KR101557123B1 - Composition for underfill and method for mounting electronic device - Google Patents

Abstract

The present invention relates to a composition comprising an epoxy resin, an acid anhydride-based curing agent and an imidazole-based curing catalyst, wherein the content of the acid anhydride-based curing agent in the composition is 30 to 60 parts by weight per 100 parts by weight of the epoxy resin, And the content of the sol-based curing agent is 0.6 to 0.8 parts by weight per 100 parts by weight of the epoxy resin. The underfill composition according to the present invention improves the bonding strength between the semiconductor chip and the substrate when the electronic device such as a semiconductor chip is mounted on the substrate by a flip chip bonding method, and at the same time, is hardened immediately after the reflow process, void) can be minimized. Accordingly, the underfill composition according to the present invention can be used as a material useful in the field of flip chip packaging.

Description

Technical Field [0001] The present invention relates to a composition for underfill,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for an underfill and an electronic device mounting method using the same. More particularly, the present invention relates to an underfill composition for an underfill which can minimize voids between a semiconductor chip and a substrate, And a method for reliably mounting an electronic device such as a resistor, a capacitor, and the like on a substrate by a flip chip packaging method using the adhesive composition.

The demand for integration and miniaturization of semiconductor devices and the reduction of weight of the semiconductor devices has been gradually increased in order to effectively respond to the development of information communication and the complexity of equipment, and in order to achieve this, a plurality of chips are mounted in a single space, Are generally used. In the packaging, a chip is mounted on a substrate having an external terminal formed and further completed through a molding operation. Here, the external terminal is a terminal formed on a substrate for electrically connecting a substrate and a chip, And can be classified into wire bonding (bonding), flip chip bonding (flip chip bonding), and the like depending on the connection type of the external terminal and the chip.

The wire bonding has various inefficiency problems. In order to overcome such a problem, a flip chip bonding method is generally used. A flip chip type packaging method is a method of electrically connecting a bonding pad on a semiconductor chip and a metal pad on a substrate by using a solder ball or a conductive bump and is electrically connected through a solder ball or a conductive bump Since the semiconductor chip can be attached to the substrate at the same time, it is a technology that can realize the smallest form among the semiconductor packaging.

The flip-chip method forms any conductive bump on the input / output terminal electrode of the semiconductor device and forms an electrical connection with the conductive contact pad which is the electrode terminal on the wiring board. In the above process, the adhesion reliability between the solder bump and the pad A weakening problem arises. Further, it has been a problem that a mismatch occurs due to a difference in the coefficient of thermal expansion (CTE) between the semiconductor chip, the wiring material and the package substrate. A sealing material is filled in the gap between the semiconductor chip and the package substrate in order to improve the weakening of the mechanical stress caused by the mismatch of the coefficient of thermal expansion (CTE) between the semiconductor chip and the substrate and to reinforce the adhesive force of the solder ball. It is called underfill.

Typical methods for forming the underfill include a capillary flow underfill method and a no-flow fluxing underfill method. The capillary flow underfill method is a method in which a liquid underfill material such as an epoxy resin is injected between a semiconductor chip and a package substrate and cured to fix the semiconductor chip and the package substrate. When capillary flow underfill is applied, the underfill injection and the curing reaction of the fed underfill are performed after the metal solder or conductive polymer is reflowed to form the interconnect. When a predetermined amount of underfill material is supplied along one or more edge surfaces of the electronic component assembly, the underfill material is drawn into the interior by capillary action at a gap between the semiconductor chip and the package substrate.

