Hygroscopic agent slurry suitable for high-temperature airtight packaging device and coating of hygroscopic agent slurry

Abstract

The invention relates to the technical field of semiconductor packaging, and discloses moisture absorbent slurry suitable for a high-temperature airtight packaging device and a coating of the moisture absorbent slurry, and the moisture absorbent slurry comprises 20-80 parts of a moisture absorbent, 30-60 parts of a polymer binder, 5-25 parts of a curing binder, 0-50 parts of an oxidizing agent, 0-60 parts of an organic solvent, 1-5 parts of cellulose and 1-5 parts of a conditioning agent. The moisture absorbent is at least one of alkali metal, alkali metal oxide, alkaline earth metal oxide, silica gel, zeolite molecular sieve, alkali metal carbonate, metal oxide, metal halide, sulfate, perchlorate or metal alcoholate with long-chain hydrocarbon; and the particle size of the moisture absorbent is 0.1-100 microns. The obtained coating is high in adsorption capacity, absorbed water vapor cannot be desorbed, the working range is wide, the coating is suitable for severe working conditions (-30 DEG C to 90 DEG C), the bonding adhesive force is good, the surface flexibility is good, impact vibration resistance is achieved, dust falling is avoided, the surface smoothness is good, and the service life is long.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor packaging, in particular to a moisture absorbent slurry and a coating thereof suitable for high-temperature airtight packaging devices. Background Art

[0002] The presence of moisture in any microelectronic package can cause immediate problems. This is not only because moisture can cause an immediate failure, but also because it is often a symptom of a larger problem. This can be caused by the intrusion of external gases if air is converted to moisture through the natural condensation process and enters what was thought to be a hermetic enclosure. This condition can be caused by external pressure, ultimately leading to catastrophic failure.

[0003] The electronic devices and display devices inside the airtight packaged devices such as fiber lasers, short-wave infrared sensors, organic light-emitting devices (OLED / PLED), semiconductor diode lasers, gas lasers, light-emitting diodes (LEDs), photovoltaic solar cells, gallium arsenide circuit packaged devices, photoelectric tubes, etc. are very sensitive to certain gases, which can easily cause dark spots, light spots, pixel shrinkage, low emission efficiency, and emission energy attenuation. This requires desiccant to selectively absorb gases that are harmful to the operation of the device for a long time to ensure the working environment of the device.

[0004] At the same time, the desiccant coating can absorb the water vapor leaked during the operation of the airtight device and can also absorb organic solvents, hydrogen, hydrocarbons, carbon dioxide, sulfides, etc., effectively drying and controlling harmful gases in the confined space, ensuring that the airtight packaged device is not disturbed by impurity-contaminated gases during operation, and improving the life and reliability of the airtight laser device.

[0005] However, the optimal working temperature of the existing desiccant coating is 8°C to 15°C. Within the optimal working temperature range, the desiccant can absorb 20% of its own weight of water vapor. The desiccant effect deteriorates after exceeding the optimal working temperature range. At 25°C, the maximum adsorption capacity is 15% of its own weight of moisture. At 90°C, the maximum adsorption capacity is only 5% of its own weight. In addition, during the operation of the device, if severe working conditions such as operating temperature ≥100°C occur, the water vapor adsorbed by itself will be released, thereby reducing the sensitivity, reliability and life of the airtight packaging device. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies of the prior art, the present invention provides a desiccant slurry and a coating thereof suitable for high-temperature airtight packaging devices, which can greatly increase the adsorption capacity of the desiccant and permanently lock the absorbed water vapor.

[0008] (II) Technical solution

[0009] A desiccant slurry and coating material components suitable for high-temperature airtight packaging devices include: one of ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate, magnesium perchlorate trihydrate and other desiccant agents or any combination of several desiccant agents, wherein the combined components account for 5-80 parts, zeolite molecular sieve 20-80 parts, oxidant 0-50 parts, polymer binder 30-60 parts, curing binder 5-25 parts, 0-60 parts of organic solvent, 1-5 parts of cellulose and 1-5 parts of regulator, the parts are by mass; the particle size of ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate, and magnesium perchlorate trihydrate moisture absorbent is 0.1-100μm, and the zeolite molecular sieve is: 3A / 4A / 5A / 10X / 13X type molecular sieve, and the zeolite molecular sieve particle size is 0.1-100μm.

