JP5468954B2 - Liquid epoxy resin composition and semiconductor device - Google Patents

Description

  The present invention relates to a liquid epoxy resin composition and a semiconductor device in which a flip chip connecting portion is reinforced by a cured product thereof.

  As small portable electronic devices become widespread, LSI devices are becoming smaller. For this reason, packages such as CSP and BGA have become widespread.

  Further, a flip chip connection method is employed to reduce the mounting area of the packages such as CSP and BGA.

However, since the solder of the connecting portion used in the flip chip connecting method has a small bump area, an improvement in the reinforcing function of the connecting portion is required. Then, the hardened | cured material of a liquid epoxy resin is used as an underfill which has the reinforcement function of a connection part (for example, patent document 1).
However, when a shock is applied to a package using such an underfill, there is a problem in that a conduction failure occurs due to the occurrence of a resin crack, and thus both a reinforcing function and a resin crack resistance performance are required. Conventionally, in order to suppress the occurrence of resin cracks, a method of reducing the elastic modulus of the resin composition and imparting toughness has been reported, but the problem that the reinforcement function to the package is reduced due to low elasticity. was there.

Japanese Patent No. 3819148

  In view of the background as described above, the present invention provides a new liquid epoxy resin composition capable of solving the conventional problems and improving the resin crack resistance without lowering the reinforcing function of the package, and It is an object of the present invention to provide a semiconductor device in which a flip chip connecting portion is reinforced with a cured product using the above.

  The liquid epoxy resin composition of the present invention is characterized by the following in order to solve the above problems.

First: (A) epoxy resin that is liquid at normal temperature, (B) curing agent, and (C) inorganic filler as essential components, (A) the blending amount of epoxy resin that is liquid at normal temperature is 75 to 90% by mass in the range, (C) an inorganic filler and has a single talc, the amount of the talc is in the range of 0.5 to 10 mass% relative to the total amount of the composition.

  Second: The average particle diameter of the talc is in the range of 0.5 to 25 μm.

  The present invention also provides a semiconductor device characterized in that the flip chip connecting portion is reinforced by a cured product of the above liquid epoxy resin composition.

  Furthermore, the semiconductor device is characterized in that the cured product has an elastic modulus of 0.1 GPa or more.

  According to the liquid epoxy resin of the first invention, in the semiconductor device in which the flip chip connecting portion is reinforced with this, when the mechanical impact is applied to the semiconductor PKGH, the flip chip connecting portion has a function to be reinforced. And generation | occurrence | production of a resin crack can be suppressed.

  Further, according to the second invention, the effect is realized more reliably and more stably.

  As the third and fourth inventions, a semiconductor device in which the above effects are embodied is realized.

  As for the (A) normal temperature liquid epoxy resin as the resin component constituting the liquid epoxy resin composition in the present invention, the room temperature is around 18 ° C. under atmospheric pressure as the so-called “normal temperature”, and 5 ° C. as a guideline. Various epoxy resins which are liquid in a temperature range of 28 ° C. may be used.

  If the epoxy resin composition at room temperature becomes liquid, a commercially available liquid epoxy resin or solid epoxy resin can be used in combination as appropriate. Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin having a biphenyl skeleton, naphthalene ring-containing epoxy resin, alicyclic epoxy resin, diester Dicyclopentadiene type epoxy resin having cyclopentadiene skeleton, pheno novolac type epoxy resin, cresol novolac type epoxy resin, triphenylmethane type epoxy resin, bromine-containing epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate, etc. Can do.

  These may be used alone or in combination of two or more.

  Similarly, (B) a curing agent may be used as long as it normally cures an epoxy resin. For example, amine curing agents such as diaminodiphenylmethane and metaphenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl hymic anhydride, nadic anhydride Examples thereof include acid anhydride curing agents such as acid and trimellitic anhydride.

(A) About the epoxy resin and (B) hardening | curing agent which are liquid at normal temperature, the compounding ratio is normally as a ratio with respect to the whole quantity of a liquid epoxy resin composition,
(A): 50 to 90% by mass
(B): 5 to 30% by mass
It is preferable to be within the range. If it is out of this range, it may be difficult to improve the effect of reinforcing the flip chip connecting portion and suppressing the occurrence of resin cracks.

  In the present invention, (C) an inorganic filler is blended, and it is essential that the (C) inorganic filler contains at least talc. Talc is an ore whose main component is hydrous magnesium silicate, and its granular material is widely used as a filler in various fields. In the liquid epoxy resin composition of the present invention, the blending of talc is essential.

  The blend of this talc with respect to the total amount of the liquid epoxy resin composition of the present invention is in the range of 0.5 to 10% by mass. More preferably, it exists in the range of 3-7 mass%. When the amount is less than 0.5% by mass, the reinforcing function cannot be sufficiently obtained. On the other hand, if it exceeds 10% by mass, the cured resin becomes brittle and cracks are likely to occur.