Such a capillary flow underfill method involves complicated processes, low throughput and voiding problems. To overcome this problem, a no-flow fluxing underfill method is proposed. . A non-flowable fluxing underfill process includes applying an underfill resin composition onto a package substrate; Aligning and bringing the solder bumps 16 formed on the semiconductor chip and the metal pads 12 of the package substrate into correspondence with each other using a flip chip alignment; And passing the aligned semiconductor chip and the package substrate through a solder reflow oven to complete the electrical connection through soldering and at the same time curing the underfill resin composition. In a no-flow fluxing underfill process, it is important to maintain the proper viscosity and proper cure rate of the underfill material during the above-described curing steps of soldering and underfilling. It is preferred that the curing reaction of the underfill should not be cured during the reflow process and is immediately cured immediately after the reflow process. If the underfill is cured during the reflow process, voids may be generated between the semiconductor chip and the substrate, resulting in lowering of the bonding strength and deformation due to external force or heat.

SUMMARY OF THE INVENTION The present invention has been made under the background of the related art, and an object of the present invention is to provide a semiconductor device and a method of manufacturing the semiconductor device, which can improve the bonding strength between the semiconductor chip and the substrate during the flip chip bonding, Thereby minimizing voids between the semiconductor chip and the substrate.

Another object of the present invention is to provide a method for reliably mounting an electronic device such as a semiconductor chip on a substrate using a composition for underfill.

The present invention provides a composition comprising an epoxy resin, an acid anhydride-based curing agent and an imidazole-based curing catalyst, wherein the content of the acid anhydride-based curing agent in the composition is 30 to 100 parts by weight per 100 parts by weight of the epoxy resin, Wherein the content of the imidazole-based curing agent in the composition is 0.6 to 0.8 parts by weight per 100 parts by weight of the epoxy resin.

At this time, the epoxy resin is preferably a polyfunctional glycidyl ether epoxy resin, more preferably a diglycidyl ether of bisphenol A.

The acid anhydride-based curing agent may be selected from the group consisting of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, 5-norbornene anhydride, -2,3-dicarboxylic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, dodecylsuccinic anhydride, phthalic anhydride and succinic anhydride, and methylhexahydrophthalic anhydride More preferably a combination of Methyl-5-norbornene-2,3-dicarboxylic anhydride and Methyl Hexahydrophthalic Anhydride. When the acid anhydride-based curing agent is composed of a combination of methylhexahydrophthalic anhydride and methyl-5-norbornene-2,3-dicarboxylic anhydride, methylhexahydrophthalic anhydride to methyl The weight ratio of methyl-5-norbornene-2,3-dicarboxylic anhydride is preferably 2: 8 to 8: 2.

The imidazole-based curing catalyst may be selected from the group consisting of 1-methyl imidazole, 2-methyl imidazole, 2-undecyl imidazole, 2-heptadecyl imidazole, 4-methylimidazole, 4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, Methyl-5-ethylimidazole, 2-octyl-4-hexylimidazole, 2,5-chloro-4-ethylimidazole 4-ethylimidazole, and 2-butoxy-4-allyl imidazole.

The underfill composition may further comprise a coupling agent or an inorganic filler. The coupling agent is preferably a silane coupling agent. The content of the coupling agent in the composition is preferably 0.01 to 1 part by weight per 100 parts by weight of the epoxy resin. The content of the inorganic filler in the composition is preferably 0.5 to 15 parts by weight per 100 parts by weight of the epoxy resin.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a substrate having at least a plurality of conductive pads on a surface thereof; Applying a solder paste on a plurality of conductive pads present on a surface of the substrate; Applying the composition for underfill according to any one of claims 1 to 12 to a surface of a substrate corresponding to a space between the plurality of conductive pads on which the solder paste is applied; Aligning the conductive pads formed on the surface of the electronic device to be located on the conductive pads of the corresponding substrate and contacting the electronic device with the substrate; And reflowing the contacted electronic element and the substrate. At this time, the electronic device is preferably in the form of a semiconductor chip, and may be selected from, for example, a transistor, a resist, or a capacitor. Further, it is preferable that the solder paste is applied onto the conductive pad by a printing method. The underfill composition is preferably applied to the surface of the substrate in a dot type. The peak temperature of the reflow step is preferably 200 to 280 ° C.

