JP2006160852A - Liquid sealing resin composition and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underfill material capable of effectively dissolving and removing flux residues therein when filling and curing the underfill material in a flip chip type semiconductor element. <P>SOLUTION: The liquid sealing resin composition is composed mainly of (1) a thermosetting resin, (2) an additive capable of dissolving a flux, and (3) a filler, wherein, preferably, the thermosetting resin is composed mainly of an epoxy resin and an aromatic amine, and the additive capable of dissolving a flux is a flux detergent, a surfactant capable of dissolving the flux or a compatibilizer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid sealing resin composition and a semiconductor device using the same.

  In recent years, with the increase in the size of semiconductor elements, the increase in the number of pins of semiconductor devices, and the diversification, the requirement for reliability of resin materials used in the periphery of semiconductor elements and the like has become severe. Conventionally, a semiconductor device in which a semiconductor element is bonded to a lead frame and sealed with a sealing resin has been mainstream. However, in recent years, a semiconductor device such as a ball grid array (BGA) is increasing due to the limit of the number of pins. . As a method of connecting a semiconductor element mounted on a BGA to an interposer (substrate), there are a method of connecting a semiconductor element to the interposer by wire bonding, a method of connecting a flip chip to the interposer, and the like. In particular, in the latter case, the production volume has increased remarkably in recent years from the viewpoint of signal response, heat dissipation, and the like.

In the method of assembling a semiconductor device in which a flip chip is connected to an interposer, solder electrodes are used for the connection,
1) Step of applying flux to substrate or solder electrode 2) Step of connecting solder electrode by reflow process 3) Step of cleaning flux 4) Filling gap between flip chip and substrate with sealing resin called underfill material -The process of hardening is included (FIG. 1). The step 3) is a step necessary for preventing an electrical failure caused by the impurities of the flux residue, and 4) is essential for improving the reliability of the entire apparatus. In recent years, a high-purity, low-residue type flux has appeared in the step 3), and it has become possible to omit the cleaning step 3) (see, for example, Patent Document 1).
However, with the recent trend toward electronic chip miniaturization, the pitch between solder electrodes of flip chips, the height of solder is becoming narrower, or the chip is becoming larger, even when using the above-mentioned improved flux, There is now a problem that tends to remain. Since the flux is used to connect the solder electrode, a residue is often formed around the solder electrode after the reflow process (FIG. 3), and this residue is often a process of filling and curing the underfill material. In this case, it was found that it remained around the solder electrode without being compatible with the underfill material (FIG. 4). The flux residue originally has poor adhesion to the base material, and may cause peeling in reliability. Further, since the flux residue generally has a very high linear expansion coefficient, there is a risk that a large stress is applied to the solder in reliability, particularly in a thermal shock test, and serious defects such as solder cracks may be caused. In order to prevent these problems, it is conceivable to perform the cleaning step 3) for the improved flux. However, due to the narrowing of the solder electrode described above, the cleaning is not performed in detail, and the flux residue is partially removed. There was a problem of continuing.
JP-A-8-288638

  An object of the present invention is to provide an underfill material capable of effectively dissolving and removing a flux residue in the underfill material when filling and curing the flip chip type semiconductor element with the underfill material. As a result, the reliability of the semiconductor device using the underfill material is improved.

Such an object is achieved by the present invention described in the following [1] to [7].
[1] A liquid sealing resin composition comprising as main components 1) a thermosetting resin, 2) an additive capable of dissolving a flux, and 3) a filler.
[2] The liquid sealing resin composition according to [1], wherein the thermosetting resin is mainly composed of an epoxy resin and an aromatic amine.
[3] The liquid sealing resin composition according to [1] or [2], wherein the additive capable of dissolving the flux is a flux cleaning agent.
[4] The liquid sealing resin composition according to [1] or [2], wherein the additive capable of dissolving the flux is a surfactant capable of dissolving the flux.
[5] The liquid sealing resin composition according to [1] or [2], wherein the additive capable of dissolving the flux is a compatibilizing agent capable of dissolving the flux.
[6] The liquid seal according to any one of [1] to [5], wherein the ratio of the additive capable of dissolving the flux with respect to 100 parts by weight of the liquid sealing resin composition is 0.005 to 15 parts by weight. Resin composition.
[7] The liquid resin composition according to any one of items [1] to [6], wherein a gap between the element and the substrate in which the substrate corresponding to the semiconductor element provided with the solder electrode is connected via the solder electrode is provided. A semiconductor device characterized by being sealed using

