JPH0256956A - Electronic part, sealing medium for electronic part and sealing method - Google Patents

Abstract

PURPOSE:To improve weatherability, chemical resistance, etc., by sealing an electronic element by the polymer of a polymerizable liquefied substance containing the single substance or mixture of the monomer or oligomer of a di(metha)acrylic group compound as an essential ingredient. CONSTITUTION:In a light-emitting or light-receiving device 1, a light-emitting element or a photo-detector 4 such as a diode is sealed by the polymer 3 of a polymerizable liquefied substance including a monomer or an oligomer or these mixture comprising a di(metha)acrylic group compound as an essential ingredient. Lead frames 6, 6 are formed projected from the polymer 3 to the top face of the polymer 3, and the lower sections of the lead frames 6, a section 7 for die bonding and a bonding wire 5 are sealed into the polymer 3. Accordingly, optical quality such as weatherability chemical resistance, hardness transparency, etc., is improved.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to light emitting or light receiving devices (components) such as LEDs, laser diodes, photosensors, etc. IC, LS
Regarding electronic parts (equipment) such as I, in particular, a sealing agent that does not cause trouble due to chlorine contamination and has excellent weather resistance, chemical resistance, hardness, and optical properties, a sealing method thereof, and the excellent properties mentioned above using the same. related to electronic components.

<Prior art and its problems> Conventionally, in the production of electronic components such as LEDs, laser diodes, and photosensors, the sealing of light emitting diodes and the like has been performed by casting polymerization of epoxy resin.

However, the sealing method using epoxy resin has the following drawbacks.

■ Epoxy resin has poor weather resistance, so when used outdoors, the optical power of the light emitting element will decrease significantly over time, and the light receiving sensitivity of the light receiving element will decrease over time, so it cannot be used outdoors. use is severely restricted.

(2) The curing time of the epoxy resin is long, 5 to 20 hours, and the productivity of the light emitting or light receiving device is poor.

■ Epoxy resin has poor release properties from molds, resulting in low productivity of light-emitting or light-receiving devices.

Further, when a mold release agent is used to improve mold release properties, the removal of the mold release agent adhering to the surface of the epoxy resin sealant becomes an important problem in the production process.

Furthermore, conventionally, in the manufacture of electronic components such as ICs and LSIs, IC elements and the like have been encapsulated with resins such as epoxy resins.

In general, epoxy resins have excellent chemical resistance, electrical properties, mechanical properties, and adhesive properties, and are widely used as sealants in the electronic and electrical material fields. , chloride, free chlorine, hydrolyzable chlorine, etc. remain in the resin.

If a resin containing such chlorine is used as a sealant, depending on the usage conditions, a large amount of chlorine ions may be liberated, reducing the reliability of electronic components. This makes the workability worse.

For this reason, in JP-A-58-134112, a method is used in which epoxy resin is treated with an excess alkali compound in a mixed solvent of methyl ethyl ketone/isobutyl ketone to reduce hydrolyzable chlorine in the resin. Alkaline compounds act as catalysts for ketones, causing high-boiling point metals to remain in product resins and forming fine polymers (gelled products). It is difficult to remove chlorine.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the problems in the prior art, to provide a light emitting or light receiving device with excellent weather resistance, chemical resistance, hardness, and optical properties, and to solve problems caused by chlorine contamination. We aim to provide electronic components with excellent chemical resistance and hardness.

Another object of the present invention is to provide a sealant for electronic components that can be used in electronic components having the above characteristics, has a short curing time, and has good mold releasability.

Another object of the invention is to provide a suitable sealing method for producing electronic components with the above characteristics.

Means for Solving the Problems> A first aspect of the present invention is that the electronic device is a polymerizable liquid polymer containing as an essential component monomers or oligomers of di(meth)acrylic compounds or a mixture thereof. To provide an electronic component characterized by being sealed with.

A second aspect of the present invention provides an encapsulant for electronic components characterized by containing monomers or oligomers of di(meth)acrylic compounds alone or in mixtures.

A third aspect of the present invention provides a method for sealing an electronic component, which comprises placing the above-described sealant into a mold in which an electronic element is placed, and polymerizing the sealant.

In a fourth aspect of the present invention, the above-mentioned encapsulant is placed in a mold in which an electronic element is installed, and the encapsulant has a low solubility with the encapsulant, and the encapsulant is placed on the encapsulant. Provided is a method for sealing electronic components, characterized in that the sealant is polymerized in the presence of a liquid material having a lower density.

A fifth aspect of the present invention is to place the above-mentioned sealant into a mold in which an electronic device is installed, and to bring the surface of the sealant into contact with an atmosphere of an inert gas having an oxygen concentration of 1% or less. , provides a method for sealing an electronic component, which comprises polymerizing the sealant.

The monomers, oligomers, or mixtures thereof that contain a di(meth)acrylic compound as an essential component include 100% monomer, oligomer only, a mixture of a monomer and an oligomer, a mixture of 2 or more types of 1000mer, and 2 or more types of oligomers. and a mixture of one or more types of oligomers and one or more types of oligomers.

Further, the polymer may be a homopolymer or a copolymer.

<Configuration of the Invention> The present invention will be described in detail below using preferred embodiments shown in the drawings.

In the present invention, electronic devices include light emitting and light receiving devices such as light emitting diodes and ultraviolet light emitting diodes, and also include IC devices, LSI devices, semiconductor devices (pellets), semiconductor resistance devices, transistors, and diodes.

Further, in the present invention, electronic components include light emitting components, light receiving components, RC components, LSI components, transistor components, diode components, biristors, thyristors, semiconductor IC components, and the like.

The electronic component, the encapsulant for electronic components, and the encapsulation method of the present invention are not limited to the encapsulation of electronic elements, but may also be used to encapsulate between electronic elements, or to encapsulate a part of an electronic component. Alternatively, the entire electronic component may be sealed.

A preferred embodiment of a light emitting or light receiving device is shown in FIG. 1 as an example of the electronic component of the present invention.

The following description will typically be made using a light emitting or light receiving device as an example of the electronic component.

The light emitting or light receiving device 1 may be of any type as long as the light emitting or light receiving element 4 such as a diode (for example, a light emitting diode or an ultraviolet light emitting diode) 4 is sealed with a specific polymer 3, and the shape etc. is not particularly limited.

Generally, on the upper surface of the polymer 3, protruding from the polymer 3,
A lead frame 6.6 is provided, one lead frame 6 is connected to a die bonding 7 to which a light emitting or light receiving element 4 is fixed, the other lead frame 6 is connected to a bonding wire 5 such as a gold wire, The bonding wire 5 is connected to the light emitting/light receiving element 4.

In addition, the lower part of the lead frame 6, the die bonding 7
and a bonding wire 5 is encapsulated in the polymer 3.

Examples of uses of the light emitting device or light receiving device to which the present invention is applied include light emitting devices such as LEDs, laser diodes, photosensor photodiodes, electroluminescence devices, and light receiving devices such as photodiodes.

The electronic component such as the light receiving device of the present invention is characterized by being sealed with a specific polymer, specifically a monomer or oligomer containing a di(meth)acrylic compound as an essential component, or a mixture thereof. It is characterized in that it is sealed with a polymer of a polymerizable liquid material (hereinafter referred to as sealant A) containing.

The encapsulant (A), which is the state before polymerization of the polymer for sealing the light emitting or light receiving device of the present invention, is a polymer containing a monomer or oligomer containing a di(meth)acrylic compound as an essential component, or a mixture thereof. It is a possible liquid substance.

Di(meth)acrylic compounds used in the present invention include diacrylic compounds and dimethacrylic compounds, and although there are no particular limitations, di(meth)acrylates represented by the following structural formula are preferably used.

