JP2778125B2 - Electronic component encapsulated with polyphenylene sulfide resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial application field" The present invention is excellent in mechanical properties including crack resistance and low stress, and electrical properties including moisture resistance, and heat deformation resistance at high temperatures, Further, the present invention relates to an electronic component sealed with a polyphenylene sulfide (hereinafter abbreviated as PPS) resin composition having excellent chemical resistance.

"Conventional technology" PPS resin has heat resistance, rigidity, electrical insulation, chemical resistance,
It is known as a high-performance engineering plastic excellent in flame retardancy and the like, and maintains excellent properties even in a low-molecular-weight PPS resin having a low melt viscosity.
Therefore, the PPS resin having a low melt viscosity has attracted attention as an electronic component sealing material instead of the epoxy resin.

"Problems to be solved by the invention" However, there is a problem that the reliability of the electronic components sealed with the PPS resin is poor due to the characteristics of the PPS resin as compared with the electronic components sealed with the epoxy resin. is there.

As a method for improving the reliability of electronic parts sealed with this PPS resin composition, a method of adding a copolymer comprising a hydrogenated conjugated diene compound and a monovinyl-substituted aromatic compound to a PPS resin composition is known. (Japanese Unexamined Patent Publication No. 59-1670
No. 40). We have found that PPS containing this copolymer
Various electronic components were encapsulated using a resin composition or a PPS resin composition that does not contain the resin composition, but the electronic components encapsulated with these PPS resin compositions have poor thermal deformability at high temperatures. was there. In particular, with the development of surface mounting technology in recent years, many electronic components have become surface-mounted products, and therefore, higher temperature heat is applied to the electronic components during the soldering process compared to conventional lead-through mounted products It became so. Therefore, poor thermal deformability at high temperatures is a major drawback in sealed electronic components.

On the other hand, a PPS resin composition comprising a block copolymer of a PPS resin and a vinyl aromatic compound containing a carboxylic acid group or an acid anhydride group thereof and an olefin compound is known, and various moldings including electric parts are known. Although it is used for applications (Japanese Patent Application Laid-Open No. 58-27740), sealed electronic components are increased in water absorption rate and inferior in electrical insulation as compared with a composition to which no block copolymer is added. Turned out to be rather unreliable. In addition, when this composition is used for encapsulating electronic components, if the PPS resin has a low melt viscosity (ie, low molecular weight), the acid-modified block copolymer in the composition causes poor dispersion and is sealed. It has been found that electronic components have a problem with chemical resistance such as trichlene resistance.

The present invention has been made in view of the above circumstances, and, while enhancing the reliability of a sealed electronic component, is also sealed with a PPS resin composition that has improved thermal deformability at high temperatures and chemical resistance. It is intended to provide an electronic component.

"Means for Solving the Problems" The present inventors, based on 100 parts by weight of a PPS resin containing a filler, a vinyl aromatic compound containing a carboxylic acid group or an acid anhydride group thereof and an olefin compound. 0.2 to 10 parts by weight of the resulting copolymer and 0.1 to 10 parts by weight of the organosilane compound are found to be achieved by sealing the electronic component using a PPS resin composition containing 0.1 to 10 parts by weight, This has led to the present invention.

Hereinafter, the electronic component sealed with the PPS resin composition of the present invention will be described.

The PPS resin containing a filler used in the present invention (hereinafter referred to as a filled PPS resin) contains 10% by weight of a filler in the PPS resin.
8080% by weight.

As the PPS resin used for the filled PPS resin, an uncrosslinked or partially crosslinked PPS resin is preferable, and this PPS resin is used in order to provide a PPS resin composition that seals electronic components without applying stress. A resin having a reduced melt viscosity, that is, a low molecular weight PPS resin is preferably used. The melt viscosity of this PPS resin is 1000 to 30,000 g / 10, as measured by ASTM method D-1238-74 (315.5 ° C., 5 kg load).
Minutes are preferred.

The PPS resin used in the present invention may contain a random block, a graft copolymer, and a mixture thereof as long as the object of the present invention is not impaired.

Specific examples of the above copolymer, (Where R represents an alkyl group, a nitro group, a phenyl group, a carboxyl group, a metal base of a carboxylic acid, an alkoxy group, or an amino group), a trifunctional bonding group Other linking groups, such as And the like.

Further, as the filler used in the filled PPS resin, for example, glass fiber, potassium titanate fiber, asbestos, silicon carbide, silicon nitride, ceramic fiber, zirconia fiber, silica fiber, alumina fiber, stone fiber, organic Fibrous fillers such as fibers (eg aramid fibers), and barium sulfate, calcium sulfate, calcium sulfite, kaolin, clay, virophilite, bentonite, sericite, zeolite, mica, mica, nepheline sinite, talc, atarval Kite, wollastonite, PMF, calcium silicate, calcium carbonate, magnesium carbonate, dolomite, antimony oxide,
Inorganic fillers such as zinc oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide, alumina, iron oxide, molybdenum disulfide, stone beads, glass beads, glass balloons, glass powder, glass flakes, silica powder, silica beads, etc. Is mentioned.

The filler preferably contains at least one or more fibrous fillers. By including one or more kinds of fibrous fillers, the crack resistance of the electronic component sealed with the PPF resin composition of the present invention is improved.

The above-mentioned copolymer (hereinafter abbreviated as a modified copolymer) composed of a vinyl aromatic compound containing a carboxylic acid group or an acid anhydride group thereof and an olefin compound added to the filled PPS resin, It is obtained by a method in which a vinyl aromatic compound and an olefin compound are copolymerized, and this copolymer (hereinafter referred to as an unmodified copolymer) is modified with a carboxylic acid or an acid anhydride thereof.

Examples of the vinyl aromatic compound include styrene, α-methylstyrene, and vinyl toluene. Also,
Olefin compounds include ethylene, propylene,
Monoolefins such as butene and isobutylene; conjugated diolefins such as butadiene, isoprene and 1,3-pentadiene; and non-conjugated diolefins such as 1,4-hexadiene, norbornene and norbornene derivatives.

The unmodified copolymer is obtained by copolymerizing at least one of the vinyl aromatic compounds and at least one of the olefin compounds. The unmodified copolymer may be in any form such as random, block, or graft copolymer, but is preferably a block copolymer.

Examples of the carboxylic acids or acid anhydrides that modify the unmodified copolymer include maleic acid, fumaric acid, itaconic acid, maleic halide, cis-4-cyclohexene-1,2-dicarboxylic acid, and endo-acid. Dicarboxylic acids such as cis-bicyclo [2,2,1] -5-heptene-2,3-dicarboxylic acid; acid anhydrides of these dicarboxylic acids; and monocarboxylic acids such as acrylic acid and methacrylic acid. . A modified copolymer is obtained by reacting at least one carboxylic acid or an acid anhydride thereof selected from the above carboxylic acids or acid anhydrides with the unmodified copolymer.

The reaction between the unmodified copolymer and the carboxylic acid or the acid anhydride is performed by the addition reaction of the carboxylic acid or the acid anhydride to an aliphatic double bond in the unmodified copolymer. It is.

The ratio of the vinyl aromatic compound contained in the modified copolymer is preferably from 5 to 50% by weight. Less than 5% by weight of PP
Poor dispersion of modified copolymer in S resin composition, poor chemical resistance of electronic parts encapsulated with PPS resin composition, 50% by weight
When the ratio exceeds the above, crack resistance and low stress resistance of the electronic component sealed with the PPS resin composition are impaired.

The content of the carboxylic acid or its anhydride in the modified copolymer is 0.05 to 2 parts by weight based on 100 parts by weight of the unmodified copolymer.
0 parts by weight, preferably 0.1 to 10 parts by weight, more preferably
It is in the range of 0.3 to 5 parts by weight. When this content is less than 0.05 parts by weight, the amount of thermal deformation of the electronic component sealed with the PPS resin at a high temperature is large, and when it is more than 20 parts by weight,
It is not preferable because the moisture resistance of the electronic component sealed with the PPS resin composition is reduced.

The added amount of the modified copolymer is preferably in the range of 0.2 to 10 parts by weight based on 100 parts by weight of the filled PPS resin. When the amount is less than 0.2 parts by weight, the electronic parts encapsulated with the PPS resin composition are inferior in heat deformability at high temperatures. When the amount exceeds 10 parts by weight, the moisture resistance of the electronic parts encapsulated with the PPS resin composition is high. Is reduced.

In the modified copolymer, it is preferable that the number of aliphatic double bonds remaining in the modified copolymer is small. By reducing the residual aliphatic double bond, the thermal stability of the electronic component sealed with the PPS resin composition at the time of sealing is improved, and the long-term heat resistance is further improved.

