KR20120038119A - Melamine compound for semiconductor mold cleaning - Google Patents

Abstract

PURPOSE: A melamine compound is provided to satisfy the properties of accurate semiconductors, and to effectively remove contaminant from an epoxy resin of various semiconductor sealing material. CONSTITUTION: A melamine compound comprises a mixture In which formaldehyde and melamine is mixed with the molar ratio of 1.5:1-2:1, and comprises an alkyd resin, an acrylic resin, an epoxy resin, and rubber as additives. When additionally comprising filler for strengthening the adhesion of the melamine resin, the particle size of the filler is 40-60 micron, and the filler is one or more selected from silica, mica, glass fiber, emery, siliceous and metal particles.

Description

Melamine compound for semiconductor mold cleaning

The present invention relates to the composition of the melamine compound that can clean the semiconductor molding die, the melamine compound is mounted between the top mold (bottom mold) and the bottom mold (bottom mold) and thermally compressed, contaminants attached to the mold Will be removed.

Melamine mold cleaning compound (Melamine mold cleaning compound), which is a mold cleaning material for semiconductor encapsulation, is a contaminant that causes surface stains generated during encapsulation of semiconductor elements with an epoxy molding compound (EMC). A material made of a thermosetting polymer compound that removes a substance from a mold.

Therefore, since the mold is cleaned through the melamine mold cleaning compound, the semiconductor element encapsulation time is minimized and the wear of the mold is reduced as much as possible, thereby reducing defects and working efficiency when performing a process of encapsulating with an EMC compound. It will be possible to improve production, such as improvement.

A method for effectively cleaning a mold or a mold that encapsulates a semiconductor device with an epoxy molding compound (EMC) to remove the contaminants attached to the surface may be said to belong to the technical field of the present invention. have.

In recent years, IC and LSI have been refined, and melamine compounds also need to meet the characteristics of precision semiconductors. Also. The thermosetting resin molding material to seal also needs to change a composition according to the required characteristic, and many varieties are used. Accordingly, the state of mold contamination and the components of the contaminants that occur due to the repetition of molding of the seal molding also vary.

Therefore, there is an increasing need for the production of melamine compounds having various compositions for various types and for the characteristics of precision semiconductors.

On the other hand, instead of the conventional Novolak-based epoxy resin, a biphenyl-based epoxy resin, a polyfunctional epoxy resin, and a molding material using a dicyclopentadiene-based epoxy resin as a main component is used. As for the contaminants of the mold when the molding is repeated, the mold contamination due to seizure to the mold surface becomes serious.

In particular, the contamination of the biphenyl-based epoxy resin is serious, and the number of moldings required to completely remove the contamination of the mold is remarkably increased in the resin composition for mold cleaning, which is conventionally provided, and the productivity of IC, LSI and the like is greatly reduced. there is a problem.

Therefore, there is a need for a new composition of melamine compound that enhances the strength of the melamine resin to improve the cleaning effect.

The present invention relates to a melamine compound used to clean a mold, which is a mold used to encapsulate semiconductor devices, wherein the melamine compound is mixed with formaldehyde and melamine in a molar ratio of 1.5: 1 to 2: 1, and as an additional additive. Alkyd resins, polyester resins, acrylic resins, epoxy resins and rubbers, when the filler further to enhance the adhesion of the melamine resin, the particle size of the filler is 70 μm or less, the size of the filler average particle Is 40-60 μm, and the filler includes silica, mica, glass fiber, diamond steel, siliceous and metal particles.

In addition, when the lubricant is contained in the melamine compound, the lubricant is zinc stearate, calcium stearate, and the lubricant is 1 to 1.5%.

