JP2598585B2 - Epoxy resin composition for semiconductor encapsulation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for a resin-encapsulated semiconductor device capable of making clear markings on its surface by using either a carbon dioxide laser or a YAG laser.

[0002]

2. Description of the Related Art In recent years, due to environmental issues, resin-encapsulated semiconductor devices have been stamped by passing a laser generated from a laser oscillator from an ink stamp requiring pre-cleaning with a chlorofluorocarbon or chlorine-based solvent through a mask that has been die-cut. An image has been focused on the semiconductor device, and the laser marking method has been shifted to a method of applying a predetermined marking or directly writing a character on the semiconductor device by a laser beam. Laser marking methods include pulse marking (mask type) with a carbon dioxide laser, pulse marking (mask type) with a YAG laser, and scan marking (one-stroke writing).

In this marking method, the surface layer of a resin-encapsulated semiconductor device is several μm thick by the energy of a laser beam.
This is a method in which the surface is roughened by breaking to a depth of several tens μm, and the marking is visually recognized as a marking by comparing the surface properties of the broken portion and the non-destructed portion. However, when the marking is performed by using the laser as described above, in the conventional resin-encapsulated semiconductor device, the comparison between the destructive portion and the non-destructive portion is not always good, and therefore, the marking is performed in comparison with ink marking. However, it had a drawback that it could not be clearly seen.

[0004] Furthermore, in the recent trend of high integration, low stress encapsulating materials, in which a silicone compound is added for the purpose of reducing stress, have a more unclear printing than conventional materials. There is a strong demand for improved visibility.

[0005] Under such circumstances, various studies have been made to improve the visibility, and it has been found that it is particularly effective to adjust the components of the coloring agent. For example, diazo-based and azine-based dyes are effective in improving visibility for carbon dioxide laser printing (see, for example, JP-A-60-1).
No. 19760) has also been filed. However, even if such a colorant shows a good seal with a carbon dioxide gas laser, it cannot absorb laser energy at all in the case of a YAG laser, so that the seal is completely invisible. This is thought to be due to the difference in the laser wavelength between the carbon dioxide laser and the YAG laser.

On the other hand, carbon black shows a good seal with a YAG laser, but has a drawback that visibility is poor when a carbon dioxide laser is used. At present, since both a carbon dioxide gas laser printer and a YAG laser printer are used, development of an epoxy resin composition for semiconductor encapsulation having good visibility with either laser type is desired. As described above, none of the conventional epoxy resin encapsulants showed good visibility in both laser types, carbon dioxide gas laser marking and YAG laser marking.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a carbon dioxide laser marking machine, Y
An object of the present invention is to provide an epoxy resin composition for encapsulating a semiconductor in which marking by a laser can be clearly seen even when stamped by an AG laser stamping machine, even in a relatively dark atmosphere, or when the resin molded portion is gray or black.

[0008]

That is, the present invention provides an inorganic filler, an epoxy resin, a phenol resin, a curing accelerator, a silicone compound and a mixture of compounds represented by the following formulas (1), (2) and (3). An epoxy resin composition for semiconductor encapsulation comprising an anthraquinone-based black colorant as an essential component, and containing 0.1 to 2.0% by weight of the anthraquinone-based black colorant in the entire resin composition.

[0009]

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That is, as the epoxy resin composition, a thermosetting resin, particularly one containing an epoxy resin as a main component, has been widely used. Such a resin composition containing an epoxy resin as a main component is generally other than an epoxy resin,
Usually, a curing agent, a curing accelerator, a filler, and a release agent are blended, and if necessary, a flame retardant, a coloring agent, a coupling agent, and the like are blended. As the pigment, carbon black or a diazo dye is usually used. In a resin-sealed semiconductor device obtained by sealing using such a resin composition,
As described above, in any of the carbon dioxide gas laser and the YAG laser, the contrast between the destructed portion and the non-destructed portion on the semiconductor device surface by the laser beam is not clear, and the marking is not clearly seen.

The present inventor has conducted various studies with the aim of obtaining a clear comparison between a destructed portion and a non-destructed portion on the surface of a semiconductor device by laser light. As a result, the present inventors have found that an anthraquinone-based colorant has a great effect. As a result of further study focusing on this dye, formulas (1), (2) and (3)
Anthraquinone-based black colorant consisting of a mixture of the compounds shown in (1) (hereinafter referred to as anthraquinone-based mixed black colorant)
It has been found that the use of a laser makes the contrast between the destructive part and the non-destructive part clear in any laser marking. As a result of further research based on this, anthraquinone-based black colorant was added to the entire resin composition in an amount of 0.1%.
By adding 2.0% by weight (hereinafter abbreviated as%), the sharpness of the marking is particularly improved, and even if the resin molded portion of the semiconductor device is colored such as gray or black, the atmosphere is relatively dark. It has been found that even underneath the markings are clearly identifiable and the invention has been reached.

The epoxy resin composition for encapsulation of the present invention comprises an epoxy resin, a phenolic resin, a curing accelerator, a silicone compound, an inorganic filler such as fused silica or crystalline silica, and an anthraquinone-based mixed black colorant as essential components. In addition, if necessary, a silane coupling agent, a brominated epoxy resin, a flame retardant such as antimony trioxide, hexabromobenzene, a release agent such as a natural wax and a synthetic wax and various additives are appropriately blended. No problem.

In order to produce the encapsulating epoxy resin composition of the present invention as a molding material, the epoxy resin, phenolic resin, curing accelerator, silicone compound, filler, and other additives are sufficiently homogenized by a mixer or the like. , And then melt-kneaded with a hot roll or a kneader, cooled, and pulverized to obtain a molding material.

