin on the lower surface of the insulating base and the lower surface of the metal base is higher than 0.3 μm. The flow characteristics on the side are different, as a result, air is entrapped in the mold resin, a through hole is formed in the mold resin, the hermetic sealing of the semiconductor element is broken, and the semiconductor element is normal for a long time, and The semiconductor device cannot be operated stably, or conduction and dissipation of heat to the outside are hindered by air in the mold resin, and the semiconductor device becomes high in temperature due to the heat generated by the semiconductor device itself. The disadvantage of inducing change is induced.

[0009]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to effectively prevent air from being entrapped in a mold resin and to allow a semiconductor element to operate normally for a long period of time.
It is another object of the present invention to provide a semiconductor device which can be operated stably.

[0010]

According to the present invention, there is provided an aluminum oxide sintered body having a mounting portion on which a semiconductor element is mounted at a central portion of an upper surface and a plurality of wiring layers which are led out in a fan-like manner from the periphery of the mounting portion to the outer peripheral portion. Body, aluminum nitride sintered body,
An insulating base made of any of a mullite-based sintered body, a silicon carbide-based sintered body, and a glass-ceramic sintered body, and mounted on a semiconductor element mounting portion of the insulating base; and an electrode connected to one end of the wiring layer. A semiconductor element, a plurality of external lead terminals attached to the other end of the wiring layer and connecting the semiconductor element to an external electric circuit, and an epoxy covering a part of the insulating base, the semiconductor element and the external lead terminal. A semiconductor device comprising a mold resin made of a resin, wherein a surface roughness of a lower surface of the insulating base is 0.5 μm ≦ Ra ≦ 2.0 at a center line average roughness (Ra) specified in JIS-B-0601.
μm.

[0011]

[0012]

According to the semiconductor device of the present invention, the lower surface of the insulating base on which the semiconductor elements and the like are disposed is formed according to JIS-B-06.
0.5 at the center line average roughness (Ra) specified in 01 ≦ R
Since the surface was roughened to a ≦ 2.0 μm, the insulating substrate on which the semiconductor element and the external lead terminals were mounted on the upper surface was set in a predetermined jig, and a liquid epoxy resin was dropped into the jig. When coating semiconductor elements with mold resin
The flowability of the liquid resin on the lower surface of the insulating substrate is almost equal to the flowability on the upper surface side, effectively preventing the entrapment of air in the mold resin. As a result, the semiconductor element is completely hermetically sealed with the mold resin. In addition, it is possible to operate the semiconductor element normally and stably for a long period of time, and to radiate the heat generated during the operation of the semiconductor element to the outside. It can be effectively prevented from being invited.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows an embodiment of a semiconductor device according to the present invention, wherein 1 is an insulating base, 2 is an external lead terminal, and 3 is a semiconductor element.

The insulating substrate 1 has a mounting portion 1a in the center of the upper surface on which the semiconductor element 3 is mounted. The mounting portion 1a is made of a semiconductor element 3 made of an adhesive such as resin, glass, brazing material or the like. It is bonded and fixed through.

The insulating substrate 1 is made of an electrically insulating material made of any of an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body and a glass ceramic sintered body. For example, in the case of an aluminum oxide sintered body, a raw material powder such as aluminum oxide, silicon oxide, calcium oxide, and magnesium oxide is mixed with a suitable binder and a solvent to form a slurry, which is then mixed with a conventionally known doctor. A ceramic green sheet (ceramic green sheet) is obtained by forming into a sheet by a blade method, a calendar roll method, or the like. Thereafter, the ceramic green sheet is punched into an appropriate shape by a punching method or the like, and a plurality of sheets are formed as necessary. And finally, the ceramic green sheet is placed in a reducing atmosphere for about 16 hours. It is manufactured by firing at a temperature of 0 ° C..