In addition, in the melamine compound used for cleaning the mold which is a metal mold | die used for sealing semiconductor elements, melamine formaldehyde-phenol resin powder (melamine type resin impregnation pulp) 30 (weight% or less abbreviation), melamine resin 30, methyl 0.3 ethylenebisstearic acid amide is added to the pulverized mixture of oleated resin 20, 0.5 benzoic acid and 0.5 zinc stearate, and methylolated resin is substituted for methylolated resin 20 and acetoguanamine 5, instead of the composition methylolated resin 20. When the methylolated resin 30 is used in place of the resin 20, and further includes a filler to enhance the adhesion of the melamine resin, the particle size of the filler is 70 μm or less, and the filler average particle size is 40-60 μm. As the filler, silica, mica, glass fiber, diamond steel, siliceous and metal particles are used.

In addition, when the lubricant is contained in the melamine compound, the lubricant is zinc stearate, calcium stearate, and the lubricant is 1 to 1.5%.

According to the technical configuration of the present invention described above, by using the melamine compound composition of the present invention can be matched to the characteristics of the precision semiconductor, it is possible to effectively remove contaminants even in the epoxy resin of the diversified semiconductor encapsulant.

1 is a view showing a process of melamine mold cleaning compound.
2 and 3 are diagrams showing a melamine compound.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The present invention relates to a melanin compound composition used for cleaning a mold, which is a mold for encapsulating semiconductor devices (which uses an epoxy resin as a semiconductor encapsulant).

And, based on the usual melamine resin composition to obtain a new material composition.

Melamine resins are obtained from melamine resins, melamine-phenol polycondensates, melamine-urea polymerized condensates and the like. The melamine-phenol polymerization condensate is a product obtained by polymerization condensation from aldehydes such as melamine, phenols and formaldehyde, and the melamine-urea polymerization condensation product is obtained by polymerization condensation from melamine, urea and aldehydes. to be.

In addition, other compositions can be further added to melamine, and as the resins which can be added, alkyd resins, polyester resins, acrylic resins, epoxy resins, rubbers and the like can be colored.

Usually, melamine compounds are prepared by adding additives without using melamine resin alone. And in actual use, it will be molded and used as shown in FIG.

Example 1

The melamine compound used to clean the mold for semiconductor encapsulation is prepared by mixing additives with melamine resin. And Example 1 shows the use example of the filler as an additive.

In order to act as a force to separate the contaminants from the melamine compound, a filler is used. At this time, in the present invention, the type of the filler is changed and the composition ratio of the filler is also changed. In addition, the average distribution of filler particles was optimized and applied.

As the filler in the present invention, silica, carbon fiber, mica, glass fiber, and the like are used. Recently, fine fillers having a particle size of 70 μm or less can be used according to the precision of semiconductor molding.

At this time, the average distribution of the filler particles is shown in Table 1.

At this time, if the particle distribution has, the characteristics of the semiconductor device to be precise day by day will be well reflected.

In addition, the filler is added within 40-50% of melamine. By using mica, carbon fiber or glass fiber, the filler content can be reduced by 30%. To this end, 2-3% of the fluorine resin can be added.

In addition, in order to increase the dispersibility of the filler in the melamine composition, a coupling agent (Coupling agent) is used within 1%, the coupling agent is coated on the silica surface to increase the adhesion and uniformity, and to improve the surfactant properties Make it even better. Experimental results show that mixing the coupling agent can reduce the content of filler by 10%.

Therefore, the addition amount of filler can be reduced to 30% or less of the melamine amount by using mica, using glass fiber, and then adding the coupling agent.

On the other hand, in addition to silicon, natural materials such as emery, garnet and siliceous stone and oxides or carbides such as iron, titanium, sodium, calcium, magnesium, aluminum, chromium and boron may be used as the filler. As the oxides or carbides thereof, silicon oxide, magnesium oxide, aluminum oxide, silicon carbide, boron carbide, or the like may be used.

In addition, when a lubricant is contained in the resin composition for metal mold | die cleaning of this invention, the said lubricant is used, for example, zinc stearate and calcium stearate, and in order to maintain mold cleaning property favorable, content of the said lubricant is carried out. It is 1.5 weight part or less with respect to 100 weight part of silver melanin resin, Preferably you may be 1 weight part or less.

