JPS61220446A - Resin sealed electronic device - Google Patents

Abstract

PURPOSE:To obtain highly reliable resin sealed devices, by performing oxidation treatment of polyphenylene sulfide, washing the material with hot water, and decreasing the amount of inclusion of water-soluble electrolytic component. CONSTITUTION:An inorganic filler such as dissolved silica is compounded in polyphenylene sulfide PPS. Silane and Ti coupling agents are compounded as required, and the adhesion of the resin and the part is increased. At first the PPS is immersed in a water solution of hydrochloric acid and acetic acid. Then, remaining acid and salt are removed by several times of washings using water or hot water. Thereafter, the material is treated by the hot water at 170 deg.C or higher, and the water-soluble electrolytic component, which is present in a form of acid or salt, is physically removed. The chemical denaturation of the end of polymer, which has the electrolytic component that can undergo hydrolysis is efficiently performed. The electric conductivity of the washing water is made to be 5muS/cm. The bath ratio of 200gr of the PPS with respect to 1l of water is specified. The granule is washed in an O2 atmosphere several times. When the resin sealing is performed by the PPS having this constitution, highly reliable devices having especially good moisture resistance are obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a resin-sealed electronic component coated or sealed with a polyphenylene sulfide resin, and more specifically relates to a polyphenylene sulfide resin with a reduced content of water-soluble electrolyte components. This invention relates to resin-sealed electronic components coated or sealed with sulfide resin.

[Conventional technology]

Thermoplastic resins, which have characteristics such as material yield and molding speed, are attracting attention in place of conventional thermosetting resins as resins for encapsulating electronic components. This is known from Japanese Patent Publication No. 52-14958 (known).Furthermore, it is known that the water-soluble electrolyte component contained in the polyphenylene sulfide resin can cause corrosion of the electrodes and wiring of electronic components, resulting in wire breakage, increased leakage current, etc. For the purpose of reducing failures, electronic components encapsulated using water-soluble 'tyy < 100 ppm or less of phytochemicals containing solute components are disclosed in Japanese Patent Application Laid-Open No. 55-156.
It is disclosed in Japanese Patent No. 542.

[Problem that the invention seeks to solve]

In the resin-sealed electronic component disclosed in JP-A-55-156542, as a method of reducing the content of water-soluble electrolyte components in the polyphenylene sulfide resin used, hot water of 120° C. or lower is used. Although cleaning has been proposed, this method has the disadvantage that it takes a lot of time to reduce the water-soluble electrolyte components.

Therefore, the present inventors conducted extensive studies with the aim of reducing the content of water-soluble electrolyte components in polyphenylene ulphite in a short time and efficiently.
, /I/Phytoin Acid M By washing with hot water after embedding, the content of water-soluble solute components, especially the content of sodium ions and chloride ions, which are problematic in this application, can be reduced in an extremely short time. We have found that this can be reduced and have arrived at the present invention.

[Means to solve the problem]

That is, the present invention provides a resin-sealed electronic component characterized by being coated or sealed with a polyphenylene sulfide resin that has been acid-treated and then washed with hot water.

Borifene phyto (hereinafter pps) used in the present invention
"abbreviated as" is a polymer containing repeating units represented by the structural formula ÷ () - 8,000 at 7O-Th4796 or more, more preferably at least qa mo tv96, and where the repeating unit is less than 70 mo tv96. This is not preferred because heat resistance is impaired.

Generally, pps is a polymer with a relatively small molecular weight obtained by the production method typified by Japanese Patent Publication No. 45-5568, and an essentially t-linear polymer obtained by the production method typified by Japanese Patent Publication No. 52-12240. There are relatively high molecular weight polymers, etc., and for the above-mentioned polymer C, it is possible to heat it in an oxygen atmosphere after polymerization, or by adding a crosslinking agent such as peroxide and heating it. It is also possible to increase the degree of polymerization and use it by increasing the degree of polymerization, and in the present invention 1, it is also possible to use pps obtained by any method.

Furthermore, less than 50 mol% of the repeating units of pps can be composed of repeating units having the following structural formula, etc.

The melt viscosity of pps used in the present invention is not particularly limited as long as it is possible to mold the electronic device without damaging it. In order to avoid damage to the resin, those with low melt viscosity are preferably used.

Further, the PPB used in the present invention may contain conventional additives such as antioxidants, heat stabilizers, lubricants, crystal nucleating agents, ultraviolet inhibitors, copper damage inhibitors, colorants, and mold release agents. Furthermore, for the purpose of controlling the degree of crosslinking of C P P S, a crosslinking accelerator such as a peroxidant, or JP-A-58-204045.
It is also possible to incorporate crosslinking inhibitors such as sia tv * tv mr cica boxylate and amino triacy .mu. described in JP-A-58-204046 and the like.