The insulating substrate 1 is formed with a large number of wiring layers 4 extending in a fan shape from the periphery of the semiconductor element mounting portion 1a on the upper surface thereof to the outer peripheral portion thereof, and a portion of the wiring layer 4 around the semiconductor element mounting portion 1a. Each electrode of the semiconductor element 3 is electrically connected via a bonding wire 5, and an external lead terminal 2 connected to an external electric circuit is attached to an outer peripheral portion of the insulating base 1.

The wiring layer 4 is made of a metal material such as tungsten, molybdenum, manganese, or aluminum. When the wiring layer 4 is made of a metal having a high melting point such as tungsten, molybdenum, or manganese, an appropriate binder or solvent is added to a powder of tungsten or the like. The metal paste obtained as described above is applied to a ceramic green sheet serving as the insulating substrate 1 in a predetermined pattern in advance by a known thick film method such as a screen printing method, so that the periphery of the semiconductor element mounting portion 1a of the insulating substrate 1 is formed. From an aluminum or the like, and an aluminum film having a predetermined thickness is deposited on the upper surface of the insulating substrate 1 by a vapor deposition method, a sputtering method, or the like. Process the film into a predetermined pattern using the well-known photolithography technology It is deposited and formed so as to fan out to the outer portion from the semiconductor element mounting portion 1a around on the insulating substrate 1 by Rukoto.

The external lead terminals 2 attached to the wiring layer 4 serve to connect the semiconductor element 3 housed therein to an external electric circuit, and connect the external lead terminals 2 to the wiring conductors of the external electric circuit board. By the connection, the semiconductor element 3 is electrically connected to an external electric circuit via the wiring layer 4 and the external lead terminal 2.

The external lead terminal 2 has a wiring layer 4 to which the external lead terminal 2 is attached. The wiring layer 4 extends in a fan shape from the periphery of the semiconductor element mounting portion 1a located in the center region of the upper surface of the insulating base 1 to the outer peripheral portion. Since the line width at the outer peripheral portion of the base 1 and the space between adjacent wiring layers 4 are wide, the line width and the space between adjacent lines can be widened. As a result, external force is applied to the external lead terminals 2. Is applied, the external lead terminal 2 does not cause a large deformation, and the external lead terminal 2 is accurately connected to a predetermined external electric circuit while maintaining electrical insulation between the adjacent external lead terminals 2. It is possible to reliably perform the electrical connection.

The external lead terminal 2 is made of a metal such as a copper alloy containing copper as a main component or an iron alloy containing iron as a main component. For example, an ingot of a copper alloy containing copper as a main component is used. ) Is formed into a plate having a predetermined thickness by using a conventionally known rolling method, and is subjected to etching or punching to form a predetermined shape.

The external lead terminals 2 are attached to the wiring layer 4 by using a brazing material made of a gold-tin-lead-silver alloy, a gold-tin-lead-palladium alloy, or the like. By external brazing or through external lead terminals 2
To the wiring layer 4, specifically, the external lead terminal 2 is placed on the upper surface of the wiring layer 4, and then an ultrasonic vibrator (horn) is attached to the external lead terminal 2 by 0.5 to 5.0 kgf / mm ²
With a pressure of 20 to 60 kHz and an amplitude of 1.0
It is performed by applying ultrasonic vibration of 110.0 μm for 0.3 to 1.0 second.

Further, the insulating substrate 1 to which the semiconductor element 3 and the external lead terminals 2 are attached is covered with a mold resin 6 made of an epoxy resin except for a part of the external lead terminals 2. By completely isolating the semiconductor device from the semiconductor device, a semiconductor device as a final product is obtained.

The coating of the semiconductor element 3 and the external lead terminals 2 with the molding resin 6 is performed by setting the insulating substrate 1 on which the semiconductor element 3 and the external lead terminals 2 are attached on the upper surface in a predetermined jig, and This is carried out by dropping and injecting a liquid epoxy resin into the component, and then thermally curing the injected resin by applying a temperature of about 180 ° C. and a pressure of 100 kgf / mm ² .

