JP2831219B2 - 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 an improvement in a semiconductor device in which a semiconductor element is housed in a semiconductor element housing package.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device in which a semiconductor element is hermetically housed in a semiconductor element housing package is used for an information processing apparatus such as a computer.

A semiconductor device used in such an information processing apparatus is generally made of an electrically insulating material such as alumina ceramics, and has an insulating base having a mounting portion on which a semiconductor element is mounted at a substantially central portion of the upper surface thereof. An insulating frame body made of a material and having an opening at a central portion so as to surround the semiconductor element mounting portion of the insulating base; and a plurality of external frames for electrically connecting the semiconductor element housed therein to an external electric circuit. Prepare a package for housing semiconductor elements composed of lead terminals and external lead terminals and an insulating frame are sequentially placed on the upper surface of the insulating base, and each is bonded and fixed with a resin adhesive such as epoxy resin and insulated. The semiconductor element is fixed to the semiconductor element mounting portion of the insulating base located in the opening of the frame, and thereafter, each electrode of the semiconductor element is connected via a bonding wire. Part filled with filler such as an epoxy resin with is connected to a lead terminal in the opening of the insulating frame member,
A semiconductor device is obtained by hermetically sealing a semiconductor element.

[0004]

However, recently,
Semiconductor devices are rapidly increasing in density and integration, and the amount of heat generated per unit area and unit volume of semiconductor devices is increasing rapidly. The insulating base of semiconductor device storage package and semiconductor devices are hermetically sealed. Each of the resin fillers is made of alumina ceramics, epoxy resin, etc., all of which have poor thermal conductivity and are difficult to conduct heat. The disadvantage is that the semiconductor element is heated to a high temperature by being accumulated in the insulating base or the resin filler, and as a result, the semiconductor element is thermally destroyed by the heat generated by the element itself, or the characteristics are changed by heat and a malfunction is caused. Had.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to dissipate the heat generated by a semiconductor element to the atmosphere satisfactorily and to keep the semiconductor element at a low temperature in a normal and stable manner for a long period of time. It is to provide a semiconductor device which can be operated.

According to the present invention, a plurality of external lead terminals and an insulating frame having an opening are sequentially attached to a base via an adhesive, and a semiconductor element is accommodated in the opening of the insulating frame. A semiconductor device in which the semiconductor element is hermetically sealed with a resin filler filled in an opening of an insulating frame,
The adhesive has a particle size of 1 to 100 parts by weight of epoxy resin.
200 to 400 parts by weight of silica powder of 50 to 50 μm,
A composite metal formed by adding 1.5 to 15 parts by weight of silica powder having a particle size of 0.5 μm or less, and wherein the base is formed by bonding an aluminum plate to upper and lower surfaces of a plate made of an iron-based alloy; It is characterized by being formed of a body.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a semiconductor device according to the present invention.
Denotes a base, and 2 denotes an insulating frame.

The base 1 has a mounting portion 1c for mounting the semiconductor element 3 substantially at the center of the upper surface thereof. The semiconductor element 3 is bonded and fixed to the mounting portion 1c via an adhesive made of resin or the like. You.

The substrate 1 is made of Kovar metal, 42 alloy,
Above and below the plate-shaped body 1a made of an iron-based alloy such as Invar alloy,
It is composed of a composite metal body to which an aluminum plate 1b is joined. The composite metal body has a thermal conductivity of 50 W / mK or more and is easy to conduct heat. Therefore, even if the semiconductor element 3 generates a large amount of heat during operation, The heat is well absorbed by the base 1 and dissipated into the atmosphere, so that the semiconductor element 3 is always kept at a low temperature so that the semiconductor element 3 can operate normally and stably for a long period of time.

The base 1 made of the composite metal body is composed of a plate 1a made of an iron-based alloy and an aluminum plate 1b. The thermal stress generated due to the difference in the thermal expansion coefficient between the two is canceled on the upper and lower surfaces, and as a result, the substrate 1 is flattened and the semiconductor element 3 is adhered to the upper surface of the substrate 1 with good adhesion. The heat generated by the semiconductor element 3 can be favorably absorbed by the base 1.

The base 1 made of the composite metal body is, for example, an aluminum plate 1b placed on and under a plate 1a made of an iron-based alloy such as Kovar metal. It is manufactured by pressing with a pressure of / cm ² or more.

