JPH08222661A - Semiconductor - Google Patents

Abstract

PURPOSE: To prevent the air from being trapped into mold resin by employing an insulating substrate or a metal substrate having specified center line mean roughness on the lower surface thereof. CONSTITUTION: An insulating substrate 1 fixed with a semiconductor element and outer lead terminals 2 has center line mean roughness Ra regulated by JIS-B-0601 in the range of 0.5μm○ai2.0μm on the lower surface thereof. When the insulating substrate 1 having upper surface fixed with a semiconductor element 3 and outer lead terminals 2 is set in a predetermined jig and a liquid epoxy resin, for example, is injected into the jig in order to coat the semiconductor element 3 with mold resin 6, fluidity of liquid resin on the lower surface of the insulating substrate 1 is substantially equalized to that on the upper surface side thus preventing the air from being trapped into the mold resin 6 effectively. Consequently, the semiconductor element 3 is sealed hermetically with the mold resin 6 and can be operated normally and stably over a long time.

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 in an information processing device such as a computer.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device used in an information processing device 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 from the periphery of the die pad at predetermined intervals, and the semiconductor element. element,
A lead frame, which is composed of a die pad and a mold resin that covers a part of the external lead terminals, and in which the die pad and a large number of external lead terminals are integrally connected and formed via a frame-like connecting band, is prepared. A semiconductor element is mounted and fixed on the upper surface of the die pad of the lead frame, and then each electrode of the semiconductor element and an external lead terminal are electrically connected through 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 metal processing such as conventionally known punching or etching. Produced by.

Further, in such a conventional semiconductor device, after covering a part of the semiconductor element and the external lead terminal with a molding resin, the external lead terminal is cut and separated from a frame-shaped connecting band,
By electrically separating each external lead terminal and connecting each external lead terminal to the external electric circuit, the internal semiconductor element is electrically connected to the external electric circuit.

[0005]

However, in recent years,
The number of electrodes of semiconductor devices is rapidly increasing due to the higher density and higher integration, and along with this, the external lead terminals for connecting each electrode of the semiconductor device to an external electric circuit have a line width of 0.3 mm. The distance between the external lead terminals is as narrow as the following, and the distance between the adjacent external lead terminals is extremely narrow at 0.3 mm or less.
Therefore, this conventional semiconductor device is easily deformed by an external force when the 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 come into contact with each other to cause a short circuit,
It has a drawback 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 substrate having a mounting portion on which a semiconductor element is mounted in the central portion 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 peripheral portion, and the insulation 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 including a plurality of external lead terminals attached to the other end of the wiring layer and connecting a semiconductor element to an external electric circuit, and a mold resin covering a part of the insulating substrate, the semiconductor element and the external lead terminal. A device, or a metal base having a mounting portion on which a semiconductor element is mounted in the center of the top surface, and a plurality of wiring layers attached to the outer circumference of the top surface of the metal base and leading out in a fan shape from the inner circumference to the outer circumference. An insulating frame having the same, a semiconductor element mounted on the mounting portion of the metal base and having an electrode connected to one end of the wiring layer, and attached to the other end of the wiring layer to attach the semiconductor element to an external electric circuit. A semiconductor device including a plurality of external lead terminals to be connected and a mold resin that covers 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 spreading in a fan shape, the external lead terminals are effectively prevented from being deformed by increasing the line width and the adjacent space of the external lead terminals. It is possible to maintain the electrical insulation between the adjacent external lead terminals.

However, in these semiconductor devices, an insulating base having a semiconductor element and external lead terminals mounted and attached on the upper surface, or a metal base having the semiconductor element, an insulating frame and external lead terminals arranged on the upper surface is predetermined. When set in the jig, liquid resin such as epoxy is dropped and injected into the jig, and then the injected resin is heated at a temperature of about 180 ° C for 100K.
The insulating substrate, the semiconductor element, etc. are covered with the mold resin by applying a pressure of gf / mm ² and thermosetting, and the insulating substrate and the metal substrate generally have a center line average roughness (Ra) of Ra.
Since a liquid resin such as epoxy is dropped into a jig in which an insulating substrate or a metal substrate is set, the fluidity of the liquid resin on the lower surface of the insulating substrate or the lower surface of the metal substrate is the upper surface because the smoothness is ≦ 0.3 μm or less. As a result, air is enclosed in the mold resin, a through hole is formed in the mold resin, the airtight sealing of the semiconductor element is broken, and the semiconductor element is kept normal for a long period of time. It becomes impossible to operate it stably, or the air inside the mold resin blocks the conduction and dissipation of heat to the outside, and the semiconductor element becomes high temperature due to the heat generated by the semiconductor element itself, causing the semiconductor element to be destroyed by heat or its characteristics. The drawback is that it induces change.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and its purpose is to effectively prevent air from being trapped in the mold resin, and to keep the semiconductor element normal for a long period of time.
Another object of the present invention is to provide a semiconductor device that can be stably operated.

