WO2011074496A1

WO2011074496A1 - Resin bleeding inhibitor

Info

Publication number: WO2011074496A1
Application number: PCT/JP2010/072247
Authority: WO
Inventors: 玲宏相場; 剛志中山
Original assignee: Jx日鉱日石金属株式会社
Priority date: 2009-12-17
Filing date: 2010-12-10
Publication date: 2011-06-23
Also published as: TWI429720B; MY163131A; JP5437393B2; TW201127914A; JPWO2011074496A1

Abstract

Disclosed is a fluorine-free resin bleeding inhibitor which is capable of providing a sufficient RBO preventing effect without having an adverse effect on die bonding strength and assembly characteristics and without deteriorating the effects of discoloration preventing treatment and pore sealing treatment. Specifically disclosed is a resin bleeding inhibitor which is mainly composed of a compound that has a hydrocarbon group (R₁) with 8-30 carbon atoms, an alkylene oxide group (R₂) and a polar group (R₃) in each molecule. The compound is preferably a compound that is represented by general formula: R₁-(R₂)n-R₃. R₁: an alkyl group, an alkenyl group or an alkynyl group, each having 8-30 carbon atoms R₂: -OCH₂CH₂- or -OCH₂CH₂CH₂- R₃: a carboxyl group, a mercapto group, a hydroxyl group, an amino group, an imidazole group, a triazole group, a tetrazole group, a thiazole group or an oxazole group n: an integer of 1-20

Description

Resin bleed-out prevention agent

The present invention relates to a resin for preventing bleeding (resin bleed out (RBO)) of a die bonding resin or an additive in a die bonding process in which a semiconductor device such as a lead frame or a printed wiring board and an IC chip are bonded and fixed with a resin. It relates to a bleed-out inhibitor.

Semiconductor devices such as semiconductor chips and lead frames and printed wiring boards are usually bonded and fixed by die bonding resin. The adhesive surface of the substrate is generally plated with gold, silver, palladium, copper, nickel, etc., but the surface roughness is too large or the surface is plated with additives, anti-discoloring agents, sealing If it is contaminated with an organic substance such as a hole treating agent, the resin or additive oozes out (resin bleed out (RBO)) when the die bonding resin is applied in the die bonding step. This RBO lowers the die bonding strength or adversely affects the subsequent steps of wire bonding and molding.

Conventionally, in order to prevent RBO, the surface roughness of the plating surface of the adhesive surface is reduced to suppress capillary action, or the surface is washed to remove contaminants. However, since the surface roughness of the bonding surface affects the die bonding strength and the image recognition capability of the assembly machine, it cannot be generally reduced. Further, when cleaning the surface, it has been a problem that the discoloration prevention coating or the sealing treatment coating is detached.

In order to solve these problems, the surface roughness of the substrate surface is changed by immersing the substrate in a solution containing carboxylic acid, thiol or the like as a main component and adsorbing an organic film of about 1 to several molecules. RBO can be prevented without adversely affecting assembly properties such as wire bonding and molding properties, because the organic coating to be adsorbed is extremely thin without washing and peeling off the anti-discoloration coating or sealing treatment coating. It is shown in Patent Document 1.
Further, as a result of further investigations, the present inventors have shown that a fluoroalkyl compound having a polar group has a stronger RBO prevention effect than the carboxylic acid, thiol compound and the like of Patent Document 1 (Patent Document 2).
However, since the fluoroalkyl compound contains fluorine, drainage may be a problem.

Japanese Patent Laid-Open No. 11-195562 International Publication No. 2007/083538

The present invention provides a non-fluorine resin bleedout preventing agent that does not adversely affect die bonding strength and assembly characteristics, and can provide a sufficient RBO prevention effect without impairing the discoloration prevention treatment or sealing treatment effect. For the purpose.