The underfill composition according to the present invention improves the bonding strength between the semiconductor chip and the substrate when the electronic device such as a semiconductor chip is mounted on the substrate by a flip chip bonding method, and at the same time, is hardened immediately after the reflow process, void) can be minimized. Accordingly, the underfill composition according to the present invention can be used as a material useful in the field of flip chip packaging.

FIG. 1 shows an experiment for mounting a semiconductor chip on a printed circuit board in a stepwise manner.
2 shows a temperature profile applied to a reflow oven in an experiment in which a semiconductor chip is mounted on a printed circuit board.
Fig. 3 shows the bonding strengths of the types of semiconductor chips mounted on the printed circuit board by Test Example 1, Control Test Example 1 and Control Test Example 2, and Fig. 4 shows the results of Test Example 1, Test Example 10 and Control Test Example 1 The bonding strengths of the semiconductor chips mounted on the printed circuit board are shown.
5 shows the result of measuring the void height between the semiconductor chip and the printed circuit board for each type of semiconductor chip mounted on the printed circuit board according to Test Example 1, Control Test Example 1 and Control Test Example 2, Is a result of measuring the void height between the semiconductor chip and the printed circuit board for each type of semiconductor chip mounted on the printed circuit board by the test example 1, the test example 10 and the verification test example 1.

Hereinafter, the present invention will be described in detail.

The composition for underfilling according to the present invention comprises an epoxy resin, an acid anhydride-based curing agent and an imidazole-based curing catalyst. Hereinafter, the underfill composition according to the present invention will be described separately for each constituent component.

Epoxy resin

In the present invention, the epoxy resin is not particularly limited as long as it exhibits hardening and adhesion, and examples thereof include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin, Bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin , And aliphatic chain epoxy resins. These epoxy resins may be halogenated or hydrogenated. These epoxy resins may be used singly or in combination of two or more.

In the present invention, the epoxy resin is preferably a polyfunctional epoxy resin containing at least two or more functional groups, and more preferably a polyfunctional glycidyl ether epoxy resin. The type of the polyfunctional glycidyl ether epoxy resin is not particularly limited, and examples thereof include diglycidyl ether of bisphenol A or diglycidyl ether of bisphenol F, among which diglycidyl of bisphenol A Ether.

In the present invention, the epoxy resin may have an epoxy equivalent of 100 to 1500 g / eq, preferably 150 to 800 g / eq, and an epoxy equivalent of 150 to 400 g / eq. desirable.

mountain Anhydride system  Hardener

In the present invention, the acid anhydride-based curing agent is used for polymerizing an epoxy resin having a low molecular weight, and the kind thereof is not particularly limited. Acid anhydrides are also referred to as anhydrous acids, and are oxides that dehydrate an acid in inorganic acids or in which a carboxyl group of a carboxylic acid separates one molecule of water by a condensation reaction. In the present invention, the acid anhydride-based curing agent includes, for example, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, dodecylsuccinic anhydride, phthalic anhydride and succinic anhydride. In the present invention, the acid anhydride-based curing agent may be selected from the group consisting of methylhexahydrophthalic anhydride and methyl-5-anhydride, in consideration of the improvement of adhesion between the semiconductor chip and the substrate and the curing rate of the underfill composition immediately after the reflow process. -norbornene-2,3-dicarboxylic anhydride). At this time, the weight ratio of methylhexahydrophthalic anhydride to methyl-5-norbornene-2,3-dicarboxylic anhydride is preferably 2: 8 to 8: 2, more preferably 3: 7 to 7: : 3, and most preferably from 4: 6 to 6: 4.

The content of the acid anhydride-based curing agent in the composition for underfilling according to the present invention can be determined in various ranges depending on the reaction equivalent ratio with the epoxy resin and the type of curing agent and the like. It is possible to improve adhesion between the semiconductor chip and the substrate, Is preferably 30 to 60 parts by weight, more preferably 40 to 55 parts by weight, and most preferably 40 to 50 parts by weight per 100 parts by weight of the epoxy resin, considering the curing rate of the underfill composition immediately after the reflow process.

