JP2001261941A - Tablet and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tablet capable of reducing the formation of leek defect, and excellent in properties to be stamped by YAG laser. SOLUTION: This tablet for sealing a semiconductor is characterized in that a resin composition (I) comprising (A) an epoxy resin, (B) a phenol resin, (C) a curing accelerator, (D) a fused silica powder and (E) a carbon black, and a resin composition (II) not containing (A) the epoxy resin, (B) the phenol resin, (C) the curing accelerator, (D) the fused silica powder and (E) the carbon black are present in the same tablet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tablet for semiconductor encapsulation which has less leakage defects between wirings, bonding wires, and bonding pads and has excellent YAG laser printing properties, and a semiconductor device sealed thereby. It is.

[0002]

2. Description of the Related Art In order to protect an IC body from mechanical and chemical actions, an epoxy resin composition comprising an epoxy resin, a phenol resin, a curing accelerator, a fused silica powder, and a carbon black as a coloring agent has been developed. Has been produced. Items required for this resin composition are changing according to the type of IC chip, the structure of the package to be sealed, the environment in which it is used, and the like. The distance between them is becoming narrower, and it is necessary to cope with a narrow pitch. However, carbon black compounded as a colorant has a very small particle diameter but is easily aggregated and has electrical conductivity, and is considered to be a cause of leak failure due to the narrow pitch of the pads. In order to solve this problem, reductions in the amount of carbon black agglomeration and the amount of carbon black added have been studied. However, there is a limit to reducing the amount of carbon black agglomeration. There is a problem of decline. Further alternative colorants for carbon black are being studied,
There is an effect on the curability of the resin composition or deterioration of the printability, and the resin composition has not been put to practical use.

[0003]

According to the present invention, as a result of various studies to solve these problems, a resin composition containing carbon black and a resin composition containing no carbon black are contained in the same tablet. It has been found that a semiconductor device obtained by encapsulating a semiconductor element using a certain existing tablet can maintain YAG laser printability and improve leakage defects.

[0004]

The present invention provides (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator,
(D) a resin composition (I) containing fused silica powder and (E) carbon black, (A) an epoxy resin, and (B)
A tablet for semiconductor encapsulation wherein the phenolic resin, (C) a curing accelerator, (D) fused silica powder, and (E) a resin composition containing no carbon black (II) are in the same tablet. In particular, the semiconductor element is sealed with a resin composition in which the softening point of the resin composition (I) is lower by 10 ° C. than the softening point of the resin composition (II) and a cured product of the tablet. It is a semiconductor device.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The epoxy resin used in the present invention refers to all monomers, oligomers and polymers having two or more epoxy groups in one molecule, such as biphenyl epoxy resin, bisphenol epoxy resin, phenol novolak epoxy resin, and cresol novolak epoxy. Resins, triphenolmethane-type epoxy resins, dicyclopentadiene-modified epoxy resins, and the like, may be used alone or in combination. Examples of the phenol resin used in the present invention include a phenol novolak resin, a xylylene-modified phenol resin, a terpene-modified phenol resin, and a triphenolmethane-type resin. These may be used alone or in combination. The ratio of the number of epoxy groups in the epoxy resin to the number of hydroxyl groups in the phenol resin is preferably 0.8 to 1.2.

The curing accelerator used in the present invention may be any one that promotes the curing reaction between an epoxy group and a hydroxyl group, and those generally used for a sealing material can be widely used. For example, 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, 2-methylimidazole and the like can be mentioned, and they may be used alone or in combination. Examples of the inorganic filler include fused silica powder, crystalline silica, alumina, silicon nitride and the like, and the fused silica powder is preferred from the viewpoint of reliability and expansion coefficient. The compounding amount is preferably 60 to 93% by weight in the total epoxy resin composition in view of the balance between moldability and reliability.