In the following examples, either a diacrylic compound or a dimethacrylic compound is used, but the corresponding other compound is also included.

n=1-23 CH3 CH2=CH-COO-(CH2)a 0OC-CH=
CHzn=1-9 n Cape 9 CH2=CH-CoO(CH2CH20). Co
CH=CH2n=4-14 Preferably, tetraethylene glycol dimethacrylate and diethylene glycol dimethacrylate are used.

Other monomers 1 and other fillers can be added to the polymerizable liquid material to the extent that the physical properties of the resulting polymer are not impaired. For example, polyfunctional compounds such as trimethylolpropane trimethacrylate, pentaerythritol pentamethacrylate, etc.
meth)acrylates, up to 30% by weight of bisallyl compounds, vinyl compounds such as vinyl acetate, styrene, or unsaturated carboxylic acids such as maleic anhydride, or vinyltriethoxysilanes, up to 10% by weight. A silane coupling agent can also be added.

In the present invention, the sealant (A) may contain a polymerization initiator (B).

Polymerization initiator (B) used when polymerizing the sealant (A)
As the polymerization initiator, any one such as a photopolymerization initiator, a thermal polymerization initiator, a photo/thermal polymerization initiator, or a combination thereof may be used.

In addition to photopolymerization initiators, photopolymerization initiators include electron beam and radiation polymerization initiators.

Examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one.

As the thermal polymerization initiator, peroxydicarbonates such as diisopropyl peroxydicarbonate, di-secandabutyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, tertiary butyl perbenzoate, benzoyl peroxide, acetyl peroxide, t
- Organic peroxides and inorganic peroxides such as butyl hydroperoxide, cumene hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, lauroyl peroxide, diisopropyl peroxydicarbonate, methyl ethyl ketone peroxide, diacyl peroxides, etc. and radical initiators such as azobisisobutyronitrile and azobismethylisovaleronitrile.

Examples of the photo/thermal polymerization initiator include the following formula: The following compounds are mentioned.

Polymerization initiator (B) used when polymerizing the sealant (A)
The amount used is 0.01 to 10w for the sealant (A).
t%, preferably 0.1 to 3 wt%.

The sealant (A) is in a semi-cured state (B stage) if necessary.
It can also be used in

The method of sealing electronic components such as light emitting or light receiving elements using the sealant (A) is not particularly limited, but it is preferable to use the following sealing method.

(2) The surface of the sealant (A) is brought into contact with an inert gas atmosphere having an oxygen concentration of 1% or less, preferably 0.5% or less, more preferably 0.01% or less, and polymerized.

When polymerizing the encapsulant (A) using a radical polymerization initiator, if the encapsulant (A) is in contact with air, active radicals will be consumed by oxygen, so the interaction between the polymer and the air will increase. The contact surface may remain in a viscous liquid or gel without increasing its molecular weight.

In order to complete the polymerization uniformly and have a surface hardness of 2B or more in pencil hardness, preferably H8 or more, the oxygen concentration in the atmosphere in which the polymerization is carried out is 1% or less, preferably 0.5% or less,
More preferably, 0.01% or less of an inert gas such as nitrogen or argon is used.

■ Apply sealant (A) to the surface of sealant (A) in the mold.
The liquid substance (C) has low solubility with the sealant and has a density lower than that of the sealant (A), and the liquid substance (C) is polymerized.

The liquid material (C) may be any liquid material as long as it has low solubility with the sealant (A) and has a density lower than that of the sealant (A).

The density of the liquid material (C) is preferably 0.7 to Ig/cm
' More preferably, it is 0.8 to 0.95 g/cm3.

For the same reason as (2) above, consumption of radicals in the sealant (A) can be suppressed.

The liquid substance (C) is water, for example, and seals the open part to block oxygen. Since water has a high vapor pressure, it is suitable for polymerization at relatively low temperatures.

It may also be a low molecular weight liquid synthetic hydrocarbon polymer or a liquid hydrocarbon mixture such as mineral oil.

Examples of synthetic hydrocarbon polymers include poly(α-olefin) oil such as polydecene-1, alkyl aromatic oil such as alkylbenzene, polybutene oil, (liquid polybutene) polyhexene, and 2,4-dicyclohexyl-2-methylpentane. Alkylnaphthene oils such as oil, and ethylene/α-olefin random copolymer extracted oils such as ethylene-propylene random copolymer oils are used.