Imidazole  Curing catalyst

In the present invention, the imidazole-based curing catalyst serves to control the curing peak temperature and the curing rate of the underfill composition. The types of imidazole-based curing catalysts usable in the present invention are not particularly limited, and examples thereof include 1-methylimidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1 2-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2 4-methylimidazole, 2-methyl-5-ethylimidazole, 2-octyl-4-hexylimidazole, 2,5-chloro-4- (2-butoxy-4-allyl imidazole), which is selected from the group consisting of 2,5-chloro-4-ethylimidazole and 2- . In the present invention, it is preferable that the imidazole-based curing catalyst is in the form of a liquid having a relatively low melting point in consideration of the compatibility with the acid anhydride-based curing agent and compatibility with other components. As the imidazole- 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole (1- benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1- 2-ethyl-4-methylimidazole and the like, and 2-ethyl-4-methylimidazole (2-ethyl- methylimidazole).

The content of the imidazole-based curing agent in the composition for underfilling according to the present invention is 0.6 to 0.8 parts by weight per 100 parts by weight of the epoxy resin, considering the viscosity of the underfill composition and the curing rate of the underfill composition immediately after the reflow process More preferably 0.65 to 0.8 part by weight.

Other additives

The composition for underfilling according to the present invention may further include a coupling agent for compatibility between the constituting components or for improving adhesion to various materials (for example, an inorganic material). The coupling agent usable in the present invention is not limited to a silane coupling agent, a titanate coupling agent, a chromium coupling agent, etc., and is preferably a silane coupling agent in consideration of compatibility with other components. Specific examples of the silane-based coupling agent include 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, 3-glycidoxytrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3- N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, Aminopropyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, Siloxane-containing silanes such as ethoxysilane, isocyanates such as 3-isocyanate propyltriethoxysilane, Silane containing vinyl groups such as silane, vinyl trichlorosilane, vinyltri (2-methoxyethoxy) silane, vinyltriethoxysilane, and vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane And silane containing a methacryl group such as methoxy silane, etc. These may be used singly or in combination of two or more kinds. The amount of the coupling agent in the underfill composition according to the present invention is preferably 0.01 to 1 part by weight, more preferably 0.02 to 0.5 part by weight, most preferably 0.02 to 0.2 part by weight per 100 parts by weight of the epoxy resin .

The underfill composition according to the present invention may further contain an inorganic filler for the purpose of improving mechanical strength and reducing thermal expansion coefficient. Specific examples of the inorganic filler usable in the present invention include alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, silica, boron nitride, titanium dioxide , Glass, iron oxide, and ceramics. The content of the inorganic filler in the underfill composition according to the present invention is preferably 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight, per 100 parts by weight of the epoxy resin.

Another aspect of the present invention relates to a method of mounting an electronic device using the composition for underfill described above. An electronic device mounting method according to the present invention includes: preparing a substrate having at least a plurality of conductive pads on a surface; Applying a solder paste on a plurality of conductive pads present on a surface of the substrate; Applying the composition for underfill according to any one of claims 1 to 12 to a surface of a substrate corresponding to a space between the plurality of conductive pads on which the solder paste is applied; Aligning the conductive pads formed on the surface of the electronic device to be located on the conductive pads of the corresponding substrate and contacting the electronic device with the substrate; And reflowing the substrate and the contacted electronic device. Considering that the underfill composition according to the present invention is suitable for the flip chip bonding method, the electronic device is a concept including both a semiconductor chip having a fine pitch and an electronic component having a relatively large pitch. . In the present invention, a specific example of the electron emitter is a transistor, a resist, an inductor or a capacitor. Further, in the electronic device mounting method according to the present invention, the solder paste can be applied on the conductive pads (for example, metal terminals) of the substrate by various known methods. In consideration of the fine pattern of the conductive pads, It is preferably applied on the conductive pad by a printing method such as ink jet printing. In addition, the underfill composition is applied to a portion of the surface of the substrate corresponding to a portion between the plurality of conductive pads on which solder paste is applied, and is preferably applied in a dot type such as a droplet.

