JPH04222818A - Epoxy resin composition for sealing semi-conductor - Google Patents

Abstract

PURPOSE:To provide the subject composition containing a colorant based on copper oxide. iron oxide or manganese oxide in a specific proportion and capable of brilliantly forming clearly distinguishable marks even under a gloomy atmosphere, etc., when the marks are formed with carbon dioxide and YAG laser. CONSTITUTION:The objective composition comprises as essential components, (A) an inorganic filler (e.g. fused silica), (B) an epoxy resin (e.g. bisphenol A type epoxy resin), (C) a phenolic resin as a curing agent, (D) a curing accelerator (e.g. diazabicycloundecene), (E) a silicone compound (e.g. silicone oil), and (F) a colorant based on copper oxide. iron oxide or manganese oxide in an amount of 0.1-3wt.%, preferably 0.3-1.5wt.%, in the composition.

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 use in resin-sealed semiconductor devices, which allows clear markings to be made on the surface using either a carbon dioxide gas laser or a YAG laser marking device.

0002

[Prior Art] In recent years, due to environmental issues, marking of resin-sealed semiconductor devices has become difficult.In addition to ink marking, which requires pre-cleaning with fluorocarbon or chlorine-based solvents, the laser emitted from a laser oscillator is passed through a die-cut mask. A shift has been made to a laser marking method in which a predetermined marking is performed by focusing an image on the semiconductor device, or characters are drawn directly on the semiconductor device with a laser beam. Laser marking methods include pulse marking using a carbon dioxide laser (mask type) and Y
There are pulse markings (mask type) and scan markings (single stroke) using an AG laser.

This marking method uses the energy of a laser beam to mark the surface layer of a resin-sealed semiconductor device by several micrometers.
In this method, the surface is roughened by breaking to a depth of several tens of micrometers, and the marking is visually recognized by comparing the surface properties of the broken part and the non-destructed part. However, when marking is performed using a laser as described above, in conventional resin-sealed semiconductor devices, the contrast between the destroyed portion and the non-destructive portion is not necessarily good, and therefore the marking is more difficult than with ink marking. It had the disadvantage that it could not be seen clearly.

Furthermore, the low-stress sealing materials that have become mainstream in the recent trend toward higher integration contain silicone compounds for the purpose of reducing stress, so the markings are less clear than conventional materials. There is a strong desire to improve visibility.

Under these circumstances, various studies have been made to improve visibility, and it has been found that adjusting the components of the colorant is particularly effective. For example, a patent states that diazo and azine dyes are effective in improving the visibility of carbon dioxide laser marks (e.g., JP-A No. 60-11
No. 9760) has also been filed. However, although these colorants show good marking with a carbon dioxide laser, they cannot be used with YA.
When the laser becomes a G laser, no laser energy can be absorbed, and therefore the stamp cannot be visually recognized at all. This seems to be due to the difference in laser wavelength between the carbon dioxide laser and the YAG laser.

On the other hand, carbon black shows good marking with a YAG laser, but has the disadvantage of poor visibility when using a carbon dioxide laser. Currently, both carbon dioxide gas laser marking machines and YAG laser marking machines are used, so it is desired to develop an epoxy resin composition for semiconductor encapsulation that has good visibility with both laser types.

As described above, none of the conventional epoxy resin sealing materials exhibits good visibility in both laser types, carbon dioxide gas laser marking and YAG laser marking.

[0008]

[Problems to be Solved by the Invention] The present invention was made in view of the above circumstances, and includes a carbon dioxide gas laser marking machine, Y
To provide an epoxy resin composition for semiconductor encapsulation in which the laser marking is clearly visible even when stamped with any AG laser marking machine in a relatively dark atmosphere and even when the resin molded part is gray or black. .

[0009]

[Means for Solving the Problems] The present invention includes an inorganic filler, an epoxy resin, a phenolic resin, a curing accelerator, a silicone compound, and a coloring agent based on copper oxide, iron oxide, and manganese oxide as essential components, and the entire resin composition. Copper oxide, iron oxide,
This is an epoxy resin composition for semiconductor encapsulation containing 0.1 to 3.0% by weight of a manganese oxide colorant.

