JPH03209747A - Sealing member for electronic parts - Google Patents

Abstract

PURPOSE:To control the fluidity of sealing agent, and restrain the flow into the inside of a semiconductor device or to a connection lead, by using the following as adhesive agent composition used at the bonding part of a substrate and a lid member; epoxy resin wherein a specified amount of thermoplastic resin, inorganic filler, and curing agent are compounded in epoxy resin. CONSTITUTION:As to a sealing member, a lid member is bonded to a substrate for mounting a semiconductor chip, and the inside is hermetically sealed. Adhesive agent composition used at the bonding part of the substrate and the lid member is constituted as follows; thermoplastic resin of 25 pts. wt. or less, inorganic filler of 10-180 pts. wt. and curing agent are compounded in epoxy resin of 100 pts. wt. As the epoxy resin, bisphenol A type epoxy resin is used. As the thermoplastic resin, the following are used; polyamide based resin, polycarbonate based resin, and polyurethane based resin. As the inorganic filler, mica, silica, and glass fiber are used. As examples of the curing agent, ammine based hardener and anhydride based hardener are quoted.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is an electrical/electronic device that controls the sealing properties of semiconductor packages, particularly the flowability of the sealant, and suppresses the occurrence of blowholes. The present invention relates to a sealing member for parts (hereinafter simply referred to as electronic parts) and a sealing method.

(Prior art) In general, a semiconductor package is made by mounting a semiconductor element such as silicon on a substrate with a conductor formed on its surface, and bonding the lid member and the substrate with an adhesive after wire bonding. It has an airtight structure. Conventionally used adhesives include plus, solder,
resin is known. Among these, thermosetting epoxy resins are particularly mainstream.

Next, the conventional method of bonding the substrate on which the semiconductor chip is mounted and the blue material is to melt epoxy resin in advance on either the peripheral surface of the lIn material or the top surface of the package that the lid material contacts (or both surfaces). The viscous state is
It is mainly applied by screen printing, and when a lid is attached, a widely used method is to leave the lid member in a predetermined position and then heat and press it to join.

Also, the semiconductor element is irradiated with ultraviolet rays to erase the memory signal.
ROM (Program Read Only Me
mory) and charge-coupled devices (Ch.
In large coupled devices (hereinafter abbreviated as CCDs), it is necessary to illuminate a semiconductor element housed in a cavity, and glass with excellent translucency is used for the lid member. In this case, especially CC
In D, in order to obtain a homogeneous image, there must be no dust or dirt on the glass surface that would impede translucency.

In a sealing method in which the top surface of the package or the lid member coated with epoxy resin by screen printing is integrated by pressure heat treatment, when applying the epoxy resin to the lid member, the predetermined position of the transparent lid member is removed during the coating process. Easy to fly off site. Particularly in the case of a CCD, this results in a decrease in imaging performance. Furthermore, when the adhesive is pre-applied to a predetermined location on the package side, the applied adhesive may react and harden or flow away due to the heat generated during semiconductor element mounting or wire bonding. Furthermore, mechanical vibration during wire bonding may cause peeling, cracking, or chipping, and the adhesive may be washed away by chemical cleaning after wire bonding.

Next, there is a problem that the adhesive melted during sealing flows out into the semiconductor device, connection leads, and through holes, resulting in poor connection. Moreover, if an attempt is made to suppress the flow, there is a possibility that the adhesiveness during sealing will be reduced.

Therefore, it is extremely difficult to solve all of the above problems by applying adhesive to the top surface of the package or the lid member in advance by screen printing.

(Problem to be Solved by the Invention) The purpose of the present invention is to control the flowability of a sealant in a semiconductor device, etc., and to prevent the flow of the sealant into the semiconductor device or to the connection leads, thereby preventing connection failures in electronic components. To provide a sealing method for integrally joining a lid member and a package in an airtight manner without flying off, cracking, chipping, or washing away the sealing member and especially the lid member having translucency.

(Means for Solving the Problems) The present invention provides a sealing member in which a lid member is adhered to a substrate on which a semiconductor element is mounted and the inside thereof is hermetically sealed, and an adhesive used in the bonding portion between the substrate and the lid member. A sealing member for electronic components characterized in that the agent composition is comprised of 100 parts by weight of an epoxy resin, 25 parts by weight or less of a thermoplastic resin, 10 to 180 parts by weight of a mechanical filler, and a curing agent. .

Further, the present invention provides the above adhesive composition in an uncured state at a concentration of 0.01
After forming into a film or sheet with a thickness of ~10 mm,
A molded article for encapsulating an electronic component, characterized in that the film or sheet is punched into a shape that approximately matches the peripheral shape of a cavity that accommodates a semiconductor chip, and the molded article is placed at a predetermined location on a lid member or package. The present invention also relates to a method for sealing a lid member in an electronic component, characterized in that the lid member is bonded to the package after doing so.