On the other hand, the solder paste includes a soldering flux and a solder powder, and may have a cream form or an ink form. Cream type solder paste is formed by mixing solder flux and solder powder (usually alloy powder) into a creamy state. The soldering flux used to form the cream solder paste generally comprises an auxiliary additive such as a rheology modifier or thickener. The solder powder is not particularly limited and, in addition to a commonly used tin-lead alloy, an alloy containing silver, bismuth, indium or the like added to the tin-lead alloy can be used. The particle diameter of the solder powder is suitably from 5 to 50 mu m. The weight ratio (flux: solder powder) of the flux for soldering to the solder powder in the solder paste may be suitably set according to the purpose and function of the solder paste required. For example, the weight ratio of the solder paste in the range of 5:95 to 20:80 ≪ / RTI > In addition, the solder paste may contain a predetermined organic solvent. The type of the organic solvent is not limited as long as it is used in the solder paste, and examples thereof include alcohol solvents such as ethyl alcohol, isopropyl alcohol, ethyl cellosolve, butyl carbitol and hexyl carbitol; Ester solvents such as butyl acetate, hydrocarbon solvents such as toluene and terphenyl oil, and the like. The content of the organic solvent may be selected in consideration of the viscosity of the solder paste, and may be selected in a range of about 10 to 50 wt% based on the total weight of the solder paste, for example.

Further, in the present invention, the reflow step comprises soldering the contacted electronic element and the substrate through a reflow oven having a predetermined temperature profile. The temperature profile of the reflowing step generally consists of a preheating section, a peak section and a cooling section. The peak section usually has a temperature range of 160 to 300 ° C, and a peak temperature exists within the peak section. The peak temperature of the reflowing step in the present invention is preferably 200 to 280 ° C, more preferably 220 to 260 ° C, in view of ensuring melting of the solder paste and controlling the curing rate of the underfill composition.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are intended to clearly illustrate the technical features of the present invention, and do not limit the scope of protection of the present invention.

One. For underfill  Preparation of composition

Production Examples 1-11.

The raw materials were blended as shown in Table 1 below to prepare a composition for underfilling.

Manufacturing Example Component Ingredient Ratio (parts by weight) Epoxy resin Hardener Curing catalyst Coupling agent Inorganic filler DGEBA DICY MHHPA MNA 2E4MZ MPTS Calcium carbonate Production Example 1 100 7 - - 2 0.05 10 Production Example 2 100 7 - - - - - Production Example 3 100 21.95 23.8 0.006 - - Production Example 4 100 21.95 23.8 0.014 - - Production Example 5 100 21.95 23.8 0.044 - - Production Example 6 100 21.95 23.8 0.09 - - Production Example 7 100 21.95 23.8 0.34 - - Production Example 8 100 21.95 23.8 0.42 - - Production Example 9 100 21.95 23.8 0.56 - - Production Example 10 100 21.95 23.8 0.72 - - Production Example 11 100 21.95 23.8 0.88 - -

The information of the components used in Table 1 is as follows.

* DGEBA: bisphenol A type epoxy resin [main component: diglycidyl ether of bisphenol A; Epoxy Equivalent Weight: 187 g / eq; Product name: YD-128; Manufacturer: Kukdo Chemical, Korea)

* DICY: dicyanodiamide (manufactured by Air Products and Chemicals, Inc., USA)

MHHPA: methylhexahydrophthalic anhydride (manufactured by Sigma-Aldrich, USA)

MNA: Methyl-5-norbornene-2,3-dicarboxylic anhydride (manufactured by Sigma-Aldrich, USA)

* 2E4MZ: 2-ethyl-4-methylimidazole (manufacturer: Shikoku Chemicals, Japan)

MPTS: 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, Japan)

2. For underfill  Semiconductor chip mounting using composition

Test Examples 1 to 11.