When the thickness b of the aluminum plate 1b with respect to the thickness a of the plate-like body 1a made of an iron-based alloy is 4.5 <b / a, the coefficient of thermal expansion of the Since the coefficient of thermal expansion of the element 3 is greatly different from that of the element 3, it is difficult to firmly adhere the semiconductor element 3 on the base 1. If b / a <0.2, the thermal conductivity of the base 1 becomes small. It becomes difficult to satisfactorily dissipate the heat generated during operation of the semiconductor element 3 into the atmosphere. Accordingly, it is preferable that the thickness b of the aluminum plate 1b relative to the thickness a of the plate-like body 1a is set to 4.5 ≧ b / a ≧ 0.2.

External lead terminals are also provided on the upper surface of the base 1.
The insulating frame 2 is bonded and fixed via a resinous adhesive 5 with 4 interposed therebetween.

The insulating frame 2 has an opening A at the center thereof, and has a frame shape surrounding the mounting portion 1c of the base 1 on which the semiconductor element 3 is mounted. This insulation frame
2 is the semiconductor element between the opening A at the center and the upper surface of the base 1.
A space for accommodating the semiconductor element 3 therein is formed, and the semiconductor element 3 is bonded and fixed on the semiconductor element mounting portion 1c of the base 1 with an adhesive such as glass, resin, or the like.
In the opening A.

The insulating frame 2 is made of an electrically insulating material such as an aluminum oxide sintered body, and is made of alumina (Al ₂ O ₃ ),
A suitable organic solvent and a solvent are added to silica (SiO ₂ ), calcia (CaO), magnesia (MgO) and the like to prepare a raw material powder, and then the raw material powder is filled into a mold having a predetermined shape. This is pressed at a constant pressure to obtain a formed article, and then manufactured by firing the formed article at a temperature of about 1600 ° C.

An external lead terminal 4 is also sandwiched between the base 1 and the insulating frame 2.
Each electrode of the semiconductor element 3 has a bonding wire at one end
6 and the other end is electrically connected to an external electric circuit via a brazing material such as solder.

The external lead terminal 4 is made of an iron alloy such as Kovar metal (iron-nickel-cobalt alloy) or 42 alloy (iron-nickel alloy), or a copper alloy made of copper, nickel, silicon, zinc, or the like. A metal ingot is formed into a predetermined plate shape by employing a conventionally known metal working method such as a rolling method or a punching method.

When the external lead terminal 4 is coated with silver, aluminum or the like to a thickness of 0.5 to 20.0 μm on its surface by plating, vapor deposition, or cladding, a bonding wire 6 is attached to the external lead terminal 4. When joining
The joining can be made very strong. Therefore, the external lead terminal 4 has silver, aluminum, etc. on its surface.
Preferably, it is applied to a thickness of 0.5 to 20.0 μm.

The external lead terminals 4 are bonded and fixed to the base 1 and the insulating frame 2 via a resin adhesive 5. The resin adhesive 5 is a bisphenol A type epoxy resin of 60 to 80% by weight. Novolak type epoxy resin 20
Silica powder having a particle size of 1 to 50 μm is added in an amount of 200 to 40 parts by weight with respect to 100 parts by weight of an epoxy resin consisting of
It is formed by adding 1.5 to 15 parts by weight of silica powder having a particle size of 0.5 μm or less, and 10 to 40 parts by weight of an imidazole-based curing agent. Inside the epoxy resin, 200 to 400 parts by weight of silica powder having a particle size of 1 to 50 μm and silica powder having a particle size of 0.5 μm or less are used.
Resin adhesive 5 formed by adding 5 to 15 parts by weight
Has a coefficient of thermal expansion close to the coefficients of thermal expansion of the base 1, the insulating frame 2 and the external lead terminals 4, so that the base 1, the insulating frame 2 and the external lead terminals 4 can be bonded very firmly. At the same time, the moisture resistance of the resin adhesive 5 is greatly improved, and moisture is prevented from entering the interior of the semiconductor element 3 from the outside via the resin adhesive 5, and
Oxidation and corrosion due to adhesion of water to the electrodes and the like can be effectively prevented.