[0010] Preferably, when applied to airtight packaging devices such as fiber laser pumping, micro-opto-electromechanical systems (MOMES), organic light-emitting devices (OLED / PLED), semiconductor diode lasers, light-emitting diodes (LED), photovoltaic solar cells, gallium arsenide circuits, photoelectric tubes, etc., the main components of the desiccant are: ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate, magnesium perchlorate trihydrate and the like desiccant, or any combination of any of the above desiccant ratios, and the zeolite molecular sieve is one or a combination of 3A / 4A / 5A / 10X / 13X molecular sieves.

[0011] Preferably, the polymer binder is a copolymer emulsion of at least one of epoxy acrylate, polyurethane acrylate, polyether acrylate, polyester acrylate, acrylic resin, methacrylate, α-cyanoacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, octyl acrylate, methyl methacrylate, silicone acrylate, acrylamide, methacrylamide, β-hydroxyethyl methacrylate, ethylene glycol dimethacrylate, phenolic resin, urea-formaldehyde resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, polyurethane, polymethyl methacrylate or polyethyl methacrylate; and the curing binder is a suspension or sol of at least one of sodium fluorosilicate, magnesium fluorosilicate, ammonium chloride, ammonium phosphate, ethyl acetate, zinc oxide, aluminum oxide, titanium dioxide, magnesium oxide, calcium silicate, aluminum hydroxide, aluminum powder, aluminum phosphate, magnesium phosphate, aluminum borate, calcium borate, silicon dioxide, zinc powder or silver chloride.

[0012] Preferably, the polymer binder is acrylate copolymer emulsion or silicone-acrylic emulsion; and the curing binder is alumina sol.

[0013] Preferably, the oxidant is at least one of palladium oxide, platinum oxide, cobalt oxide, copper oxide, nickel oxide or iron oxide; the organic solvent is at least one of ethyl acetate, anhydrous ethanol, isopropanol, alcohol, aromatic hydrocarbons, toluene, high boiling point alcohols, ethylene glycol, terpineol, ethyl acetate, glycol, acetate, ether alcohol, alcohol ester, ketone, pineol, kerosene, butyl carbitol acetate, dibutyl phthalate or butyl carbitol; the cellulose is at least one of methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose or hydroxypropyl cellulose.

[0014] Preferably, the organic solvent is anhydrous ethanol; and the cellulose is ethyl cellulose.

[0015] Preferably, the regulator is at least one of a defoamer, a plasticizer, a release agent, a thickener, a dispersant or a water retaining agent.

[0016] Preferably, the preparation steps are as follows:

[0017] A. Prepare the raw material components in proportion, and then stir and mix at a speed of 300±50r / min for 24±2h;

[0018] B. Place the material obtained in step A in a centrifugal degassing machine, degas and mix thoroughly to obtain a desiccant slurry.

[0019] Preferably, the desiccant slurry is applied to the carrier by screen printing, dispensing injection, spin coating, dip coating, doctor blade coating or casting deposition, and then cured at room temperature for 60±5min or at 60-80°C for 10±2min to obtain the desiccant coating; or it is made into a shape suitable for the carrier space by mold injection, pressing or pouring, and then cured at room temperature for 60±5min or at 60-80°C for 10±2min to obtain the desiccant coating; the thickness of the desiccant coating is 10-300μm, and the carrier refers to the cover plate, shell or internal structural surface of the airtight packaging device that can be used for the desiccant coating.

[0020] Preferably, the carrier is mainly: a material used in the field of airtight packaging, including: metal, ceramic, glass, resin, polymer material, silicone resin.

[0021] Preferably, the activation temperature under vacuum conditions is 100-200° C., and the activation time is 3-7 hours.

[0022] Preferably, the getter coating is sealed inside the device through the airtight packaging of the device. After packaging, the getter coating plays a hygroscopic role. The hygroscopic coating has strong hygroscopic properties at -30°C to 90°C. Its ingredients ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate, and magnesium perchlorate trihydrate are chemical reactions for water vapor adsorption and permanently lock in moisture.

[0023] (III) Beneficial technical effects

[0024] The coating prepared by the desiccant slurry of the present invention has a low curing and bonding temperature. After coating on a carrier by screen printing, dispensing injection, spin coating, dip coating, scraper coating, casting deposition and the like, the coating can be cured and bonded to the carrier at room temperature. By controlling the material formula, a desiccant slurry with any viscosity, consistency and rheology can be prepared. The prepared slurry has good thixotropy and rheology. The shape and size can be adjusted arbitrarily according to needs. The activation temperature of the desiccant coating is low. After the activation, the carrier with the desiccant coating and the film layer can be directly disassembled in a glove box after vacuum packaging, and only needs a short degassing and activation before the device sealing process is completed to be applicable. The material after curing and bonding has good bonding adhesion, sufficient surface flexibility, impact and vibration resistance, no dust shedding, good surface finish, high temperature resistance, acid resistance, alkali resistance, aging resistance and ultraviolet resistance. After the desiccant coating absorbs a large amount of harmful gases, the coating will not expand and deform and age and fall off, and can be used in the device at extreme temperatures of -30°C to 90°C, ensuring that the desiccant coating works normally in the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of a laser packaged with a moisture absorbent coating (obtained in Example 1) of the present application;

[0026] Figure 2 This is a structural diagram of a flexible OLED packaged with a hygroscopic coating (obtained in Example 2) of the present application;

[0027] In the figure, 1 is a metal, ceramic or glass cover plate, 2 is a desiccant coating, 3 is a pigtail, 4 is a lens, 5 is a laser, 6 is a heat sink, 7 is a base, 8 is a tube shell, 9 is a flexible polymer substrate, a glass or metal substrate, 10 is an OLED working layer, 11 is a glass or metal cover plate, and 12 is an epoxy resin. DETAILED DESCRIPTION

[0028] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0029] Example 1

[0030] 1. This embodiment is a desiccant coating for fiber lasers, which mainly absorbs water vapor and hydrogen. The slurry of the desiccant is a suspension dispersion of a desiccant and an oxidant in a polymer binder and an alumina sol, and comprises the following components:

[0031]

[0032]

[0033] (In the table, "PH4" means the pH value is 4, and "-11%" means the solid content is ≥11%)

[0034] 2. Place the 4A molecular sieve powder in a vacuum furnace for degassing and activation at an activation temperature of 300°C for 2h. Place the activated molecular sieve powder in a vacuum ball mill for ball milling and screening to obtain particles with a particle size in the range of 1-10μm.

[0035] 3. According to the above formula, the prepared and fully mixed materials are placed in a planetary mixer for closed mixing and stirring at a stirring speed of 300r / min and a stirring time of 24h. After the stirring is completed, the desiccant slurry is placed in a centrifugal degassing machine for sufficient degassing to finally obtain the desiccant slurry.

[0036] 4. The prepared desiccant slurry is screen-printed on the package cover of the fiber laser. The printing thickness is about 0.25mm and the area is about 0.84cm 2 .

[0037] 5. Place the printed desiccant cover plates in a drying oven at 70°C for 10 minutes to solidify them, and then place them in a vacuum annealing furnace for heating, vacuuming, degassing and activation. The heating temperature is 150°C and the heating time is 6 hours. The vacuum degree is required to be better than 1×10 - 2 pa.

[0038] 6. After cooling to room temperature, place the desiccant cover plate in a 5000PPMV water vapor pressure device at a constant temperature of 25°C. After 12 hours of absorbing water vapor, the amount of water vapor adsorbed is greater than 39% of the desiccant's own weight, which is higher than the 15% self-adsorption index of similar products.

[0039] Example 2

[0040] 1. This embodiment is a hygroscopic coating for OLED, which mainly absorbs water vapor, oxygen, hydrogen, carbon dioxide, hydrocarbons, sulfides, etc. The slurry of the hygroscopic coating is a suspension dispersion of hygroscopic coating and oxidant in polymer binder and alumina sol, and comprises the following components:

[0041]

[0042] 2. Place the 10X molecular sieve powder in a vacuum furnace for degassing and activation at 300°C for 2h. Place the activated molecular sieve powder in a vacuum ball mill for ball milling and screening to obtain particles with a particle size in the range of 1-10μm.