As a result of intensive studies, the present inventors have found that the above problems can be solved by a resin bleedout preventing agent containing a specific non-fluorine compound as a main component, and have reached the present invention.
That is, the present invention is as follows.
(1) The main component is a compound having a hydrocarbon group having 8 to 30 carbon atoms (R ₁ ), an alkylene oxide group (R ₂ ), and a polar group (R ₃ ) in the molecule. Resin bleed-out prevention agent.
(2) A compound having a hydrocarbon group (R ₁ ) having 8 to 30 carbon atoms, an alkylene oxide group (R ₂ ), and a polar group (R ₃ ) in the molecule is represented by the following general formula: The resin bleed-out inhibitor according to (1) above, wherein
General formula: R _1- (R ₂ ) n-R ₃
R ₁ : an alkyl group having 8 to 30 carbon atoms, an alkenyl group, or an alkynyl group R ₂ : —OCH ₂ CH ₂ — or —OCH ₂ CH ₂ CH ₂ —
R ₃ : carboxyl group, mercapto group, hydroxyl group, amino group,
Imidazole group, triazole group, tetrazole group,
Either a thiazole group or an oxazole group n: an integer from 1 to 20 (3) a nitrogen-containing heterocyclic compound system wherein the resin bleedout inhibitor is selected from the group consisting of imidazole derivatives, triazole derivatives, tetrazole derivatives, thiazole derivatives The resin bleed-out inhibitor as described in (1) or (2) above, which contains a discoloration inhibitor.
(4) A resin bleed-out prevention method comprising performing resin bleed-out prevention treatment using the resin bleed-out preventing agent according to any one of (1) to (3).
(5) A resin bleed-out preventing treatment using the resin bleed-out preventing agent according to any one of (1) to (3) above, and having a coating of the resin bleed-out preventing agent Wood.

By using the resin bleed-out preventing agent of the present invention, the resin bleed-out preventing treatment is performed by adsorbing an organic compound having a resin bleed-out preventing function on the surface of a semiconductor wiring substrate such as a lead frame or a printed wiring board. It is possible to prevent resin bleed-out in the die bonding process without impairing the discoloration preventing effect and the sealing effect. Further, the assembly characteristics such as wire bonding characteristics and molding properties are not adversely affected.
Furthermore, since it is a non-fluorine resin bleedout prevention agent, the load of wastewater treatment is small.

FIG. 1 is a diagram illustrating a method for measuring the resin bleed-out amount in the resin bleed-out resistance evaluation of the example.

The resin bleedout preventing agent of the present invention comprises a compound having a hydrocarbon group having 8 to 30 carbon atoms (R ₁ ), an alkylene oxide group (R ₂ ), and a polar group (R ₃ ) in the molecule. The main component.
The hydrocarbon group (R ₁ ) has the effect of increasing the contact angle of the resin (preventing RBO), the alkylene oxide group (R ₂ ) has the effect of increasing the water solubility of the component, and the polar group (R ₃ ) adsorbs the component to the metal. The compound which has these has the RBO prevention effect outstanding as a water-soluble RBO prevention agent.
If the number of carbon atoms of the hydrocarbon group (R ₁ ) is less than 8, the RBO prevention effect is weak, and if it exceeds 30, the RBO effect is good, but there are problems of resin adhesion deterioration and wire bonding failure, so it should be 8-30 is important.

Compounds having a hydrocarbon group (R ₁ ) having 8 to 30 carbon atoms, an alkylene oxide group (R ₂ ), and a polar group (R ₃ ) in the molecule include compounds represented by the following general formula: Is preferred.
General formula: R _1- (R ₂ ) n-R ₃
R ₁ : Any of an alkyl group, alkenyl group, and alkynyl group having 8 to 30 carbon atoms R ₂ : —OCH ₂ CH ₂ — or —OCH ₂ CH ₂ CH ₂ —
R ₃ : carboxyl group, mercapto group, hydroxyl group, amino group,
Imidazole group, triazole group, tetrazole group,
Either a thiazole group or an oxazole group n: an integer from 1 to 20

The hydrocarbon group (R ₁ ) is preferably an alkyl group, alkenyl group, or alkynyl group having 8 to 30 carbon atoms. Among them, a linear alkyl group having 12 to 24 carbon atoms, an alkenyl group, or an alkynyl group is preferable. Is more preferable. The position of the double bond or triple bond of the alkenyl group or alkynyl group is not particularly limited.
As the alkylene oxide group (R ₂ ), —OCH ₂ CH ₂ — and —OCH ₂ CH ₂ CH ₂ — are preferable, and —OCH ₂ CH ₂ — is particularly preferable.
As the polar group (R ₃ ), a carboxyl group, a mercapto group, a hydroxyl group, an amino group, an imidazole group, a triazole group, a tetrazole group, a thiazole group, and an oxazole group are preferable. Among these, a carboxyl group, a mercapto group, a hydroxyl group, and an amino group are preferable. The group is particularly effective.
A plurality of isomers exist for the imidazole group, triazole group, tetrazole group, thiazole group, and oxazole group, and any of them can be used.
n is preferably an integer of 1 to 20, and more preferably an integer of 1 to 10. When n exceeds 20, the water solubility of the component is improved, but the adsorptivity to metal is lowered, and the RBO prevention effect is lowered.

