JP2015168691A - Resin composition, pre-feed type semiconductor sealing agent, film for semiconductor sealing, and semiconductor device - Google Patents

Abstract

In a method of mounting a semiconductor chip on a substrate, a resin composition that can be used in a pre-feed type process and has improved connection stability is provided. (A) Bifunctional or higher functional (meth) acrylate (B) Maleic anhydride modified polybutadiene (C) Organic peroxide (D) Silica filler (E) Silane coupling agent (F) Formula 1 as a flux agent , 2 compound containing 0.2 to 2.2% by mass with respect to the total of A to F, and the molar ratio of the compounds of formulas 1 and 2 is 1: 0.3 to 1: 3.1. . [Selection figure] None

Description

  The present invention relates to a resin composition, a pre-feed type semiconductor sealing agent, a semiconductor sealing film, and a semiconductor device.

  One technique for mounting a semiconductor chip (semiconductor element) on a substrate (or package) is flip chip mounting. Flip chip mounting is a technique for electrically connecting a semiconductor chip and a substrate using bumps. In order to reinforce the periphery of the bump, a resin composition (so-called underfill agent) is filled between the semiconductor chip and the substrate. In flip chip mounting, conventionally, a process of connecting a semiconductor chip and a substrate and then filling a resin composition into a gap between the semiconductor chip and the substrate (hereinafter referred to as a “post-feed type” process) has been widely used. ing.

  In order to reduce the size and reliability of products, it is required to narrow the gap. In order to realize a narrow gap, flip chip mounting using a copper pillar has been developed. However, the post-feed type process has a problem in dealing with the narrowing of the gap. On the other hand, in recent years, a process of applying a resin composition on a substrate, placing a semiconductor chip thereon, and then curing the resin composition and connecting the semiconductor chip and the substrate (hereinafter referred to as “first supply type” process). Has been developed. The resin composition for the pre-feed type process is required to have characteristics different from those of the resin composition for the post-feed type process, such as low viscosity due to the narrow gap. For example, Patent Document 1 discloses a thermosetting liquid sealing resin composition used in a pre-feed process.

JP 2009-96886 A

  The properties required for the resin composition used in the pre-feed type process are becoming strict. One of the required characteristics is connection stability.

  The present invention provides a resin composition that can be used in a pre-feed process and has improved connection stability.

The present invention includes (A) a bifunctional or higher functional (meth) acrylate, (B) maleic anhydride-modified polybutadiene, (C) an organic peroxide, (D) a silica filler, and (E) a silane coupling. And (F) the compound f1 of the formula (1) and the compound f2 (o-phthalic acid) of the formula (2) as a fluxing agent, and the above (F) with respect to the total of the above (A) to (F) Is contained in an amount of 0.2 to 2.2% by mass, and the molar ratio of f1 to f2 is 1: 0.3 to 1: 3.1.

Said (E) may contain at least one of the compounds of formula (3) and formula (4).

Said (A) may contain at least 1 of the compound of Formula (5) and Formula (6) (however, R < ¹ > and R < ² > are a hydrogen atom or a methyl group, respectively).

  Moreover, this invention provides the pre-feed type semiconductor sealing agent containing said resin composition.

  Furthermore, this invention provides the film for semiconductor sealing containing said resin composition.

  Furthermore, this invention provides the semiconductor device which has a semiconductor element sealed using said pre-feed type semiconductor sealing agent or said film for semiconductor sealing.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can be used with a pre-feed type process and improved connection stability can be obtained.

FIG. 6 illustrates a semiconductor device. The figure which illustrates the outline of the board | substrate and semiconductor chip which were used for the mounting test. The figure which illustrates the temperature profile of mounting. The figure which illustrates the result of ultrasonic image observation. The schematic diagram which shows the result of the microscope observation of an opening part.

The resin composition of the present invention comprises (A) a bifunctional or higher functional (meth) acrylate, (B) maleic anhydride-modified polybutadiene, (C) an organic peroxide, (D) a silica filler, (E ) A silane coupling agent, (F) a compound f1 of formula (1) (1,8-diazabicyclo (5.4.0) undecene-7) as a fluxing agent, and a compound f2 of formula (2). The resin composition is preferably liquid at room temperature.

The component (A) is an acrylate or methacrylate having two or more functional groups. Examples of the component (A) include EO-modified bisphenol A dimethacrylate (2.2 Bis [4- (Methacryloxy Ethoxy) Phenyl] Propane, formula (5)) and tricyclolodecane dimethanol diacrylate, formula (6). )) Is used.