The primary particles of carbon black as a colorant used in the present invention preferably have a diameter of 5 to 100 nm and secondary particles of 0.1 to 30 μm. The amount of carbon black added is 0.2 to 1 in the total resin composition (I).
% By weight is preferred. The resin composition (II) does not contain carbon black, but may contain a black dye such as an azo dye having no conductive properties. In the present invention, by controlling the flow behavior at the time of molding, the surface and the inside of the semiconductor device obtained by molding are filled with different resin compositions, and the resin composition containing carbon black (I) Is filled in the package first, and when the filling is completed, the resin composition (I) rubs the surface of the semiconductor device with the resin composition (I
I) needs to constitute the periphery of the semiconductor element. Accordingly, examples of the tablet include a tablet double structure as shown in FIG. 1 and a tablet two-stage structure as shown in FIG. 2. In the present invention, the resin composition (I) containing carbon black is used. Is filled in the package first, and when the filling is completed, the resin composition (I)
There is no particular limitation as long as the resin composition (II) to be charged late is a tablet constituting the periphery of the semiconductor element. In the double structure tablet shown in FIG. 1, the resin composition (I) containing carbon black is placed on the outside, and in the two-stage structure shown in FIG. 2, the resin composition (I) containing carbon black is placed on the runner side of the molding machine. (Opposite the plunger). Further, it is desirable that the softening point of the resin composition (I) containing carbon black is lower by at least 10 ° C. than the softening point of the resin composition (II) not containing carbon black. Due to the difference of 10 ° C or more, the resin composition with a low softening point melts and flows quickly, more evenly covers the package surface, and has less leakage failure between wiring, bonding wires, and bonding pads. An excellent semiconductor device can be obtained. If the difference in the softening points is less than 10 ° C., the difference in the melting time in the mold is short, and the resulting carbon black-containing layer on the surface of the semiconductor device may lack uniformity.

The resin composition (I) and the resin composition (II) used in the tablet of the present invention may contain, if necessary, a brominated epoxy resin, a flame retardant such as antimony trioxide, a coupling agent, a natural wax, A release agent such as a synthetic wax or a low-stress component such as silicone oil or rubber may be appropriately blended. In order to obtain a resin composition, the components are mixed, heated and kneaded with a heating kneader or a hot roll, and then cooled and pulverized to obtain a desired resin composition. The tablet having the dual structure shown in FIG. 1 is formed by tableting the resin composition (II) into a tablet having a size smaller than the target tablet diameter and height, and placing the tablet in a mold having a predetermined tablet diameter. The powder is put together and compressed to make a tablet. The tablet of FIG. 2 is prepared by charging a predetermined amount of the resin composition (I), then charging the resin composition (II) from above, and performing pressure tableting. Using the tablet of the present invention, electronic components such as semiconductors are sealed,
To manufacture a semiconductor device, a transfer molding method is preferable, and a multi-pot plunger type is particularly preferable.

[0009]

The present invention will be specifically described below with reference to examples. << Example 1 >> Resin composition (I) Resin composition (II)-Biphenyl type epoxy resin 12.3 parts by weight 12.3 parts by weight-Phenol novolak resin 6.6 parts by weight 6.6 parts by weight-Triphenylphosphine 0.3 parts by weight 0.3 parts by weight ・ Spherical fused silica 80.0 parts by weight 80.3 parts by weight ・ Carnauba wax 0.5 parts by weight 0.5 parts by weight ・ Carbon black 0.3 parts by weight Biphenyl type epoxy resin , Yuka Shell Epoxy Co., Ltd.
YX-4000H, melting point 105 ° C, epoxy equivalent 1
95. Phenol novolak resin has a softening point of 80 ° C. and a hydroxyl equivalent of 105. Carbon black is 10n primary particles
m. After mixing all the above components with a mixer, the mixture was kneaded 30 times using two rolls having a surface temperature of 90 ° C. and 45 ° C., and the resulting kneaded material sheet was cooled and pulverized to obtain a resin composition (I). (Hereinafter referred to as composition A) and resin composition (II)
(Hereinafter, referred to as composition B). The obtained two types of resin compositions were tableted into tablets having the above-described structure shown in FIG. The following methods were used to evaluate the softening point, YAG laser printability, package appearance, and leak rate of the resin composition. Table 1 shows the evaluation results.

<< Evaluation Method >> YAG laser printability: 14 × 20 × 2.7 mm 80p
QFP was molded with a multi-pot plunger die and evaluated with a mask-type YAG laser marking machine. Softening point of the resin composition: A strain is applied to the sheet-like resin composition after kneading (before pulverization) so that the load becomes 500 g with a three-point bending measuring machine. The temperature at which the load became 0 when heated at a heating rate of 5 ° C./min was defined as the softening point. Package appearance: The package PKG appearance was visually checked for color unevenness. Leakage defect rate: 80 bonded at a pitch of 50 μm
pQFP was molded in the same manner as above, and the presence or absence of leakage between pads was determined. Defects of other causes such as gold wire deformation were excluded.

<< Examples 2 to 4 and Comparative Examples 1 and 2 >> Examples 2 to 4 were blended according to Table 1, and compositions A and B were obtained in the same manner as in Example 1. The tablet was compressed into a tablet having the configuration shown in FIG. Evaluation was performed in the same manner as in Example 1. Comparative Examples 1 and 2 were blended in accordance with Table 2 to obtain Composition A in the same manner as in Example 1, and tableted into a tablet consisting of Composition A alone. Evaluation was performed in the same manner as in Example 1. Tables 1 and 2 show the evaluation results. The properties of the epoxy resin used in addition to Example 1 are described below. Orthocresol novolak epoxy resin 1 has a softening point of 55
° C, epoxy equivalent 200. Orthocresol novolak type epoxy resin 2 has a softening point of 65 ° C. and an epoxy equivalent of 20.
0. In Examples 3 and 4, tablets were set in pots so that Composition A was near the runner.

[Table 1]

[0012]

[Table 2]

[0013]

The semiconductor device of the present invention reduces the occurrence of leak failure and is excellent in YAG laser marking.

[Brief description of the drawings]

FIG. 1 shows a perspective view (a) and a sectional view (b) of a tablet having a double structure.

FIG. 2 shows a perspective view (a) and a sectional view (b) of a two-stage tablet.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 3/20 CFC C08J 3/20 CFCD C08K 3/04 C08K 3/04 3/36 3/36 5/00 5/00 7/18 7/18 C08L 61/08 C08L 61/08 H01L 21/56 H01L 21/56 C 23/29 23/30 R 23/31 F term (reference) 4F070 AA46 AB10 AB23 AC11 AC23 AC87 AE01 AE04 FA03 FA17 FB06 4J002 CC04Y CD04W CD00X DA038 DJ017 FD140 FD156 GQ05 HA09 4J036 AA01 AA05 DA04 FA02 FA05 FB07 JA07 4M109 AA02 CA03 CA21 EA03 EB03 EB04 EB06 EB07 EB08 EB09 EB12 EC01 GA13

Claims (3)

[Claims] 1. A resin composition (I) comprising (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator, (D) fused silica powder, and (E) carbon black,
(A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator, (D) a fused silica powder, and (E) a resin composition containing no carbon black (II) in the same tablet. Characteristic tablet for semiconductor encapsulation. 2. The tablet for semiconductor encapsulation according to claim 1, wherein the softening point of the resin composition (I) is lower than the softening point of the resin composition (II) by 10 ° C. or more. 3. A cured product of the resin composition (I), wherein a semiconductor element is sealed with the cured product of the tablet according to claim 1 or 2, wherein the surface of the cured product contains carbon black. Wherein the periphery of the semiconductor element is a cured product of the resin composition (II) containing no carbon black.