The resin bleedout inhibitor of the present invention is used as a resin bleedout inhibitor solution by dissolving the above compound in a solvent such as water. The concentration of the organic compound in the inhibitor solution is preferably 1 mg / L to 100 g / L, more preferably 10 mg / L to 10 g / L. If the concentration of the above compound is less than 1 mg / L, the resin bleed-out prevention effect is weak, and if it exceeds 100 g / L, the effect is saturated and no further effect can be expected.

Furthermore, the resin bleed-out preventing agent of the present invention can contain a metal oxidation discoloration preventing agent. As the discoloration inhibitor, specifically, known discoloration inhibitors can be used, and in particular, a nitrogen-containing heterocyclic compound-based discoloration inhibitor selected from the group consisting of imidazole derivatives, triazole derivatives, tetrazole derivatives, and thiazole derivatives. preferable.
Examples of these discoloration preventing agents include benzimidazole, benzotriazole, tetrazole, benzothiazole, mercaptobenzothiazole, and the like.

The discoloration inhibitor is preferably contained in a resin bleedout inhibitor solution in an amount of 1 mg / L to 100 g / L, more preferably 10 mg / L to 10 g / L. If it is less than 1 mg / L, the effect of preventing discoloration is weak, and if it exceeds 100 g / L, the effect is saturated, and further effects cannot be expected.
By containing a discoloration preventing agent, a discoloration preventing effect can be imparted simultaneously with a resin bleed out preventing effect.

If the above compound is difficult to dissolve in water, an organic solvent such as alcohol or ketone can be added as necessary. As such an organic solvent, methanol, ethanol, isopropyl alcohol, 2-methyl-2,4-pentanediol, methyl ethyl ketone and the like can be preferably used. The amount of the organic solvent to be added may be a concentration necessary for the above compound to dissolve in water, but is usually 0.1 g / L to 200 g / L, preferably 1 g / L to 50 g / L. If the amount to be added is less than 0.1 g / L, the solubility is low, and if it exceeds 200 g / L, the effect is saturated and no further effect can be expected.

Further, when the above compound is hardly soluble in water, if necessary, any one of anionic, cationic, nonionic, and amphoteric surfactants or a mixture thereof is preferably 1 μg / L to 10 g / L, preferably 10 μg / L to 1 g / L may be added. If the addition amount is less than 1 μg / L, the solubility is low, and even if it exceeds 10 g / L, the effect of dissolving the above compound does not change, which is not preferable.

Examples of the anionic surfactant include a sulfate ester type, a sulfonate salt type, a phosphate ester salt type, and a sulfosuccinate type. Examples of the cationic surfactant include a quaternary ammonium salt type and an amine salt type. However, as a nonionic surfactant, higher alcohol ethylene oxide adduct, higher alcohol propylene oxide adduct, alkylphenol ethylene oxide adduct, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene block polymer of ethylenediamine, Higher aliphatic amine ethylene oxide adducts, aliphatic amide ethylene oxide adducts, and the like are preferred as the amphoteric surfactants such as amino acid type and betaine type.

When using the pH in the range of 5 or less, it is preferable to use one or more anionic and nonionic types as appropriate. Among these, polyethylene glycol type is particularly preferable for nonionic surfactants, and higher alcohol ethylene oxide adducts, higher alcohol propylene oxide adducts, alkylphenol ethylene oxide adducts, polyoxyethylene polyoxypropylene block polymers, etc. are particularly preferably used. In addition, as the anionic surfactant, a sulfate ester salt type and a phosphate ester salt type are particularly preferable.