“EO-modified” means having an ethylene oxide unit (—CH ₂ —CH ₂ —O—) block structure. Here, R ¹ and R ² are each a hydrogen atom (H) or a methyl group (CH ₃ ). Moreover, it is preferable that it is m + n = 2.3-4.0. The compounds exemplified here may be used alone or in combination of two or more. (A) It is preferable that 25-40 mass% is contained with respect to the sum total of (A)-(F) component, and it is more preferable that 29-36 mass% is contained. When the compound of formula (5) and the compound of formula (6) are used as the component (A), the compound of formula (5) is preferably contained in an amount of 10 to 15% by mass, and the compound of formula (6) is 15 to It is preferable that 25 mass% is contained.

  (B) It is preferable that 1-10 mass% is contained with respect to the sum total of (A)-(F) component, and it is more preferable that 3-5 mass% is contained.

As the component (C), for example, a compound of the formula (7) or the formula (8) is used. (C) It is preferable that 0.1-0.6 mass% of component is contained with respect to the sum total of (A)-(F) component. In the resin composition, the compounds exemplified here may be used alone, or two or more compounds may be mixed and used.

  (D) It is preferable that 50-70 mass% of component is contained with respect to the sum total of (A)-(F) component.

Examples of the component (E) include various silane coupling agents such as epoxy, amino, vinyl, methacrylic, acrylic, mercapto, and glycidoxy. Among these, the compounds of formula (3) and formula (4) are preferable. In the resin composition, the compounds exemplified here may be used alone, or two or more compounds may be mixed and used. (E) It is preferable that 0.1-0.5 mass% of component is contained with respect to the sum total of (A)-(F) component.

  (F) It is preferable that 0.2-2.2 mass% of component is contained with respect to the sum total of (A)-(F) component. Moreover, it is preferable that the compound f1 and the compound f2 are in the range of 1: 0.3-1: 5 by molar ratio, and it is more preferable that it exists in the range of 1: 0.3-1: 3.1.

  The resin composition may contain an additive (G) in addition to the components (A) to (F). Examples of additives include other (meth) acrylate compounds, epoxy compounds, bismaleimide compounds, cyanate ester compounds, and other thermosetting components, thermosetting component curing agents and curing accelerators, rheology modifiers, dispersants, Examples thereof include thermoplastic resins such as antisettling agents, antifoaming agents, colorants, surface conditioners, elastomers, phenoxy resins, polyester resins, and solvent-soluble polyimide resins. Curing agents and curing accelerators are used to cure and accelerate the thermosetting component. The rheology modifier is used to adjust coating suitability and flow suitability. The dispersant and the anti-settling agent are used for improving the dispersibility of the filler and the colorant and preventing the settling. An antifoaming agent is used for adjustment of antifoaming property. The colorant is used for coloring. The surface conditioner is used for adjusting the surface condition and wettability. Elastomers are used for adjustment of elastic modulus and stress. The solid resin is used for adjusting viscosity and toughness. These additives may be used alone or in combination of two or more.

  This resin composition is produced, for example, by putting raw materials in a predetermined blend into a mixer such as a likai machine, a pot mill, a three-roll mill, a rotary mixer, a twin screw mixer, and the like. In addition, the resin composition may be manufactured by other methods.

  This resin composition is used, for example, for sealing electronic devices such as semiconductor elements, in particular for sealing electronic devices in so-called pre-applied processes. The pre-feed process refers to a process in which a sealing agent is first applied to a substrate, a semiconductor element is placed thereon, and then the sealing agent is cured and the semiconductor element and the substrate are connected.

  FIG. 1 is a diagram illustrating a semiconductor device 10 having a semiconductor element sealed with a resin composition according to this embodiment. The semiconductor device 10 includes a semiconductor chip 1 and a substrate 2. Each of the semiconductor chip 1 and the substrate 2 is provided with a copper pillar 3. Solder 4 is used to connect the semiconductor chip 1 and the substrate 2. First, the resin composition 5 is applied onto the substrate 2 using, for example, a dispenser. For example, the semiconductor chip 1 and the substrate 2 are aligned using a flip chip bonder. Thereafter, the semiconductor chip 1 is pressed against the substrate 2 with a predetermined load while being heated to a temperature equal to or higher than the melting point of the solder 4. In this way, the semiconductor chip 1 and the substrate 2 are connected, and the gap is filled with the softened resin composition. 1 is merely an example, and the configuration of the semiconductor device according to the present embodiment is not limited to this.

  In another example, the resin composition may be formed into a film. In this case, this film is used in place of the liquid resin composition in mounting the semiconductor chip. That is, first, a film containing a resin composition is attached on a substrate. Next, the semiconductor chip is pressed against the substrate with a predetermined load while heating to a temperature equal to or higher than the melting point of the solder using a flip chip bonder.

(1) Adjustment of resin composition Tables 1 and 2 show the compositions of the resin compositions of Examples 1 to 8 and Comparative Examples 1 to 7, and the results of evaluation described later. In Tables 1 and 2, the composition of the resin composition is expressed in parts by mass.

