Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J183/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Adhesives based on derivatives of such polymers
  • C09J183/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/01—Manufacture or treatment
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/10—Encapsulations, e.g. protective coatings characterised by their shape or disposition
  • H10W74/111—Encapsulations, e.g. protective coatings characterised by their shape or disposition the semiconductor body being completely enclosed
  • H10W74/127—Encapsulations, e.g. protective coatings characterised by their shape or disposition the semiconductor body being completely enclosed characterised by arrangements for sealing or adhesion
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
  • C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors

Definitions

• the present invention relates to a heat-resistant adhesive film used in the manufacturing process of semiconductor packages.
• QFN Quad Flat Non-leaded package
• the manufacturing method for such QFNs involves arranging a plurality of QFN semiconductor chips on the die pad in the package pattern area of the lead frame, sealing them together with a sealing resin in the cavity of a mold, and then manufacturing individual QFNs. A method has been adopted in which the productivity per lead frame area is improved by cutting the lead frame into structures.
• a common method for manufacturing QFNs is to attach a heat-resistant adhesive film to the back side of the lead frame to prevent resin leakage to the back side of the lead frame during resin sealing.
• a heat-resistant adhesive film attached to a lead frame in a method for manufacturing a QFN package a heat-resistant adhesive film using a silicone adhesive as disclosed in Patent Document 1, for example, has been used.
• a heat-resistant adhesive film is first used by being attached to a lead frame, and then subjected to a semiconductor chip mounting process or a wire bonding process.
• Patent Document 2 describes a heat-resistant adhesive tape for semiconductor package manufacturing processes that is slightly adhesive at room temperature and increases in adhesive strength in a high-temperature atmosphere. This heat-resistant adhesive tape is also first applied to a lead frame in semiconductor package manufacturing, and then subjected to a semiconductor chip mounting process or a wire bonding process.
• a heat-resistant adhesive film When a heat-resistant adhesive film is used by being attached to a lead frame prior to the semiconductor chip mounting process and wire bonding process, such a heat-resistant adhesive film not only prevents leakage of the sealing resin but also , heat resistance that can withstand the high temperatures of the semiconductor chip mounting process or wire bonding process, and the ability to withstand the high temperatures of the wire bonding process, or to ensure that the lead terminals and seals do not interfere with the wire connection during the wire bonding process, or when the adhesive film is peeled off after going through each process in a high temperature environment. Characteristics such as no adhesive residue on the adhesive resin surface are required.
• a heat-resistant adhesive film is installed on the back side of the lead frame after the wire bonding process.
• the method of pasting is adopted.
• This kind of heat-resistant adhesive film has low adhesion when pasting, and has good adhesion and reworkability, and the adhesive strength increases in the high temperature environment of the subsequent sealing process to prevent resin leakage. Characteristics that can be used are required.
• the heat-resistant adhesive tape described in Patent Document 2 has a structure in which its adhesive strength increases in a high-temperature environment, but in order to obtain a sufficiently increased adhesive strength, it is necessary to It is necessary to expose it to the environment. Even if the heat-resistant adhesive tape described in Patent Document 2 is used by being attached to a lead frame after the wire bonding process, the short time of about 5 minutes exposed to the high temperature environment of the sealing process is sufficient. Since the adhesive strength does not increase, in order to prevent resin leakage, it is necessary to separately subject it to a heat treatment process to increase the adhesive strength.
• the present invention is a heat-resistant adhesive film that can be used by being attached to the back side of a lead frame after the wire bonding process in a semiconductor package manufacturing method, and has low adhesive strength at room temperature and can be used in high-temperature environments for a short time.
• the purpose of the present invention is to provide a heat-resistant adhesive film whose adhesive strength can be sufficiently increased just by being exposed to the heat-resistant adhesive film.
• the inventor of the present invention found that by incorporating a phenolic hydroxyl group into the resin constituting the adhesive layer of a heat-resistant adhesive film for manufacturing semiconductor packages, the film has low adhesive strength at room temperature and can be used in high-temperature environments for a short time. It was found that the adhesion strength could be sufficiently increased by simply applying the adhesive. Invention? Based on this knowledge, we completed further studies. That is, the present invention includes the inventions listed below.