Furthermore, the pps used in the present invention includes fused silica, crystalline silica, and hydrochloric acid/l/l for the purpose of improving the dimensional stability, mechanical properties, or thermal conductivity properties of sealed electronic components.
! It is preferable to include non-fillers such as lithium sulfate, lithium sulfate, glass fibers, and glass peas, and it is desirable that the content of water-soluble electrolyte components in these fillers is also small. Two or more of these fillers can be used in combination, and if necessary, they can be pretreated with a silane-based and titanium-based coupling agent before use. Moreover, these coupling agents can also be directly blended into PPS for the purpose of improving the adhesion between the sealing resin and the electronic device.

The acid used in the acid treatment of pps in the present invention is not particularly limited as long as it does not have the effect of decomposing pps (hydrochloric acid,
Examples include sulfuric acid, acetic acid, phosphoric acid, rL acid, carbonic acid, propylic acid, etc. Among them, hydrochloric acid, acetic acid, etc. can be used more preferably, but those that decompose and deteriorate pps such as nitric acid are not preferred. .

Methods for acid treatment include immersion in an acid or an aqueous solution of an acid, and it is also possible to stir or heat as necessary. When using hydrochloric acid, immersion in an aqueous solution with a pH of 2 for about 30 minutes. Sufficient effects can be obtained by letting it grow.

Furthermore, after the acid treatment, it is preferable to wash with water or hot water several times to physically remove residual acids, salts, etc., in order to improve the efficiency of subsequent hot water washing.

In the subsequent hot water cleaning, the higher the temperature of the hot water, the higher the ppsct.
lIce is preferable because it has excellent physical removal efficiency of water-soluble electrolyte components present in the form of salts, and also excellent efficiency of chemical modification of polymer terminals having hydrolyzable electrolyte components, and the temperature of the hot water is Preferably, the temperature is selected to be 100°C or higher, more preferably 150°C or higher, and still more preferably 170°C or higher.

The water used for cleaning is preferably distilled water or deionized water with a low content of water-soluble electrolyte components, and the electrical conductivity of the water is 1 μ3/ax or less, preferably 15 μS/ax.
Those below at are used.

The cleaning operation is usually performed by adding a predetermined amount of pps to a predetermined amount of water, heating and stirring in a pressure vessel. P
As for the ratio of PS to water, more water is better, but usually water is 1 part.
1, a bath ratio of less than 200 g pps is selected.

Furthermore, the cleaning atmosphere does not need to be an inert atmosphere;
For preferred chemical modification below ps, it is desirable to perform the cleaning under an oxygen atmosphere.

It is preferable to wash the pps after the washing operation several times with warm water in order to physically remove residual salts and the like.

The pps to be subjected to acid treatment and hot water washing in the present invention is preferably a powder or granule, and particularly preferably an am powder from the viewpoint of efficiency of acid treatment and washing.

Since pps produced by a known method is usually obtained in the form of powder or granules, it is preferable to use these without pe-V-izing, acid treatment, and washing. If required to be a value,
It is also possible to use it by classifying or pulverizing it.

The thus obtained p containing reduced water-soluble electrolyte components
If necessary, the PS is mixed with a filler and used for molding, either as it is or after pe-V tizing.

The electronic component of the present invention is not particularly limited as long as it can be considered as an ordinary electronic component, but examples include a capacitor, a resistor, and an integrated circuit (Engineering CJ).

Transistors, diodes, triodes, thyristors, coils, varistors, connectors, converters, microswitches! ! ! and composite parts thereof.

There are no particular limitations on the method of covering or sealing with ppsc according to the present invention. Some pps tl-
Examples include a method of packaging under heat and pressure.

Further, the resin-sealed electronic component of the present invention can be treated with a peroxide such as a hydrogen peroxide solution after molding, or heat treated at a temperature below the melting point of pps to increase the degree of crosslinking or crystallinity. , mechanical properties, etc. can be revised.

The present invention will be explained in more detail with reference to Examples below.

〔Example〕

Reference example + (pps stand) 50% sodium hydrogen sulfide aqueous solution in autoclave 4.6
7 kg (sodium hydrosulfide 257μ), 505M sodium hydroxide 2.0 kg (sodium hydroxide 25μ
Mofi/)'jd, N-MethiA/-2-pyrrolidone, and IMP below, and 4 groups of J8kg were prepared.