  As the component (A), (meth) acrylate a1 (compound of formula (6)) and a2 (compound of formula (5)) were used. As (meth) acrylate a1, DCP-A manufactured by Kyoeisha Chemical Co., Ltd. was used. As (meth) acrylate a2, BP-2EMK manufactured by Kyoeisha Chemical Co., Ltd. was used. As the component (B), Ricon130MA13 manufactured by Cray Valley was used. As the component (C), organic peroxides c1 (compound of formula (7)) and c2 (compound of formula (8)) were used. As the organic peroxide c1, Park Mill (registered trademark) D manufactured by NOF Corporation was used. As the organic peroxide c2, Perbutyl (registered trademark) P manufactured by NOF Corporation was used. As component (D), SOE2 manufactured by Admatechs Co., Ltd. was used. As component (E), silane coupling agents e1 (compound of formula (3)) and e2 (compound of formula (4)) were used. As the silane coupling agent e1, KBM403 manufactured by Shin-Etsu Chemical Co., Ltd. was used. As the silane coupling agent e2, KBM503 manufactured by Shin-Etsu Chemical Co., Ltd. was used. (F) As the compound f1 of the component, DBU manufactured by San Apro Co., Ltd. was used. As the compound f2, o-phthalic acid manufactured by Tokyo Chemical Industry Co., Ltd. was used. In some comparative examples, o-toluic acid manufactured by Tokyo Chemical Industry Co., Ltd. was used instead of compound f2.

(2) Mounting test A mounting test was performed on Examples 1 to 8 and Comparative Examples 1 to 7. The sample used for the test was prepared by mounting a semiconductor chip having a predetermined shape on a substrate having a predetermined shape. As a substrate, Cu is used as an electrode material, a Cu electrode is plated with Ni, and further plated with Au (hereinafter referred to as a Ni / Au substrate), and a surface is treated with OSP (Organic Solderability Preservative) using Cu (hereinafter referred to as “Ni”). Two types of Cu / OSP substrates) were adopted. FIG. 2 shows an outline of the substrate and the semiconductor chip used for preparing the sample. Flip chip bonder FCB3 manufactured by Panasonic Factory Solutions Co., Ltd. was used for mounting. The implementation conditions are as follows. First, the substrate was baked at 125 ° C. for 30 minutes. After baking, the substrate was placed on the stage, and the resin composition was applied onto the substrate with a dispenser. After the application of the resin composition, the substrate was moved to a stage at a temperature of 70 ° C., and the semiconductor chip was placed on the substrate. At the same time, the resin composition was cured and the semiconductor chip and the substrate were bonded according to the temperature profile of FIG. The load was 15N. After bonding, heat treatment was performed at 165 ° C. for 60 minutes as post-curing.

  The sample prepared as described above was evaluated by ultrasonic image observation, microscopic observation, and resistance value measurement. Ultrasonic image observation was performed using an image obtained by an ultrasonic imaging device (Scanning Acoustic Tomography, SAT). Seven samples were observed, and it was confirmed whether the resin composition was filled on the entire surface under the semiconductor chip and whether voids were generated. Those in which the resin composition was not filled over the entire surface and those in which voids were confirmed were judged as defective products. For microscopic observation, the semiconductor chip portion of the sample was removed by polishing, and then the opening was observed with a microscope. Those in which voids were confirmed in the opening were judged as defective. About resistance value measurement, resistance value was measured using the resistance value measurement pad of the sample. Seven samples were measured, and those showing resistance values of 28 to 32Ω were judged as good products, and those showing resistance values outside this range were judged as defective products. The reason why a resistance value of 28 to 32Ω was judged as a non-defective product is as follows. When a cross section of a sample having a resistance value of 28 to 32Ω was observed, growth of an alloy layer was observed between the solder and the substrate electrode, and a good bonding state was confirmed. If it is 27Ω or less, contact of solder may be observed between the substrate electrodes. When the resistance was 33Ω or more, a sample in which no growth of the alloy layer was observed or no solder spread was observed was confirmed.

(3) Hygroscopic reflow test A hygroscopic reflow test was performed on Examples 1-8 and Comparative Examples 1-7. Of the samples used for the evaluation of mountability, five samples (those without polishing the semiconductor chip) were placed in a constant temperature and humidity chamber with a temperature of 30 ° C. and a relative humidity of 60%, and were allowed to absorb moisture for 192 hours. After moisture absorption, the sample was repeatedly passed through a reflow furnace having a maximum temperature of 260 ° C. three times, and then ultrasonic image observation was performed. In the ultrasonic image observation, delamination (resin composition peeling) was judged as a defective product. In addition to ultrasonic image observation, resistance value measurement was performed. In the resistance value measurement, similarly to the resistance value measurement in the evaluation of mountability, those showing a resistance value of 28 to 32Ω were judged as non-defective products, and those showing resistance values outside this range were judged as defective products.

