JP4984564B2 - Epoxy resin composition, method for producing the same, and semiconductor device - Google Patents

Description

  The present invention relates to an epoxy resin composition used for flip-chip mounting of a semiconductor element and a substrate, a manufacturing method thereof, and a semiconductor device using the epoxy resin composition.

  In the field of manufacturing a semiconductor device by mounting a semiconductor element on a substrate, there is an increasing demand for mounting semiconductor elements at high density, and a flip chip mounting system is attracting attention as a system that satisfies the demand. This is an alternative to the conventional face-up mounting that achieves electrical connection between the semiconductor element (chip) and the substrate through wire bonding. The semiconductor element is mounted face-down and formed on the circuit surface side of the semiconductor element. In this method, the bumps and the electrodes of the wiring board are electrically and mechanically connected.

  In the flip chip mounting described above, a resin composition is filled between the semiconductor element and the substrate in order to protect the circuit surface, suppress bump breakage, and the like. This resin composition requires a function of protecting the semiconductor element against moisture and dust and a function of suppressing breakage of the joint due to the difference in thermal expansion coefficient between the semiconductor element and the substrate. Properties, high elasticity, water absorption resistance and the like are required. For this reason, the said resin composition is made to contain the inorganic filler about 40 to 60 weight% normally for the low thermal expansion coefficient (for example, refer patent document 1, patent document 2, patent document 3).

Moreover, there exist patent document 4 and patent document 5 as a prior art document relevant to this invention, for example.
JP-A-10-101906 JP 2004-346232 A JP-T-2004-518996 JP-A-5-121578 JP-A-10-101906

  However, in the past, since the inorganic filler was used as it was added to the resin composition, (1) the viscosity of the resin composition increased and workability decreased, (2) the adhesion strength between the inorganic filler and the epoxy resin There are problems such as weak and poor water absorption resistance, and (3) the inorganic filler in the resin composition hinders the movement of the epoxy resin molecules, thereby inhibiting the curing reaction of the epoxy resin and lowering the connection reliability.

  The present invention solves the above problems, and provides an epoxy resin composition having high workability, water absorption resistance and connection reliability, a method for producing the same, and a semiconductor device using the epoxy resin composition.

  The epoxy resin composition of the present invention is an epoxy resin composition containing an inorganic filler, an epoxy resin main component, and an epoxy resin curing agent, and the inorganic filler has a basic functional group on its surface, And it is previously coated with an epoxy resin through the functional group.

  Moreover, the manufacturing method of the epoxy resin composition of the present invention is a manufacturing method of the above-described epoxy resin composition of the present invention, which includes the step of imparting a basic functional group to the surface of the inorganic filler, and the functional group. A step of coating the surface of the inorganic filler with an epoxy resin, and a step of mixing the inorganic filler coated with the epoxy resin, an epoxy resin main component, and an epoxy resin curing agent.

  The semiconductor device of the present invention is characterized in that a semiconductor element and a substrate are bonded using the epoxy resin composition of the present invention.

  According to the epoxy resin composition of the present invention, the compatibility between the inorganic filler and the epoxy resin main agent is improved and the viscosity is lowered, so that the workability is improved, the adhesion strength between the inorganic filler and the epoxy resin is increased, and the water absorption resistance is increased. And connection reliability is improved.

  Moreover, according to the manufacturing method of the epoxy resin composition of this invention, the said epoxy resin composition of this invention can be manufactured rationally.

  Further, according to the semiconductor device of the present invention, a semiconductor device with high connection reliability between the semiconductor element and the substrate can be provided.

(Embodiment 1)
First, an embodiment of the epoxy resin composition of the present invention will be described. The epoxy resin composition of the present embodiment includes an inorganic filler, an epoxy resin main component, and an epoxy resin curing agent, and the inorganic filler has a basic functional group on the surface thereof, and the functional group is interposed therebetween. And pre-coated with an epoxy resin. The inorganic filler has a basic functional group on its surface and is pre-coated with an epoxy resin via the functional group, so that the compatibility between the inorganic filler and the epoxy resin main agent is improved and the viscosity is increased. Since it falls, workability | operativity improves and the adhesive strength of an inorganic filler and an epoxy resin increases, and water absorption resistance and connection reliability improve.