[0043] 3. According to the above formula, the prepared and fully mixed materials are placed in a planetary mixer for closed mixing and stirring at a stirring speed of 300r / min and a stirring time of 24h. After the stirring is completed, the desiccant slurry is placed in a centrifugal degassing machine for sufficient degassing to finally obtain the desiccant slurry.

[0044] 4. The prepared desiccant slurry is screen-printed on the package cover of the fiber laser. The printing thickness is about 0.25mm and the area is about 0.84cm 2 .

[0045] 5. Place the printed desiccant cover plates in a drying oven at 25°C for 60 minutes to solidify them, and then place them in a vacuum annealing furnace for heating, vacuuming, degassing and activation. The heating temperature is 150°C and the heating time is 4 hours. The vacuum degree is required to be better than 1×10 - 2 pa.

[0046] 6. After cooling to room temperature, place the desiccant cover plate in a 5000PPMV water vapor, oxygen, hydrogen, carbon dioxide, hydrocarbon, and sulfide (volume ratio of 1:1.2:0.3:0.3:0.1:0.2) device at a constant temperature of 90°C. After 12 hours of absorption, the adsorption amount is greater than 35.3% of the desiccant's own weight, which is higher than the 5% self-adsorption amount of similar products.

[0047] Example 3

[0048] The method is basically the same as Example 2, except that the raw materials used are different, as follows:

[0049]

[0050]

[0051] 2. Place the 3A molecular sieve powder in a vacuum furnace for degassing and activation at 300°C for 2h. Place the activated molecular sieve powder in a vacuum ball mill for ball milling and screening to obtain particles with a particle size in the range of 1-10μm.

[0052] 3. According to the above formula, the prepared and fully mixed materials are placed in a planetary mixer for closed mixing and stirring at a stirring speed of 300r / min and a stirring time of 24h. After the stirring is completed, the desiccant slurry is placed in a centrifugal degassing machine for sufficient degassing to finally obtain the desiccant slurry.

[0053] 4. The prepared desiccant slurry is screen-printed on the package cover of the fiber laser. The printing thickness is about 0.25mm and the area is about 0.84cm 2 .

[0054] 5. Place the printed desiccant cover plates in a drying oven at 25°C for 60 minutes to solidify them, and then place them in a vacuum annealing furnace for heating, vacuuming, degassing and activation. The heating temperature is 150°C and the heating time is 4 hours. The vacuum degree is required to be better than 1×10 - 2 pa.

[0055] 6. After cooling to room temperature, place the desiccant cover plate in a 5000PPMV water vapor, oxygen, hydrogen, carbon dioxide, hydrocarbon, and sulfide (volume ratio of 1:1.2:0.3:0.3:0.1:0.2) device at a constant temperature of 65°C. After 12 hours of absorption, the adsorption amount is greater than 37.8% of the desiccant's own weight, which is higher than the 5% self-adsorption amount of similar products.

[0056] The activated carriers with hygroscopic coatings and film layers obtained in the above examples can be directly disassembled in the glove box after vacuum packaging, and can be used after only a short degassing and activation before the device welding process is completed; after the hygroscopic coating absorbs a large amount of harmful gases, the coating will not expand, deform, or age and fall off. The impact resistance and other properties obtained in each example are shown in the following table:

[0057]

[0058]

[0059] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A desiccant slurry and coating thereof suitable for high temperature airtight packaging devices, characterized in that: The raw material components of the desiccant slurry include: ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate, magnesium perchlorate trihydrate and other desiccant agents, or any combination of several desiccant agents, wherein the combined components account for 5-80 parts, zeolite molecular sieve 20-80 parts, oxidant 0-50 parts, polymer binder 30-60 parts, curing binder 5-25 parts, organic solvent The invention discloses a novel moisture absorbent comprising 0-60 parts of an agent, 1-5 parts of cellulose and 1-5 parts of a regulator, wherein the parts are by mass; the particle size of the moisture absorbents of ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate and magnesium perchlorate trihydrate is 0.1-100 μm; the zeolite molecular sieve is 3A / 4A / 5A / 10X / 13X type molecular sieve, and the particle size of the zeolite molecular sieve is 0.1-100 μm.