To bond the external lead terminals 4 between the base 1 and the insulating frame 2 via the resin adhesive 5, first, a bisphenol A type epoxy resin 60 to 80 Weight% and novolak type epoxy resin 20 ~
200 to 400 parts by weight of silica powder having a particle size of 1 to 50 μm per 100 parts by weight of an epoxy resin composed of 40% by weight,
A resin paste containing 1.5 to 15 parts by weight of a silica powder having a particle size of 0.5 μm or less and 10 to 40 parts by weight of an imidazole-based curing agent is applied by printing using a screen printing method, and then external lead terminals 4 are formed on the upper surface of the base 1. The external lead terminals 4 are fixed on the upper surface of the base 1 by heating the resin paste to a temperature of about 150 ° C. and thermally curing the resin paste. Next, the bisphenol A type is mounted on the lower surface of the insulating frame 2. For 100 parts by weight of an epoxy resin composed of 60 to 80% by weight of an epoxy resin and 20 to 40% by weight of a novolak type epoxy resin, 200 to 400 parts by weight of silica powder having a particle size of 1 to 50 μm.
A resin paste containing 1.5 to 15 parts by weight of silica powder having a particle size of 0.5 μm or less and 10 to 40 parts by weight of an imidazole-based curing agent is printed and applied using a screen printing method, and the resin paste is applied to the external lead terminals 4. Substrate with fixed
This is carried out by placing the resin paste on the upper surface of 1 and then thermally curing the resin paste applied to the lower surface of the insulating frame 2 at a temperature of about 150 ° C.

Further, a resin filler 7 is filled in the opening A of the insulating frame 2, and the semiconductor element 3 accommodated in the opening A of the insulating frame 2 by the resin filler 7 is airtight. Sealed.

A resin filler 7 for hermetically sealing the semiconductor element 3 is made of an epoxy resin, a polyimide resin, a phenol resin, or the like. For example, a liquid resin that becomes a polyimide resin is filled in the opening A of the insulating frame 2. The semiconductor element 3 is filled so as to be completely buried, and is thermally cured at a temperature of about 150 ° C., so that the semiconductor element 3 is disposed in the insulating frame 2 so as to hermetically seal it.

Thus, according to the semiconductor device of the present invention, the external lead terminal 4 is joined to the wiring conductor of the external electric circuit via the solder or the conductive adhesive, and the internal semiconductor element 3 is electrically connected to the external electric circuit. By being connected, it is mounted on an information processing device such as a computer.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention.

[0025]

According to the semiconductor device of the present invention, the base on which the semiconductor element is mounted is formed by bonding an aluminum plate to the upper and lower surfaces of a plate made of an iron-based alloy having a thermal conductivity of 50 W / m · K or more. Even if the semiconductor device generates a large amount of heat during operation, the heat is absorbed by the base and is well radiated into the atmosphere, and as a result, the semiconductor device is kept at a low temperature for a long time. It is possible to operate normally and stably over a period. Further, according to the semiconductor device of the present invention, an epoxy resin is used as a resin adhesive for bonding and fixing the external lead terminals between the base and the insulating frame, and a particle size of 1 to 50 μm with respect to 100 parts by weight of the epoxy resin. Since the silica powder was added with 200 to 400 parts by weight of silica powder and 1.5 to 15 parts by weight of silica powder having a particle size of 0.5 μm or less, the coefficient of thermal expansion of the resin-based adhesive was Approximate the coefficient of thermal expansion of each of the external lead terminals, making it possible to bond the base, the insulating frame and the external lead terminals very firmly, and greatly improve the moisture resistance of the resin adhesive, Water is prevented from entering the inside of the semiconductor device from the outside via the agent,
It is possible to effectively prevent the occurrence of oxidative corrosion due to moisture adhesion to the electrodes and the like of the semiconductor element, and to operate the semiconductor element normally and stably for a long period of time.

[Brief description of the drawings]

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

[Explanation of symbols]

 1 ... Base 1a ... Plate 1b ... Aluminum plate 2 ... Insulating frame 3 ... Semiconductor element 4 ... External lead terminal 5 ... .... Resin adhesive 7 ... Resin filler A ... Opening

Claims (2)

(57) [Claims] A plurality of external lead terminals and an insulating frame having an opening are successively attached on a substrate via an adhesive, and a semiconductor element is accommodated in the opening of the insulating frame and the semiconductor is mounted. A semiconductor device in which an element is hermetically sealed with a resin filler filled in an opening of an insulating frame, wherein the adhesive has a particle size of 1 to 50 μm per 100 parts by weight of an epoxy resin.
m to 200 to 400 parts by weight of silica powder, particle size 0.5
The base is formed of a composite metal body in which an aluminum plate is joined to upper and lower sides of a plate-like body made of an iron-based alloy, to which 1.5 to 15 parts by weight of silica powder of μm or less is added. A semiconductor device characterized in that: 2. The semiconductor device according to claim 1, wherein the composite metal body has a thickness b of the aluminum plate with respect to a thickness a of the plate-like body satisfying 4.5 ≧ b / a ≧ 0.2.