  The underfill material of the present invention can effectively dissolve and remove the flux residue in the underfill material when filling and curing the flip chip type semiconductor element. By using the underfill material of the present invention, This is to improve the reliability of the semiconductor device.

Hereinafter, the liquid sealing resin composition (underfill material) and the semiconductor device of the present invention will be described in detail.
The liquid sealing resin composition of the present invention is essentially composed of a thermosetting resin, an additive capable of dissolving flux, and a filler.
As an example of the thermosetting resin used in the present invention, an existing thermosetting resin such as an epoxy resin, an acrylate resin, a butadiene resin, a maleimide resin, a cyanate resin, or a urethane resin can be used. Among them, epoxy resin is preferable in terms of reliability, diversity, productivity, and the like. The epoxy resin requires a curing agent such as an amine, an acid anhydride, or a phenol resin in order to be cured, and a combination with an aromatic amine as the curing agent is particularly preferable in order to express the present invention. A more preferable example is an oligomer having the following structure (formula 1).

Ｒ：水素、またはアルキル基
Ｘ：水素、またはアルキル基

R: hydrogen or alkyl group X: hydrogen or alkyl group

For example, aromatic amines disclosed in JP-A-10-158365 (in the case of R = H-, X = C2H5-), etc., JP-A 2004-35668 (in the case of R = CH3-, X = H), etc. The aromatic amine is suitable because it is liquid at room temperature and excellent in reliability.
Next, an additive capable of dissolving the flux used in the present invention is, for example, a flux cleaning agent, and a commercially available product can be used. Examples include Pine Alpha ST-100SX manufactured by Arakawa Chemical Co., Ltd., CLEAN THROUGH 750H manufactured by Kao Corporation, and MicroClean WS-1942 manufactured by Kaken Tech.

In addition, as an additive capable of dissolving the flux used in the present invention, as a flux cleaning agent having an equivalent action, it is compatible with a thermosetting resin such as a surfactant or a compatibilizing agent, and the flux agent A compound having a structure that dissolves can be used. For example, a typical example of the flux is an active rosin flux. In this case, a nonionic surfactant such as polyoxyalkylene alkyl ether, a polyoxyalkylene phosphate ester surfactant, a polyoxyalkylene amine surfactant is used. It is preferable to use an oligomer such as In general, a compound having a soluble structure may be added according to the content component of the flux to be used. The amount of the compound capable of dissolving the flux is preferably 0.005 to 15 parts by weight with respect to 100 parts by weight of the total liquid sealing resin composition. When the amount is less than 0.005 parts by weight, the effect of the present invention is not exhibited. When the amount exceeds 15 parts by weight, the physical properties of the cured product are deteriorated, and voids are generated.

  Next, as a filler used in the liquid sealing resin composition of the present invention, for example, silicates such as talc, fired clay, unfired clay, mica, glass, oxides such as titanium oxide, alumina, silica, and fused silica, Carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate and calcium sulfite, zinc borate And borate salts such as barium metaborate, aluminum borate, calcium borate, and sodium borate, and nitrides such as aluminum nitride, boron nitride, and silicon nitride. Among these, silica (especially spherical fused silica) is preferable. Thereby, fluidity | liquidity and supply stability can be improved. The average particle diameter of the filler (particularly, spherical silica) is not particularly limited, but is preferably 10 μm or less, and particularly preferably 5 μm or less. When the average particle diameter is within the above range, the filling property can be particularly improved. Furthermore, the surface of the filler may be surface-treated with a coupling agent.