The lower surface of the insulating substrate 1 on which the semiconductor element 3 and the external lead terminals 2 are attached is JIS-B-0.
601: 0.5 μm ≦ in center line average roughness (Ra)
The roughness is Ra ≦ 2.0 μm, whereby the insulating substrate 1 on which the semiconductor element 3 and the external lead terminals 2 are mounted and mounted on the upper surface is set in a predetermined jig. When the semiconductor element 3 and the like are covered with the mold resin 6 by dropping and injecting the liquid resin, the flowability of the liquid resin on the lower surface of the insulating base 1 is substantially equal to the flowability on the upper surface side, so that air is held in the mold resin 6. The semiconductor element 3 is completely hermetically sealed with the mold resin 6 so that the semiconductor element 3 can be operated normally and stably for a long period of time. Heat generated during the operation of the insulating substrate 1 and the mold resin 6
And the semiconductor element 3 is always kept at a low temperature, thereby preventing the semiconductor element 3 from being thermally destructed or causing a characteristic change due to heat.

The roughness of the lower surface of the insulating substrate 1 is such that the center line average roughness (Ra) is 0.5 μm> Ra, or Ra> 2.
When the thickness is 0 μm, when the epoxy liquid resin is dropped into the jig on which the insulating base 1 is set, the flowability of the liquid resin on the lower surface of the insulating base 1 is different from the flowability on the upper surface side, and the molding resin is changed. 6 embraces the air. Therefore, the roughness of the lower surface of the insulating base 1 is specified in the range of 0.5 μm ≦ Ra ≦ 2.0 μm in center line average roughness (Ra).

[0026]

[0027]

[0028]

Thus, the semiconductor device of the present invention is mounted on an information processing apparatus such as a computer by connecting the external lead terminals to an external electric circuit and electrically connecting the internal semiconductor elements to the external electric circuit. .

[0030]

According to the semiconductor device of the present invention, the lower surface of the insulating base on which the semiconductor element and the like are disposed on the upper surface is JIS-B
0.5 μm in center line average roughness (Ra) specified in −0601
Since the surface was roughened so that m ≦ Ra ≦ 2.0 μm, the insulating substrate on which the semiconductor element and the external lead terminals were mounted on the upper surface was set in a predetermined jig, and a liquid epoxy resin was set in the jig. When the semiconductor element and the like are coated with the mold resin by dropping and injecting, the flowability of the liquid resin on the lower surface of the insulating base is substantially equal to the flowability on the upper surface side, and the entrapment of air in the mold resin is effectively prevented. As a result, the semiconductor element is completely hermetically sealed with the mold resin, and the semiconductor element can be operated normally and stably for a long period of time, and the heat generated during the operation of the semiconductor element is radiated well to the outside. In addition, it is possible to effectively prevent the semiconductor element from being thermally destructed or from causing a thermal change in characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a semiconductor device of the present invention.

Claims (1)

(57) [Claims] An aluminum oxide sintered body having a mounting portion on which a semiconductor element is mounted at a central portion of an upper surface, and a plurality of wiring layers which are led out in a fan shape from a periphery of the mounting portion to an outer peripheral portion ;
Aluminum nitride sintered body, mullite sintered body, silicon carbide
Either an elementary sintered body or a glass ceramic sintered body
An insulating base comprising: a semiconductor element mounted on a semiconductor element mounting portion of the insulating base; an electrode connected to one end of the wiring layer; and a semiconductor element mounted on the other end of the wiring layer. A semiconductor device comprising: a plurality of external lead terminals connected to a circuit; and a mold resin made of an epoxy resin covering a part of the insulating base, the semiconductor element and the external lead terminals, wherein a surface roughness of a lower surface of the insulating base is provided. Is the center line average roughness (R) specified in JIS - B - 0601.
a) the semiconductor device according to a), wherein 0.5 μm ≦ Ra ≦ 2.0 μm.