Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/70—Maintenance
  • B29C33/72—Cleaning
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
  • H01L23/29—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the material, e.g. carbon
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
  • H01L23/31—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape

Definitions

• the technology disclosed herein relates to a mold cleaning compound and a method for cleaning a semiconductor packaging mold. More particularly, the present invention relates to a mold cleaning compound and a method for cleaning a semiconductor packaging mold, which can clean the semiconductor packaging mold easily and efficiently.
• Highly integrated semiconductor devices produced by highly developed semiconductor thin film technology are very sensitive to external environments such as humidity and temperature, and have poor shock resistance to withstand external shocks.
• the semiconductor device is packaged to enable signal input and output of an external device.
• such semiconductor devices include a die attach process for attaching a semiconductor chip to a lead frame, a wire bonding process for electrically connecting the semiconductor chip and the lead frame, and protecting the electrically connected wire. It is packaged through a molding process and the like.
• EMC epoxy compound
• Molding of the semiconductor chip is made by compressing the EMC in powder form. Specifically, in the molding process, the powder-formed EMC is filled into the upper mold and the lower mold having a cavity formed therein according to a thickness of a desired package, and after the molding process is finished, contaminants are stacked in the mold. In addition, the surface of the EMC is stained by the contaminants, resulting in poor appearance, or the molding itself sticks to the mold surface, making continuous work difficult.
• the contaminants include residues of epoxy resins and various oxidized waxes.
• the EMC consists of a mixture of various additives such as curing agents, binders, colorants, etc. in addition to epoxy resins, in order to satisfy various physical properties such as moldability, heat resistance, moisture resistance, and adhesiveness. Solid waste) is the mainstream. Accordingly, in the post-semiconductor step, the mold is cleaned at least once or twice a day regularly.
• a typical method of cleaning the mold is sheet cleaning using a thermosetting resin or rubber-based mold cleaning compound sheet, specifically, inserting the mold cleaning compound sheet between the semiconductor molds to which heat is applied. And repeatedly compressed to remove contaminants in the mold.
• the mold cleaning compound sheet has a flat plate shape and is supplied with a knife to be easily torn, and a user tears a sheet having a suitable thickness and length and applies it to a mold to be cleaned, even if a knife is put in the rubber. It is difficult to break smoothly because it is not easily broken and stretches, and there are various types of semiconductor packaging molds, so even if you stack several sheets with several thicknesses and lengths, you can not match countless mold types and you have to inject some excess amount than necessary.
• the sheet has a disadvantage in that work loss is severe and workability is poor, such as stacking a sheet on a thick mold.
• high viscosity materials such as modified epoxy resins are used as molding materials, and molds are also used in ultra-thin or matrix shapes, and thus, contamination in molds is increasing.
• semiconductor packaging has been largely developed in press molding, single cavity transfer molding, multi-cavity transfer molding, injection molding, or the like, that is, in the direction of improving productivity and precision.
• the present inventors pour the mold cleaning compound into the pot of the molding machine in the transfer molding, and when the press is closed, it is transferred to the inside of the mold (gate) through the runner at the port, so that the cleaning of the entire section becomes possible, and the cleaning compound even during injection molding Is injected into the molding machine's hopper, and not only the injection machine cylinder, nozzle, and even the entire mold are cleaned at once, but also the exact amount can be transferred or ejected to reduce the loss of materials and the room temperature stickiness of the rubber.
• the technique disclosed herein has an object to provide a mold cleaning compound capable of cleaning the semiconductor packaging mold.
• the compound provides a spherical or cylindrical mold cleaning compound.
• It provides a cleaning method of a semiconductor packaging mold comprising the step of taking out the compound cleaned by the impurity adsorption.
• the step of pouring and injecting the above-described mold cleaning compound into the hopper (Hopper) of the injection molding machine is completed the sealing process
• Adsorbing impurities while the supplied mold cleaning compound delivers the entire mold at once including the cylinder and the nozzle of the injection machine
• It provides a cleaning method of a semiconductor packaging mold comprising the step of removing the compound cleaned by the impurity adsorption from a mold.