  In addition, the liquid sealing resin composition of the present invention is mixed with additives such as a curing accelerator, a coupling agent, a low stress agent, a pigment, a dye, a leveling agent, and an antifoaming agent as long as the object of the present invention is not impaired. can do. As a manufacturing method, it can produce by mixing with a roll, a planetary mixer, etc., and carrying out vacuum defoaming.

  A known method can be used as a method of sealing a flip chip type semiconductor element using the liquid sealing resin composition of the present invention and manufacturing a semiconductor device.

Hereinafter, although it demonstrates in detail based on the Example and comparative example of this invention, this invention is not limited to this.
Example 1
(1) Preparation of liquid sealing resin composition 28.5% by weight of bisphenol F type epoxy resin (Nippon Kayaku, RE-403S, epoxy equivalent 166) as curable resin, and diethyldiaminodiphenylmethane (curing agent) as curing agent A, active hydrogen equivalent 63) 10.8% by weight, commercially available flux detergent Pine Alpha ST-100SX (manufactured by Arakawa Chemical) as a component capable of dissolving the flux, 5.0% by weight, and spherical as an inorganic filler Silica (manufactured by Admatechs, SO-25H, average particle size 0.5 μm) 55.0% by weight, and γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-403) 0.6 weight as a coupling agent % And carbon black (Mitsubishi Chemical, MA-600) 0.1% by weight as a pigment were kneaded at room temperature with three rolls, To obtain a liquid encapsulating resin composition was vacuum defoamed using machine.

(2) Filling with sealing resin (sealing)
TSF-6502 (manufactured by Kester, rosin-based flux) or TSF-6522 (manufactured by Kester, rosin-based) is applied to the substrate as a soldering flux, and the solder electrode (solder composition: 67% Sn33) is applied in advance by a flip chip bonder. % Pb) corresponding to a semiconductor device (circuit protection film: silicon nitride, 176 electrodes, size: 10 mm × 10 mm × 0.35 mmt, solder height 50 μm) (352 pBGA (size 35 mm × 35 mm × 0 .56mmt bismaleimide / triazine resin / glass cloth substrate, resist: PSR-4000 / AUS308, manufactured by Taiyo Ink Co., Ltd., and then soldered to the substrate through a reflow oven (see temperature profile Fig. 6). Got.
The above-mentioned semiconductor package is heated on a hot plate at 110 ° C., and the liquid sealing resin composition prepared in (1) is dispensed and filled on one side of the semiconductor element, and the resin is cured in an oven at 150 ° C. for 90 minutes, A semiconductor device was obtained.

(Example 2)
The same procedure as in Example 1 was conducted except that the composition of the liquid sealing resin composition was as follows.
Bisphenol F-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-403S, epoxy equivalent 166) 23.7% by weight as a curable resin, and an amine-based curing agent (curing agent B, Active hydrogen equivalent 116) 16.6% by weight, commercially available flux cleaner Pine Alpha ST-100SX (manufactured by Arakawa Chemical) as a component capable of dissolving flux, 4.1% by weight, and spherical silica (inorganic filler) 55.0% by weight, manufactured by Admatechs, SO-25H, average particle size 0.5 μm), and 0.5% by weight of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-403) as a coupling agent Then, 0.1% by weight of carbon black (manufactured by Mitsubishi Chemical, MA-600) as a pigment is kneaded at room temperature with three rolls, and then subjected to vacuum defoaming treatment using a vacuum defoamer. It was to obtain a liquid sealing resin composition.
A semiconductor device was obtained in the same manner as in Example 1 using the obtained liquid sealing resin composition.

