JPH0485321A - Sealing resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE:To provide a sealing resin composition excellent in moldability, humidity resistance, etc., by mixing a specified epoxy resin, a polyfunctional phenol resin, a novolac phenol resin, a specified amount of dialkylamino-1,8- diazabicycloundecene and a silica powder. CONSTITUTION:A sealing resin composition is produced by mixing an epoxy resin of formula I (wherein n is 1 or greater; and m is O, 1 or greater) with a polyfunctional phenol resin of formula II or III (wherein n is 0, 1 or greater; R is CmH2m+1; and m is 0, 1 or greater), a novolac phenol resin, 0.01-5wt.%, based on the resin composition, dialkylamino-1,8-diazabicyclo[5.0.4]undecene cure accelerator of formula TV (wherein R<1> and R<2> are each CnH2n+1; and n is 0, 1 or greater) and a silica powder. This composition can be desirably used for sealing especially a semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a sealing resin composition and a semiconductor sealing device that have good moldability and excellent moisture resistance and soldering heat resistance.

(Prior Art) In recent years, the practical use of thin packages has been promoted in semiconductor devices. For example, flat packages in integrated circuits, SOP (5 lall out-ne
pachage), T S OP (thin sn
+all outline package), and insulation type packages for power transistors, etc., fill a thin part of about 0.1 to 0.5n+Il with resin on the top surface of the semiconductor element or the back surface of the insulation type package. It has become necessary. On the other hand, surface-mounted packages use a solder dipping method or a solder reflow method when attaching them to a circuit board, creating an even harsher environment for the sealing resin of thin packages6. , a novolac type epoxy resin, a novolac type phenolic resin, silica powder, and a normal curing accelerator suitable for the resin. When encapsulated with this conventional sealing resin, the thin part is filled with resin. It has disadvantages such as poor moldability such as the formation of cavities and bags, and a decrease in moisture resistance and poor appearance. Further, the semiconductor device sealed with the conventional sealing resin described above has a disadvantage in that moisture resistance decreases when the entire device is immersed in a solder bath.

In particular, when a semiconductor device that has absorbed moisture is immersed, the sealing resin and the semiconductor element, the sealing resin and the lead frame may peel off, internal resin cracks may occur, resulting in a significant deterioration of moisture resistance, and wire breakage due to corrosion of the electrodes. leakage current due to water and moisture. As a result, semiconductor devices have had the disadvantage that long-term reliability cannot be guaranteed.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned drawbacks, and has excellent formability in thin-walled parts, less influence of moisture absorption, and especially after solder immersion or solder reflow. The object of the present invention is to provide a sealing resin composition and a semiconductor sealing device that have excellent moisture resistance and soldering heat resistance and can guarantee long-term reliability.

"Structure of the Invention" (Means for Solving the Problems) As a result of extensive research into device design in an attempt to achieve the above object, the present inventors have discovered that thin-walled parts can be improved by using a composition as described below. It has been found that a sealing resin composition and a semiconductor sealing device having excellent moldability, moisture resistance, and soldering heat resistance can be obtained, and the present invention has been completed.6 That is, the present invention includes the following: <A> Epoxy resin represented by the formula (wherein, n represents an integer of 1 or more, and t represents 0 or an integer of 1 or more) (B) Polymer represented by the following general formula (I) or (...) Functional phenolic resin (where n is an integer of 0 or 1 or more, R is C□H2
1, ++, [represents M number of 0 or 1 or more] (C)
Novolak type phenolic resin (D) dialkylamino 1.8- represented by the following general formula
Diazabicyclo[5,0,4]undecene curing acceleration (wherein R' and R' are CnH)n++, n is 0
or represents an integer of 1 or more) (E,) silica powder is an essential component, and the dialkylamino-1,
This is a resin composition for sealing, characterized in that it contains an 8-diazabicyclo(5,0,4]undecene curing accelerator in a proportion of 0.01 to 5% by weight based on the resin composition.

Further, the present invention is a semiconductor sealing device characterized in that a semiconductor device is sealed with a cured product of this sealing resin composition.

The present invention will be explained in detail below.

As the epoxy resin (A) used in the present invention, one represented by the above formula is used. This epoxy resin has tetrafunctional glycidyl, and as long as it has the skeleton structure in the molecule, it is not limited to the molecule 1, and can be widely used4.In addition, novolak type epoxy resin Epibis epoxy resin can also be used in combination.

These epoxy resins can be used alone or in combination of two or more.

The polyfunctional phenol resin (B) used in the present invention is the above-mentioned (
As shown in the formulas I) and (n), as long as the hydroxyl is at least trifunctional or at least tetrafunctional phenolic resin and has the above-mentioned skeleton structure in the molecule, there is no particular restriction on molecular weight etc., and it can be widely used. can be used. Specific examples of trifunctional phenolic resins and tetrafunctional phenolic resins include the following, and these can be used alone or in a mixture of two or more.