That is, as epoxy resin compositions, thermosetting resins, particularly those containing epoxy resin as a main component, have been widely used. In addition to the epoxy resin, such resin compositions containing epoxy resin as a main component generally contain a curing agent, a curing accelerator, a filler, a mold release agent, and, if necessary, a flame retardant, a colorant, Coupling agents and the like are added. As the pigment, carbon black or diazo dye is usually used. In a resin-sealed semiconductor device obtained by sealing using such a resin composition,
As mentioned above, in both carbon dioxide and YAG lasers, the contrast between the damaged and non-destructed areas on the surface of the semiconductor device caused by the laser beam is not clear, and the markings cannot be clearly seen.

[0011] As a result of repeated research with the aim of obtaining a clear contrast between the destroyed and non-destructed areas on the surface of a semiconductor device caused by laser light, the inventor has found that metal oxide colorants have a large effect. As a result of further research focusing on this pigment, we found that when copper oxide, iron oxide, and manganese oxide colorants (hereinafter referred to as Cu, Fe, and Mn colorants) are used, the broken parts are not damaged when marking with any laser. It was found that the contrast between the non-destructive part and the non-destructive part becomes clear. As a result of further research based on this, we found that 0.1 to 3.0 of Cu/Fe/Mn colorants were added to the resin composition.
When it is made to contain % by weight (hereinafter abbreviated as "%"),
In particular, we have found that the clarity of markings has been improved, and the markings can be clearly recognized even if the resin molded parts of semiconductor devices are colored such as gray or black, or even in a relatively dark atmosphere. , arrived at this invention.

The epoxy resin composition for sealing of the present invention contains an epoxy resin, a curing agent, a curing accelerator, a silicone compound, and an inorganic filler such as fused silica or crystalline silica as essential components. There is no problem in adding a silane coupling agent, a brominated epoxy resin, a flame retardant such as antimony trioxide or hexabromobenzene, a mold release agent such as natural wax or synthetic wax, and various additives as appropriate.

[0013] In order to produce the epoxy resin composition for sealing of the present invention as a molding material, the epoxy resin, curing agent, curing accelerator, silicone compound, filler, and other additives are sufficiently uniformly mixed using a mixer or the like. After mixing, the mixture is further melt-kneaded using a hot roll or a kneader, cooled, and then pulverized to obtain a molding material.

[0014] These molding materials can be applied to electronic parts or for sealing, covering, and insulating electronic parts. The epoxy resin used in the present invention is not particularly limited in molecular structure, molecular weight, etc. as long as it is a compound having at least two or more epoxy groups in its molecule, and is generally used as a sealing material. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin,
Bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy type epoxy resin, glycidyl ester type epoxy resin, dilycidylamine type epoxy resin,
Examples include isocyanurate type epoxy resins, glycidyl etherified polycondensates of bisphenol A or bisphenol F and formaldehyde, and halogenated and hydrogenated products thereof, and these may be used alone or in combination of two or more.

[0015] The curing agent is a novolak type phenolic resin or a modified resin thereof, such as phenol novolac, o-cresol novolac, or alkyl-modified phenol novolak resin.
These may be used alone or in combination of two or more without any problem.

The compounding ratio of the epoxy resin and the curing agent is such that the equivalent ratio of the epoxy groups of the epoxy resin to the hydroxyl groups of the curing agent is 0.
It is desirable that it be within the range of 5 to 5. Equivalence ratio is 0.5
If it is less than 5 or more than 5, the moisture resistance, molding workability, and electrical properties of the cured product will deteriorate, so it is not preferable.

The curing accelerator used in the present invention may be one that promotes the reaction between the epoxy group and the phenolic hydroxyl group, and a wide variety of those commonly used in sealing materials can be used. For example, diazabicycloundecene (DBU), triphenylphosphine (TPP), dimethylbenzylamine (BDMA), 2methylimidazole (2MZ), and the like are used alone or in combination of two or more.