In addition, in the resin bleedout inhibitor solution, if it is desired to improve the pH buffering property of the solution, if necessary, phosphoric acid such as potassium pyrophosphate, boric acid such as potassium tetraborate, organic acid The system pH buffer may be added in an amount of 0.1 g / L to 200 g / L, preferably 1 to 50 g / L. If it is less than 0.1 g / L, the pH buffering effect is low, and even if it exceeds 200 g / L, the effect is saturated, and no further effect can be expected.

In addition, when there is metal elution in the resin bleedout inhibitor solution, a metal masking agent can be used as necessary. As the metal concealing agent, basically known ones can be used. In particular, azole, amine, aminocarboxylic acid, and carboxylic acid complexing agents are preferable, and 0.1 g / L to 200 g / L. Preferably, 1 g / L to 50 g / L may be added. If it is less than 0.1 g / L, the complexing power of the metal is low, and if it exceeds 200 g / L, the effect is saturated and no further effect can be expected. As such a metal shielding agent, ethylenediaminetetraacetic acid or the like can be preferably used.

The pH of the resin bleedout inhibitor solution need not be particularly limited, but is usually between pH 1 and 14, and is preferably treated at pH 2-12. If it deviates from this range, the damage of the material is large, and the resin bleed out prevention effect is low.
When adjusting the pH, as a pH adjuster, alkali hydroxide (for example, sodium hydroxide, potassium hydroxide, etc.), ammonia, amines, mineral acid (for example, phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, etc.), organic acid (For example, acetic acid, formic acid, citric acid, etc.) can be used.

The temperature of the resin bleedout inhibitor solution can be within the temperature range that can be used with an aqueous solution, but is usually 5 to 90 ° C., preferably 10 to 60 ° C. If the temperature is too low, the resin bleed-out effect is low, and even if the temperature exceeds 90 ° C., the workability only deteriorates, and there is no merit of increasing the temperature.

Furthermore, the treatment time with the resin bleed-out preventing agent solution may be appropriately adjusted in view of the effect in 0.1 seconds to 300 seconds, and is preferably 1 second to 60 seconds in consideration of work reproducibility and efficiency. If it is less than 0.1 seconds, the effect of preventing resin bleed out is low, the reproducibility of the work becomes difficult, the effect is saturated even if it exceeds 300 seconds, and the work efficiency is lowered.

Also, the resin bleedout prevention method of the present invention includes immersing the wiring substrate in the resin bleedout inhibitor solution, or spraying the resin bleedout inhibitor solution on the substrate by shower, spraying, spin coater, etc. After the contact by applying, etc., it may be washed with water and dried.
Examples of wiring base materials include semiconductor wiring base materials such as lead frames and printed wiring boards, and the surface of the base material that performs resin bleed out prevention treatment is plated with gold, silver, palladium, copper, nickel, or the like. Are preferred. Moreover, the surface of the base material which performs a resin bleed out prevention process may be a copper material etc. which are not plated, for example.

For example, when the above-described resin bleed-out prevention treatment is carried out using a wiring substrate having the surface plated, the compound is adsorbed on the plated surface of the wiring substrate surface, and 1 to several molecules A film made of the above-mentioned compound having a thickness of about a degree is formed. Therefore, it is possible to increase the contact angle between the plating surface and the die bonding resin, and to suppress the bleeding of the die bonding resin. In addition, since the coating film of the compound adsorbed is very thin, it does not adversely affect assembly characteristics such as wire bonding property and molding property. Further, the discoloration preventing effect and the sealing treatment effect are not impaired. The present invention also includes a wiring substrate that has been subjected to resin bleed-out prevention treatment by the above-described method to form a film of the inhibitor, and a semiconductor package using the wiring substrate.

The die bonding resin effective as the die bonding resin to be used after the resin bleed out prevention treatment of the present invention may be a low stress type die bonding resin, and examples thereof include epoxy resins and acrylic resins. Resins are preferred.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to these Examples.
Examples 1-7, Comparative Examples 1-4
Copper strike plating is applied as a base to improve adhesion to a lead frame substrate made of copper alloy (Cu: 97.7%-Sn: 2.0%-Ni: 0.2%-P: 0.03%) After that, silver plating, gold plating, or copper plating was applied to the entire lead frame. Thereafter, a resin bleedout inhibitor solution containing the compound represented by the above general formula (main component) and subcomponents having the composition shown in Table 1 was prepared and immersed in the plated substrate under the conditions described in Table 1. The resin bleed out inhibitor treatment was performed by the above.