The epoxy resin used in the present invention includes bisphenol A epoxy resin [manufactured by Yuka Shell Epoxy Co., Ltd.
Ebihut 828.834.1001.1002゜10
03, 1004.1005.1007.1010. l
100L, etc.], brominated bis7er7-A type epoxy resin [manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 5050y
5051y5051H, etc.], o-cresol novolac type epoxy resin [manufactured by Juju Kagaku Co., Ltd., ESCN-
220L.

ESCN-220F, ESCN-220H, ESCN-
220HH, etc.], brominated novolac type epoxy resins (manufactured by Nippon Kayaku Co., Ltd., BREN-8, etc.), phenol novolak type epoxy resins [manufactured by Sumitomo Chemical Co., Ltd., ESPN-1]
80, etc.] and epoxy resins modified with these. These epoxy resins can also be used in combination.

As the thermoplastic resin used in the present invention, Bo 177
Mido resin, polycarbonate resin, polyurethane resin, polyester resin, silicone resin, phenoxy resin, vinyl chloride resin, polystyrene resin, AB
S-based resin, polyvinyl alcohol-based resin, ionomer-based resin, methacrylic resin, polyphenylene oxide M-resin, thermoplastic resin or elastomer such as chlorinated polyethylene, natural rubber, inbrene rubber, butanoene rubber, styrene-butadiene rubber, nitrile rubber, chlorobrene Examples include rubbers such as rubber, silicone rubber, and norbornene polymer.

The blending amount of the thermoplastic resin used in the present invention is epoxy resin 1
001! ! The amount should be 25 parts or less based on lS (parts by weight, the same applies hereinafter). If the amount exceeds 25 parts, the crosslinking density of the cured product will decrease, resulting in a decrease in heat resistance and moisture resistance reliability.

*m-filled materials used in the present invention include mica, silica, lath fiber, lath 7 lake, glass powder, carbon 111
141. Examples include talc, calcium carbonate, titanium oxide, and zinc oxide. The proportion of the inorganic filler is 10 to 180 parts per 100 parts of the epoxy resin! Is. If the blending amount is less than 10 parts, the melt viscosity of the encapsulant will be low, making it easier for blowholes to occur due to the expansion of the air present inside the semiconductor device during sealing.
If the amount exceeds 0 parts, the melt viscosity of the sealant increases, resulting in poor fluidity and poor adhesion. If the average particle size of the inorganic filler is less than 0.01 part, the thixotropic properties of the blend will be very high, resulting in poor fluidity and poor adhesion. Also, the average particle size is 5μ
If it exceeds this, the melt viscosity of the sealant decreases, making blowholes more likely to occur.

Examples of the curing agent in the present invention include amine curing agent, R
There are no particular limitations on the curing agent as long as it is capable of curing reaction with the epoxy resin, such as anhydride curing agents, phenol resin curing agents, catalyst curing agents, and the like.

Specific examples of amines include diethylenetriamine, triethylenetetramine, bis(hexamethylene)triamine, trinotylhexamethylenediamine, menthenediamine, isophoronediamine, metaxylylenediamine, 3,9-bis(3-aminopropyl) -2,4,8-
Specific examples of acid anhydrides include tetraspiro(5,5)undecane, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, 4.4゛-methylenebis(2-chloro7niline), and 7-ducts of this and epoxy resin. Examples include 7-talic anhydride, trimetic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, maleic anhydride, tetrahydro-7-talic anhydride, hexahydro-7-talic anhydride, methylnadic anhydride,
Methylcyclohexenetetracarboxylic anhydride, tetrachloro heptatalic anhydride, tetrabromo heptatalic anhydride, etc.
Specific examples of air/ols include phenol, 0-cresol novolak, phenol novolak, phenol aralkyl, and the like. Examples of the catalytic curing agent include tertiary amines such as pencilzmethylamine, 2,4.6-F lis(dimethylaminomethyl)7ethyl-piperidine, pyrinone, and picoline, and 2-ethyl-4-
Imidazole represented by methyl imiguzole, other 1,8-noazabicyclo(5,4,0) undecene,
Examples include Lewis acids such as BF3, non-andiamides, amine imides, organic acid hydranides, mixtures of these, and those modified into salts, complexes, and the like.

The amount of curing agent is usually 1 to 10 parts by weight per 100 parts by weight of epoxy resin in the case of a catalytic curing agent! In other cases, the equivalent ratio to the epoxy group is preferably in the range of 0.5 to 2.