Fillers used in the present invention include fused silica, crystalline silica, alumina silicon nitride, magnesium oxide, etc., and these may be used alone or in combination of two or more. Examples of silicone compounds include silicone oil, silicone rubber, and silicone gel, which may be used alone or in combination of two or more, and are blended in order to impart low stress properties to the epoxy resin composition. As the colorant, a Cu-Fe-Mn colorant is used, and this colorant is a fine powder having a spinel structure, which is considered to be a solid solution of CuFe2O4 and CuMn2O4.

[0019] This Cu/Fe/Mn colorant is contained in the entire composition in an amount of 0.1 to 3%, more preferably 0.3 to 1.5%.
% content is preferable. In other words, when the amount of Cu/Fe/Mn colorant added is less than 0.1%, the contrast between the destroyed part and the non-destructed part is not clear, whereas when it exceeds 3%, the resin-sealed semiconductor device This is because disadvantages such as a decrease in reliability (moisture resistance) occur. In particular, when the content of titanium black is set to 0.3 to 1.5%, the marking becomes extremely clear. In addition, there is no problem in using colorants conventionally added to resin compositions, such as carbon black, organic dyes, etc., in addition to the above-mentioned colorants. As described above, a major feature of this invention is the use of Cu/Fe/Mn colorants as colorants, which allows for clear coloring even in a relatively dark atmosphere or on resin molded parts, such as gray or black. Markings will be made.

The present invention will be specifically illustrated below with examples.

[0021]

[Example] Example 1 Fused silica
6
7.0 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
mold epoxy resin
1.7 parts by weight (Br content 46%, epoxy equivalent 3
60) DBU

0.2 parts by weight antimony trioxide

1.7 parts by weight carnauba wax

0.3 parts by weight Silicone oil (SF-8413, Toray Dow Corning Silicone) 3.0 parts by weight γ-glycidomethoxysilane
0.8 parts by weight c
u・Fe・Mn colorant
0.15 parts by weight were mixed at room temperature in a mixer, kneaded at 70 to 100°C with a twin-screw roll, cooled, and then ground to obtain a molding material.

[0022] The obtained molding material was made into tablets and heated at 175°C at 70kg/c using a low-pressure transfer molding machine.
After sealing in a 16p DIP package under conditions of m2 and 120 seconds and post-curing at 175°C for 8 hours, laser marking was performed and visibility was evaluated using a 21-step sensitivity guide.

[0023] As a laser marking machine, CO2 gas laser mark 940 model manufactured by Lumonics and YA manufactured by NEC are used.
G Lasermark SL-476A was used.

Examples 2 to 4 Molding materials were obtained in the same manner as in Example 1 using the same formulation as in Example 1 except that the amount of the Cu/Fe/Mn colorant was changed, and this molding material was used for testing. A molded product was created and a laser marking test was conducted. The test results are shown in Table 1.

Comparative Example 1 A test was carried out in the same manner as in Example 1 except that 0.3 parts by weight of carbon black was added as a coloring agent. The results are shown in Table 1.

Comparative Example 2 A test was conducted in the same manner as in Example 1 except that 0.5 parts by weight of black organic dye was used as the coloring agent. The test results are shown in Table 1.

Comparative Examples 3 and 4 Tests were carried out in the same manner as in Example 1, except that the amount of colorant blended in Example 1 was changed. The results are shown in Table 1.

[0028]

[Table 1]

[0029]

According to the present invention, a resin-sealed semiconductor device that is covered and molded can be clearly marked even when the resin molded part is gray, black, etc. or in a dim atmosphere when marking is formed by laser light. It becomes possible to apply distinguishable markings, and it becomes possible to realize a significant improvement in the clarity of the markings.

Claims (1)

[Claims] Claim 1: (A) Inorganic filler (B) Epoxy resin (C) Phenol resin (D) Curing accelerator (E) Silicone compound (F) Copper oxide, iron oxide, manganese oxide colorant as essential ingredients. , (F) copper oxide in the entire resin composition.
0.1-3.0% by weight of iron oxide/manganese oxide colorant
An epoxy resin composition for semiconductor encapsulation characterized by containing: