JP3159428B2 - Liquid sealing resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid sealing resin excellent in low stress and adhesiveness.

[0002]

2. Description of the Related Art In recent years, as semiconductor chips have become larger, packages have more pins, and diversification, the demand for reliability of resin materials as peripheral materials has been stricter year by year.
Conventionally, a package in which a semiconductor chip is bonded to a lead frame and sealed with a mold resin has been mainstream, but a package such as a ball grid array (BGA) has been increasing due to the limit of increasing the number of pins. The BGA is sealed with a mold resin or a liquid resin. Further, since the sealing material is mounted by a surface mounting method, a so-called solder crack resistance is required. Factors that are important for the solder crack resistance of the liquid resin are 1) adhesion to an adherend and its moisture resistance reliability, 2) toughness (low stress) of the sealing resin, and its moisture resistance reliability. Regarding 1), since the BGA substrate is composed of an organic substrate, a solder resist, or a plated portion of gold, nickel, or the like, adhesion to them is important. However, there was no material satisfying the adhesiveness to these at the same time. on the other hand,
Regarding 2), it is particularly important that the conventional liquid resin has a toughness as low as possible during the humidity treatment. Many studies have been conducted on the reduction of toughness, but improvements to the resin skeleton and modifications with polymer alloys have been performed. Was not reached.

[0003]

SUMMARY OF THE INVENTION The present invention, as a result of intensive studies to solve these problems, provides a liquid sealing resin excellent in low stress and adhesiveness.

[0004]

SUMMARY OF THE INVENTION The present invention relates to (A) a liquid epoxy resin, and (B) an epoxy resin (a) represented by the formula (1) and a liquid aromatic diamine (b) having an equivalence ratio of 0.01 to 0.01.
A liquid sealing resin characterized by comprising a reaction product (C) insulating inorganic filler obtained by pre-reaction under 0.1 as an essential component.

[0005]

Embedded image (Wherein R1 and R2 are divalent aliphatic groups having 1 to 5 carbon atoms,
Or a residue obtained by removing two hydrogen atoms from an aromatic having 6 or more carbon atoms, which may be the same or different from each other)

The epoxy resin used in the present invention includes, for example, diglycidyl ether of bisphenols and glycidyl ether obtained by the reaction of phenol novolak with epichlorohydrin, which is liquid at ordinary temperature. A liquid epoxy resin such as a diglycidyl ether of dihydroxynaphthalene and a diglycidyl ether of tetramethylbiphenol may be mixed with these liquid resins and used as a liquid.

The epoxy resin of the formula (1) used in the present invention has characteristics of low elastic modulus and low water absorption. R1 in the formula,
As the divalent aliphatic group represented by R2, those having 6 or more carbon atoms have not been industrialized. R1 and R2 in the present invention are preferably propylene. Further, the epoxy resin of the formula (2) containing a siloxane unit having a long chain length from the formula (1) is also industrialized.

[0008]

Embedded image (Where m is an integer of 1 or more)

[0009] However, the epoxy resin having a long chain length or the reaction product obtained by the method of the present invention is not preferred because it has excellent low stress properties, but lowers the adhesive strength, particularly the strength when heated. Examples of the liquid aromatic diamine used in the present invention include diaminodiethyldiphenylmethane, a molten mixture of solid diamine, and the like. As an example of the reaction between the epoxy resin of the formula (1) and the liquid aromatic diamine bisphenol, the equivalent ratio of the epoxy resin (a) of the formula (1) and the liquid aromatic diamine (b) [ Number of moles /
(B) the number of moles of amine active hydrogen groups] is 0.01 to 0.1.
In step 1, the epoxy resin and the liquid aromatic bisphenol are mixed, and a solvent is added if necessary, and the mixture is reacted at 80 ° C. or higher. If the equivalent ratio exceeds 0.1, the viscosity of the reaction product is too high and does not function as a liquid sealing resin. Also,
If it is less than 0.01, the adhesion and toughness effects cannot be exhibited.

The amount of the reactant to be added to the liquid epoxy resin is from 0.9 to 1. the effective amine active hydrogen equivalent (the liquid aromatic amine active hydrogen equivalent—the epoxy resin equivalent of the formula (1)) per 1 equivalent of the liquid epoxy resin. It is preferably 1.
If the amount exceeds this range, the physical properties of the cured product decrease.

Polyphenols such as novolak-type phenolic resins and amine-based compounds such as imidazole, diaza compounds, hydrazide compounds, dicyandiamide, etc., to which other curing agents can be added as long as the properties of the present invention are not impaired. No. Examples of the insulating inorganic filler used in the present invention include calcium carbonate, silica, alumina, aluminum nitride and the like. A plurality of these may be mixed depending on the application, but silica is preferred from the viewpoint of reliability. The amount of addition is not particularly limited, but is preferably 60% by weight to 85% by weight of the liquid sealing resin in order to maintain the properties (moisture resistance, workability, etc.) as the sealing resin.

Since the epoxy resin represented by the formula (1) has a low reactivity, if it is merely added, it remains as an unreacted component and causes deterioration in physical properties. According to the present invention, by pre-reacting an epoxy resin containing a low-chain-length siloxane unit represented by the formula (1) with a liquid aromatic amine, there is almost no unreacted component, low stress, and liquid sealing excellent in adhesiveness. A resin can be obtained.