SAC 305 solder paste (alloy composition: Sn 96.5 / Ag 3.0 / Cu 0.5 (model name: M705-SHF; manufacturer: SENJU, Japan) was printed on the surface of the metal pad of the printed circuit board. Thereafter, the underfill compositions prepared in Production Examples 1 to 11 were applied in dot-like fashion on portions of the surface of the printed circuit board corresponding to the spaces between the metal pads printed with the solder paste. Then, the semiconductor chip was mounted so that the electrode terminals of the semiconductor chip were in contact with the solder paste-printed metal pads, and soldered through a reflow oven. Specifically, Chip 1608 is a capacitor made of a ceramic material having a size of 1.6 mm x 0.8 mm x 1.6 mm, and Chip 2012 is a ceramic material having a size of 2.0 mm x 1.2 mm x 1.6 mm And Chip 3216 is a resistor made of a ceramic material having a size of 3.2 mm x 1.6 mm x 1.6 mm. Table 2 below shows the composition for underfill used for each test example.

Test Example Solder paste used Used underfill composition One SAC 305 Production Example 1 2 Production Example 2 3 Production Example 3 4 Production Example 4 5 Production Example 5 6 Production Example 6 7 Production Example 7 8 Production Example 8 9 Production Example 9 10 Production Example 10 11 Production Example 11

In Comparative Control Example 1, solder was performed using only the SAC 305 solder paste without using the underfill composition. In Comparative Test Example 2, solder was used instead of the underfill composition prepared in Production Examples 1 to 11 using a commercial underfill adhesive SMD Glue (model: HT-130DM; manufactured by HITECH KOREA).

FIG. 1 shows an experiment for mounting a semiconductor chip on a printed circuit board in a stepwise manner. 2 shows a temperature profile applied to a reflow oven in an experiment in which a semiconductor chip is mounted on a printed circuit board. As shown in FIG. 2, the temperature was increased from about 150 ° C. to about 200 ° C. during the preheating period during the reflow process, about 200 seconds to 240 ° C. during the peak period, and the peak temperature was about 240 ° C. .

3. For underfill  Adhesive strength by material

In the test example, the bonding strength between the semiconductor chip and the printed circuit board after mounting the semiconductor chip on the printed circuit board was measured through shear test. The shear test was conducted using a Dage 4000 model and a 100 kg cartridge. The shear rate was 200 μm / sec and the shear height was 50 μm. Fig. 3 shows the bonding strengths of the types of semiconductor chips mounted on the printed circuit board by Test Example 1, Control Test Example 1 and Control Test Example 2, and Fig. 4 shows the results of Test Example 1, Test Example 10 and Control Test Example 1 The bonding strengths of the semiconductor chips mounted on the printed circuit board are shown. As shown in FIG. 3 to FIG. 4, the difference in bonding strength was observed for each of the test examples for Chip 3216 (a resistor made of a ceramic material having a size of 3.2 mm × 1.6 mm × 1.6 mm), and the underfill composition , And Test Example 10 using the underfill composition prepared in Test Example 1 and Test Example 10, the bonding strength was improved when the chip 3216 was mounted on a printed circuit board.

4. For underfill  Between substrate and semiconductor chip by material Boyd  Height

In the test example, the semiconductor chip was mounted on a printed circuit board, and then the void height between the semiconductor chip and the printed circuit board was observed with an optical microscope. 5 shows the result of measuring the void height between the semiconductor chip and the printed circuit board for each type of semiconductor chip mounted on the printed circuit board according to Test Example 1, Control Test Example 1 and Control Test Example 2, Is a result of measuring the void height between the semiconductor chip and the printed circuit board for each type of semiconductor chip mounted on the printed circuit board by the test example 1, the test example 10 and the verification test example 1. As shown in FIGS. 5 to 6, the void height between the semiconductor chip and the printed circuit board was largely affected by the composition for underfill used, rather than the type of semiconductor chip used. The composition for underfill prepared in Production Example 10 was used In Test Example 10, the void height was the smallest.