Example 2

Example 2 relates to the composition and preparation method of the melamine phenolic resin.

The composition is 100 parts by weight of melamine resin, 0.5 ~ foam stabilizer which is a siloxane-based surfactant 10 parts by weight, acid curing agent 5? The composition consists of 30 parts by weight. In addition, phenols are 50? 80 parts by weight, formaldehyde degree 50? Further 80 parts by weight.

The mixture is reacted to prepare a methylolphenol precursor and a methylolmelamine precursor, followed by condensation polymerization to prepare a modified melamine-phenol resin.

The thermal stability of the resin itself is high and the flame retardancy is maximized, and the problem of a large amount of residual toxic gas generated in the resin can be solved. It is no surprise that flame retardancy and thermal stability could ultimately reduce the emission of toxic gases in the cleaning process.

The melamine resin is a thermosetting resin, which is harmless to a heat-stable substance, and methylamine melamine is formed by reacting melamine and formaldehyde, and is obtained by condensation reaction. Therefore, the unreacted free formaldehyde and melamine remaining in the reaction with the conventional phenol can be reacted with each other to completely remove formaldehyde remaining in the resin and improve the working environment.

At this time, the method included in the manufacturing process to prepare an aqueous solution of the initial condensate reacted in an aqueous solution of formaldehyde and melamine in a molar ratio of 1: 1 to 4: 1, advantageously 1.5: 1 to 3: 1. Melanin crystal concentration 20 ~ 60%, reaction temperature 70 ~ 100 ℃, can be reacted at weak alkaline, the reaction is completed in 10 to 100 minutes.

Example 3

Example 3 has the purpose of improving the strength of the cleaning resin, thereby improving the bonding between the molded article of the cleaning resin and the dirt.

For example, formaldehyde and melamine crystals are reacted in a molar ratio of 1: 1-3: 1, advantageously 1.5: 1-2: 1 in an aqueous solution to prepare a precondensate aqueous solution. The reaction may be carried out at a melamine crystal concentration of 20 to 60% at a temperature of 70 to 100 ℃ in a weak alkaline state. The reaction is completed in 10-100 minutes.

In the melamine resin used in the present invention, a part of the melamine resin may be substituted with melamine and other compounds which can be multicondensed with formaldehyde such as urea, benzoguanamine and phenol, while being compatible with the effects of the present invention. The amount of such composites used is preferably less than 10 parts by weight with respect to 100 parts by weight of melamine.

In addition, some of the formaldehyde may be, for example, aliphatic aldehydes such as acetaldehyde; Aromatic aldehydes such as benzaldehyde; Furfural; And paraformaldehyde and non-formaldehyde aldehydes, such as melamine, formaldehyde and other aldehydes that can react with other compounds described above that may be polycondensed. The amount of such composites used is preferably less than 10 parts by weight relative to 100 parts by weight of formaldehyde.

On the other hand, it may include an auxiliary amount of other resin that can be mixed with the melamine resin in an additional amount that does not adversely affect the effects of the present invention. Such resins include alkyd resins, polyester resins, acrylic resins, epoxy resins and rubbers.

Other 346 parts of melamine, 522 parts of formalin (37% aqueous solution) and 131 parts of phenol are used as a composition for preparing the melamine phenol-formaldehyde resin, 480 parts of melamine and 522 parts of formalin (37% aqueous solution) The composition of is also used as a method for preparing the melamine-formaldehyde resin.

Example 4

Example 4 is an example using a guamine-based pulp and the purpose is to improve the strength as in Example 3. And the composition example for this is as follows.

100 parts by weight of melamine resin, 3 to 65 parts by weight of at least one guanamine and / or 5 to 200 parts by weight of at least one guanamine resin, 5 to 70 parts by weight of pulp, and a particle size of # 100 to # 4000 10 to 90 parts by weight of the mineral powder and 1 to 30 parts by weight of the fibrous inorganic compound are used, respectively.