  In Tables 1 and 2, the items “SAT”, “planar polishing”, and “conductivity” indicate the results of ultrasonic image observation, microscopic observation, and resistance value measurement, respectively. The evaluation result is indicated by (number of defective products) / (number of measurements).

  FIG. 4 is a diagram illustrating the result of ultrasonic image observation. 4A shows an example of a non-defective product, and FIG. 4B shows an example of a defective product. In the example of FIG. 4B, delamination occurs in the upper right part and lower right part of the chip.

  FIG. 5 is a schematic diagram showing the result of microscopic observation of the opening. FIG. 5A shows an example of a non-defective product, and FIG. 5B shows an example of a defective product. In the example of FIG. 5B, voids are generated near some of the bumps.

(4) Heat cycle test The heat cycle test was done with respect to Examples 1-8 and Comparative Examples 1-7. The sample used for the moisture absorption reflow test was tested in an air tank heat cycle tester. The test conditions were to expose to a high temperature of 125 ° C. and a low temperature of −55 ° C. for 30 minutes each. Samples were taken out every 500 cycles, and ultrasonic image observation and resistance measurement were performed. A product that had undergone delamination in ultrasonic image observation was judged as a defective product. Moreover, in resistance value measurement, what showed the resistance value of 28-32 (ohm) was judged to be a non-defective product, and what showed the resistance value out of this range was judged to be inferior goods.

(5) Evaluation results

  Examples 1 to 3 and Comparative Examples 1 to 2 show examples in which an organic peroxide c2 is used as the component (C) and a silane coupling agent e1 is used as the component (E). In these examples, the content of the component (F) is different. In the example (Comparative Example 1) in which the content of the component (F) is 0.1% by mass, in a heat cycle test using a Cu / OSP substrate, a resistance value failure occurred in 1500 cycles or more. In the example (Comparative Example 2) in which the content of the component (F) is 2.3% by mass, defects occurred in the ultrasonic image observation of the mounting test and the microscopic observation of the opening. On the other hand, in Examples 1 to 3, no defect occurred in the heat cycle test using any substrate.

  Example 4 is an example using the organic peroxide c1 as the component (C). Example 5 is an example using a silane coupling agent e2 as the component (E). Example 6 is an example in which silane coupling agents e1 and e2 are used in combination as the component (E). In these samples, no defect occurred in the heat cycle test using any substrate.

  Examples 7 to 8 and Comparative Examples 3 to 4 are examples in which the molar ratio of compound f1 and compound f2 was different from that of Example 1. In the example where the molar ratio is 1.00: 0.11 (Comparative Example 3) and the example where the molar ratio is 1.00: 5.74 (Comparative Example 4), ultrasonic image observation of the mounting test and microscopic observation of the opening are performed. A defect occurred. On the other hand, in Comparative Examples 1 and 7 to 8, no defect occurred in the heat cycle test using any substrate.

  Comparative Example 5 is an example in which compound f2 was not used, and Comparative Example 6 was an example in which compound f1 was not used. Comparative Example 7 is an example in which o-toluic acid was used instead of compound f2. In these examples, defects occurred in the mounting test. In particular, in Comparative Example 6, the resin composition was gelled and could not be evaluated.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor chip, 2 ... Board | substrate, 3 ... Copper pillar, 4 ... Solder, 5 ... Resin composition

Claims (6)

(A) a bifunctional or higher functional (meth) acrylate;
(B) maleic anhydride-modified polybutadiene,
(C) an organic peroxide;
(D) a silica filler;
(E) a silane coupling agent;
(F) Compound f1 of formula (1) and compound f2 of formula (2) as fluxing agents
Including
(F) is included in an amount of 0.2 to 2.2% by mass based on the total of (A) to (F),
The resin composition, wherein a molar ratio between the f1 and the f2 is 1: 0.3 to 1: 3.1. The (E) includes at least one of the compounds of the formula (3) and the formula (4)
The resin composition according to claim 1. Said (A) contains at least 1 of the compound of Formula (5) and Formula (6) (however, R < ¹ > and R < ² > are a hydrogen atom or a methyl group, respectively)
The resin composition according to claim 1 or 2, wherein:   A pre-supplied semiconductor encapsulant comprising the resin composition according to any one of claims 1 to 3.   The film for semiconductor sealing containing the resin composition as described in any one of Claims 1 thru | or 3.   The semiconductor device which has a semiconductor element sealed using the pre-feed type semiconductor sealing agent of Claim 4, or the film for semiconductor sealing of Claim 5.