• Item 1 comprising a base material and a silicone adhesive layer laminated on the base material, A heat-resistant adhesive film for manufacturing semiconductor packages, wherein the silicone adhesive layer is a cured product of an addition-curable silicone adhesive composition and has a phenolic hydroxyl group.
• Item 2. The heat-resistant adhesive film according to Item 1, wherein the cured product is an addition-cured product of a pressure-sensitive adhesive composition containing an addition-curable silicone pressure-sensitive adhesive composition and an alkenyl group-containing arylol compound.
• the alkenyl group-containing arylol compound is a compound represented by the following formulas (1) to (3): (In formulas (1) to (3), Ar is an aryl group, In formula (1), R 1 is a direct bond or a hydrocarbon chain that may or may not have a double bond between carbon atoms constituting the main chain, In formula (2), R 2 is a hydrocarbon chain that may or may not have double bonds between carbon atoms constituting the main chain. ) Item 2.
• the heat-resistant adhesive film according to Item 2 which is selected from the group consisting of: Item 4.
• Item 4 The heat-resistant adhesive film according to Item 2 or 3, wherein the alkenyl group-containing arylol compound is allylphenol.
• the heat-resistant adhesive film according to any one of Items 2 to 4, wherein the adhesive composition contains 0.20 to 2.85% by mass of the phenolic hydroxyl group possessed by the alkenyl group-containing arylol compound.
• Item 6 The cured product is an addition cured product of an adhesive composition containing a diorganopolysiloxane having an alkenyl group, a crosslinking agent, and an alkenyl group-containing arylol compound, The mole of the SiH group (C) contained in the crosslinking agent relative to the total of the alkenyl group (A) in the diorganopolysiloxane having the alkenyl group and the alkenyl group (B) in the alkenyl group-containing arylol compound.
• the semiconductor package manufacturing includes: A wire bonding step of electrically connecting the semiconductor chip and a terminal portion of the lead frame in a lead frame on which a semiconductor chip is mounted; A pasting step of pasting the heat-resistant adhesive film according to Item 1 on the surface of the lead frame opposite to the surface on which the semiconductor chip is mounted; a sealing step of sealing the semiconductor chip with a sealing resin; Item 7.
• the heat-resistant adhesive film according to Item 7 which does not include a heating step between the adhesion step and the sealing step.
• the heat-resistant adhesive film of the present invention is a heat-resistant adhesive film that can be used by being attached to the back side of a lead frame after the wire bonding process in a semiconductor package manufacturing method, and has low adhesive strength at room temperature.
• FIG. 3 is a process diagram showing an example of a method for manufacturing a semiconductor package using the heat-resistant adhesive film of the present invention.
• the heat-resistant adhesive film of the present invention includes a base material and a silicone adhesive layer laminated on the base material, the silicone adhesive layer being a cured product of an addition-curing silicone adhesive composition, and It is composed of a cured product having a phenolic hydroxyl group and is used for manufacturing semiconductor packages.
• FIG. 1 shows a schematic cross-sectional view of an embodiment of the heat-resistant adhesive film of the present invention.
• the heat-resistant adhesive film (10) shown in FIG. 1 includes a base material (12) and a silicone adhesive layer (11) laminated on the base material (12).
• the base material for the heat-resistant adhesive film of the present invention is not particularly limited, but a synthetic resin film or metal foil that can withstand the high temperature environment of 150 to 200°C during the sealing process can be used. From the viewpoint of ease of handling the adhesive film, it is preferable to use a synthetic resin film as the base material.
• the synthetic resin is not particularly limited, but heat-resistant synthetic resins with a melting point of 250°C or higher are preferable, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Examples include polyimide (PI), polyetherimide (PEI), polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS), and polyetheretherketone (PEEK).
• PET polyethylene terephthalate
• PEN polyethylene naphthalate
• Examples include polyimide (PI), polyetherimide (PEI), polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS), and polyetheretherketone (PEEK).
