JPS61154151A - Semiconductor device - Google Patents

Abstract

PURPOSE:To ensure high reliability with respect to insulation and adhesive property, by bonding and fixing the inner leads of a multiple-pin leadframe by polyimide bonding film, in which a fluorine polymer having a specified melting point is made to be a fusing agent, and sealing the lead part with a resin. CONSTITUTION:The inner leads of a multiple-pin leadframe are bonded and fixed by polymide bonding film, in which a fluorine polymer having a melting point of 200-320 deg.C is made to be a fusing agent, and sealed by a resin. As the fluorine polymer, it is desirable to use the polymer including 50-76wt.% fluorine. As the fluorine polymer, a homopolymer or a copolymer of a perfluoroalkene or perfluorovinyl ether is especially suitable. Thus high temperature characteristics are improved and the following defects can be all solved: separating phenomena of the bonding agent during use: corrosion of the leadframe due to teh compositions of the bonding agent during use for a long period; and deterioration of reliability of a semiconductor element.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a semiconductor device in which the inner leads of a multi-pin lead frame are adhesively fixed with a polyimide tape using a fluoropolymer as a fusion agent and sealed with a resin. Regarding 131, the purpose is to fully meet the demands for thinner, smaller, and more functional semiconductor devices themselves, which correspond to the thinner and smaller size of electronic equipment. An object of the present invention is to provide a semiconductor device that does not interfere with single-twist bonding between a semiconductor element and an inner lead even if the lead pin spacing is narrow.

(FF view of the invention) In recent years, as semiconductor devices have become more highly integrated, the number of pins on the inner leads of lead frames has increased in the direction of increasing the number of bins, and accordingly, the lead pin spacing has also increased from the conventional 1.78-p.
It is getting shorter to 65++u++Pitusen.

Furthermore, as electronic devices tend to become thinner and smaller,
The thickness of the semiconductor device itself has increased from 2.5ms for a conventional dual in-line package to 1.51ms for a flat package.
1IIIl, the trend is toward thinning.

Therefore, a slight deformation between the inner leads tends to interfere with the wire bonding between the semiconductor element and the inner leads, and a semiconductor device manufactured with such deformation between the inner leads lacks reliability as a semiconductor device. There was a drawback.

(Conventional disadvantages) Therefore, in order to solve the conventional disadvantages, the inner leads of a multi-pin lead frame are adhesively fixed with an adhesive film and then sealed with resin to prepare a semiconductor device. Attempts have been made to manufacture a semiconductor device that does not impede wire bonding between a semiconductor element and an inner lead even if the number of pins is large and the distance between the lead pins is short.

However, the fixing tape for bonding the inner leads of such a multi-bin lead frame is required not only to have adhesive properties at room temperature but also to have adhesive properties and insulation properties at high temperatures.

The reason for this is that the salinity of the wire bonding between the semiconductor element and the inner lead is 150 to 280 degrees Celsius, so the adhesive fixing tape has high reliability (not only in terms of adhesion at room temperature but also in terms of adhesion at high temperatures). It is necessary that

Therefore, a so-called heat-resistant adhesive-coated polyimide tape, that is, a polyimide-based insulating tape, is made by uniformly coating a heat-resistant polyimide adhesive composition with a heat-resistant adhesive composition and cutting it at a predetermined angle. It was assumed that the conditions were met.

As adhesives that can be applied uniformly to such polyimide-based insulating tapes, conventionally known adhesive compositions include silicone-based adhesives, epoxy-based, phenol-based, acrylonitrile-butadiene rubber-based, butyral resin-based, and acrylic rubber-based adhesives. was.

However, polyimide insulating tapes made using the above-mentioned seed adhesive compositions have weak adhesive strength in high-temperature atmospheres, and as a result, the reliability of the manufactured semiconductor devices is low, and in particular, there are problems such as peeling during use. there were.

In addition, particularly in acrylic rubber-based adhesive compositions, carboxyl group-containing monoethylenic polymers consisting of acidic components such as acrylic acid, methacrylic acid, and itaconic acid are used to increase adhesiveness and react with crosslinking agents. Because the main component is a copolymer of this and acrylic acid ester, the adhesive composition is not chemically neutral and may corrode the lead frame during long-term use, leading to damage to semiconductors. There was a new drawback that reduced the reliability of the device.