[0010]

According to the present invention, there is provided an insulating base having a mounting portion on which a semiconductor element is mounted in a central portion of an upper surface and a plurality of wiring layers extending in a fan shape from a periphery of the mounting portion to an outer peripheral portion, and the insulating body. It is mounted on the semiconductor element mounting part of the base,
A semiconductor element having electrodes connected to one end of the wiring layer, a plurality of external lead terminals attached to the other end of the wiring layer to connect the semiconductor element to an external electric circuit, the insulating substrate, and the semiconductor element. And a mold resin that covers a part of the external lead terminals, wherein the surface roughness of the lower surface of the insulating substrate is 0.5 μm in terms of center line average roughness (Ra) specified in JIS-B-0601. ≦ Ra ≦ 2.0 μm
It is characterized by being.

Further, according to the present invention, 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 metal bases attached to the outer peripheral surface of the upper surface and led out in a fan shape from the inner peripheral portion to the outer peripheral portion. An insulating frame having a wiring layer, a semiconductor element mounted on a semiconductor element mounting portion of the metal base, and having electrodes connected to one end of the wiring layer; and a semiconductor element attached to the other end of the wiring layer. What is claimed is: 1. A semiconductor device comprising: a plurality of external lead terminals for connecting an element to an external electric circuit; and a metal base, an insulating frame, a semiconductor element, and a mold resin that covers a part of the external lead terminal. It is characterized in that the surface roughness of the lower surface is 0.5 μm ≦ Ra ≦ 2.0 μm in terms of center line average roughness (Ra) specified in JIS-B-0601.

[0012]

According to the semiconductor device of the present invention, the lower surface of the insulating base or the metal base on which the semiconductor element and the like are arranged is JIS.
-B-0601 has a center line average roughness (Ra) of 0.
Since it is a rough surface of 5 μm ≦ Ra ≦ 2.0 μm, an insulating substrate on which a semiconductor element and an external lead terminal are mounted and attached on the upper surface, or a metal substrate on which a semiconductor element, an insulating frame and an external lead terminal are arranged Is set in a predetermined jig, and when a liquid resin such as epoxy is dropped into the jig and the semiconductor element or the like is covered with the mold resin, the flowability of the liquid resin on the lower surface of the insulating substrate or the lower surface of the metal substrate is reduced. The flowability on the upper surface side is almost equal to effectively prevent the inclusion of air in the molding resin, and as a result, the semiconductor element is completely hermetically sealed with the molding resin, and the semiconductor element is kept normal for a long period of time. In addition, it is possible to operate stably and dissipate the heat generated during the operation of the semiconductor element to the outside well,
It is possible to effectively prevent the semiconductor element from being thermally destroyed and the characteristics from being thermally changed.

[0013]

The present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a semiconductor device of the present invention, 1 is an insulating substrate, 2 is an external lead terminal, and 3 is a semiconductor element.

The insulating base 1 has a mounting portion 1a on the upper surface of which a semiconductor element 3 is mounted, and the mounting portion 1a is covered with an adhesive material such as resin, glass or brazing material. It is adhesively fixed through.

The insulating substrate 1 is made of an electrically insulating material such as 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. When it is made of an aluminum-based sintered body, it is made into a sludge form by adding and mixing an appropriate binder and solvent to raw material powders of aluminum oxide, silicon oxide, calcium oxide, magnesium oxide, etc. A ceramic green sheet (ceramic green sheet) is obtained by forming it into a sheet shape by a calender roll method or the like, and thereafter, the ceramic green sheet is punched into an appropriate shape by a punching method or the like, and a plurality of sheets are laminated as necessary. Finally, in the reducing atmosphere, the ceramic green sheet is about 160
It is manufactured by firing at a temperature of 0 ° C.

On the upper surface of the insulating substrate 1, a large number of wiring layers 4 that spread out in a fan shape from the periphery of the semiconductor element mounting portion 1a to the outer peripheral portion are adhered and formed, and the wiring layer 4 is surrounded by the semiconductor element mounting portion 1a. The electrodes of the semiconductor element 3 are electrically connected to each other via bonding wires 5, and external lead terminals 2 connected to an external electric circuit are attached to the outer peripheral portion of the insulating substrate 1.

The wiring layer 4 is made of a metal material such as tungsten, molybdenum, manganese and aluminum. By surrounding the semiconductor element mounting portion 1a of the insulating substrate 1 by printing and applying the metal paste thus obtained in advance to the ceramic green sheet to be the insulating substrate 1 in a predetermined pattern by a thick film method such as a conventionally known screen printing method. From the aluminum to the outer peripheral portion so as to spread in a fan shape, and when it is made of aluminum or the like, 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. The film is processed into a predetermined pattern by 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 have a function of connecting the semiconductor element 3 housed therein to an external electric circuit, and the external lead terminals 2 serve as wiring conductors of the external electric circuit board. By connecting, the semiconductor element 3 is electrically connected to the external electric circuit via the wiring layer 4 and the external lead terminal 2.