• the technique disclosed herein replaces the existing sheet cleaning method and provides a mold cleaning compound that can clean the semiconductor packaging mold easily and efficiently, and supplies the entire section of the mold at a time by supplying it to the mold of the transfer molding or the injection molding to be cleaned. Cleaning, but not only eliminate the room temperature stickiness of the rubber, but also to solve the entanglement in the cleaning compound and to provide a cleaning method for the semiconductor packaging mold with improved workability and cleaning performance.
• the mold cleaning compound according to one embodiment of the technology disclosed herein is a cleaning compound of a semiconductor packaging mold, and the compound may be spherical or cylindrical.
• the spherical or cylindrical shape is provided as a substitute for a conventional mold cleaning compound sheet, and is provided in spherical or cylindrical form instead of a sheet form, and thus a content required without loss of compound regardless of the type and thickness of a mold requiring cleaning. It has the advantage of providing as much.
• sphere is a spherical or atypical spherical, unless otherwise specified, and may be a pellet of 30 mm or less in diameter, or 1 to 30 mm in diameter (in the spherical sphere, the diameter means the average diameter).
• the spherical shape may be preferably 2 to 20mm in diameter.
• the diameter is less than 1mm may be undesirable in terms of workability because it imparts an excessive number of filling on the lower mold of the mold to be cleaned during the operation, when the diameter exceeds 30mm to achieve in the technology disclosed herein compared to the existing sheet cleaning method It may not be desirable to fine control the amount used.
• cylindrical may be pellets of regular or atypical cross-section, having a diameter of 30 mm or less and a height of 30 mm or less, or a diameter of 1 to 30 mm and a height of 1 to 30 mm. Where diameter is the mean diameter.
• the cylindrical shape may have a diameter of 2 to 20 mm, a height of 2 to 20 mm, and more preferably, a diameter of 2 to 10 mm and a height of 2 to 20 mm.
• the diameter is less than 1mm, since the number of filling on the lower mold of the mold to be cleaned during operation may be undesirable in terms of workability, when the diameter exceeds 30mm to achieve in the technology disclosed herein compared to the existing sheet cleaning method It may not be desirable to fine control the amount used.
• the compound preferably includes a crosslinkable base material and a peroxide crosslinking agent, because the crosslinking with the peroxide crosslinking agent increases the overall strength, thereby increasing the adsorption power of the solid residue of the compound.
• the crosslinkable main material may be a rubber or room temperature tackiness reducing agent alone, and room temperature tackiness reducing agent in consideration of the property of sticking by room temperature stickiness (adhesiveness) of rubber itself when processing rubber into spherical or cylindrical shape described above. It can also mix and use.
• the room temperature adhesiveness reducing agent may be used a kind that can be crosslinked with a peroxide-based crosslinking agent, for example, may be a crosslinkable thermoplastic rubber or a crosslinkable resin having a DSC melting point of 140 ° C. or less alone or in combination.
• the crosslinkable thermoplastic rubbers are those which can be crosslinked with a peroxide crosslinking agent, such as styrene-butadiene-styrene block (SBS), styrene-ethylene-butadiene-styrene block (SEBS), and styrene-ethylene-propylene-styrene block (SEPS).
• SBS styrene-butadiene-styrene block
• SEBS styrene-ethylene-butadiene-styrene block
• SEPS styrene-ethylene-propylene-styrene block
• styrene-butadiene-based block copolymers such as styrene-isoprene-styrene block (SIS), polybutadiene-based thermoplastic rubber (12-PB), chlorinated polyethylene rubber (CPE), and polyolefin-based thermoplastic elastomer (TPO) It may be one or more selected from.
• the crosslinkable resin may also be crosslinked with a peroxide crosslinking agent, and at the same time, the DSC melting point may be 140 ° C. or less, or 35 to 140 ° C., and may be at least one selected from ethylene polymer and ethylene copolymer. For example, if it is less than 35 degrees Celsius, crosslinkable resin may melt
• the ethylene polymer may be, for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), or the like.