These substrates were subjected to die bonding and evaluated for resin bleed out resistance (RBO resistance), wire bonding characteristics (W / B characteristics), molding properties, and discoloration resistance. The results are shown in Table 1. In Table 1, "-" in the bath composition indicates that no addition is made, and "-" in the evaluation indicates that it is not subject to evaluation.
In Table 1, R ₁ , R ₂ , R ₃ , n represent R ₁ , R ₂ , R ₃ , n in the compound represented by the above general formula, and all of the alkyl groups and alkenyl groups of R ₁ It is linear, and C ₁₇ H ₃₃ of R ₁ in Example 1 is an oleyl group. The imidazole group in Example 7 and Comparative Example 2 is 1-imidazolyl.

RBO resistance A die bonding resin (8340A manufactured by Able Stick Co., Ltd.) is dispensed in a shape of about 2 mmφ on the base material subjected to the resin bleed out prevention treatment, and cured at room temperature for 1 hour at + 175 ° C. for 1 hour. Were observed with a metallographic microscope. As shown in FIG. 1, the resin bleed-out seen around the die bonding resin (in FIG. 1, the die-bonding resin is shown by a black circle, and the narrow portion that appears slightly around the black circle is the resin bleed-out portion. 2), the amount of bleeding (RBO amount) at the portion with the most severe resin bleed-out was measured and evaluated as follows.
○: Resin bleed out amount is less than 5 μm △: Resin bleed out amount is 5 μm or more and less than 20 μm ×: Resin bleed out amount is 20 μm or more

Wire bonding (W / B)
Wire bonding was performed by a thermocompression bonding method using ultrasonic waves (temperature: 200 ° C., load: 50 g, time: 10 ms) using a 25 μm gold wire, and the pull strength was measured with a pull tester and evaluated as follows.
○: Strength is 10 gf or more Δ: Strength is 7 gf or more and less than 10 gf ×: Strength is less than 7 gf

Molding property Epoxy molding resin (EME-6300 manufactured by Sumitomo Bakelite Co., Ltd.) was applied to the plated surface that had been treated to prevent resin bleed out, then cured by heating at 175 ° C for 5 hours, and then measured for adhesion (shear strength). And evaluated as follows.
○: 30 kgf / cm ² or more Δ: 20 kgf / cm ² or more and less than 30 kgf / cm ² ×: less than 20 kgf / cm ²

Discoloration resistance After humidifying at 40 ° C. and a humidity of 90% for 96 hours, appearance was observed and evaluated as follows.
○: No discoloration △: Some discoloration ×: Discoloration

Claims

A resin comprising a compound having a hydrocarbon group having 8 to 30 carbon atoms (R 1 ), an alkylene oxide group (R 2 ), and a polar group (R 3 ) in a molecule as a main component Bleed-out prevention agent.
A compound having a hydrocarbon group having 8 to 30 carbon atoms (R 1 ), an alkylene oxide group (R 2 ), and a polar group (R 3 ) in the molecule is a compound represented by the following general formula: The resin bleed-out preventing agent according to claim 1, wherein the resin bleed-out preventing agent is present.
General formula: R 1- (R 2 ) n-R 3
R 1 : an alkyl group having 8 to 30 carbon atoms, an alkenyl group,
Any of alkynyl groups R 2 : —OCH 2 CH 2 —, or —OCH 2 CH 2 CH 2 —
R 3 : carboxyl group, mercapto group, hydroxyl group, amino group,
Imidazole group, triazole group, tetrazole group,
Either a thiazole group or an oxazole group n: an integer from 1 to 20
3. The resin bleed-out inhibitor contains a nitrogen-containing heterocyclic compound-based discoloration inhibitor selected from the group consisting of imidazole derivatives, triazole derivatives, tetrazole derivatives, and thiazole derivatives. Resin bleed-out prevention agent.
A resin bleed-out prevention method comprising performing a resin bleed-out preventing process using the resin bleed-out preventing agent according to any one of claims 1 to 3.
A base material which is subjected to a resin bleed-out preventing treatment using the resin bleed-out preventing agent according to any one of claims 1 to 3 and has a coating of the resin bleed-out preventing agent.