  Moreover, it is preferable that the average particle diameter of the talc to mix | blend exists in the range of 0.5-25 micrometers. More desirably, it is in the range of 3 to 20 μm. Although depending on the blending ratio as described above, in general, when the thickness is less than 0.5 μm, it is not always easy to improve the reinforcing function, and when it exceeds 25 μm, the occurrence of resin cracks can be suppressed. Not always easy.

  In addition, as the inorganic filler component (C), the use of talc is essential as described above, so as to improve other performances such as heat resistance, as long as the purpose and effect of the present invention are not impaired, etc. Other types may be used in combination. As the inorganic filler in this case, an appropriate one can be used without particular limitation, and specific examples thereof include fused silica, crystalline silica, finely divided silica, alumina, silicon nitride, magnesia and the like. These may be used alone or in combination of two or more. The average particle diameter of these inorganic fillers is generally considered to be in the range of 0.5 to 25 μm as in the case of the talc.

  Moreover, in this invention, you may mix | blend and use a hardening accelerator as needed.

  Examples of the curing accelerator include imidazole curing accelerators such as 2-methylimidazole and 2-phenylimidazole, organic phosphine curing accelerators such as triphenylphosphine, tributylphosphine, and trimethylphosphine, 1,8-diazabicyclo (5,4 , 0) A tertiary amine curing accelerator such as undecene 7, triethanolamine, benzyldimethylamine and the like can be used. These may be used alone or in combination of two or more.

  In the present invention, the blending ratio of these curing accelerators is 10% by mass or less with respect to the total amount of the liquid epoxy resin, and the ratio is about 1/3 to 2/3 with respect to the (B) curing agent component. preferable.

  The liquid epoxy resin composition of the present invention can be adjusted by various methods and means including conventionally known methods.

  For example, an epoxy resin that is liquid at normal temperature, a curing agent, and other required additives are blended simultaneously or separately, and stirring, dissolution, mixing, and dispersion are performed while performing heat treatment and cooling treatment as necessary. Subsequently, an inorganic filler is added to this mixture, and the resin composition of the present invention can be obtained by stirring and mixing again while performing heat treatment or cooling treatment as necessary.

  Further, the flip chip can be used as an underfill in the same manner as before. As a result, the semiconductor device of the present invention is realized.

  The cured product of the liquid epoxy resin of the present invention preferably has an elastic modulus of 0.1 GPa or more. This is because if it is less than 0.1 GPa, it is difficult to obtain a sufficient reinforcing function.

  Therefore, an example will be shown below and will be described in more detail. Of course, the present invention is not limited by the following examples.

  Table 1 shows the blending components and the blending ratio (mass%). The blending components in Table 1 are as follows.

・ Bisphenol A type epoxy resin Toto Kasei YD8125 (epoxy equivalent 170)
・ Curing agent Ajinomoto PN-H (epoxy adduct, amine)
Inorganic filler: Talc Nippon Talc L-1 (average particle size 0.5 μm, 5 μm, 25 μm)
<Examples 1-5>
<Comparative Examples 1-3>
Each component was mixed and stirred at the blending ratio shown in Table 1 to prepare a liquid epoxy resin composition. About the obtained liquid epoxy resin composition, the following tests were done.
<Drop impact test>
A semiconductor substrate (chip) (chip size 0.75 mm thickness, 14 mm square) was used, and an FR-4 circuit board was used as the circuit board. After mounting the semiconductor chip on the circuit board, the resin composition was injected and filled in the gap between the semiconductor chip and the circuit board and cured at 120 ° C. for 1 hour to manufacture a semiconductor device.

  For the cured semiconductor device, the operation of the semiconductor device was measured using a falling ball.

  The number of NG times until poor conduction was evaluated. The results are also shown in Table 1. When the number of NG is less than 25, the semiconductor device is evaluated as having no practicality.

  Table 1 also shows the measurement results of the elastic modulus of the cured resin composition.

<Evaluation results>
As is clear from the results of the drop impact tests of Examples 1 to 5 and Comparative Examples 1 to 3 shown in Table 1, according to the examples of the present invention, the number of NGs is 30 or more. In FIG. 2, it can be seen that 70 is achieved, and both the reinforcement of the semiconductor package and the improvement of the resin crack resistance performance can be achieved in comparison with the comparative example. In addition, the elasticity modulus of the hardened | cured material of an Example was all 0.1 GPa or more.

Claims (4)

(A) An epoxy resin composition containing, as essential components, an epoxy resin that is liquid at normal temperature, (B) a curing agent, and (C) an inorganic filler, (A) a blending amount of the epoxy resin that is liquid at normal temperature is 75 in the range of 90 mass%, the (C) inorganic filler is a single talc, the amount of the talc is in the range of 0.5 to 10 mass% relative to the total amount of the composition A liquid epoxy resin composition.   The liquid epoxy resin composition according to claim 1, wherein the average particle diameter of talc is in the range of 0.5 to 25 µm.   3. A semiconductor device, wherein a flip chip connecting portion is reinforced by a cured product of the liquid epoxy resin composition according to claim 1.   The semiconductor device according to claim 3, wherein the cured product has an elastic modulus of 0.1 GPa or more.