2. The desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices according to claim 1, characterized in that: When used in airtight packaging devices such as fiber laser pumps, micro-opto-electromechanical systems (MOMES), organic light-emitting devices (OLED / PLED), semiconductor diode lasers, light-emitting diodes (LED), photovoltaic solar cells, gallium arsenide circuits, photoelectric tubes, etc., the main components of the desiccant are: ammonium sulfate, magnesium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, sodium ammonium sulfate, potassium ammonium sulfate, potassium sodium sulfate, calcium sodium sulfate, potassium chloride, ferric chloride, magnesium chloride, lithium chloride, calcium chloride, sodium chloride, magnesium perchlorate, magnesium perchlorate trihydrate and other desiccant, or any combination of any of the above desiccant ratios; the zeolite molecular sieve is one or a combination of 3A / 4A / 5A / 10X / 13X molecular sieves.

3. A desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices according to claim 1 or 2, characterized in that: The polymer binder is a copolymer emulsion of at least one of epoxy acrylate, polyurethane acrylate, polyether acrylate, polyester acrylate, acrylic resin, methacrylate, α-cyanoacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, octyl acrylate, methyl methacrylate, silicone acrylate, acrylamide, methacrylamide, β-hydroxyethyl methacrylate, ethylene glycol dimethacrylate, phenolic resin, urea-formaldehyde resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, polyurethane, polymethyl methacrylate or polyethyl methacrylate; the curing binder is a suspension or sol of at least one of sodium fluorosilicate, magnesium fluorosilicate, ammonium chloride, ammonium phosphate, ethyl acetate, zinc oxide, aluminum oxide, titanium dioxide, magnesium oxide, calcium silicate, aluminum hydroxide, aluminum powder, aluminum phosphate, magnesium phosphate, aluminum borate, calcium borate, silicon dioxide, zinc powder or silver chloride.

4. A desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices according to claim 3, characterized in that: The polymer binder is acrylate copolymer emulsion and silicone-acrylic emulsion; the curing binder is alumina sol.

5. A desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices according to claim 1 or 2, characterized in that: The oxidant is at least one of palladium oxide, platinum oxide, cobalt oxide, copper oxide, nickel oxide or iron oxide; the organic solvent is at least one of ethyl acetate, anhydrous ethanol, isopropanol, alcohol, aromatic hydrocarbons, toluene, high boiling point alcohol, ethylene glycol, terpineol, ethyl acetate, glycol, acetate, ether alcohol, alcohol ester, ketone, pineol, kerosene, butyl carbitol acetate, dibutyl phthalate or butyl carbitol; the cellulose is at least one of methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose or hydroxypropyl cellulose.

6. The desiccant slurry for absorbing harmful gases in airtight packaging devices according to claim 5, characterized in that: The organic solvent is anhydrous ethanol; the cellulose is ethyl cellulose.

7. A desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices as claimed in claim 1 or 2, characterized in that: The regulator is at least one of a defoamer, a plasticizer, a release agent, a thickener, a dispersant or a water retaining agent.

8. A desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices according to any one of claims 1 to 7, characterized in that: The preparation steps are as follows: A. Prepare the raw material components in proportion, and then stir and mix at a speed of 300±50r / min for 24±2h; B. Place the material obtained in step A in a centrifugal deaerator, deaerate and mix thoroughly to obtain a desiccant slurry; The carrier is mainly: a material used in the field of airtight packaging, including: metal, ceramic, glass, resin, polymer material, silicone resin.

9. The desiccant slurry and coating thereof suitable for high-temperature airtight packaging devices according to claim 8, characterized in that: Apply the desiccant slurry to the carrier by screen printing, dispensing injection, spin coating, dip coating, doctor blade coating or casting deposition, and then cure it at room temperature for 60±5min or at 60-80°C for 10±2min to obtain the desiccant coating; or make it into a shape suitable for the carrier space by mold injection, pressing or pouring, and then cure it at room temperature for 60±5min or at 60-80°C for 10±2min to obtain the desiccant coating; The thickness of the desiccant coating is 10-300 μm, and the carrier refers to a cover plate, a shell or an internal structural surface of an airtight packaging device that can be used for the desiccant coating.

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