  As the inorganic filler, silica powder or alumina powder can be used. In the case where the epoxy resin composition of the present embodiment is used for joining semiconductor elements described later, from the viewpoint of controlling the thermal expansion coefficient to an appropriate range, the content of the inorganic filler is based on the total weight of the epoxy resin composition. 30 to 70% by weight is preferable, and 50 to 70% by weight is preferable from the viewpoint of improving connection reliability.

  Although it does not specifically limit as said basic functional group, An amine group, an imidazole group, etc. are preferable. This is because these functional groups function as a curing accelerator or reaction accelerator for the epoxy resin main component, as will be described later.

  Moreover, it is preferable that the said basic functional group is provided to the surface of the inorganic filler through the modification group. Thereby, a basic functional group can be reliably held on the surface of the inorganic filler. Although it does not specifically limit as a modifying group, Silicon-containing modifying groups, such as a silane group and silicone, can be used.

  As the epoxy resin main component, for example, bisphenol A type epoxy, bisphenol F type epoxy, naphthalene type epoxy, brominated epoxy, phenol novolak type epoxy, cresol novolak type epoxy, biphenyl type epoxy, etc., are used. be able to. Among these, at least one epoxy resin selected from bisphenol-type epoxy and naphthalene-type epoxy is particularly preferable. This is because the connection reliability is particularly high.

  As the epoxy resin curing agent, at least one curing agent selected from imidazole curing agents, amine curing agents and acid anhydride curing agents can be used. Examples of the imidazole curing agent include 2-phenyl-4-methylimidazole, 2-undecylimidazole, 2,4-diamino-6- [2-methylimidazole- (1)]-ethyl-S-triazine, 1 -Cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, etc. are used. be able to. As the amine curing agent, for example, diethylenetriamine, triethylenetetramine, mensendiamine, isophoronediamine, metaxylenediamine, diaminodiphenylmethane, metaphenylenediamine, diaminodiphenylsulfone and the like can be used. Examples of the acid anhydride curing agent include phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hymic anhydride, tetrabromophthalic anhydride, Trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, and the like can be used.

  Also, when the inorganic filler coated with the epoxy resin comes into contact with the epoxy resin main agent, a part of the coated epoxy resin is dissolved, the basic functional group on the surface of the inorganic filler is exposed, and the basic functional group is epoxy. May come into contact with resin base. In this case, the basic functional group of the inorganic filler functions as a curing accelerator or reaction accelerator for the epoxy resin main component.

  Moreover, it is preferable that the epoxy resin composition of this embodiment further contains a coupling agent. Thereby, the connectivity of each component contained in the epoxy resin composition is further improved. As the coupling agent, for example, a silane coupling agent, a titanium coupling agent, or the like can be used. The addition amount of the coupling agent can be 0.1 parts by weight or more and 7 parts by weight or less with respect to 100 parts by weight of the epoxy resin main agent.

  FIG. 1 is an image diagram of the epoxy resin composition of the present embodiment. The epoxy resin composition of the present embodiment is usually formed in a liquid state, and has, for example, an inorganic filler 11 having a basic functional group and coated with an epoxy resin, a liquid epoxy resin main agent 12, and an epoxy resin curing agent 13. Including.

FIG. 2 is a conceptual diagram of the surface of the inorganic filler used in this embodiment. The inorganic filler used in the present embodiment has, for example, an amine filler on the surface of the inorganic filler via silicone [— (Si—O) _n —], and the amine group is bonded to the epoxy resin, thereby the inorganic filler. The whole is covered with an epoxy resin.

  Next, an embodiment of a method for producing an epoxy resin composition of the present invention will be described. The manufacturing method of the epoxy resin composition of this embodiment is a manufacturing method of the epoxy resin composition containing the inorganic filler demonstrated above, an epoxy resin main ingredient, and an epoxy resin hardening | curing agent, and is basic on the surface of an inorganic filler. The step of imparting the functional group of the step, the step of coating the surface of the inorganic filler to which the functional group has been imparted with an epoxy resin, the inorganic filler coated with the epoxy resin, the epoxy resin main agent, and the epoxy resin curing agent are mixed. Including the step of.

  In order to impart a basic functional group to the surface of the inorganic filler, for example, after sufficiently stirring a mixed liquid of the inorganic filler and ethanol, 0.5 to 2.0% by weight of an amine group or the like is added to the mixed liquid. A silane compound or a silicone compound to which a basic functional group is added is added and stirred at room temperature (25 ° C.), and then filtered and dried at 100 to 150 ° C. After sufficiently drying, it is preferable to classify by further sieving.

  In order to coat the surface of the inorganic filler provided with the functional group with an epoxy resin, for example, the surface of the inorganic filler may be coated with the epoxy resin by an interfacial polymerization method, an in-situ polymerization method, a phase separation method, or the like. In that case, the epoxy resin reacts with the basic functional group of the inorganic filler, and the epoxy resin is stably coated on the inorganic filler.

  In order to mix the inorganic filler coated with the epoxy resin, the epoxy resin main component, and the epoxy resin curing agent, an ordinary mixing device or the like may be used. At this time, a coupling agent or the like may be further added and mixed.

  As described above, the epoxy resin composition obtained by the production method of the present embodiment improves the workability because the compatibility between the inorganic filler and the epoxy resin main component is improved and the viscosity is lowered, and the inorganic filler and the epoxy resin are improved. Adhesion strength with water increases and water absorption resistance and connection reliability are improved.

(Embodiment 2)
Next, embodiments of the semiconductor device of the present invention will be described. In the semiconductor device of the present embodiment, the semiconductor element and the substrate are bonded using the epoxy resin composition of the first embodiment. By using the epoxy resin composition of Embodiment 1, a semiconductor device with high connection reliability can be provided.

  Examples of the semiconductor element include an LSI chip and a wafer. The substrate includes a printed circuit board, a ceramic substrate, a semiconductor substrate, and the like.

  Next, a method for manufacturing the semiconductor device of this embodiment will be described with reference to the drawings. 3A to 3C are process cross-sectional views illustrating the manufacturing process of the semiconductor device of this embodiment. In the method for manufacturing a semiconductor device of this embodiment, first, as shown in FIG. 3A, the epoxy resin composition 23 of Embodiment 1 is applied onto a substrate 22 on which a plurality of electrodes 21 are formed. Here, since the epoxy resin composition 23 can keep viscosity low, workability | operativity at the time of application | coating improves. At this time, the substrate 22 is heated to 50 to 100 ° C., for example. Next, as shown in FIG. 3B, the semiconductor element 25 having a plurality of bumps 24 formed thereon is aligned on the substrate 22. Finally, as shown in FIG. 3C, for example, the semiconductor element 25 heated to 200 to 250 ° C. is pressed against the substrate 22 to connect (heat press contact) the electrode 21 and the bump 24.

  The substrate 22 is heated to 50 to 100 ° C. in advance by reducing the temperature difference between the temperature (200 to 250 ° C.) when the semiconductor element 25 and the substrate 22 are finally heat-welded. This is to reduce the thermal expansion of 22. For this reason, the epoxy resin composition 23 does not cure at a temperature of 50 to 100 ° C. when applied on the substrate 22, and does not increase in viscosity, and then quickly cures when heated to 200 to 250 ° C. The characteristic to be desirable is desirable.

  Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited to the following examples.

Example 1
Silicone made by Shin-Etsu Silicone to which amine groups were further added after mixing 100 parts by weight of Admatex alumina powder “AO802” (trade name) and 100 parts by weight of ethanol and thoroughly stirring at room temperature (25 ° C.) 1.0 part by weight of the compound “KBM-573” (trade name) was added and stirred at room temperature. Thereafter, the mixed solution was filtered, dried at 130 ° C., and classified to obtain alumina powder having an average particle diameter of 5 μm.