And in manufacture of the resin composition for metal mold | die cleaning of this invention, the method obtained by uniformly mixing melamine type resin, other secondary resin, pulp, mineral powder, and other additives is obtained. For example, a ribbon blender, a Henschel mixer, a ball mill, a roll mill, a grinder, a tumbling mixer, and the like can be exemplified.

As curable resin molding material which can clean a metal mold | die using the resin composition for metal mold | die cleaning of a present Example, an epoxy resin molding material, a phenol resin molding material, etc. are mentioned, For example, Preferably it is an epoxy resin molding material, Especially semiconductor sealing Epoxy resin molding material. In addition, the resin composition for metal mold | die cleaning of this invention can be used for any metal mold | die, if it is a metal mold | die used at the time of auto-molding the said curable resin molding material, it is generally applicable to the metal mold | die made of iron, chromium, etc ..

On the other hand, as another example, melamine (126 parts by weight), BG (benzoguamine) 126 parts by weight and formalin (37% aqueous solution) 271 parts by weight (2 moles of formaldehyde per 1 mole of the total amount of melamine and BG) Is heated at a temperature of 85 ~ 90 ℃, pH 9.5 ~ 10.

In addition, as another example, 346 parts by weight of melamine, 522 parts by weight of formalin (37% aqueous solution) and 131 parts by weight of phenol (85% aqueous solution) are heated and reacted, and a resin obtained by making a melamine-phenol-formaldehyde resin in a conventional manner 248 parts by weight of pulp is added to the solution, mixed and kneaded, and dried under reduced pressure.

Example 5

Example 5 is another example of preparing a chemically stable melamine resin.

Since there is a risk of unnecessary formaldehyde emission in a high formaldehyde content, efforts have been made to produce melamine resins having a low formaldehyde content. However, the production of such a resin is difficult, because the amount of formaldehyde in the synthesis is small, the dissolution operation of melamine takes a relatively long time.

It is an object of the present invention to prepare a melamine, pepol, formaldehyde resin solution having a low formaldehyde / melamine ratio which does not have the above-mentioned problems without the addition of a modifier in a simple manner.

 Melamine, phenol and formaldehyde are mixed in a molar ratio of 2: 1: 0.7 and then heated separately and mixed with each other, but the mixing temperature (Tm) present in the mixing process is higher than 100 ° C., under elevated pressure and higher than 7 A mixture of melamine, phenol formaldehyde and water with high pH is prepared, and then the reaction is run at the mixing temperature (Tm) until the clearing point is reached, and then until the desired water compatibility is achieved. This is accomplished by continuing the concentration at the concentration temperature (Tk) and then cooling the resin solution to room temperature and evacuating.

Since the reactants are heated separately, an elevated temperature already exists when mixing the mixture.

The mixing temperature (Tm) is understood to mean the temperature formed when the melamine, fennel, formaldehyde and water are mixed. The concentration temperature Tk is understood to mean the temperature in the state where the resin concentration is continued until the transparent point is reached and the desired water compatibility is obtained.

The object of the present invention is a melamine, phenol, formaldehyde resin solution (stable MF resin solution), F / M ratio ≤ 1.5, water solubility of 0.15 to 4.0 at 20 ℃, stability at F / M 1.0 is 5h The above is the stability at F / M 1.1 of 6 h or more.

And when the following ratio is called V1,

V1 = (cumulative contents of melamine and monomers / (cumulative contents of dimers, trimers and oligomers). In this case, the ratio is advantageously 1.1 to 1.7.

The resin solution of the present invention is characterized by very good storage stability and simple manufacturing possibilities. The resin solution does not have a highly concentrated fraction or an excessive fraction of unreacted melamine. As a result of this chemical homogeneity, the resin solution exhibits a storage stability of 5 h or more and 250 h or more.

Particularly preferred melamine, phenol and formaldehyde resin solutions are resin solutions in which V1 is 1.2 to 1.5 and / or the following ratio is 0.8 to 1.4, in particular 0.85 to 1.25.