4. Gradually raise the temperature to 205°C while stirring and distilled water containing 18 kg of water. I l was removed. residual mixture ic1
．． 4-Diclo~Hensen i75kg (25,5 mo/l/
) and 2 kg of IMP were added and heated at 250°C for 2 hours, and further heated at 260°C for 1 hour.

The reaction product was washed twice with water and five times with warm water at 70°C,
It was used in the following examples in a wet state.

The amount of pps achieved in dry form corresponds to about 2.5-S, and the melt viscosity measured on the powder obtained by drying a portion under reduced pressure at 120°C for 24 hours was 40 poise (520°C, The shear rate was 1000 seconds-1). In addition, 20 g of similarly dried powder, 100 a- ion-exchanged water, and a wetting agent (Triton The sodium and chlorine content measured in the liquid is p
Based on the weight of ps, 224 ppm and 516 ppm, respectively.
m, and the electrical conductivity of the extract was 557 μS/m.

Example 1 Approximately 2 pps (approximately 50%) in the wet state obtained in Reference Example 1
(containing water) was kept at room temperature and the pFI2 containing hydrochloric acid c5 was
After immersing for 0 minutes, it was filtered and the pH of solution F was 7.
It was washed with ion-exchanged water at room temperature until . The wet pps and ion-exchanged water were placed in an autoclave, which was sealed at normal pressure, heated to 180° C. with stirring, kept at this temperature for about 2 hours, and then cooled. The contents were taken out from the autoclave, passed through, and further washed with ion-exchanged water at room temperature until the pR of the P solution reached 7, and then dried under reduced pressure at 120° C. for 24 hours to form a powder.

After acid treatment and water washing, the pps was dried under reduced pressure at 120°C for 24 hours to form a powder, and the powder was further washed with hot water and extracted in the same manner as in Reference Example 1. The water-soluble sodium and chlorine contents and the electrical conductivity of the extract were as shown in Table 1.

Subsequently, the powdered pps after hot water washing and the melting force (
30:700 with an-80J manufactured by Toshiba Ceramic Co., Ltd.
Tri-blend with violet weight ratio and set at 310℃ 4
The mixture was supplied to a screw extruder with a zero vibration diameter, melted and kneaded, taken out in the form of a strand, and pelletized using a strand cutter.

Next, this pellet was heated to 520°C for screw in-line injection molding 41! P-type MO9) Tunsistor element supplied with IC and attached with lead wire (maximum rated voltage between source and drain 20Y).

Threshold voltage! L5V), insert 160-17
Using a mold set at a temperature of 0℃, the injection pressure was 40~
Sealing molding was performed at 70 cm/a11.

The resulting pps sealed transistor was heated to 121°C.

After being left in pressurized steam at 2 atm for 24 hours, (hereinafter P
When a pressure of 127 was applied between the source and drain (abbreviated as "after CT") and the leakage current was measured, the results shown in Table 1 were obtained.

Example 2 A pps sealed transistor was obtained in exactly the same manner as in Example 1, except that the temperature of the hot water used for hot water cleaning was 150°C. The evaluation results were as shown in Table 1.

Example 3 Instead of using acid treatment CpH2 hydrochloric acid in Example 1, pF
A ppB sealed transistor was obtained in exactly the same manner as in Example 1 except that it was treated with I2 acetic acid. The evaluation results were as shown in Table 1.

Comparative Example 1 Example 1 except that the pps in Example 1 was not treated with PT12 hydrochloric acid and the temperature of the hot water treatment was 120°C.
A pps sealed transistor was obtained in exactly the same manner as described above. The evaluation results were as described in Table 1.

Example 4 Instead of using the pps obtained in Reference Example 1 in Example 1,
The method was exactly the same as in the example blind, except that the melt viscosity was 100 poise pps (US 1 Phillips Petrium Inc. fi 11 Lydon II y-1 was used, and the injection molding pressure was 70 to I 10 q/lx". A pps sealed transistor was obtained.The evaluation results were as shown in Table 1.

8. Regarding the pps "Rydon" 1v-1 used here, the water-soluble sodium and chlorine contents evaluated in exactly the same manner as in Reference Example 1 were 265 ppm and 555 ppm, respectively.
m, and the electrical conductivity of the extract was 389 μF3/ex.

〔Effect of the invention〕

The pps resin-sealed electronic component of the present invention has an extremely small amount of water-soluble electrolyte-containing components in the resin, and has extremely high reliability as represented by moisture resistance.

Claims (1)

[Claims] A resin-sealed electronic component characterized by being coated or sealed with a polyphenylene sulfide resin that has been acid-treated and then washed with hot water.