JP2667499B2 - Plastic package for semiconductor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic package for semiconductors, and more specifically, dust in the air adheres to a semiconductor element housed in a hollow portion of a plastic package by static electricity. The present invention relates to a plastic package for a semiconductor that can provide a semiconductor device having good light-transmitting properties by preventing the occurrence of the semiconductor device.

Technical Background of the Invention Recently, CCD (Charge Coupled Device), MOS (Metal Oxi
de Semiconductor), CPD (Charge Primming Device)
Solid-state image sensor such as EPROM (Erasable and Progra
2. Description of the Related Art Semiconductor devices using semiconductor elements, such as memories that can be written and erased by light, such as mmable read only memories, are being widely used as electronic components.

In the above-described optical semiconductor device, if dust adheres to the semiconductor element, the light-transmitting property is lost and the function is impaired. Therefore, dust management is one of the most important issues.

By the way, since the plastic package body used in the semiconductor device as described above is a dielectric (volume resistivity: about 10 ¹⁵ to 10 ¹⁶ Ωcm), static electricity is easily generated. Dust adheres on the semiconductor element housed in the hollow portion of the plastic package body in the process of manufacturing the semiconductor device, and has no light transmission.
Alternatively, there is a problem that the obtained image is damaged.

Conventionally, as a semiconductor device in which the above problems are solved, dust adhered on the semiconductor element accommodated in the hollow portion of the package is removed by cleaning with ultrasonic waves, and There are semiconductor devices manufactured in an environment where cleanliness (class 100 or higher) is ensured.

However, the above-described method of cleaning a semiconductor device is not very efficient, and thus more efficient prevention of dust adhesion has been desired.

Therefore, the present inventors diligently studied and made a heat-resistant resin composition composed of a specific heat-resistant resin, a specific inorganic filler, and a specific conductive filler, and a plastic package having a specific volume resistivity. As a result of manufacturing a semiconductor device using a body, the present inventors have found that the attachment of dust can be prevented more efficiently than in the above-described cleaning method, and have completed the present invention.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to prevent dust in the air from adhering to a semiconductor element housed in a hollow portion of a plastic package body due to static electricity. An object of the present invention is to provide a plastic package suitable for efficiently preventing a semiconductor device having good light transmission.

SUMMARY OF THE INVENTION A plastic package for a semiconductor according to the present invention comprises:
A plastic package having a hollow portion in which a semiconductor element is accommodated and a lead frame, wherein the plastic package comprises a heat-resistant resin (A), an inorganic filler (B), and a conductive filler (C). Made of a water-soluble resin composition and has a volume resistivity of 10 ⁹ to 1
It is characterized in that it is 0 ¹² Ωcm.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the plastic package for a semiconductor according to the present invention will be specifically described.

The plastic package for semiconductor according to the present invention,
CCD, MOS, CPD in the hollow part of the plastic package
This is a package used for a semiconductor device having a light-transmitting property that accommodates a semiconductor element such as a solid-state imaging device such as an EPROM and a semiconductor element such as an EPROM or the like that can be written and erased by light.

The plastic package according to the present invention comprises a heat-resistant resin (A), an inorganic filler (B), and a conductive filler (C).
And a package formed using a heat-resistant resin composition comprising:

Specific examples of the heat-resistant resin (A) used in the present invention include thermosetting resins such as epoxy resins, polyimide resins, bismaleimide triazine resins, phenol resins, unsaturated polyester resins, silicone resins, and urethane resins. No. Among them, epoxy resin and polyimide resin are preferable.

Specific examples of the inorganic filler (B) used in the present invention include heat-resistant inorganic fillers such as silica powder, alumina powder, silica-alumina powder, calcium carbonate powder, and glass fiber. Among them, silica powder and alumina powder are preferred.

In the present invention, usually, an inorganic filler having a particle size of 0.1 to 100 μm, preferably 1 to 40 μm is used. In the present invention,
The amount of the inorganic filler varies depending on the type of the heat-resistant resin (A) and the type of the conductive filler (C).

As the conductive filler (C) used in the present invention,
Specifically, carbon, tungsten, ferrite,
Fine powders of copper, silver, zinc oxide, etc. are used. Among them,
Fine powders of carbon, tungsten and ferrite are preferred.

The particle size of the conductive filler (C) in the present invention varies depending on the type of the conductive filler (C). For example, in the case of carbon, carbon having a primary (agglomerated) particle size of 0.1 to 200 μm is used. In the case of tungsten and ferrite, tungsten and ferrite having a primary (agglomerated) particle size of 0.1 to 50 μm are used.

Further, the compounding amount of the conductive filler (C) in the present invention depends on the particle size of the conductive filler (C), the heat-resistant resin (A).
Depends on the type, the type of inorganic filler, and the particle size.
For example, in the case of carbon, it is preferable to mix it in an amount of 1 to 10% by weight based on 100% by weight of the heat-resistant resin composition. In the case of tungsten, 100% by weight of heat resistant resin composition
In the case of ferrite, it is preferable that the amount of the ferrite is 10 to 70% by weight based on 100% by weight of the heat-resistant resin composition.

The above-mentioned heat-resistant resin (A), inorganic filler (B) and conductive filler (C) are usually compounded by heating and kneading using a known melt-kneading apparatus such as a hot roll, a twin-screw extruder or a buscon kneader. Done.