In the external lead terminal 2, the wiring layer 4 to which the external lead terminal 2 is attached spreads in a fan shape from the periphery of the semiconductor element mounting portion 1a located in the central area of the upper surface of the insulating substrate 1 to the outer peripheral portion, and insulation is provided. Since the line width in the outer peripheral portion of the base 1 and the space between the adjacent wiring layers 4 are wide, the line width and the space between adjacent wiring layers can be wide, and as a result, external force is applied to the external lead terminals 2. Does not cause large deformation of the external lead terminals 2, and the external lead terminals 2 are accurately and accurately connected to a predetermined external electric circuit while maintaining electrical insulation between the adjacent external lead terminals 2. It is possible to make a reliable electrical connection.

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

The external lead terminals 2 are attached to the wiring layer 4 by connecting the external lead terminals 2 to the wiring layer 4 through a brazing material made of gold-tin-lead-silver alloy or gold-tin-lead-palladium alloy. By brazing or external lead terminal 2
Is ultrasonically bonded 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 transducer (horn) is placed on the external lead terminal 2 at 0.5 to 5.0 kgf /. mm
Pressing with pressure of ² and vibration frequency 20-60KHz, amplitude
It is performed by applying ultrasonic vibration of 1.0 to 10.0 μm for 0.3 to 1.0 seconds.

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 epoxy resin or the like, leaving a part of the external lead terminals 2, and the semiconductor element 3 is The semiconductor device as the final product is obtained by completely shutting off from the outside air.

To cover the semiconductor element 3 and the external lead terminals 2 with the mold resin 6, the insulating substrate 1 having the semiconductor element 3 and the external lead terminals 2 attached to the upper surface is set in a predetermined jig and the curing is performed. Liquid resin such as epoxy is dropped into the tool, and then the injected resin is thermally cured by applying a temperature of about 180 ° C. and a pressure of 100 Kgf / mm ² .

The lower surface of the insulating substrate 1 to which the semiconductor element 3 and the external lead terminals 2 are attached is JIS-B-0.
The center line average roughness (Ra) specified in 601 is 0.5 μm ≦
The roughness is Ra ≦ 2.0 μm, whereby the insulating substrate 1 having the semiconductor element 3 and the external lead terminals 2 mounted and attached on the upper surface is set in a predetermined jig, and epoxy or the like is placed in the jig. When the semiconductor element 3 and the like are covered with the molding resin 6 by dripping and injecting the liquid resin, the flowability of the liquid resin on the lower surface of the insulating substrate 1 becomes substantially equal to the flowability on the upper surface side, so that air flows into the molding resin 6. The hugging is effectively prevented, and as a result, the semiconductor element 3 is completely hermetically sealed with the molding resin 6, and the semiconductor element 3 is kept normal for a long period of time.
In addition, the semiconductor element 3 can be stably operated, and the heat generated during the operation of the semiconductor element 3 is satisfactorily dissipated to the outside through the insulating substrate 1 and the molding resin 6, so that the semiconductor element 3 is always kept at a low temperature and thermally destroyed by the semiconductor element 3. It does not occur that the heat generation occurs or the characteristics change due to heat.

The roughness of the lower surface of the insulating substrate 1 has a center line average roughness (Ra) of 0.5 μm ≧ Ra, or Ra ≧ 2.
When it becomes 0 μm, when liquid resin such as epoxy is dropped and injected into the jig in which the insulating base 1 is set, the flowability of the liquid resin on the lower surface of the insulating base 1 becomes different from that on the upper surface side, and the mold is formed. The air is caught in the resin 6. Therefore, the roughness of the lower surface of the insulating substrate 1 is specified in the range of 0.5 μm ≦ Ra ≦ 2.0 μm in terms of center line average roughness (Ra).

FIG. 2 shows another embodiment of the present invention. In a semiconductor device, a metal base 11 having a mounting portion 11a on which a semiconductor element 10 is mounted in the center of the top surface, and an outer peripheral portion of the top surface of the metal base 11. Is mounted on the semiconductor element mounting portion 11a of the metal base 11 and the insulating frame 13 having a plurality of wiring layers 12 which are attached to the outer peripheral portion in a fan shape from the inner peripheral portion to the outer peripheral portion, and the electrodes are mounted on the wiring layer 12 A semiconductor element 10 connected to one end of the wiring layer 12, a plurality of external lead terminals 14 attached to the other end of the wiring layer 12 for connecting the semiconductor element 10 to an external electric circuit, the metal base 11, an insulating frame. Body 13, semiconductor element 10 and external lead terminals
It is formed of a mold resin 15 which covers a part of 14.