• LDPE low density polyethylene
• LLDPE linear low density polyethylene
• MDPE medium density polyethylene
• HDPE high density polyethylene
• the ethylene copolymer is i) ethylene, and ii) C 3 -C 10 alpha olefins, C 1 -C 12 alkyl esters of C 3 -C 20 monocarboxylic acids, unsaturated C 3 -C 20 mono or dicarboxylic acids, unsaturated C 4 It may be a copolymer of at least one ethylenically unsaturated monomer selected from anhydrides of —C 8 dicarboxylic acids and vinyl esters of saturated C 2 -C 18 carboxylic acids or an ionomer of the copolymer.
• ethylene copolymers include ethylene vinyl acetate (Ethylene Vinylacetate, EVA), ethylene butyl acrylate (Ethylene Butylacrylate, EBA), ethylene methacrylate (Ethylene Methacrylate), ethylene ethyl acrylate (Ethylene Ethylacerylate, EEA), ethylene Methyl methacrylate (Ethylene Methylmethacrylate, EMMA), ethylene butene copolymer (Ethylene Butene Copolymer, EB-Co), ethylene octene copolymer (Ethylene Octene Copolymer, EO-Co) and the like.
• the room temperature tack reducing agent may be included in at least 5 wt%, up to 100 wt% of the total components constituting the crosslinking agent main body.
• the room temperature tackiness reducing agent is included in 5 to 40 wt%, or 5 to 20 wt% of the total components constituting the crosslinking agent main body can exhibit an effect of reducing the room temperature tack of the rubber.
• crosslinkable thermoplastic rubber and crosslinkable resin can be used individually or in mixture.
• the rubber may be a natural rubber, a synthetic rubber, or a mixture thereof, and particularly, the rubber may be a kind crosslinkable with a peroxide crosslinking agent.
• the natural rubber may be general natural rubber or modified natural rubber.
• the natural rubber contains cis-1,4-polyisoprene as a main component as polyisoprene, but may also contain trans-1,4-polyisoprene depending on the required properties. Therefore, in the natural rubber, in addition to the natural rubber mainly containing cis-1,4-polyisoprene, natural rubber including trans-1,4-isoprene, such as balata, which is a kind of rubber of South American Sapotagua. It may include.
• the modified natural rubber is epoxidized natural rubber (ENR). Deproteinized natural rubber (DPNR), hydrogenated natural rubber, and the like.
• the natural rubber may be crepe rubber, sheet rubber, skim rubber, or the like, but is not limited thereto.
• the synthetic rubber is styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPR), ethylene-propylene diene rubber (EPDM), isobutylene-isoprene It may be at least one selected from the group comprising rubber (IIR) and silicone rubber.
• the peroxide-based crosslinking agent has a peroxide functional group and uses a kind capable of peroxide crosslinking of both the rubber and the room temperature tackifier, and the content thereof is 0.5 to 10 parts by weight, or 1 based on 100 parts by weight of the crosslinkable base material. It may be from 5 parts by weight, by reinforcing the rubber and room temperature adhesiveness reducing agent together in the above range can reinforce the strength and increase the adsorption power of the solid residue during cleaning.
• the peroxide crosslinking agent is, for example, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl cyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, t-butyl Peroxy maleic acid, t-butylperoxylate, t-butylperoxy-3,3,5-trimethylhexanoate, cyclohexanone peroxide, t-butylperoxy aryl carbonate, t-butylperoxy isopropyl Carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,2-bis (t-butylperoxy) octane, t-butylperoxy acetate, 2,2-bis (t-butyl Peroxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butylperoxy) vale
• it may further include one or more additives of a detergent, a tax aid and an adsorbent.
• an amino alcohol salt prepared by reacting (neutralizing) an amino alcohol or an amino alcohol with an organic or inorganic acid may be used.
• the amino alcohol salt By using the amino alcohol salt, the amino alcohol is fixed as a salt during cleaning to prevent volatilization of the amino alcohol, and decomposes into amino alcohol at a normal mold cleaning temperature (165 ° C. or higher and 200 ° C. or lower), thereby providing a predetermined mold cleaning effect.
• the said amino alcohol salt may mix
• the amino alcohol is, for example, monoethanol amine, diethanol amine, triethanolamine, N-methyl ethanolamine, N, N-dimethyl ethanolamine, N, N-dibutyl ethanolamine, N, N-diethyl ethanolamine, At least one selected from the group consisting of N-methyl-N, N-diethanol amine, 2-amino-2-methyl propanol, 3-amino propanol and 2-amino propanol, preferably monoethanol amine, di It may be at least one selected from the group consisting of ethanol amine, 2-amino-2-methyl propanol, 3-amino propanol and 2-amino propanol.
• the organic acid may be, for example, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, gilacetic acid, isogilic acid, pivalic acid, crotonic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, and palmitic acid.
• the inorganic acid may be, for example, hydrochloric acid or acetic acid.
• the cleaning agent may be used in an amount of 1.0 to 30 parts by weight, or 3.0 to 25 parts by weight based on 100 parts by weight of the crosslinkable base material, and may provide sufficient mold cleaning effect within this range, and may also provide mold cleaning compound after mold cleaning. When taken out from the mold, it does not break or remain clean.
• the detail information aid is, for example, at least one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, glycol ethers, and glycol esters, wherein 100 parts by weight of the crosslinkable base material As a reference, it can be used in 1.0 to 30 parts by weight, or 3.0 to 25 parts by weight, within this range can provide a sufficient mold cleaning effect without the problem that excess glycols remain in the mold representation.
• the adsorbent is one or more selected from the group consisting of carbon black, silica, activated alumina, activated carbon, magnesium oxide, titanium oxide, magnesium carbonate, calcium carbonate, bentonite and diatomaceous earth, based on 100 parts by weight of the crosslinkable base material. It can be used in the range of 10 to 90 parts by weight, or 20 to 70 parts by weight, and within this range, the solid residues, which are contaminants, are well peeled off from the mold surface. Since the phenomenon which remains in a mold is common, sufficient reinforcement can be provided.
• the mold cleaning compound is not only excellent in scorch property, cleaning adsorption power, cleaning property, detergent suitability, but also can provide easy properties such as underwater pelletizing, dry cross-sectional cutting pelletizing, underwater strand pelletizing.
• the mold cleaning compound according to one embodiment of the technology disclosed herein may be further contained in a range in which a crosslinking aid such as a softener such as stearic acid or ethylene bis stearamide and zinc oxide does not adversely affect the reaction as necessary.
• a crosslinking aid such as a softener such as stearic acid or ethylene bis stearamide and zinc oxide
• the softener 0.1 to 5 parts by weight, or may be further included in the range of 0.1 to 3 parts by weight
• the crosslinking aid may be further included in the range of 0.5 to 8 parts by weight, or 3 to 7 parts by weight.
• the cleaning method of the transfer mold using the mold cleaning compound according to the technology disclosed herein instead of the existing sheet cleaning method may be performed as follows, for example:
• the mold cleaning compound is poured into the port of the transfer molding machine where the sealing process is completed, and the press is closed.
• the use content of the compound here can be optimized by the skilled person for various mold shapes.
• the supplied mold cleaning compound is transferred from the pot through the runner into the mold to adsorb impurities.
• the pressurization may be carried out under heating conditions of at least 165 ° C., up to 200 ° C.
• pellets provides the benefits of not only transferring the correct amount but also reducing the loss of material.
• the compound cleaned by the impurity adsorption is taken out from the mold. At this time, a clean takeout can be performed without any residue over the entire section of the mold.
• the cleaning method of the injection mold using the cleaning compound disclosed herein may be performed as follows, for example:
• the mold cleaning compound is poured into a hopper of an injection molding machine where the sealing process is completed and injected.
• the use content of the compound here can be optimized by the skilled person for various mold shapes.
• the supplied mold cleaning compound delivers the cylinder, nozzle, and even the entire mold of the injection molding machine at once to adsorb impurities.
• the pressurization may be performed under heating conditions of 165 ° C. or more and a maximum of 200 ° C.
• the use of pellets provides the benefits of not only injecting the correct amount but also reducing the loss of material.
• the compound cleaned by the impurity adsorption is taken out from the mold. At this time, a clean takeout can be performed without any residue over the entire section of the mold.