Further, as the organic silane, which is another component added to the filled PPS resin in the present invention, what is generally called a silane coupling agent is used. Its structure is Or a polycondensate thereof. Here, Q is a carbon having or not having a functional group such as a vinyl group, an acrylate group, an amino group, a halogen group, an epoxy group, a mercapto group, R is a lower alkyl group, X is a chloro group, an alkoxy group. Is shown. Specifically, vinyl trichlorosilane, vinyl tris (β-methoxyethoxy)
Silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Xypropylmethyldiethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)-
γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, nC ₁₀ H ₂₁ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , N-cyclohexyl-δ-aminopropyltrimethoxysilane, N-β- (N-vinylbenzylamino) ethyl- Examples include, but are not limited to, δ-aminopropyltrimethoxysilane, δ-ureidopropyltriethoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, and the like.

This organic silane is prepared by pre-treating the filler contained in the filled PPS resin with the organic silane and adding the pre-treated filler by mixing the PPS resin into the PPS resin. It is added by a method of adding an agent or a modified copolymer when mixing, or a method of using the above two methods in combination.

The amount of the organic silane is preferably in the range of 0.1 to 10 parts by weight, more preferably in the range of 0.2 to 5 parts by weight, based on 100 parts by weight of the filled PPS resin. If the amount is less than 0.1 part by weight, the chemical resistance such as moisture resistance and trichlene resistance of the electronic component sealed with the PPS resin composition decreases, and if it exceeds 10 parts by weight, the heat resistance at the time of sealing the electronic component decreases. Is not preferred.

An antioxidant, a heat stabilizer, a corrosion inhibitor, a lubricant, a coloring agent, and the like can be added to the filled PPS resin as necessary. Further, a thermoplastic or thermosetting resin can be added as long as the object of the present invention is not impaired.

Examples of the resin to be added include a polyamide resin, an epoxy resin, an epoxy-modified silicone resin, and an amino-modified silicone resin. The addition amount is preferably in the range of 0.01 to 20 parts by weight based on 100 parts by weight of the filled PPS resin.

Thus, the melt viscosity of the PPS resin composition obtained by adding the modified copolymer, the organic silane, and other necessary additives to the filled PPS resin is 300 ° C., under the measurement conditions of a shear rate of 1000 sec ⁻¹ , It is preferably within the range of 200 to 3000 poise. If the melt viscosity exceeds 3,000 poise, the possibility of applying unnecessary stress to electronic components increases, which is not preferable.

The sealing of the electronic component of the present invention with the PPS resin composition can be performed using an injection molding machine, a transfer molding machine, a compression molding machine, or the like. The molding conditions in this case are the resin temperature
260-380 ℃, mold temperature room temperature-250 ℃, injection pressure 20-300
kg / cm ² .

In the electronic component sealed with the PPS resin composition of the present invention, the target electronic component includes a lead-through mounted product, a surface mounted product, and the like. Be demonstrated.

Specific examples of the above electronic components include IC and hybrid
ICs, transistors, diodes, triodes, capacitors, resistors, resistor networks, thyristors,
Chip inductors, transformers, motors, LC filters,
Connectors, coils, varistors, transducers,
Examples include a crystal oscillator, a fuse, a current sensor, a power supply, a switch, a relay, a sensor, a Hall element, a surge absorber, an arrester, a pin grid array, a photocoupler, and a composite part thereof.

"Example" Hereinafter, an electronic component sealed with the PPS resin of the present invention will be specifically described using an example.

(Production Example 1) As a non-modified copolymer, 2 of a butadiene block portion was used.
A hydrogenated styrene-butadiene block copolymer having a styrene content of 30% by weight was used, wherein about 90 mol% of the heavy bonds were hydrogenated. For 100 parts by weight of the styrene-butadiene block copolymer, 3 parts by weight of maleic anhydride, 0.1% After uniformly mixing parts by weight of Perhexa 2.5B (manufactured by NOF Corporation), the mixture was extruded at a cylinder temperature of 250 ° C. to perform a maleation reaction. From the copolymer after extrusion, unreacted maleic anhydride was removed by heating under reduced pressure to obtain a modified copolymer. When the modified copolymer was analyzed, the addition amount of maleic anhydride was 1.7
% By weight.