These molding materials can be applied to electronic parts or sealing, coating and insulation of electronic parts. The epoxy resin used in the present invention is not particularly limited in molecular structure, molecular weight and the like as long as it is a compound having at least two epoxy groups in its molecule, and is generally used as a sealing material. For example, bisphenol A epoxy resin, bisphenol F epoxy resin,
Bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alicyclic epoxy type epoxy resin, glycidyl ester type epoxy resin, diglycidylamine type epoxy resin, isocyanurate type epoxy resin, bisphenol A or bisphenol F And aldehydes of formaldehyde and glycidyl ethers thereof, and their halides and hydrogenated products. These may be used alone or in combination of two or more.

[0015] Further, as the phenol resin of the curing agent,
Novolak-type phenolic resins and modified resins thereof, for example, phenol novolak, O-cresol novolak, and alkyl-modified phenol novolak resins and the like. These may be used alone or in combination of two or more. Absent.

The mixing ratio of the epoxy resin and the curing agent is such that the equivalent ratio of the epoxy group of the epoxy resin to the hydroxyl group of the curing agent is 0.5.
It is desirably within the range of ~ 5. If the equivalent ratio is less than 0.5 or more than 5, the moisture resistance, the molding workability and the electrical properties of the cured product are undesirably deteriorated.

The curing accelerator used in the present invention may be any as long as it promotes the reaction between the epoxy group and the phenolic hydroxyl group, and those commonly used in sealing materials can be widely used. For example, diazabicycloundecene (DBU), triphenylphosphine (TPP), dimethylbenzylamine (BDMA), 2-methylimidazole (2MZ), or the like is used alone or in combination of two or more.

The filler used in the present invention includes fused silica, crystalline silica, alumina, silicon nitride, magnesium oxide and the like, and these may be used alone or as a mixture of two or more. Examples of the silicone compound include silicone oil, silicone rubber, and silicone gel. These compounds may be used alone or as a mixture of two or more kinds, and are blended to impart low stress to the epoxy resin composition. As the colorant, an anthraquinone-based mixed black colorant is used, and this colorant is represented by formulas (1), (2),
This is a fine powder dye mixture containing the three compounds shown in (3).

The anthraquinone-based mixed black colorant accounts for 0.1 to 2.0%, more preferably 0.1 to 2.0%, of the total composition.
The content is preferably 3 to 1.5%. That is, when the added amount of the anthraquinone-based mixed black colorant is less than 0.1%, the contrast between the destructed portion and the non-destructed portion is not clear, and when it exceeds 2%, the resin device is sealed. This is because defects such as a decrease in the reliability (moisture resistance) are caused.
In particular, when the content of the anthraquinone-based mixed black colorant is set to 0.3 to 1.5%, the marking becomes remarkably sharp. The anthraquinone-based mixed black colorant contains 5% by weight of any of the compounds of formulas (1), (2) and (3).
Must be included. If even one compound is less than 5% by weight, the desired blackness cannot be obtained. In addition, a coloring agent conventionally added to the resin composition, such as carbon black, may be used together with the coloring agent. As described above, the use of this anthraquinone-based mixed black colorant as a colorant is a major feature of the present invention, whereby clear marking can be performed even in a relatively dark atmosphere or a resin molded part is gray or black. Will be done.

Hereinafter, the present invention will be specifically described with reference to Examples.

[0021]

Example 1 Fused silica 68.0 parts by weight O-cresol novolak epoxy resin 16.0 parts by weight (epoxy equivalent 200, softening point 65 ° C) Phenol novolak resin 9.0 parts by weight (OH equivalent 104, softening point 100 ° C) Brominated bisphenol A type epoxy resin 1.7 parts by weight (Br content 46%, epoxy equivalent 360) DBU 0.2 parts by weight Antimony trioxide 1.7 parts by weight Carnova wax 0.3 parts by weight Silicone oil 3.0 parts by weight (SF-8413, Toray Dow Corningda Silicone) 0.8 parts by weight of γ-glycidmethoxysilane 0.15 parts by weight of anthraquinone-based mixed black colorant was mixed at room temperature with a mixer, kneaded at 70 to 100 ° C. with a biaxial roll, cooled, and pulverized to obtain a molding material.

The obtained molding material is tableted, and it is 175 ° C., 70 kg / cm ² , 1 with a low pressure transfer molding machine.
Sealed in 16pDIP package under the condition of 20 seconds, 175 ℃,
After post-curing under the conditions of 8 hours, laser marking was performed, and the visibility was evaluated using a 21-step sensitivity guide.

As a laser marking machine, a carbon dioxide laser mark 940 manufactured by Lumonics and a YA manufactured by NEC are used.
G laser mark SL-476A was used.

Examples 2 to 4 A molding material was obtained in the same manner as in Example 1 except that the amount of the anthraquinone-based mixed black colorant was changed, and a molding material was obtained in the same manner as in Example 1. A product was prepared and subjected to a laser marking test. Table 1 shows the test results.

Comparative Examples 1 to 4 Resin compositions were prepared in the same manner as in Example 1 at the compounding ratios shown in Table 2 and tested in the same manner. Table 2 shows the results.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

According to the present invention, the resin-encapsulated semiconductor device to be coated and molded can be clearly identified even when the resin molded portion is gray, black, or the like or in a dim atmosphere when forming a marking by laser light. It is possible to perform marking that can be performed, and it is possible to significantly improve the sharpness of the marking.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 23/31

Claims (1)

(57) [Claims] An essential component is an anthraquinone black colorant comprising a mixture of an inorganic filler, an epoxy resin, a phenol resin, a curing accelerator, a silicone compound and a compound represented by the following formulas (1), (2) and (3). And the anthraquinone-based black colorant in the entire resin composition is 0.1 to
An epoxy resin composition for encapsulating a semiconductor, comprising 2.0% by weight. Embedded image