• Rubber 1 high sheath-butadiene rubber
• Rubber 2 synthetic rubber: ethylene-propylene-diene rubber (EPDM)
• Thermoplastic Rubber 1 Styrene-Butadiene Block Copolymer (LG Ghem, LG401: Styrene 20wt%, Density 0.93 kg / cc, Hardness 57 Shore A)
• Thermoplastic rubber 2 Polybutadiene-based thermoplastic rubber (12-PB) (JSR, RB820: Density: 0.91 g / cc, DSC melting point 95 ° C)
• Thermoplastic Rubber 1 Thermoplastic Polyurethane (TPU) (Dongsung Hi-Chem, 5075A: Hardness 75 Shore A, Softening Point 75 °C)
• crosslinkability / non-crosslinkability is based on the presence or absence of crosslinkability with the peroxide crosslinking agent.
• Tax preparation Diethylene glycol
• Adsorbent Hydrated Silica Zeosil 45
• a crosslinkable (or noncrosslinkable) thermoplastic rubber and a crosslinkable (or noncrosslinkable) resin are mixed and mixed for 5 minutes in a kneader having a capacity of 1 L as a pressure-sensitive adhesive reducing agent. It was. 60 parts by weight of adsorbent, 20 parts by weight of detergent, 20 parts by weight of cross-linking agent (DCP), 1.0 parts by weight of stearic acid softener, 1.0 parts by weight of stearic acid softener and 5.0 parts by weight of zinc oxide as zinc cross-linking aid after mixing After addition and further mixing for 1 minute, the reaction was terminated and a total of 15 sheet-like mixtures were obtained in Open Mill.
• DCP cross-linking agent
• Underwater Cutting When cutting underwater, it is not possible to get tangled in the die, or even if it is cut, cool it after cutting and put it in a bag, put it in a bag, put it in a 40 °C oven, press it with a 1kg weight, and put it on the plate for 24 hours. If there was, it evaluated as bad (X).
• Dry Face Cutting When dry face cutting, sprinkle talc powder so that the pellets do not get tangled, then put 30g into a bag, put it in a 40 °C oven, press it with a 1kg weight, and take it out for 24 hours. If stuck together, it evaluated as bad (X).
• Scorch characteristics The melt index of each cleaning compound was measured at 130 ° C. and 10.0 Kg. When the measured value was less than 10 g / 10 min, the scorch property was evaluated as poor (X).
• Desorption power 10cm X 10cm X 5mm molds with holes 1mm in diameter x 2mm in height are arranged in the transfer molding machine at the bottom, and the cleaning compound is poured into the pot of 70g molding machine and pressed for 10 minutes at 175 °C. After vulcanization, the mold was demolded, and if the mold was completely demolded, it was evaluated as good ( ⁇ ), and if it was stuck in one hole, it was regarded as bad (X).
• Detergent suitability Machinability is marked as good if at least one of the two underwater cutting sections is suitable, and not suitable if both are bad. Scorching, detergency, and detergency were all good and good.
• spherical or cylindrical pellets are prepared by cutting underwater or cutting in section, and have scorch characteristics, cleaning adsorption, cleaning and suitability. In terms of both, it was preferred. ⁇
• the mold cleaning compound of the technique disclosed in the present specification effectively solves the entanglement of pellets during underwater cutting and cross-section cutting according to the use of a room temperature tackifier, and has a scorch property, a cleaning adsorption power, a cleaning property and a cleaning agent. This has the advantage of providing excellent improvement in terms of suitability.
• Example 3 As a further experimental example, the same process as in Example 1 was repeated except that the composition according to Table 3 was applied in Example 1, and the results of underwater cutting and cross-section cutting, pellet shape and physical properties were measured together with Table 3 below. Indicated.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)

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• 2015
  • 2015-07-27 KR KR1020150105676A patent/KR101580818B1/ko active IP Right Grant
• 2016
  • 2016-07-12 JP JP2017555748A patent/JP2018514416A/ja active Pending
  • 2016-07-12 BR BR112017028154A patent/BR112017028154A2/pt not_active Application Discontinuation
  • 2016-07-12 WO PCT/KR2016/007537 patent/WO2017018690A1/ko active Application Filing
  • 2016-07-12 CN CN201680025521.XA patent/CN107580609A/zh active Pending

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