Among these, those having a molecular weight of 500 or more, preferably 1000
~toooo is preferred.

Furthermore, the number average molecular weight (TX n ) is 500 to 5000
In particular, ethylene/α-olefin random copolymer extracted oil having a molecular weight of 1,500 to 3,000 is preferred.

In addition, in the present invention, the ethylene component unit is composed of 30 to 70 mol% and the α-olefin component unit is 30 to 70 mol%, the number average molecular weight (Mn) is in the range of too to 5000, and the Q value (weight average molecular weight / number A liquid low molecular weight ethylene/α-olefin copolymer having an average molecular weight of 3 or less is particularly preferred.

When a liquid polyolefin or the like is used as the liquid material (C), the liquid material itself also exhibits a mold release effect, making mold release extremely easy. After polymerization, the liquid polyolefin can be easily removed with an organic solvent such as hexane, kerosene, or trichlene.

■Use the above and ■ sealing methods together.

The surface of the sealant (A) in the mold is covered with the liquid material (C), and the liquid material (C) is further covered with an inert gas atmosphere having an oxygen concentration of 1% or less for polymerization.

In this way, when the sealing methods (1) and (2) are used in combination, more preferable results can be obtained.

Polymerization can be carried out under various conditions depending on the polymerization initiator. In thermal polymerization, for example, it is placed in a heating tank at 30 to 150°C, preferably 40 to 120°C, for 0.5 to 72 hours, preferably 1
It is best to heat for ~10 hours. In photopolymerization, for example, under a high-pressure mercury lamp of 60 W/cm to 150 W/cm,
The polymerization is preferably carried out for ~2 hours, preferably for 3 to 30 minutes, at a temperature of 40 to 120°C, preferably 60 to 100°C.

<Example> The present invention will be specifically explained below using Examples.

(Example 1) A lead frame with a GaAuAS light emitting diode was set in a polypropylene mold with an inner diameter of 5 II 1 m and a depth of 10 mm, and a liquid uniformly mixed with the following composition as a sealant (A)-I was placed in the mold. This was placed in a vacuum oven, and after replacing the inside of the oven with argon gas, the temperature was raised stepwise from 40°C to 90°C, and the polymerization was completed in 7 hours.

(A)-1 ■ 100 parts by weight of tetraethylene glycol dimethacrylate ■ 0.5 parts by weight of diisopropyl peroxydicarbonate (Example 2) A lead frame with a light emitting diode was placed in a TPX mold with an inner diameter of 5 mm and a depth of 10 mm. The arrangement shown in the figure and
Set in the same manner, the following composition was injected as a sealant (A)-TI into the mold, and on top of this, liquid ethylene-propylene copolymer ('fln2500.Q value 2.0
, specific gravity 0.846) with a thickness of about 2 mm+.
This was placed in an air oven and the temperature was raised stepwise from 40°C to 90°C to complete polymerization in 7 hours.

(A)-11 ■ Tetraethylene glycol methacrylate - 8100 parts by weight ■ Diisopropyl peroxydicarbonate 0.1 part by weight (Example 3) Same as Example 2 except that (A)-1f (A)-111 was used instead, and the polymerization was completed in 7 hours in the same manner as in Example 2.

(A)-111 ■ 100 parts by weight of diethylene glycol dimethacrylate ■ 0.1 parts by weight of diisopropyl peroxydimethacrylate (Comparative example 1) Inner diameter 5 mm, depth 10 mm 0') Lead frame with light emitting diode in TPX mold were set in the same manner as shown in Fig. 1, and in the mold, a base material of light emitting diode sealing grade Bellnox XN-1886-3,100 was added.
An epoxy resin consisting of 110 parts of a hardening agent Herkini 7

The light emitting or light receiving devices obtained in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1.

(1) 1iit type Evaluation was performed by releasing from the mold without using a mold release agent.