(Example 3)
The same procedure as in Example 1 was conducted except that the composition of the liquid sealing resin composition was as follows.
Bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-403S, epoxy equivalent 166) 32.0% by weight as curable resin, and diethyldiaminodiphenylmethane (hardener A, active hydrogen equivalent 63) 12.2% by weight as the curing agent %, Pegnol T-6 (manufactured by Toho Chemical Co., Ltd.) which is a polyoxyethylene tridecyl ether surfactant as a component capable of dissolving flux, and spherical silica (manufactured by Admatechs) as an inorganic filler. SO-25H, average particle size 0.5 μm) 55.0% by weight, γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-403) 0.6% by weight as a coupling agent, and pigment Carbon black (Mitsubishi Chemical, MA-600) 0.1% by weight was kneaded at room temperature with three rolls, and then a vacuum defoamer was used. And a vacuum defoaming treatment to obtain a liquid sealing resin composition.
A semiconductor device was obtained in the same manner as in Example 1 using the obtained liquid sealing resin composition.

Example 4
The same procedure as in Example 1 was conducted except that the composition of the liquid sealing resin composition was as follows.
Bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-403S, epoxy equivalent 166) as a curable resin, 26.1% by weight, and amine curing agent of formula 2 as a curing agent (curing agent B, active hydrogen equivalent 116) 18.2% by weight, 0.1% by weight of Pegnol T-6 (Toho Chemical Co., Ltd.) which is a polyoxyethylene tridecyl ether surfactant as a component capable of dissolving flux, and spherical silica as an inorganic filler (Manufactured by Admatechs, SO-25H, average particle size 0.5 μm) 55.0% by weight and γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-403) 0.5% by weight as a coupling agent And 0.1% by weight of carbon black (manufactured by Mitsubishi Chemical, MA-600) as a pigment are kneaded at room temperature with three rolls, and then vacuum degassed using a vacuum defoamer. Processing to obtain a liquid sealing resin composition.
A semiconductor device was obtained in the same manner as in Example 1 using the obtained liquid sealing resin composition.

(Comparative Example 1)
The same procedure as in Example 1 was conducted except that the composition of the liquid sealing resin composition was as follows.
Bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-403S, epoxy equivalent 166) 32.1% by weight as curable resin, and diethyldiaminodiphenylmethane (hardener A, active hydrogen equivalent 63) 12.2% by weight as the curing agent %, Spherical silica (manufactured by Admatechs, SO-25H, average particle size 0.5 μm) 55.0% by weight as inorganic filler, and γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., (KBM-403) 0.7% by weight and 0.1% by weight of carbon black (Mitsubishi Chemical, MA-600) as a pigment were kneaded at room temperature with three rolls, and then vacuumed using a vacuum deaerator. A defoaming treatment was performed to obtain a liquid sealing resin composition.
A semiconductor device was obtained in the same manner as in Example 1 using the obtained liquid sealing resin composition.

(Comparative Example 2)
The same procedure as in Example 1 was conducted except that the composition of the liquid sealing resin composition was as follows.
Bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-403S, epoxy equivalent 166) as a curable resin, 26.1% by weight, and amine curing agent of formula 2 as a curing agent (curing agent B, active hydrogen equivalent 116) 18.3% by weight, 55.0% by weight of spherical silica (manufactured by Admatechs, SO-25H, average particle size 0.5 μm) as inorganic filler, and γ-glycidoxypropyltrimethoxysilane (as coupling agent) Shin-Etsu Chemical, KBM-403) 0.5% by weight and carbon black (Mitsubishi Chemical, MA-600) 0.1% by weight as a pigment were kneaded at room temperature with three rolls, and then a vacuum defoamer Was subjected to vacuum defoaming treatment to obtain a liquid sealing resin composition.
A semiconductor device was obtained in the same manner as in Example 1 using the obtained liquid sealing resin composition.