  Next, the alumina powder was coated with an epoxy resin to obtain alumina powder A. That is, an epoxy resin was used as a dispersion medium, and the alumina powder as a core substance was added to the dispersion medium while stirring to form an epoxy resin film on the surface of the alumina powder, whereby alumina powder A was obtained.

  Subsequently, 100 parts by weight of a bisphenol F type epoxy resin “EXA830LVP” (trade name) manufactured by Dainippon Ink and Chemicals, Inc., which is a liquid type at room temperature, as an epoxy resin main ingredient, and an imidazole-based curing agent “Curazole C11Z, manufactured by Shikoku Kasei as a curing agent. -A "(trade name) 15 weight, γ-glycidoxypropyltriethoxysilane" KBM403 "(trade name) 2 parts by weight as a coupling agent, and 50 parts by weight of the alumina powder A as an inorganic filler. The epoxy resin composition of this example was produced by stirring and mixing uniformly.

(Example 2)
An epoxy resin composition of this example was produced in the same manner as in Example 1 except that alumina powder B provided with an imidazole group instead of an amine group was used.

Example 3
An epoxy resin composition of this example was produced in the same manner as in Example 1 except that the content of the alumina powder A was 30% by weight.

Example 4
An epoxy resin composition of this example was produced in the same manner as in Example 1 except that the content of the alumina powder A was 60% by weight.

(Example 5)
Instead of the imidazole-based curing agent “Curazole C11Z-A”, 100 parts by weight of methyltetrahydrophthalic anhydride “KRM-291-5” (trade name) manufactured by Asahi Denka Co., Ltd., which is an acid anhydride curing agent, was further used. An epoxy resin composition of this example was prepared in the same manner as in Example 1 except that 0.5 part by weight of the curing catalyst “1M2EZ” (trade name) manufactured was added.

(Example 6)
An epoxy resin composition of this example was produced in the same manner as in Example 5 except that the curing catalyst “1M2EZ” was not used.

(Example 7)
An epoxy resin composition of this example was prepared in the same manner as in Example 5 except that the alumina powder B was used in place of the alumina powder A.

(Example 8)
An epoxy resin composition of this example was produced in the same manner as in Example 7 except that the curing catalyst “1M2EZ” was not used.

(Comparative Example 1)
An epoxy resin composition of this comparative example was produced in the same manner as in Example 1 except that alumina powder “AO802” which was not provided with an amine group and was not coated with an epoxy resin was used in place of the alumina powder A. .

(Comparative Example 2)
An epoxy resin composition of this comparative example was prepared in the same manner as in Example 5 except that alumina powder “AO802” which was not provided with an amine group and was not coated with an epoxy resin was used in place of the alumina powder A. .

<Measurement of viscosity of epoxy resin composition>
The viscosities of the epoxy resin compositions of Examples 1, 2, 5 to 8 and Comparative Examples 1 and 2 were measured using a viscometer “EH viscometer” (trade name) manufactured by Tokyo Keiki Sangyo. The results are shown in Table 1. From Table 1, it can be seen that the viscosities of the epoxy resin compositions of Examples 1 and 2 were greatly reduced as compared with the viscosities of the epoxy resin composition of Comparative Example 1, and the workability was improved. Moreover, it turns out that the viscosity of the epoxy resin composition of Examples 5-8 falls greatly compared with the viscosity of the epoxy resin composition of the comparative example 2, and workability | operativity improved.

<Evaluation of water absorption resistance>
The adhesive strength before and after water absorption of the epoxy resin compositions of Examples 1, 2, 5 to 8 and Comparative Examples 1 and 2 was measured as follows to evaluate water absorption resistance.

  First, Hitachi Chemical's glass epoxy substrate was used as the adherend, and these two glass epoxy substrates were bonded together with the above epoxy resin compositions, and an Instron Japan adhesive strength tester “Instron 5581” (trade name) was used. Used to measure the adhesive strength before water absorption. The bonding conditions were a heating temperature of 150 ° C. and a heating time of 1 hour.