It is also advantageous for the mixture to have a pH between 7 and 14, in particular between 7.5 and 12. To control the pH, conventional inorganic and organic bases can be used, for example KOH, NaOH, Ca (OH) 2, amines and alkanolamines.

In the preparation of the liquid mixture, it is advantageous to separately heat the reactants melamine, phenol, formaldehyde and water. Melamine as an aqueous suspension or aqueous solution, phenol and aqueous formaldehyde are separately heated to a temperature Tm higher than 100 ° C., and then under pressure, the formaldehyde solution and the pH adjusting base are placed in an efficiently stirred melamine suspension or solution. Particular preference is given to metered infusion.

At this time, the solids content of the melamine, phenol and formaldehyde resin solution is preferably 20 to 80% by weight, more preferably 40 to 70% by weight. Melamine-formaldehyde resin solutions having such a solids content can be stored and treated more particularly efficiently.

In this water compatibility range, the resin solution of the present invention has maximum stability. The storage stability of the resin solution of this invention is 5 h or more. Particularly preferred resin solutions are those having a storage stability of 24 h or more.

And 3 to 65 parts by weight of at least one guanamine and / or 5 to 200 parts by weight of at least one guanamine resin, 5 to 70 parts by weight of pulp and particle size based on 100 parts by weight of the melamine resin thus obtained Melamine compound is prepared by adding 10 to 90 parts by weight of the mineral powders of # 100 to # 4000 and 1 to 30 parts by weight of the fibrous inorganic compound, respectively.

Example 6

Example 6 proposes a composition of several different methods to provide a melamine resin composition is more stable and cost saving.

Melamine resin, at least one type of guanamine / or at least one type of guanamine resin, pulp, mineral powders of particle size # 100 ~ # 4000 are used as main materials, and other additives can be mixed uniformly. Use any means that are present. For example, kneaders, ribbon blenders, Henschel mixers, ball mills, roll mills, grinders and the like are used.

On the basis of this composition, the first composition example is melamine formaldehyde-phenol resin powder (melamine resin impregnated pulp) 30% by weight (hereinafter omitted), melamine resin 50, silica powder 20 of particle size # 200, benzoic acid 0.5 and stearic acid 0.3 ethylenebisstearic acid amide is added to the zinc 0.5 grinding mixture.

Examples of the second composition include melamine formaldehyde-phenol resin powder (melamine resin-impregnated pulp) 30, melamine resin 30, methylolated resin 20, silica powder 20 of particle size # 200, benzoic acid 0.5 and zinc stearate 0.5, and ethylene in a pulverized mixture. 0.3 is added bis stearic acid amide.

In addition, the methylolation resin 20 and acetoguanamine 5 can be used instead of the methylolation resin 20 used by the composition 2. And methylolated resin 30 can also be used instead of methylolated resin 20.

On the other hand, melamine formaldehyde-phenol resin powder (melamine type resin impregnated pulp) 30, melamine resin 40, M / CTU-G-F resin 10, CTU-guanamine 5, silica powder 20 of particle size # 200, benzoic acid 0.2, and stearic acid 0.3 of ethylenebisstearic acid amide participates in the composition which pulverized and mixed zinc 0.5.

Using the commercially available biphenyl-based epoxy resin molding material (CEL-9002XU), melamine made through each embodiment as described above is realized by molding 500 shots in a mold of TQFP to realize mold mold dirt. Evaluation can be carried out by repeatedly molding the resin composition for mold cleaning until it is cleaned, and the properties of the composition can be confirmed.

On the other hand from the following drawings will be described an example in which the composition of the present invention is used and applied.

1 is a view showing a process of melamine mold cleaning compound.

There are two kinds of melamine mold cleaning compound, a transfer type and a compression type.