(Example 1) PPS with a melt flow rate of 20,000 which is not oxidized and crosslinked
150 parts by weight of a glass fiber having an average length of about 100μ and a diameter of 10μ with respect to 100 parts by weight of the resin, the modified copolymer obtained in Production Example 1
7.5 parts by weight and 2.5 parts by weight of vinyltriethoxysilane were added and mixed uniformly. After mixing, using a 50 mm extruder, 32
The mixture was melt-kneaded at 0 ° C. to obtain pellets of the PPS resin composition. A test piece for measuring electrical properties was prepared by injection molding using the obtained pellets, and a coil (surface mounted product) was sealed using this pellet to evaluate the performance. The results are shown in Table 1.

(Comparative Examples 1 to 3) Using the same PPS resin and glass fiber as in Example 1, the first
The same experiment as in Example 1 was performed with the formulations shown in the table. The results are shown in Table 1.

(Examples 2 to 5) Using the same PPS resin and glass fiber as in Example 1,
The same experiment as in Example 1 was performed with the formulations shown in the table. The results are shown in Table 1.

(Example 6) An experiment was performed in the same manner as in Example 1 except that Tuftec M1953 (trade name, manufactured by Asahi Kasei Corporation) was used as the modified copolymer. The results are shown in Table 1.

As is clear from Table 1, the examples are more excellent in heat deformation resistance than the comparative examples.

Hereinafter, the test methods and the compounds used in Table 1 will be described.

* 1 Tuftec M1953 (trade name) A carboxyl group-modified hydrogenated styrene-butadiene block copolymer manufactured by Asahi Kasei Corporation.

* 2 Unmodified copolymer Clayton RG1652 (manufactured by Shell Chemical Co., Ltd.), hydrogenated styrene-butadiene block copolymer, styrene block content 30% by weight.

* 3 Volume resistivity was measured in accordance with ASTM D257.

* 4 PCT (pressure cooker test) 121 ° C, 2 atm saturated steam pressurization test * 5 Inductance reduction rate after sealing Inductance reduction rate = (L ₁ -L ₀ ) / L ₀ (where L ₀ : inductance before sealing, L ₁ sealed after inductance) * 6 measured left dimensional change 5 minutes in a hot air dryer heat distortion resistance 300 ° C..

Thermal deformation (dimensional change rate%) = (l ₁ -l ₀ ) / l ₀ (where l ₁ : dimension after heating test, l ₀ : dimension before heating test) * 7 Tricrene resistance After standing at room temperature for 1 week Change in appearance of ○: No abnormality △: Some abnormality such as blisters ×: Many blisters.

(Example 7) In Example 4, an epoxy resin (Epiclon) was further added.
RN-695 (manufactured by Dainippon Ink and Chemicals, Inc.) was added, and the same experiment was carried out. Although there was no significant difference in electrical properties and thermal deformability, the performance decreased as the inductance reduction rate after sealing was 3.6%, but the tricrene resistance was good in the O evaluation.

[Effect of the Invention] An electronic component encapsulated with the PPS resin composition of the present invention is a vinyl aromatic resin containing a carboxylic acid group or an acid anhydride group thereof based on 100 parts by weight of a polyphenylene sulfide resin containing a filler. 0.2 to 10 parts by weight of a copolymer consisting of a compound and an olefinic compound and an organic silane compound 0.1 to 10
Because it is an electronic component sealed with a polyphenylene sulfide resin composition to which parts by weight have been added, not only the reliability as an electronic component is high, but also, conventionally, the heat deformability at a high temperature, which has been a problem, is improved, and And chemical resistance such as tricrene resistance. Therefore, the electronic component sealed with the PPS resin composition of the present invention can be substituted for the conventionally used electronic component sealed with an epoxy resin.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/31 H01G 1/02 J H05K 3/28 H01L 23/30 R

Claims (2)

(57) [Claims] 1. A copolymer comprising a vinyl aromatic compound containing a carboxylic acid group or an acid anhydride group thereof and an olefin compound, based on 100 parts by weight of a polyphenylene sulfide resin containing a filler, in an amount of 0.2 to 10 parts by weight. And an electronic component sealed with a polyphenylene sulfide resin composition containing 0.1 to 10 parts by weight of an organic silane compound. 2. A copolymer comprising a vinyl aromatic compound containing a carboxylic acid group or an acid anhydride group thereof and an olefinic compound has a vinyl aromatic compound content of 5 to 50% by weight. An electronic component encapsulated with the polyphenylene sulfide resin composition according to claim 1.