  Next, an accelerated water absorption test was performed using a glass epoxy substrate bonded in the same manner as described above. The accelerated water absorption test is performed using a highly accelerated life tester “PM250” (trade name) manufactured by Enomoto Kasei under conditions of a temperature of 121 ° C., a relative humidity of 100%, an atmospheric pressure of 2.1 atm, and a test time of 24 hours. In the same manner as above, the adhesive strength was measured and taken as the adhesive strength after water absorption.

  The results are shown in Table 1. From Table 1, the adhesive strength after water absorption of the epoxy resin compositions of Examples 1, 2, and 5 to 8 can be suppressed to a decrease of 10% or less compared with the adhesive strength before water absorption, and maintains high water absorption resistance. I understand that On the other hand, the adhesive strength after water absorption of the epoxy resin compositions of Comparative Examples 1 and 2 significantly decreased by over 40% compared to the adhesive strength before water absorption.

<Preparation of semiconductor element and substrate>
As a semiconductor element, an LSI chip having an electrode diameter of 70 μm, an electrode pitch of 120 μm, a gold electrode (bump) having 120 electrodes and a length of 8.5 mm, a width of 8.5 mm, and a thickness of 0.06 mm was prepared. Further, the substrate is made of Mitsubishi Gas Chemical's triazine resin “BT resin” (trade name) having an electrode diameter of 70 μm, an electrode pitch of 120 μm, an electrode number of 2700, and a length of 40 mm, a width of 40 mm, and a thickness of 0.35 mm. A wiring board was prepared.

<Fabrication of semiconductor device>
Using the epoxy resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2, semiconductor devices were produced as follows.

  That is, as shown to FIG. 3A, 6 mg of epoxy resin compositions were apply | coated to the electrode periphery of the said wiring board. Next, as shown in FIG. 3B, the LSI chip bumps and the wiring board electrodes were aligned face-down. Subsequently, as shown in FIG. 3C, pressurization is performed under the conditions of a substrate heating temperature of 60 ° C., a load of 6 kg, a bonding time of 10 seconds, a heating head temperature of 265 ° C., and an epoxy resin composition temperature of 220 ° C. Heat bonding was performed.

<Evaluation of connection reliability>
Next, each semiconductor device is subjected to an accelerated life test under the conditions of a temperature of 121 ° C., a relative humidity of 100%, and an atmospheric pressure of 2.1 atm using a high accelerated life tester “PM250”. Connection reliability was evaluated by measuring the conduction resistance between each connection point of each semiconductor device after 168 hours and 336 hours from the start. The evaluation criterion is that if the increase in conduction resistance after the test is 10% or less than the conduction resistance before the test, the connection reliability is judged to be good, and if it exceeds 10%, the connection reliability Was judged as bad. The number of tests at the start of the test was 15 each.

  The results are shown in Table 1. Table 1 shows the number of defects / number of samples. From Table 1, in the semiconductor devices joined using the epoxy resin compositions of Examples 1, 2, and 5 to 8, it was confirmed that the increase in conduction resistance was 10% or less, and the connection reliability was all judged to be good. . On the other hand, in Comparative Examples 1 and 2, it can be seen that the increase in conduction resistance increases with the passage of test time over 10%.

  Moreover, it turns out that connection reliability is favorable when content of an inorganic filler is 50 weight% or more from the comparison of Example 1, 3, and 4 produced in the same way except content of an inorganic filler.

<Measurement of curing rate>
Using the epoxy resin compositions of Examples 1, 2, 5 to 8 and Comparative Examples 1 and 2, the curing rate in a curing reaction at a heating temperature of 220 ° C. and a heating time of 5 seconds was measured. The curing rate was calculated from the curing calorific value measured using a calorific value measuring device “DSC100” manufactured by Seiko Instruments Inc. according to the following formula (1).
(1) Curing rate = 100− (curing calorific value after curing reaction / curing calorific value before curing reaction) × 100
The amount of heat generated by curing after the curing reaction was measured after leaving each epoxy resin composition on a hot plate heated to 220 ° C. for 5 seconds.