In the present invention, fillers, flame retardants, reinforcing materials, lubricants, dispersants, surfactants, pigments, dyes, coupling agents, and the like are used as compounding agents and additives as necessary. Fillers include organic fillers such as aramid fibers and nylon fibers other than inorganic fillers; anti-inflammatory materials include antimony dioxide, aluminum hydroxide, red phosphorus, and halogen compounds; lubricants, dispersants, and surfactants. wax, zinc stearate,
Examples of pigments and dyes such as silicone oil include carbon black, red iron, titanium white, and cyanine blue, and examples of coupling agents include silane coupling agents and titanium coupling agents.

Examples of means for melt-mixing these curing agents, compounding materials, additives, etc. with the epoxy resin include a kneading extruder, a heated stirring tank, a Ni-Goo, and a Banbury mixer roll.

In the present invention, the epoxy resin composition is used in a substantially uncured state as a film or sheet (hereinafter simply referred to as a sheet).
In addition to extrusion molding using an extruder equipped with a sheet guide, pressing the material with a Karen roll to form a sheet, and releasing the mold using methods such as solution coating and hot melt coating using a coating machine. It is also possible to form the sheet on a plastic substrate.

Regardless of which method is used, it is also possible to form a composite sheet by impregnating or laminating the epoxy resin mixture into the base material by supplying a fibrous base material such as glass fiber non-woven fabric or glass cloth as appropriate. It is. The sheet of the substantially uncured epoxy resin mixture obtained by the above method is further punched out with a punching machine such as a punching press using a punching die, a Thomson blade type, a carving blade type, etc., to obtain the desired shape. An epoxy resin molded body having a shape is obtained. Here, the term "substantially uncured state" means a state where crosslinking has partially progressed but has not been completed. 0.01 for sheet thickness
If it is less than mm, it will not be able to withstand the impact during punching. Moreover, even if punched through, the strength of the molded product is very low and it is difficult to handle. On the other hand, if the thickness exceeds 10 mm, accurate punching becomes difficult. It is important to keep the sheet below the plus transition temperature and below the softening temperature during punching. This is because the material strength of the epoxy resin mixture, which is formed into a sheet in a substantially uncured state, is not sufficient to withstand punching at temperatures below the glass transition temperature, and may stick to the cutting die at temperatures above its softening temperature. This is because it is not suitable for punching, as it is impossible to maintain the shape after punching. For this reason, the punching machine used in the present invention is equipped with a device such as a heating plate or a constant temperature bath that controls the temperature of the epoxy resin mixture sheet to a temperature suitable for punching, which is higher than the lath transition temperature and lower than the softening temperature. It is preferable. Furthermore, when punching is performed using a punching die, the temperature of the punching die must also be controlled. For example, when forming a sheet using an extruder, after the extruded sheet is cooled to below the softening temperature by a cooling take-off roll, etc., and before being cooled to below the plus transition temperature, the extruded sheet is continuously punched. It is also possible to process the sheet, and in this case there is no need to equip the punching machine with a sheet warming device.

In this way, the epoxy resin molded body is punched into a shape that matches the peripheral shape of the cavity that accommodates the semiconductor.
It can be airtightly sealed by placing it at a predetermined location on the lid member or package and heating it with a presser.

(Effects of the Invention) According to the sealing member for electronic components of the present invention, an adhesive suitable for airtight sealing is provided by controlling the blending amount and average particle size of the filler.

According to the epoxy resin molded article of the present invention, it is possible to mold an adhesive thermosetting molded article having a smaller, finer shape and size without cracking or chipping. In addition, the molded product obtained by the method of the present invention has sufficient strength to be handled by automated equipment such as Par'/Figu and robots, so it has excellent effects on process automation and cost reduction. . In addition, the molded product obtained by the method of the present invention is resistant to handling and vibration during transportation, so it does not break and generates little powder due to wear, so it is suitable for adherends such as parts, etc. less likely to contaminate the

On the other hand, according to the adhesive epoxy resin molded article of the present invention, quantitative management (=volume) of adhesives and sealants, positioning (=shape) of objects to be adhered or sealed, and automation of robots, etc. (solidity, strength), and assembly by adhesion and sealing becomes extremely easy. Furthermore, since the main component is epoxy resin, it has excellent heat resistance, chemical resistance, solvent resistance, electrical properties, adhesion, adhesion, etc.

(Example) Examples and comparative examples will be described below. Note that parts simply indicate parts by weight.