For the semiconductor devices obtained in the respective examples and comparative examples, the following cross-sectional observation and reliability test of the semiconductor devices were performed. The obtained results are shown in Table 1.
<Semiconductor cross-section observation 1>
Of the semiconductor devices obtained in each of the examples and comparative examples, two each using TSF-6502 and TSF-6522 as the flux were subjected to cross-sectional polishing, and the presence or absence of flux residue around the solder bumps was observed. The number of semiconductor devices in which flux residues were observed was evaluated.
<Reliability test>
Of the semiconductor devices obtained in the respective examples and comparative examples, those not used in the above <Semiconductor cross-sectional observation 1> are subjected to moisture absorption treatment (30 ° C./60%/192 hours), reflow resistance test (JEDEC 220 ° C. condition). After conducting a thermal shock test (-55 ° C./30 minutes to 125 ° C./30 minutes, 1,000 cycles) three times, a continuity test was conducted to evaluate the number of semiconductor devices that did not conduct.
<Cross-section observation of semiconductor 2>
All semiconductor devices used in the above <reliability test> were subjected to cross-sectional polishing and observed around the solder bumps.

As is clear from the table, in Examples 1 to 4, the flux residue around the solder is dissolved and removed in the underfill material (FIG. 5), and electrical conductivity is obtained even after the reliability test. It was shown that the performance was improved.
On the other hand, in Comparative Examples 1 and 2, since the additive capable of dissolving the flux is not added, the flux residue around the solder bump is not removed, and peeling occurs between the flux residue and the substrate after the reliability test. Some semiconductor devices were not conductive because the solder bumps were cracked.
In Examples 1 to 4, the flux residue around the solder was dissolved and removed in the underfill material, and the continuity was obtained after the reliability test, indicating that the reliability of the semiconductor device was improved. .

The manufacturing process example of a flip chip package is shown. FIG. 1A is a state diagram after a flux is applied to a substrate or a solder electrode. FIG. 1B is a state diagram after the solder electrodes are connected by the reflow process. FIG. 1C is a state diagram after cleaning the flux. FIG. 1D is a state diagram after filling and curing the underfill material. An example of a manufacturing process of a flip chip package in which a cleaning process is omitted will be shown. FIG. 2A is a state diagram after the flux is applied to the substrate or the solder electrode. FIG. 2B is a state diagram after the solder electrodes are connected by the reflow process. FIG. 2C is a state diagram after filling and curing the underfill material. It is sectional drawing which shows the state of a flux residue. It is sectional drawing which shows the state sealed with the underfill material in the state with a flux residue. It is sectional drawing which shows the state sealed with the underfill material of this invention. It is a temperature profile of the reflow furnace used in order to join the solder electrode of this invention through a flux.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Board | substrate 3 Solder bump 4 Flux 5 Flux residue 6 Sealing resin

Claims (7)

1. A liquid sealing resin composition comprising 1) a thermosetting resin, 2) an additive capable of dissolving a flux, and 3) a filler as main components. The liquid sealing resin composition according to claim 1, wherein the thermosetting resin is mainly composed of an epoxy resin and an aromatic amine. The liquid sealing resin composition according to claim 1 or 2, wherein the additive capable of dissolving the flux is a flux cleaning agent. The liquid sealing resin composition according to claim 1 or 2, wherein the additive capable of dissolving the flux is a surfactant capable of dissolving the flux. The liquid sealing resin composition according to claim 1 or 2, wherein the additive capable of dissolving the flux is a compatibilizing agent capable of dissolving the flux. The liquid sealing resin composition according to any one of claims 1 to 5, wherein a ratio of the additive capable of dissolving the flux with respect to 100 parts by weight of the liquid sealing resin composition is 0.005 to 15 parts by weight. The substrate corresponding to the semiconductor element provided with the solder electrode is sealed with the liquid resin composition according to any one of claims 1 to 6 at a gap between the element connected via the solder electrode and the substrate. A semiconductor device characterized by comprising:

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