(Solution Means) Therefore, as a result of intensive study to eliminate the above-mentioned conventional drawbacks, the inventors of the present invention used a fluoropolymer with a melting point of 200 to 320°C as a fusing agent to bond the inner leads of a multi-pin lead frame. By providing a semiconductor device characterized by being adhesively fixed with a polyimide adhesive film and sealed with a resin, the above-mentioned conventional drawbacks, that is, high temperature characteristics, can be improved, and the peeling phenomenon of the adhesive and the long life can be improved. The present invention has been achieved by completing a semiconductor device that eliminates the drawback that the adhesive composition corrodes the lead frame during use over a period of time, thereby reducing the reliability of the semiconductor device.

(Structure of the Invention) An embodiment of a semiconductor device according to the present invention will be described with reference to its specificity.

FIG. 1 shows a sectional view of an adhesive film for fixing a lead frame used in a semiconductor device according to the present invention.

This adhesive film (1) is made of polyimide film 2.
), and a fusing agent (3) made of a fluorine-based polymer applied by solution coating or melt coating on one side of the film (2).

The fluorine-based polymer used in this invention usually has a fluorine content of 20% by weight or more, preferably 5% by weight or more.
0 to 76% by weight is used.

In this invention, the fluorine-based polymer is
Perfluoroalkene or perfluorovinyl]--
Particularly preferred are homopolymers or copolymers of TE, such as tetraful primary coenalene-hexaful primary copropylene copolymer (hereinafter referred to as FEP), structural formula: [-CIJ-(', F-C)i-
Cdo(OHf)-)n (However, 1, in the formula, Rf is carbon number 7
Hereinafter, mention may be made of a tetraful 1-enalene-perful 1-copinyl ether copolymer (hereinafter referred to as PFA), which is preferably represented by 1 to 3 fluorinated alkyl groups.

Commercial products of the above PFA include Neoso 1con PFA manufactured by Daikin Industries, Ltd. and Teflon PF manufactured by DuPont.
There are A and others.

Other examples of the above-mentioned fluorine-based polymers include those in which part of the fluorine in PFA represented by the above structural formula is replaced with hydrogen, and Polyc-1 corotrifluoro! Coenalene, ethylene-tetrafluoroethylene copolymer, E', 'r'
1'' A), ethylene-1'' trifluoroethylene copolymers, etc. can also be suitably used in the present invention.

In this invention, the thickness of the adhesive film (1) is
Generally, it is desirable to set it to about 7 to 150μ, preferably about 20 to 110μ, among which polyimide-based Noilm (
The thickness of 2) is 5 to 90μ, preferably 10 to 70μ.
It is preferable that

Furthermore, the thickness of the adhesive made of the fluorine-based polymer coated on one side of the film (2) is usually 1 to 30 μm.
, preferably about 5 to 20μ.

FIG. 112 is a plan view of an example of a semiconductor device in which inner leads of a lead frame are adhesively fixed using an adhesive film (C film 0) before resin sealing.

In this drawing, (4) is a lead frame to which an inner lead (5) of a semiconductor device is adhesively fixed using an adhesive film +11.

The means for adhesively fixing the inner lead (5) using an adhesive film ('') is to first cut the adhesive film (1) into a predetermined size, and then attach the adhesive film (1) of a predetermined length to the inner lead (5). Place the adhesive film (1) on top of the adhesive (
3) is carried out by heating and fixing at a temperature at which it melts and softens.

After this, the semiconductor device according to the present invention can be obtained by preparing a semiconductor device according to a conventional method.6 It should be noted that impurities such as chlorine and sodium in the adhesive film should naturally be avoided from the viewpoint of moisture resistance and reliability of the semiconductor device. The fewer ions, the better.
As a specific example of the amount, salt it and sodium amount are each 1
oOpps or less, preferably 50 pp- or less.

(Effects of the Invention) As detailed above, the semiconductor device according to the present invention has inner leads of a multi-pin lead frame having a melting point of 200 to 3.
Since this is a semiconductor device characterized by being adhesively fixed to a resin with a polyimide adhesive film using a fluorine-based polymer as a fusion agent at 20°C, the inner leads are adhesively fixed with this adhesive film. Therefore, the distance between the inner leads can be adjusted to ensure dimensional stability (a fixed semiconductor device can be obtained, and the reliability of the semiconductor device can therefore be made extremely high. Moreover, this adhesive film has a melting point of 200 to 3
150 because it uses a 20°C fluorine-based polymer as a fusion agent and a polyimide film as a base material.
Even under the working temperature of wire bonding between semiconductor elements and inner leads, which is as high as 280°C, high reliability can be ensured in terms of insulation and adhesive properties, and the adhesive properties are also good at room temperature. .