5. For underfill  By material Reflow  Change of curing state with time after the process

In a state in which Chip 3216 (a resistor made of a ceramic material having a size of 3.2 mm x 1.6 mm x 1.6 mm) was in contact with the printed circuit board in Test Examples 2 to 11, it was left at room temperature from immediately after passing through the reflow oven, The change of the cured state of the composition for underfilling with the elapse of time was observed. Specifically, after separating the semiconductor chip from the printed circuit board, the phase change and cured state of the underfill composition existing between the semiconductor chip and the printed circuit board were visually observed, and the results are shown in Table 3 below.

Test Example The cure state of the underfill composition immediately after passing through the reflux oven After passing through a reflux oven and left at room temperature for 5 minutes, the cured state of the underfill composition
After passing through a reflux oven and left at room temperature for 10 minutes, the cured state of the underfill composition
Whether it is hardened Whether phase change 2 Hardening solid Hardening Hardening 3 Uncured liquid Uncured Uncured 4 Uncured liquid Uncured Uncured 5 Uncured liquid Uncured Uncured 6 Uncured liquid Uncured Uncured 7 Uncured liquid Uncured Uncured 8 Uncured liquid Uncured Uncured 9 Uncured liquid Uncured Hardening 10 Uncured come Hardening Hardening 11 Hardening solid Hardening Hardening

As shown in Table 3, in Test Example 10 using the underfill composition prepared in Production Example 10, the underfill composition was in an uncured state during the process of passing through the reflow oven, and after passing through the reflow oven, . Therefore, when the underfill composition prepared in Production Example 10 is used, the voids between the semiconductor chip and the printed circuit board can be minimized, and at the same time, the semiconductor chip can be mounted on the printed circuit board most economically.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the scope of protection of the present invention should be construed as including all embodiments falling within the scope of the appended claims.

Claims (18)

40 to 55 parts by weight of an acid anhydride-based curing agent and 0.6 to 0.8 parts by weight of an imidazole-based curing catalyst per 100 parts by weight of an epoxy resin,
The epoxy resin is a polyfunctional glycidyl ether epoxy resin
The acid anhydride-based curing agent is composed of a combination of methylhexahydrophthalic anhydride and methyl-5-norbornene-2,3-dicarboxylic anhydride,
The weight ratio of methylhexahydrophthalic anhydride to methyl-5-norbornene-2,3-dicarboxylic anhydride is 3: 7 to 7: 3
Wherein the imidazole-based curing catalyst is 2-ethyl-4-methylimidazole.
delete The composition according to claim 1, wherein the polyfunctional glycidyl ether epoxy resin is a diglycidyl ether of bisphenol A.
delete delete delete delete The underfill composition of claim 1, wherein the composition further comprises 0.01 to 1 part by weight of a silane-based coupling agent per 100 parts by weight of the epoxy resin.
delete delete The underfill composition of claim 1, wherein the composition further comprises 0.5 to 15 parts by weight of an inorganic filler per 100 parts by weight of the epoxy resin.
delete Preparing a substrate having at least a plurality of conductive pads on a surface thereof;
Applying a solder paste on a plurality of conductive pads present on a surface of the substrate;
Applying a composition for a non-flowing fluxy underfill according to any one of claims 1, 3, 8, and 11 to a surface of a substrate between the plurality of conductive pads on which the solder paste is applied;
Aligning the conductive pads formed on the surface of the electronic device to be located on the conductive pads of the corresponding substrate and contacting the electronic device with the substrate; And
And reflowing the contacted electronic element and the substrate.
14. The electronic element mounting method according to claim 13, wherein the electronic element is in the form of a semiconductor chip.
The electronic device mounting method according to claim 14, wherein the electronic device is a transistor, a resist, or a capacitor.
14. The electronic element mounting method according to claim 13, wherein the solder paste is applied onto the conductive pad by a printing method.
14. The electronic element mounting method according to claim 13, wherein the underfill composition is applied to the surface of the substrate in a dot type.
14. The electronic element mounting method according to claim 13, wherein the peak temperature of the reflowing step is 200 to 280 deg.

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