In order to clean the mold, which is a mold used to encapsulate semiconductor devices (semiconductor encapsulant), a top mold 10 and a bottom mold (as shown in FIG. 1) are cleaned. Bottom Mold) (20) is equipped with a melamine compound (100). At this time, as shown in the figure is different depending on the transfer type and the compression type.

Then, heat and pressure are applied between the tom mold 10 and the bottom mold 20 so that the melamine compound 100 flows into the mold. At this time, the transfer type is pressurized using a Plunger 15. Then, the melamine compound 100 is present between the top mold 10 and the bottom mold 20 as shown in the right side of the figure.

Then, when the melamine compound 100 is separated between the top mold 10 and the bottom mold 20, the separated melamine compound 100 is contaminated on the surface of the top mold 10 and the bottom mold 20. Matter is attached. That is, contaminants adhered to the surface of the mold 10 and 20 adhere to the melamine compound 100 and are separated from the surface of the mold 10 and 20.

2 and 3 are diagrams showing a melamine compound.

2 is a view showing the appearance of the melamine compound, Figure 3 is a view showing the chemical reaction of the melamine compound.

There are two kinds of melamine mold cleaning compound, a transfer type and a compression type.

The main raw material is melamine resin (about 65%), and 10 kinds of auxiliary raw materials are added and produced at the proper ratio, and the core technology is scientific data for various complex factors such as the mixing ratio of materials, temperature and reaction time. It is created by accumulating and experience points.

Melamine resin, the main material of the melamine composition, is related to adhesion and fluidity, organic filler is related to fluidity and mechanical force, and inorganic filler composed of more than 99% SiO2 has a scribing effect and mechanical force. The cleaning agent controls the thermal curing conditions, and the releasing agent is related to the improvement of the mold cleaning process in direct proportion to the tablet action.

Melamine resination reaction is a one-step methylolation reaction of the melanin resin and methylol reaction occurs in two stages and methyleneation reaction occurs. Dimethylene etherification also occurs in this process.

In the case of curing reaction through polymerization, various reactions are involved, and in the reaction with amino group or methylol group, one molecule of water is generated for one methylene bond.

10: top mold 20: bottom mold
100: melamine compound

Claims (6)

In the melamine compound used for cleaning the mold which is a metal mold | die used for sealing semiconductor elements,
The melamine compound is a mixture of formaldehyde and melamine in a molar ratio of 1.5: 1 to 2: 1, and additional additives include alkyd resin, polyester resin, acrylic resin, epoxy resin and rubber,
When the filler further comprises a filler to enhance the adhesion of the melamine resin, the filler has a particle size of 70 μm or less, and the average particle size of the filler is 40-60 μm, and the filler includes silica, mica, glass fiber, Melamine compound, characterized by the use of diamond steel, siliceous and metal particles. The melamine compound according to claim 1, wherein when the melamine compound contains a lubricant, the lubricant is zinc stearate and calcium stearate. The melamine compound according to claim 2, wherein the lubricant comprises 1-1.5%. In the melamine compound used for cleaning the mold which is a metal mold | die used for sealing semiconductor elements,
Ethylenebisstearic acid amide 0.3 is added to a crushed mixture of melamine formaldehyde-phenolic resin powder (melamine resin impregnated pulp) 30 (weight percent or less omitted), melamine resin 30, methylolated resin 20, benzoic acid 0.5 and zinc stearate 0.5. In place of the composition methylolated resin 20, methylolated resin 20 and acetoguanamine 5, or methylolated resin 30 in place of methylolated resin 20,
When the filler further comprises a filler to enhance the adhesion of the melamine resin, the filler has a particle size of 70 μm or less, and the average particle size of the filler is 40-60 μm, and the filler includes silica, mica, glass fiber, Melamine compound, characterized by the use of diamond steel, siliceous and metal particles. The melamine compound according to claim 4, wherein when the melamine compound contains a lubricant, the lubricant is zinc stearate and calcium stearate. The melamine compound according to claim 2, wherein the lubricant comprises 1-1.5%.

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