The effects of the invention described above will be explained in more detail by describing examples of the invention.

(Example 1) Kapton film (polyimide film) with a thickness of 20μ
An adhesive film for fixing inner leads according to the present invention was obtained by melt-coating F&, P (mentioned above) (melting point: 270° C.) to a thickness of 10 μm on one side of the film.

Using this film, the lead frame material 427
The inner lead was heat-fixed to a zero plate under the conditions of 350° C., 5-/i, and 5 seconds, and its adhesive strength was examined.

In addition, after bonding, it was placed at 40°C in an atmosphere of 90% R1.
The adhesion retention rate after being left for 8 hours was examined to determine whether the adhesion was good or not.

The results are summarized in Table 1 below along with the results of the values listed below.

(Example 2) FF! An adhesive filno of the present invention was obtained in the same manner as in Example 1 except that PFA (melting point: 305° C.) was used instead of P(7).

The test was conducted in the same manner as in Example 1.

These results are summarized in Table 1 below along with other results described below.

(Example 3) Kapton film (polyimide film) with a thickness of 25μ
An adhesive film of the present invention was obtained in the same manner as in Example 1, except that ETF (melting point: 260°C) was melt-coated to a thickness of 12.5/J on one side of the film.

Tests were conducted in the same manner as in Example 1 using this film.

These results are summarized in Table 1 below along with other results described below.

(Comparative Examples 1 and 2) 70 parts of n-butyl acrylate, 30 parts of acrylonitrile, 5 parts of 2-hydroxyethyl acrylate
j4B, 100 parts of toluene and 0.
The mixture consisting of two parts was heated at 60 to 65°C for 7 hours under stirring in a nitrogen stream to form a viscous solution, and to further increase the polymerization rate, the reaction was continued for 10 hours to reach a polymerization rate of 90% by weight. A copolymer solution was obtained.

To this copolymer solution, (a) was added to 100 parts of the copolymer.
1. Mix the crosslinking agents consisting of the component and the pseudo component in the amounts shown in the table below. Adhesive compositions of Comparative Examples 1 and 2 were prepared.

After uniformly applying this adhesive composition onto Kapton Film N (polyimide film),
The adhesive was left in a dryer for 1 minute to obtain an adhesive film with a polish of 25 μm.

゛) Next, using this film, a test was conducted in the same manner as in Example 1, and the results were as shown in Table 1 below.

(Comparative Example 3) 70 parts of acrylic acid n-butyl ester, 30 parts of acrylonitrile, 50 parts of acrylic Fl12-hydroxyenal ester, 120 parts of toluene, and 0 parts of benzoyl peroxide.
．． A copolymer solution with a polymerization rate of 90% by weight was obtained according to the method described in Comparative Example 1 using a mixture consisting of 2 parts.

To this copolymer solution, (a) was added to 100 parts of the copolymer.
An adhesive composition was obtained by adding the components (1) and (2) in the proportions shown in the table below.

Next, an adhesive film was obtained in the same manner as in Comparative Example 1 using this composition.

Next, using this film, a test was conducted in the same manner as in Example 1, and the results were as shown in Table 1 below.

(Leaving space below) @1 voice ------- (A component: Nidimethacrylic acid ethylene glycol diester, Nakagiri Tomura 12, and 1 Peng, NK Ester IG) (B component: W!M Hibenzoyl ** -・-Tomo η℃ ＊＊＊-・-Tochi℃% When applied in an atmosphere of However, in all Examples and Comparative Examples, the copper phase was
91), another test was conducted in which CD A194 (#-Lin Co., Ltd. WIJ) was used, and results similar to those described above were obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an adhesive film for fixing a lead frame used in a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a semiconductor device in which inner leads of a lead frame are adhesively fixed using an adhesive film. FIG. 2 is an explanatory plan view of an embodiment before resin restraint. (1)--Adhesive film (2)--Polyimide film (3)--Fusing agent (fil-Inner lead Figure 1 Figure 2)

Claims (3)

[Claims] (1) A semiconductor device characterized in that inner leads of a multi-pin lead frame are adhesively fixed with a polyimide adhesive film using a fluorine-based polymer having a melting point of 200 to 320° C. as a fusion agent and sealed with a resin. (2) The semiconductor device according to claim 1, wherein the fluorine-based polymer is a perfluoroalkene homopolymer or copolymer. (3) The semiconductor device according to claim 1, wherein the fluorine-based polymer is a perfluorovinyl ester homopolymer or copolymer.