• PI polyimide
• PEI polysulfone
• PSF polysulfone
• PES polyethersulfone
• PPS polyphenylene sulfide
• PEEK polyetheretherketone
• the thickness of the base material is not particularly limited, but is preferably from the viewpoint of obtaining stiffness of the base material, ease of coating the adhesive layer, and/or ease of handling when applying the adhesive film. Examples include 5 ⁇ m or more, more preferably 10 ⁇ m or more, and still more preferably 20 ⁇ m or more. Further, the upper limit of the thickness of the base material is not particularly limited, but from the viewpoint of ease of peeling during rework, it is preferably 250 ⁇ m or less, more preferably 150 ⁇ m or less, and still more preferably 100 ⁇ m or less.
• the surface of the base material on which the adhesive layer is laminated be subjected to surface treatment in order to increase the adhesion with the adhesive layer.
• surface treatments include corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, and primer treatment.
• the adhesive layer in the heat-resistant adhesive film of the present invention is a cured product of an addition-curable silicone adhesive composition and is composed of a cured product having a phenolic hydroxyl group.
• this cured product in the uncured form that is, an addition-curing silicone adhesive composition containing a phenolic hydroxyl group source
• an addition-curing silicone adhesive composition containing a phenolic hydroxyl group source will be referred to as an "adhesive composition.”
• the addition-curing silicone adhesive composition contains silicone rubber (referring to a long-chain polymer of polydimethylsiloxane having a structure consisting of D units [(CH 3 ) 2 SiO 2/2 ]) as a basic component.
• MQ resin having a structure further consisting of an M unit [R 3 SiO 1/2 : R is a monovalent organic group such as a methyl group or a phenyl group] and a Q unit [SiO 4/2 ]
• MQ resin having a structure further consisting of an M unit [R 3 SiO 1/2 : R is a monovalent organic group such as a methyl group or a phenyl group] and a Q unit [SiO 4/2 ]
• the addition-curing silicone pressure-sensitive adhesive composition contains silicone rubber and MQ resin, it is preferable in that the adhesiveness after curing is superior to the case where it does not contain MQ resin.
• the addition-curing silicone adhesive composition specifically includes a diorganopolysiloxane having two or more alkenyl groups in one molecule as a silicone rubber component, and an organohydrogenpolysiloxane having an SiH group as a crosslinking agent. , a platinum-based catalyst, and more preferably an MQ resin.
• the alkenyl group is preferably a vinyl group.
• the diorganopolysiloxane having two or more alkenyl groups in one molecule for example, (i) a linear diorganopolysiloxane having vinyl groups only at both ends, (ii) both ends and side A linear diorganopolysiloxane having a vinyl group in the chain, (iii) a branched diorganopolysiloxane having a vinyl group only at the end, and (iv) a branched diorganopolysiloxane having a vinyl group at the end and side chain. Can be mentioned.
• the combination of the compounds (i) and (iii) above is preferable as the diorganopolysiloxane having two or more alkenyl groups in one molecule, and in this combination, the compound (i) above is preferable.
• Per 100 parts by mass preferably 20 to 70 parts by mass, more preferably 25 to 60 parts by mass, still more preferably 25 to 57 parts by mass, 30 to 57 parts by mass, 35 to 57 parts by mass, 40 to 57 parts by weight, 45 to 57 parts by weight, or 50 to 57 parts by weight can be used.
• the weight average molecular weight of the diorganopolysiloxane having two or more alkenyl groups in one molecule is preferably 20,000 from the viewpoint of appropriately controlling the crosslink density and suppressing excessive adhesive force to the adherend. or more, more preferably 40,000 or more, still more preferably 60,000 or more, even more preferably 70,000 or more, 75,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, 400,000 or more , 500,000 or more, 600,000 or more, or 650,000 or more, preferably 700,000 from the viewpoint of appropriately controlling the viscosity of the silicone composition and facilitating stirring and coating during production.
• the weight average molecular weight is a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).
• the alkenyl group content of the diorganopolysiloxane having two or more alkenyl groups in one molecule is preferably 0.3 x 10 -5 mol/g or more, more preferably 0.5 x 10 -5 mol/g.