◎Easy to release from mold.

0 Grasp with your hands and release from the mold.

X It is impossible to release the mold by grasping it with your hands.

(2) Visual inspection of transparency O...Good ◎...Il Only in the comparative example, those released from the mold using a silicon-based mold release for light emitting diodes were evaluated.

In the example, no mold release agent was used.

In addition, sealants (A)-1, (A)-11, (A)-1
No. 11 was polymerized into a 3.0 mm thick plate material in the same manner as shown in Examples 1 to 3 and Comparative Example 1, and the light transmittance was measured using a spectrophotometer.

Measurement of light transmittance: Hitachi self-recording spectrophotometer (Hitachi new model U-3400) (3) Weather resistance test ■ Accelerated weather resistance tester (manufactured by Iwasaki Electric Co., Ltd., S U V -
Light irradiation was performed using a WTI type) under the following conditions.

UV intensity 100 mW/am2, black panel temperature 63°C relative humidity 50-70% (black panel temperature 63°C)
The irradiation was carried out for a total of 48 hours, with one cycle having an irradiation time of 8 hours and a dew condensation time of 4 hours.

Weather resistance test ■ Accelerated weather resistance tester (WEL-6X manufactured by Suga Test Instruments Co., Ltd.)
-HC-BEC type) Light FA 6.0kW Xenon lamp Black panel temperature 63°C Relative humidity 50% Irradiation time was 200 minutes (including 18 minutes of rain) as one cycle, and irradiation was performed for a total of 100 hours.

As a weathering test, the light transmittance and optical power were measured before and after the accelerated weathering test.

(4) Surface hardness The body of the sealed body was measured in accordance with JIS-5401.

Table <Effects of the Invention> Since the electronic component of the present invention, for example, a light emitting or light receiving device is sealed with a specific polymer, it has excellent weather resistance, chemical resistance, high hardness, and optical properties such as transparency. Excellent characteristics.

Since the electronic component of the present invention is sealed with a specific polymer, there is virtually no damage caused by chlorine in the sealing resin.
Excellent chemical resistance and high hardness.

The sealant of the present invention is used for electronic components having the above-mentioned characteristics, has a short curing time, and has good mold releasability after curing.

The sealing method using the liquid material of the present invention not only provides a resin-sealed part of an electronic component with high surface hardness, but also allows for extremely easy mold release since the liquid material has a mold release effect.

The sealing method of the present invention using an inert gas atmosphere with an oxygen concentration of 1% or less allows the atmospheric gas to be obtained at low cost, and it is possible to obtain an electronic component having a resin sealing portion with a high surface hardness at a reduced cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a light emitting or light receiving device. FIG. 2 is a longitudinal sectional view illustrating the sealing method. Explanation of symbols 1... Light emitting or light receiving device, 2...Mold 3...polymer, 4... element, 5... bonding wire, 6...Lead frame, 7... Electrode for die bonding, 8...Liquid substance, 13...Sealant

Claims (5)

[Claims] (1) An electronic component characterized in that the electronic device is sealed with a polymer of a polymerizable liquid substance containing as an essential component a di(meth)acrylic compound monomer or oligomer alone or in a mixture. (2) An encapsulant for electronic components characterized by containing monomers or oligomers of di(meth)acrylic compounds alone or in mixtures. (3) A method for sealing an electronic component, comprising placing the sealant according to claim 2 into a mold in which an electronic element is placed, and polymerizing the sealant. (4) The encapsulant according to claim 2 is placed in a mold in which an electronic element is placed, and the encapsulant has low solubility with the encapsulant and has a density smaller than that of the encapsulant. 1. A method for sealing an electronic component, comprising polymerizing the sealant in the presence of a liquid material having the following. (5) The sealant according to claim 2 is placed in a mold in which an electronic device is installed, and the surface of the sealant is brought into contact with an inert gas atmosphere having an oxygen concentration of 1% or less to seal the sealant. A method for sealing electronic components, characterized by polymerizing an agent.