  The results are shown in Table 2. From Table 2, it can be seen that the epoxy resin compositions of Examples 1, 2, and 5 to 8 have higher curing rates than Comparative Examples 1 and 2. This is presumably because the basic functional group imparted to the surface of the inorganic filler promoted the curing reaction.

  Regarding the embodiment of the present invention including Examples 1 to 8 described above, the following additional notes are disclosed.

(Appendix 1) An epoxy resin composition comprising an inorganic filler, an epoxy resin main component, and an epoxy resin curing agent,
The said inorganic filler has a basic functional group on the surface, and is previously coat | covered with the epoxy resin through the said functional group, The epoxy resin composition characterized by the above-mentioned.

  (Supplementary note 2) The epoxy resin composition according to supplementary note 1, wherein the functional group is an amine group.

  (Additional remark 3) The said functional group is an epoxy resin composition of Additional remark 1 which is an imidazole group.

  (Additional remark 4) The said functional group is an epoxy resin composition in any one of Additional remark 1-3 added to the surface of the said inorganic filler through the silane group.

  (Additional remark 5) The said functional group is an epoxy resin composition in any one of Additional remark 1-3 added to the surface of the said inorganic filler through silicone.

  (Supplementary note 6) The epoxy resin composition according to supplementary note 1, wherein the epoxy resin curing agent is at least one curing agent selected from an imidazole curing agent, an amine curing agent, and an acid anhydride curing agent.

  (Additional remark 7) The epoxy resin composition of Additional remark 1 whose content of the said inorganic filler is 50 weight% or more with respect to the total weight of an epoxy resin composition.

(Additional remark 8) It is a manufacturing method of the epoxy resin composition of Additional remarks 1-7,
Providing a basic functional group on the surface of the inorganic filler;
Coating the surface of the inorganic filler with the functional group with an epoxy resin;
The manufacturing method of the epoxy resin composition characterized by including the process of mixing the inorganic filler coat | covered with the said epoxy resin, an epoxy resin main ingredient, and an epoxy resin hardening | curing agent.

  (Additional remark 9) The semiconductor device which joined the semiconductor element and the board | substrate using the epoxy resin composition in any one of additional marks 1-7.

It is an image figure of the epoxy resin composition of Embodiment 1. 2 is a conceptual diagram of the surface of an inorganic filler used in Embodiment 1. FIG. 11 is a process cross-sectional view illustrating a manufacturing process of the semiconductor device of Embodiment 2.

Explanation of symbols

11 Inorganic filler 12 Epoxy resin main agent 13 Epoxy resin curing agent 21 Electrode 22 Substrate 23 Epoxy resin composition 24 Bump 25 Semiconductor element

Claims (5)

An epoxy resin composition comprising an inorganic filler, an epoxy resin main component, and an epoxy resin curing agent,
The inorganic filler has an imidazole group on its surface via a silane group or silicone , and is pre-coated with an epoxy resin via the imidazole group ,
Content of the said inorganic filler is 30 to 70 weight% with respect to the total weight of an epoxy resin composition, The epoxy resin composition characterized by the above-mentioned. The epoxy resin composition according to claim 1, further comprising a coupling agent . A method for producing an epoxy resin composition comprising an inorganic filler, an epoxy resin main component, and an epoxy resin curing agent ,
Providing an imidazole group on the surface of the inorganic filler;
Coating the surface of the inorganic filler provided with the imidazole group with an epoxy resin;
The manufacturing method of the epoxy resin composition characterized by including the process of mixing the inorganic filler coat | covered with the said epoxy resin, an epoxy resin main ingredient, and an epoxy resin hardening | curing agent. The manufacturing method of the epoxy resin composition of Claim 3 which further includes the process of adding a coupling agent . The semiconductor device is characterized in that bonding the semiconductor element and the substrate with an epoxy resin composition according to claim 1 or 2.

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