As the novolak type phenolic resin (C) used in the present invention, novolac type phenolic resins obtained by reacting phenols such as phenol and alkylphenols with formaldehyde or paraformaltehyde, and modified resins thereof are widely used. These can be used alone or in combination of two or more.

The dialkylamino-1,8-diazabicyclo[5,0,4]undecene curing accelerator (D) used in the present invention has the above general formula, and is 1,8-diazabicyclo[5,0,4]undecene.
5,0,4]undecene (abbreviated as DBU) is replaced with a dialkylamino group. Also, this (
D) As the curing accelerator, known imidazole accelerators, DBU accelerators not substituted with dialkylamino groups, phosphorus accelerators, and other accelerators can be used in combination. <D
) The blending ratio of the curing accelerator is 0.0 to the resin composition.
It is desirable to contain 1 to 5% by weight. The percentage is 0
．． If it is less than 0.01% by weight, the gel time of the resin composition is long and the curing properties are also poor, which is not preferable. If it exceeds 5% by weight, fluidity becomes extremely poor, resulting in poor moldability, as well as poor electrical properties and poor moisture resistance, which is undesirable.

As the silica powder (E) used in the present invention, commonly used silica powders are widely used, but among them, those with a low impurity concentration and an average particle size of 30 μI or less are preferable. If the average particle size exceeds 30 μm, the moisture resistance and moldability will be poor, and this is not preferred.

The sealing resin composition of the present invention includes a specific epoxy resin, a polyfunctional phenolic resin, a novolak type phenolic resin, a dialkylamituri, 8-diazabicyclo[5,0,41
It contains an undecene curing accelerator and silica powder as essential components, but within the limits that do not contradict the purpose of the present invention, and as necessary, for example, natural waxes, synthetic waxes, metal salts of straight S fatty acids, acid amides, esters, etc. , a mold release agent such as paraffin, a flame retardant such as antimony trioxide, a colorant such as carbon black, a silane coupling agent, a curing accelerator, a rubber-based or silicone-based low stress imparting agent, etc. may be appropriately added and blended. I can do it.

The general method for preparing the sealing resin composition of the present invention as a molding material is to prepare the above-mentioned components, namely, a specific epoxy resin, a polyfunctional phenolic resin, a novolac type phenolic resin, and a dialkylamino-1,8- The diazabicyclo[5,0,4]unthecene curing accelerator, silica powder, and other ingredients are blended and mixed sufficiently uniformly using a mixer or the like. Further, the mixture can be melt-mixed using hot rolls or mixed using a kneader, etc., and then cooled and solidified and ground to an appropriate size to form a molding material. This molding material can be used for sealing electronic or electrical parts, as well as for coating, insulation, etc., and can provide excellent properties and reliability.

The semiconductor encapsulation device of the present invention can be manufactured by encapsulating a semiconductor device using the above-mentioned encapsulation resin composition. Examples of semiconductor devices to be sealed include:
It can be widely used in integrated circuits, large-scale integrated N circuits, transistors, thyristors, diodes, etc. without being particularly limited. The most common method for sealing is low-pressure transfer molding, but sealing by injection molding, compression molding, casting, etc. is also possible. The sealing resin composition is cured by heating during sealing, and finally an unsealed semiconductor device 1 is obtained by the cured product of this composition. Curing by heating is preferably performed at a temperature of 150° C. or higher.

(Function) The mi composition for encapsulation and the semiconductor encapsulation device of the present invention can be applied to a specific epoxy resin, a polyfunctional phenol resin, a novolac type phenol resin, dialkylamino-1,8-diazabicyclo[5,0,4]undecene This objective was achieved by reacting with a curing accelerator. That is, dialkylamino-1°8-diazabicyclo[5,
By blending a predetermined amount of a 0.41 undecene curing accelerator and controlling the gelation time and fluidity of the resin composition, filling properties in thin walled areas were improved, moisture resistance was improved, and excellent moldability was imparted. In addition, by reacting specific epoxy resins, polyfunctional phenolic resins, and novolac type phenolic resins, the glass transition temperature is raised and the properties at high temperatures are improved. The alkyl group improves hygroscopicity. As a result, the hygroscopicity of the resin composition is reduced, and even when solder immersion or solder reflow is performed, greasy racks do not occur, and deterioration of moisture resistance is eliminated.

(Example) Next, Examples of the present invention will be described, but the present invention is not limited by these Examples. In the following Examples and Comparative Examples, "%" means "% by weight". do.

Example 1 17% of the above specific epoxy resin, 8% of the above trifunctional phenol resin, 0.3% of dialkylamino-1,8-diazabicyclo[5,0,4]undecene curing accelerator, 74% of silica powder, ester 0.3% wax and 0.4% silane coupling agent were mixed at room temperature, and further 90%
The mixture was kneaded at a temperature of ~95°C, cooled, and then ground to produce a molding material (A>).