The resin composition of the present invention is prepared by mixing a reaction product, a liquid epoxy resin and an inorganic filler, and if necessary, other additives such as a curing agent, a pigment, a dye, and an antifoaming agent, and subjecting the mixture to vacuum defoaming. It can be manufactured by the following.

Production Example 1 of Reaction Product Epoxy resin of the following formula (3) (epoxy equivalent 181) 1
0 g, 200 g of diaminodiethylphenylmethane (amine active hydrogen equivalent: 64) was reacted at 120 ° C. for 3 hours. This product is referred to as a reaction product (1).

[0015]

Embedded image

Production Example 2 of Reaction Product 20 g of the epoxy resin of Production Example 1 and 200 g of diaminodiethyldiphenylmethane were reacted at 120 ° C. for 3 hours.
This product is referred to as reaction product (2).

Production Example 3 of Reaction Product Epoxy resin of the following formula (4) (epoxy equivalent 330) 4
0 g, diaminodiethyldiphenylmethane 200 g 12
The reaction was performed at 0 ° C. for 2 hours. This product is referred to as reaction product (3).

Production Example 4 of Reaction Product 60 g of the epoxy resin of Production Example 1 and 200 g of diaminodiethyldiphenylmethane were reacted at 120 ° C. for 3 hours.
This product is referred to as reaction product (4).

[0019]

Embedded image

[0020]

EXAMPLES The present invention will be specifically described with reference to Examples. Example 1-2, Comparative Example 1-4 A liquid sealing resin was prepared by weighing and kneading with a mixer according to the formulation shown in Table 1. Next, the following substitute characteristics were evaluated in order to grasp the characteristics of the resin. (1) Adhesive strength-1: Bismaleimide as organic substrate
A liquid sealing resin is applied to the surface of a substrate made of a triazine (BT) resin on which a solder resist (PSR-4000 / CA-40 manufactured by Taiyo Ink Co., Ltd.) is formed, and 2 × 2 mm is applied thereon.
The silicon chip at the corner was placed and cured and bonded at 160 ° C. for 180 minutes, and the adhesive force at room temperature was measured with a push-pull gauge. Further, the adhesive strength at room temperature after the PCT (121 ° C., 96 hours) treatment was measured. (2) Adhesion strength-2: A sample was prepared on a gold-plated copper substrate in the same manner as in (1), and the adhesion strength was measured. (3) Elastic modulus: A test piece of 100 mm × 8 mm × 4 mm was prepared by casting, and the bending elastic modulus was measured by a universal testing machine. (4) Fracture toughness: A test piece of 90 mm x 14 mm x 7 mm was prepared by casting, a notch was formed at the center, and measured with a universal testing machine. Table 1 shows the measurement results.

[0021]

[Table 1]

* 1 Liquid epoxy resin: bisphenol F epoxy resin (epoxy equivalent: 170) * 2 Epoxy resin: epoxy resin of formula (3) * 3 Coupling agent: γ-glycidylpropyltrimethoxysilane * 4 Solvent: butyl cellosolve acetate * 5 Silica: spherical silica (average particle size: 6 microns) (Note 1) PCT 125 ° C, after 96 hours (normal temperature) (Note 2) PCT 125 ° C, after 96 hours (normal temperature) (Note 3) PCT 125 ° C, after 96 hours ( At normal temperature)

As shown in Table 1, in the examples, the adhesive strength to each adherend was maintained after moisture absorption, and the low toughness was excellent as indicated by the fracture toughness value. Understand. On the other hand, in Comparative Example 1, the unmodified denaturing curing agent was used, so that the moisture resistance and the fracture toughness were inferior. In Comparative Example 2, the adhesiveness was inferior because of the large molecular weight of the denatured silicone epoxy resin. Is too high to be practical. Further, in Comparative Example 4, the curability was inferior due to the composition by simple addition, and the curable physical properties were reduced.

[0024]

Industrial Applicability The liquid sealing resin of the present invention is an industrially useful liquid sealing resin having excellent low stress properties and adhesiveness.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-109932 (JP, A) JP-A-4-103615 (JP, A) JP-A-60-36527 (JP, A) JP-A 64-64 81848 (JP, A) JP-A-62-101054 (JP, A) JP-A-2-151622 (JP, A) JP-A-5-78450 (JP, A) JP-A-63-164451 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 59/50-59/60 C08L 63/00-63/10 H01L 23/29

Claims (1)

(57) [Claims] (A) a liquid epoxy resin; (B) an epoxy resin (a) represented by the formula (1) and a liquid aromatic diamine (b) in an equivalent ratio of 0.01 to 0.1, A liquid sealing resin comprising a reaction product obtained by a preliminary reaction and (C) an insulating inorganic filler as essential components. Embedded image (Wherein R1 and R2 are divalent aliphatic groups having 1 to 5 carbon atoms,
Or a residue obtained by removing two hydrogen atoms from an aromatic having 6 or more carbon atoms, which may be the same or different from each other)