The plastic package having a hollow portion and a lead frame according to the present invention is a heat-resistant resin composition obtained as described above, for example, a pressure of 10 to 2000 kg / cm ² , a molding temperature of 150 to 300 ° C. Then, a plastic package with a lead frame having a hollow portion is manufactured by an insert molding method.

The plastic package for a semiconductor according to the present invention obtained as described above has a volume resistivity of 10 ⁹ to 10 ¹² Ωc.
m, preferably 10 ⁹ to 10 ¹¹ Ωcm. If the volume resistivity of the plastic package body is less than 10 ⁹ Ωcm, current may leak from the lead frame to the plastic package body, causing an error in the detection signal. If the volume resistivity of the plastic package exceeds 10 ¹² Ωcm, static electricity is likely to be generated in the plastic package.

The shape of the hollow portion of the plastic package body according to the present invention is not particularly limited as long as the shape can accommodate a semiconductor element.

A semiconductor device using the plastic package according to the present invention generally includes a semiconductor element and a plastic package having a hollow portion that is a housing portion of the semiconductor element.
It comprises a lead frame, a bonding wire for electrically connecting the electrode of the semiconductor element and the lead frame, and a transparent window material for sealing the entire hollow portion of the plastic package.

As the above-mentioned semiconductor element, specifically, CCD, MOS,
Examples include a solid-state imaging device such as a CPD, a memory that can be written and erased by light such as an EPROM, and the like.

As the lead frame, specifically, 42% Ni
-A metal such as Fe alloy or phosphor bronze is used.

As the above-mentioned bonding wire, specifically,
Gold wire, aluminum wire and the like can be mentioned.

Specific examples of the transparent window material include translucent substrates such as a glass plate, a quartz glass plate, a sapphire plate, a transparent aluminum plate, and a transparent plastic plate.

It is preferable to use an epoxy-based conductive sealant or the like for the seal between the plastic package for semiconductors according to the present invention and the transparent window material.

Effect of the Invention The plastic package for a semiconductor according to the present invention comprises:
It is composed of a heat-resistant resin composition comprising a specific heat-resistant resin (A), a specific inorganic filler (B), and a specific conductive filler (C), and has a specific volume resistivity. The generation of static electricity in the package body is suppressed, and dust in the air does not adhere to the semiconductor element housed in the hollow portion of the plastic package body due to static electricity during the manufacture of the semiconductor device. Is good, and trouble such as image damage due to dust does not occur. Further, according to the plastic package for semiconductor according to the present invention, compared with the conventional method, more efficiently,
It is possible to easily prevent the attachment of dust as described above.

Hereinafter, the present invention will be described with reference to examples, the present invention,
It is not limited to these examples.

Example 1 27 parts by weight of a polyaminobismaleimide resin [K-601, manufactured by Nippon Polyimide Co., Ltd.] and fused silica [Haze Leck RD-8, manufactured by Tatsumori Co., Ltd., average particle diameter 20 to 30 μm]
m] 70 parts by weight and carbon black [Ketjen Black E manufactured by Ketjen Black International Co., Ltd.
C, an average particle diameter of 30 μm] and 3 parts by weight using a heating roll at 120 ° C. for 5 minutes. The kneaded product was cooled and then pulverized to obtain a heat-resistant resin composition.

Then, using this heat-resistant resin composition, a lead alloy 1 made of 4.2 alloy is insert-molded by a transfer molding machine under the following conditions to obtain a plastic package body 2 with a lead frame having a hollow portion as shown in FIG. Obtained.

[Conditions for Insert Molding] After molding at a molding temperature of 200 ° C., a molding time of 5 minutes and a pressure of 100 kg / cm ² , post-curing was performed at 200 ° C. for 12 hours.

The volume resistivity of the obtained plastic package body is 10
It was ¹⁰ Ωcm.

The adhesion of dust to the surface of the hollow portion of the obtained plastic package was evaluated by the following method. The projected surface area of the package is 2.2 cm ² .

[Dust adhesion evaluation method] The hollow package was dried in a clean room of Class 100 (concentration of suspended particles of 0.5 μm or more is 100 particles / ft ³ or less) by ultrasonic cleaning with ultrapure water for 20 minutes. Later, 20
It was confirmed that there was no dust of 5 μm or more under a stereoscopic microscope of ×. After leaving the sample of the example and the sample of the comparative example at the same time in an environment in which the amount of suspended fine particles is not controlled in a class of 100000 or more, the amount of 20
The number of dust particles of 5 μm or more adhering to the package surface was counted with a stereo microscope at × 2.

 Table 1 shows the results of the evaluation.

Comparative Example 1 A plastic package with a lead frame having a hollow portion was obtained in the same manner as in Example 1 except that carbon black was not used.

The volume resistivity of the obtained plastic package body is 10
It was ¹⁶ Ωcm.

The adhesion of dust to the surface of the hollow portion of the obtained plastic package was evaluated in the same manner as in Example 1.

 Table 1 shows the results of the evaluation.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a plastic package body with a lead frame according to the first embodiment. 1. Lead frame 2. Plastic package

Claims (1)

(57) [Claims] 1. A plastic package having a hollow portion for accommodating a semiconductor element and a lead frame, wherein the plastic package comprises a heat-resistant resin (A), an inorganic filler (B), and a conductive filler (C). ), And has a volume resistivity of 10 ⁹ to 10
¹² Ωcm plastic package for semiconductor.