Example 2 12% of the above specific epoxy resin, 6% of the above trifunctional phenol resin, dialkylamino-18-diazabicyclo[5,0,4]undecene curing acceleration jflI 013
%, 81% silica powder, 0.3% ester wax and 0.4% silane coupling agent were mixed at room temperature, further kneaded at a temperature of 90 to 95°C, cooled and then ground.
.

A molding material (B>) was produced.

Comparative Example 1 17% orthocresol novolac type epoxy resin, 8% novolac type phenol resin, 74% silica powder, imidazole curing acceleration i! A molding material (C) was prepared in the same manner as in Example 1 using 10.3% fl, 0.3% ester wax, and 0.4% silane coupling agent.

Comparative Example 2 12% orthocresol novolak epoxy resin, 6% novolak phenol resin, 81% silica powder, 0.3% imidazole curing accelerator, 0 ester wax
．． 3% and silane coupling agent 0.4% in Comparative Example 1
A molding material (D) was produced in the same manner as above.

Molding materials (A
) to (D) and semiconductor encapsulation devices manufactured using these were tested for moldability and moisture resistance, and the results are shown in Table 1.

The present invention was excellent in all cases, and the remarkable effect of the present invention on S could be confirmed.

Table (unit) Book 1: Using molding material, 100
k! A pressure of 77'C11' was applied and the flow pressure M of the spiral was measured.

*2: The time required for the molding material to gel was measured on a hot plate at 175°C.

Cat: Using molding material, mold 00 at 175°C
Applying a pressure of kg/rn2, 200μt, 30
The flow distance through gaps of 0 μm and 10 μm was measured.

*4: Using molding material, Q F P (14 x 1
4X 141111) Tummy chips of 8x8n+i were placed in a package, and the number of filling defects on one side of the chip among 500 packages was measured.

*5: Using the molding material, place the tammy chip in a TO-220 type package and measure the number of filling defects on the back side of 500 packages.

*6: Using molding material, DIR-16 pin MO5I
For each of the semiconductor sealing devices that sealed the C test element or the TO-220 type test element, the time required until the open failure of the aluminum wiring reached 50% was measured under the condition of 74 atmospheric pressure PC.

[Effect of the invention J As is clear from the above explanation and Table 1, the encapsulating resin composition of the present invention has excellent moldability, is less affected by moisture absorption, and has excellent moisture resistance after immersion in a solder bath and soldering heat resistance. Because of its excellent performance, it can be easily filled into thin-walled areas, without forming cavities or flakes, without peeling between the resin composition and the semiconductor device or between the resin composition and the lead frame, without causing internal resin cracks, and without corrosion of electrodes. An excellent and highly reliable semiconductor encapsulation device was obtained, which did not cause wire breakage due to oxidation or leakage current due to moisture.

Claims (1)

[Claims] 1 (A) Epoxy resin represented by the following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, in the formula, n is an integer of 1 or more, and m is 0 or an integer of 1 or more (B) Multifunctional phenolic resin represented by the following general formula (I) or (II)▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼…( II) (However, in the formula, n represents an integer of 0 or 1 or more, R represents C_mH_2_m_+_1, and m represents an integer of 0 or 1 or more) (C) Novolac type phenolic resin (D) Represented by the following general formula dialkylamino-1,8
-Diazabicyclo[5,0,4]undecene curing accelerator▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R^1 and R^2 are C_nH_2_n_+_
1 and n represents an integer of 0 or 1 or more) (E) silica powder is an essential component, dialkylamino-1 of (D) above,
A sealing resin composition comprising an 8-diazabicyclo[5,0,4]undecene curing accelerator in an amount of 0.01 to 5% by weight based on the resin composition. 2 (A) Epoxy resin represented by the following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, in the formula, n represents an integer of 1 or more, and m represents an integer of 0 or 1 or more) (B) Polyfunctional phenolic resin represented by the following general formula (I) or (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) (However, n in the formula represents an integer of 0 or more than 1, R represents C_mH_2_m_+_1, m represents an integer of 0 or more than 1) (C) Novolac type phenolic resin (D) Dialkyl amino-1, 8 represented by the following general formula
-Diazabicyclo[5,0,4]undecene curing accelerator▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R^1 and R^2 are C_nH_2_n_+_
1 and n represents an integer of 0 or 1 or more) (E) silica powder is an essential component, and the dialkylamino-1 of (D) above,
A semiconductor device is sealed with a cured product of a sealing resin composition containing an 8-diazabicyclo[5,0,4]undecene curing accelerator in a proportion of 0.01 to 5% by weight based on the resin composition. A semiconductor sealing device characterized by: