JPH06151651A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve the respective characteristics of a semiconductor device which are assessed by a thermal cycle test (TCT) and the cracking-resistant properties in the process of molten solder dipping by a method wherein a semiconductor chip is sealed with epoxy resin composition containing specific components. CONSTITUTION:As a semiconductor chip is sealed with new epoxy resin (formula I), special phenolic resin (formula II) and epoxy resin containing inorganic fillers to form a semiconductor device, the characteristics of the semiconductor device which are assessed by a TCT are improved and a long life can be obtained. Further, even if the semiconductor device is dipped into molten solder after it absorbs moisture, package crackings are not developed, so that a high reliability can be obtained. In the formula I, R1-R8 denote hydrogen atoms, halogen atoms, alkyl groups having 1-12 carbon atoms or 2,3-epoxyproxy groups and (n) denotes 0 or a positive integer not larger than 300. Further, in the formula II, R denotes a hydrogen atom, a hydroxyl group or an alkyl group whose carbon number is not larger than 12 and (n) denotes 0 or a positive integer not larger than 300.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having excellent reliability.

[0002]

2. Description of the Related Art Conventionally, semiconductor elements such as transistors, ICs, and LSIs have been encapsulated by a ceramic package or the like into a semiconductor device, but recently, from the viewpoint of cost and mass productivity, a resin using a plastic package is used. Sealing is the mainstream. Epoxy resin has been used for this type of resin encapsulation and has achieved good results. However, due to technological innovation in the semiconductor field, device sizes are becoming larger, wiring is becoming finer, and packages are becoming smaller and thinner due to technological innovation.
Along with this, further improvement in reliability (reduction of thermal stress of the obtained semiconductor device, reliability in moisture resistance, reliability in thermal shock test, etc.) is required for the sealing material. In particular, in recent years, the size of semiconductor devices has tended to increase,
There is a demand for further improvement in performance with respect to a thermal cycle test (TCT test) which is an accelerated test for evaluating the performance of a semiconductor encapsulating resin. In addition, surface mounting is becoming the main method of mounting semiconductor packages.Therefore, it is required that the package does not crack or swell even if it is dipped in a solder melt after being absorbed. ing. On the other hand, conventionally, in order to improve each characteristic evaluated by the TCT test, it has been studied to modify the epoxy resin with a silicone compound to reduce the thermal stress. Further, in order to improve the crack resistance during solder immersion, improvement of the adhesion of the epoxy resin to the lead frame has been studied. However, the effects of both of the above are not sufficient.

[0003]

As described above, the epoxy resin compositions for encapsulation up to now have not been satisfactory in the results of the TCT test and the crack resistance characteristics when immersed in solder.
For this reason, it is strongly desired to improve both of the above characteristics so that the semiconductor element size and surface mounting can be coped with by the above technical innovation.

The present invention has been made in view of the above circumstances, and provides a semiconductor device excellent in each characteristic evaluated by the TCT test and crack resistance when immersed in a solder melt, and an epoxy resin composition used therein. Is its purpose.

[0005]

In order to achieve the above object, the semiconductor device of the present invention seals a semiconductor element using an epoxy resin composition containing the following components (A) to (C). Take the configuration to stop. (A) An epoxy resin represented by the following general formula (1).

[Chemical 7] (B) At least one of the compound represented by the following general formula (2) and the compound represented by the following general formula (3).

[Chemical 8]

[Chemical 9] (C) Inorganic filler.

[0006]

That is, the present inventors have conducted a series of studies in order to improve the respective properties evaluated by the TCT test and the crack resistance when immersed in a solder melt. As a result, a semiconductor device sealed with an epoxy resin composition obtained from a resin having a special skeleton structure as represented by the above general formulas (1), (2), and (3) was tested by a TCT test. The inventors have found that both of them have excellent crack resistance when immersed in a solder melt after absorbing moisture, and have reached the present invention.

Next, the present invention will be described in detail.

The epoxy resin composition used in the present invention is obtained by using a novel epoxy resin (component A), a special phenol resin component (component B), and an inorganic filler (component C). Yes, it is usually in the form of powder or a tablet obtained by compressing it.

The novel epoxy resin (component A) is the polyglycidyl ether represented by the general formula (1). This novel epoxy resin (component A) is obtained by subjecting phenol or a phenol derivative and naphthaldehyde or a naphthaldehyde derivative to addition condensation using an acidic catalyst to form a glycidyl ether. In the above reaction, the condensation degree is preferably 2-6. In the general formula (1), the repeating number n is preferably 0 to 1.

As the epoxy resin component in the epoxy resin composition, an epoxy resin which is usually used together with the novel epoxy resin (component A), such as bisphenol A type, phenol novolac type, cresol novolac type, etc., is used. It is possible to use an epoxy resin together. When using these ordinary epoxy resins together,
It is preferable to set the blending ratio of the novel epoxy resin (component A) to be 50% by weight (hereinafter abbreviated as “%”) or more of the entire epoxy resin component.

The above-mentioned special phenol resin (component B) is
Used with the new epoxy resin (component A),
It acts as a curing agent for the novel epoxy resin (component A), and at least one of the phenol resin represented by the general formula (2) and the phenol resin represented by (3) is used. As the phenol resin represented by the general formulas (2) and (3), those having a repeating number n of 1 to 4, a softening point of 60 to 120 ° C. and a hydroxyl equivalent of 140 to 280 are used. Is preferred.

In the general formula (3), the positions of the substituents other than --OH and --R bonded to the naphthalene ring in the repeating number n are the following four modes (3a), ( Three
b), (3c), and (3d).

[0013]

[Chemical 10]

[0014]

[Chemical 11]

[0015]

[Chemical 12]

[0016]

[Chemical 13]

In the general formula (3), the portions of the naphthalene ring at both the left and right ends have the following two modes (3e) and (3f).

[0018]

[Chemical 14]

[0019]

[Chemical 15]

As the phenol resin component in the epoxy resin, a phenol resin such as phenol novolac or cresol novolac, which is usually used as a curing agent for the epoxy resin, is used in combination with the special phenol resin (component B). Is possible. When these ordinary phenol resins are used in combination, it is preferable to set the mixing ratio of the special phenol resin (component B) to be 50% or more of the whole phenol resin component.

The above-mentioned novel epoxy resin (component A) [also included when used in combination with a normal epoxy resin] and special phenol resin (component B) [included when used in combination with a normal phenol resin] The compounding ratio is preferably such that the hydroxyl group in the phenol resin is 0.8 to 1.2 equivalents per 1 equivalent of the epoxy group in the epoxy resin.

The inorganic filler (component C) is not particularly limited, and examples thereof include commonly used quartz glass powder, talc, silica powder, alumina powder, calcium carbonate, carbon black powder and the like. In particular, it is preferable to use silica powder. When silica powder is used, for example, the blending ratio of the inorganic filler is preferably set to 50% or more of the entire epoxy resin composition. It is particularly preferably 80% or more. That is, when the blending ratio of the silica powder is less than 50%, the effect obtained by blending the silica powder tends to be significantly reduced.

The epoxy resin composition of the present invention includes the above-mentioned epoxy resin (component A), phenol resin (B)
Component), inorganic filler (C component), if necessary, a stress reducing agent, a curing accelerator, a flame retardant, a pigment, a release agent,
Various additives such as a coupling agent can be appropriately mixed.

Silicone rubber, olefin rubber, etc. are generally used as the stress reducing agent.

Examples of the above curing accelerator include conventionally known ones such as tertiary amines, quaternary ammonium salts, imidazoles and boron compounds, which may be used alone or in combination of two or more.

As the flame retardant, antimony trioxide,
Examples thereof include phosphorus compounds.

Examples of the pigment include carbon black and titanium oxide.

Examples of the releasing agent include paraffin and aliphatic ester.

Examples of the coupling agent include silane coupling agents and the like.

The epoxy resin composition of the present invention can be manufactured, for example, as follows. That is, first, the epoxy resin (A component), the phenol resin (B component), the inorganic filler (C component), and if necessary,
A low-stressing agent, a curing accelerator, a flame retardant, a pigment, a release agent, and a coupling agent are mixed at a predetermined ratio, and heated and melt-kneaded by using a kneader such as a mixing roll. The desired epoxy resin composition can be obtained by a series of steps in which the mixture is cooled to room temperature, pulverized by a conventionally known method, and tableted if necessary.

The method of encapsulating a semiconductor element using the epoxy resin composition obtained above is not particularly limited, and the semiconductor of the present invention can be obtained by a known molding method such as ordinary transfer molding. The device is obtained.

[0032]

As described above, the semiconductor device of the present invention comprises an epoxy resin composition containing a novel epoxy resin (component A), a special phenol resin (component B), and an inorganic filler (component C). Since it is sealed by using TCT
The characteristics evaluated in the test are improved and the life is extended. Further, even after the moisture absorption, even if immersed in the solder melt, the generation of package cracks is prevented. Therefore, a large-sized semiconductor device having 8 pins or more, particularly 16 pins or more, or a long side of a semiconductor element of 4 mm or more, which is sealed by using the above epoxy resin composition, has high reliability. Become.

Next, examples will be described together with comparative examples.

Prior to the production of the epoxy resin composition, the following epoxy resin a and epoxy resin b, phenol resin c, phenol resin d, phenol resin e,
A silicone compound f was prepared.

[Epoxy resin a]

[Chemical 16]

[Epoxy resin b]

[Chemical 17]

[Phenolic resin c]

[Chemical 18]

[Phenolic resin d]

[Chemical 19]

[Phenolic resin e]

[Chemical 20]

[Silicone compound f]

[Chemical 21]

[0041]

Examples 1 to 20 and Comparative Examples 1 to 3 The raw materials shown in the following Tables 1 to 4 were blended in the proportions shown in the same table, melt-kneaded at 100 ° C. for 3 minutes with a mixing roll machine, and cooled and solidified. After that, it was pulverized to obtain the target powdery epoxy resin composition. Using these epoxy resin compositions, semiconductor elements are transfer molded (conditions: 175 ° C. × 2 minutes, 17
A semiconductor device was obtained by post-curing (5 ° C. × 5 hours). These packages are 80-pin 4-way flat package (80pinQFP, size: 20x14x2m).
m) and the die pad size is 8 × 8 mm.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[0045]

[Table 4]

The semiconductor device thus obtained was subjected to a TCT test of -50 ° C./5 min to 150 ° C./5 min. In addition, a test was conducted in which the sample was left in a constant temperature bath having a relative humidity of 85 ° C./85% RH to absorb moisture and then immersed in a solder melt at 260 ° C. for 10 seconds. The above results are shown in Tables 5 to 7 below.

[0047]

[Table 5]

[0048]

[Table 6]

[0049]

[Table 7]

From the results of Tables 5 to 7 above, the T
It is clear that the crack resistance during the CT test and immersion in the solder melt is significantly superior to the conventional product of the comparative example.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideto Kimura 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Minoru Nakao 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture No. Nitto Denko Corporation (72) Inventor Tsuyoshi Yoshida 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (2)

[Claims] 1. A semiconductor device obtained by encapsulating a semiconductor element using an epoxy resin composition having the following components (A) to (C). (A) An epoxy resin represented by the following general formula (1). [Chemical 1] (B) At least one of the compound represented by the following general formula (2) and the compound represented by the following general formula (3). [Chemical 2] [Chemical 3] (C) Inorganic filler. 2. An epoxy resin composition for semiconductor encapsulation, which comprises the following components (A) to (C). (A) An epoxy resin represented by the following general formula (1). [Chemical 4] (B) At least one of the compound represented by the following general formula (2) and the compound represented by the following general formula (3). [Chemical 5] [Chemical 6] (C) Inorganic filler.