Examples and Comparative Examples Epoxy resin (bisphenol A type epoxy resin, dipico) 1001, Yuka Shell Epoxy Co., Ltd. 1) 100 parts, as a hardening agent, 11 parts of aromatic 7mine (7minophenylmethane), A composition prepared by blending 25 parts of a polyester thermoplastic resin (Vylon RV30P, manufactured by Toyobo Co., Ltd.) and fine silica powder as a filler in the proportions shown in Table 1 was placed in a kneading extruder adjusted to 100°C. Melt and mix
Approximately 31 pellets of epoxy resin mixture were obtained.

This was further processed using a Schilling-diameter 50 mm extruder equipped with a T-guidge with a lip length of 200 mm, and the thickness was 0.2 mm.
- A substantially uncured sheet with a width of 155 mm was obtained.

Next, this sheet was supplied to a punching press and punched out using a punching die to obtain a desired epoxy resin molded product without cracking or deformation. This punching press was equipped with a constant temperature bath including the part containing the punching die, and the internal temperature was set to 40"C1, and the punching die and material sheet were preheated and then punched. The dimensions and shape of the molded body are external dimensions 21+ui
X 16-Zen, M frame shape with a width of 3 mm and a thickness of 0.2
It is an argument.

This epoxy resin molded body is placed at a predetermined position on a ceramic substrate of a semiconductor package, and a lid member is further placed thereon. After aligning the adhesive surfaces, a clip is used to apply pressure of about 1.5 kg in a direction perpendicular to the adhesive surfaces. Thereafter, it was heated in an oven set at 150° C. for 1 hour to obtain samples 1 to 23 in table wJ1.

Each sample thus obtained was subjected to an initial sealing gross leak test and evaluation of flowability. Ten semiconductor devices of each sample were immersed in 125 parts of 70 Linate at a temperature of 5° C. for 60 seconds, and the generation of bubbles from the sealing surface was visually judged and the non-defective rate was evaluated as a percentage.

In the pressure test, each sample semiconductor package is placed in a pressure tester test (PCT) device and left in a saturated steam atmosphere of 121°C and 2.1 atm for 50 hours. After drying, a gross leak test is performed to determine whether the product is acceptable. determined the rate.

Regarding the flowability of the adhesive during sealing, the adhesive that has been heated and melted hardly flows into the through-hole of the semiconductor device is marked "O", and the adhesive that flows slightly is marked "Δ".
"mark", and "×" for items that have flowed too much and cannot be used.
It was evaluated as ``a mark''. The results are shown in Table 1.

No. table Items marked 1 are outside the scope of the present invention.

As is clear from the v&1 table, sample numbers 5-7.10-1
2.15 to 17 are within the scope of the present invention, indicating that the flow suppression effect during sealing, the good product rate in initial sealing, and the good product rate after PCT are all excellent.

In samples 1 and 2.3, there was too little filler, and the viscosity at the time of sealing was too low, causing blowholes (air hole phenomenon) due to large thermal expansion of the void containing the element, and poor flowability. It was big. In sample 4, the yield rate after initial sealing and PCT was good, but the flowability was too high and it could not be used. In sample 8, the average particle size of the filler was large and the viscosity during sealing was too low, causing blowholes.

In sample 9.14, since the average particle size of the filling H was very small, the thixotropy of the compound was high, and the lack of fluidity made it impossible to achieve close contact during sealing. In sample 13, the viscosity at the time of sealing was low and the flowability was slightly large. Sample 18 had a good yield rate after initial sealing and PCT, but had a rather large flowability and could not be used. Sample 19.
In No. 20, the viscosity of the compound at the time of sealing became so high that it was no longer possible to adhere tightly. In Samples 21 to 23, the apparent flow suppressing effect was good, but the initial sealing properties were very low because they were not completely adhered.

(that's all) Sender: Toyo Tire & Rubber Industries Co., Ltd. Representative Patent Attorney 1) Iwao Mura

Claims (4)

[Claims] (1) Glue the lid member to the substrate on which the semiconductor element is mounted,
In the sealing member whose interior is hermetically sealed, the adhesive composition used for the bonding portion between the substrate and the lid member includes 100 parts by weight of epoxy resin, 25 parts by weight or less of thermoplastic resin, and 10 to 180 parts by weight of inorganic filler. 1. A sealing member for electronic components, characterized in that it contains part by weight of a curing agent. (2) The average particle size of the inorganic filler according to claim 1 is 0.01.
A sealing member for electronic components having a thickness of ~5μ. (3) The adhesive composition according to claim 1 is applied in an uncured state to 0.
1. A molded article for encapsulating an electronic component, which is formed into a film or sheet having a thickness of 0.01 to 10 mm, and then punched out into a shape that approximately conforms to the peripheral shape of a cavity for accommodating a semiconductor chip. (4) A method for sealing a lid member in an electronic component, which comprises placing the molded article according to claim 3 at a predetermined location on the lid member or package, and then bonding the lid member to the package.