In such a semiconductor device, the wiring layer 12 provided on the insulating frame body 13 spreads in a fan shape from the inner peripheral portion to the outer peripheral portion, and the line width in the outer peripheral portion of the insulating frame body 13 and the space between the adjacent wiring layers 12 are arranged. The wiring layer 12
The external lead terminal 14 attached to the external lead terminal 14 can also have a wide line width and a large adjacent spacing, and as a result, even if an external force is applied to the external lead terminal 14, the external lead terminal 14 is largely deformed. External lead terminals 14 while maintaining electrical insulation between adjacent external lead terminals 14.
Can be accurately and reliably electrically connected to a predetermined external electric circuit.

Further, in such a semiconductor device, the surface roughness of the lower surface of the metal substrate 11 is 0.5 μm ≦ Ra ≦ 2.0 μm in terms of center line average roughness (Ra) specified in JIS-B-0601. A metal substrate 11 having the semiconductor element 10, the insulating frame 13 and the external lead terminals 14 arranged on the upper surface is set in a predetermined jig, and a liquid resin such as epoxy is dropped and injected into the jig to form the semiconductor element 10 When coating etc. with mold resin 15,
The flowability of the liquid resin on the lower surface of the metal substrate 11 is substantially equal to the flowability on the upper surface side, and the air is effectively prevented from being trapped in the mold resin 15. As a result, the semiconductor element
10 is completely hermetically sealed with mold resin 15
It becomes possible to operate the semiconductor device 10 normally and stably for a long period of time, and the heat generated during the operation of the semiconductor device 10 is satisfactorily dissipated to the outside through the metal base 11 and the molding resin 15, so that the semiconductor device 10 is always kept at a low temperature. As a result, the semiconductor element 10 will not be thermally destroyed and the characteristics will not be thermally changed.

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

[0030]

According to the semiconductor device of the present invention, the center line average roughness (Ra) specified in JIS-B-0601 is used for the lower surface of the insulating base or the metal base on which the semiconductor element or the like is arranged.
Since it is a rough surface of 0.5 μm ≦ Ra ≦ 2.0 μm, the semiconductor element and the external lead terminal are mounted and attached on the upper surface, or the semiconductor element, the insulating frame and the external lead terminal are arranged on the upper surface. When the metal base is set in a predetermined jig and liquid resin such as epoxy is dropped into the jig to cover the semiconductor element and the like with the mold resin, the liquid resin on the lower surface of the insulating base or the lower surface of the metal base is The flowability is almost equal to the flowability on the upper surface side, effectively preventing the inclusion of air in the molding resin, and as a result, the semiconductor element is completely hermetically sealed with the molding resin and the semiconductor element is kept for a long time. It is possible to operate normally and stably over a long period of time, and to dissipate the heat generated during the operation of the semiconductor element to the outside satisfactorily, which effectively causes the semiconductor element to be thermally destroyed and the characteristics to be thermally changed. Can be prevented.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1-Insulating substrate 1a-Semiconductor element mounting part 2--External lead terminal 3--Semiconductor element 4--Wiring layer 6- .... Mold resin

Claims (2)

[Claims] 1. An insulating base 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 extending in a fan shape from a periphery of the mounting portion to an outer peripheral portion, and a semiconductor element mounting portion of the insulating base. A semiconductor element mounted and having electrodes connected to one end of the wiring layer; a plurality of external lead terminals attached to the other end of the wiring layer for connecting the semiconductor element to an external electric circuit; A semiconductor device comprising a semiconductor element and a mold resin covering a part of an external lead terminal, wherein the surface roughness of the lower surface of the insulating substrate is JIS.
-B-0601 has a center line average roughness (Ra) of 0.
A semiconductor device characterized in that 5 μm ≦ Ra ≦ 2.0 μm. 2. A metal base having a mounting portion on which a semiconductor element is mounted at the center of the top surface, and a plurality of wirings attached to the outer periphery of the top surface of the metal base and led out in a fan shape from the inner periphery to the outer periphery. An insulating frame having a layer, a semiconductor element mounted on a semiconductor element mounting portion of the metal base and having electrodes connected to one end of the wiring layer, and a semiconductor element attached to the other end of the wiring layer to form a semiconductor element. What is claimed is: 1. A semiconductor device comprising: a plurality of external lead terminals connected to an external electric circuit; and a metal base, an insulating frame, a semiconductor element, and a mold resin that covers a part of the external lead terminals. The surface roughness is the center line average roughness specified by JIS-B-0601 (R
The semiconductor device according to a), wherein 0.5 μm ≦ Ra ≦ 2.0 μm.