• the alkenyl group content is preferably 3.2 ⁇ 10 ⁇ 5 mol/g or less, more preferably 3 ⁇ 10 ⁇ 5 mol/g.
• the crosslinking agent examples include organohydrogenpolysiloxane.
• the organohydrogenpolysiloxane preferably has at least three SiH groups in one molecule, and the molecular shape can be linear, branched, and/or cyclic.
• the SiH group contained in the organohydrogenpolysiloxane undergoes an addition reaction with the alkenyl group of the diorganopolysiloxane having the alkenyl group to form a cured silicone product (crosslinked structure).
• the weight average molecular weight of the crosslinking agent is preferably 1,500 or more, more preferably 1,800 or more, even more preferably 2,000 or more, even more preferably 2,200 or more, 2,300 or more, 2,350 or more, or 2,450 or more, and the weight average molecular weight is preferably 3,500 or less, more preferably 3,300 or less, still more preferably 3,000 or less, even more preferably 2,800 or less, 2,450 or more. , 600 or less, or 2,450 or less.
• the SiH group content of the crosslinking agent is preferably 0.3 x 10 -2 mol/g or more, more preferably 0.6 x 10 -2 mol/g or more, and even more preferably 0.7 x 10 -2 mol. /g or more, 1.0 x 10 -2 mol/g or more, 1.3 x 10 -2 mol/g, or 1.5 x 10 -2 mol/g, and the SiH group content includes: Preferably 2.2 x 10 -2 mol/g or less, more preferably 2.0 x 10 -2 mol/g or less, even more preferably 1.8 x 10 -2 mol/g, even more preferably 1.7 x10 -2 mol/g or less, 1.3 x 10 -2 mol/g or less, 1.0 x 10 -2 mol/g or less, or 0.8 x 10 -2 mol/g or less.
• the platinum-based catalyst used in the curing reaction of the silicone composition may be a known one, and specifically, chloroplatinic acid such as chloroplatinous acid or dichloroplatinic acid, an alcohol compound or an aldehyde compound of chloroplatinic acid. , chain salts of chloroplatinic acid and various olefins, and the like. Among these platinum-based catalysts, chain salts of chloroplatinic acid and various olefins are preferred, and platinum-alkenylsiloxane complexes are more preferred.
• the addition-curing silicone pressure-sensitive adhesive composition contains M units (R 3 SiO 1/2 : R is a monovalent group such as an alkyl group such as a methyl group, an aryl group such as a phenyl group). It is preferable to contain a conventionally known MQ resin consisting of an organic group (preferably an alkyl group, more preferably a methyl group) and a Q unit (SiO 4/2 ).
• the weight average molecular weight of MQ resin is preferably 5,000 or more, more preferably 6,000 or more, still more preferably 6,500 or more, or 6,800 or more. ,000 or less, more preferably 7,500 or less, still more preferably 7,100 or less.
• the blending amount of MQ resin can be appropriately blended depending on the required adhesive strength.
• the cured product of the silicone adhesive composition constituting the silicone adhesive layer of the present invention also has a phenolic hydroxyl group.
• the phenolic hydroxyl groups in the cured product do not significantly contribute to adhesion to the adherend, the lead frame, at room temperature, but in a high-temperature environment, the phenolic hydroxyl groups immediately align toward the adherend, the lead frame. , which improves adhesion. As a result, it has a low adhesion force to the lead frame at room temperature, but after being attached to the lead frame and in a high temperature environment during resin sealing, the adhesion force to the lead frame can be increased in a short time.
• the cured product of the silicone adhesive composition constituting the silicone adhesive layer of the present invention has a phenolic hydroxyl group, and the cured product of the silicone adhesive composition has a crosslinked structure, so that it has adhesive strength with the lead frame. Even if the adhesive layer increases, the cohesive force of the adhesive layer can suppress the generation of adhesive residue when peeled off.
• the content of phenolic hydroxyl groups in the adhesive composition is preferably 0.20 to 2.85% by mass. From the viewpoint of further increasing the effect of preventing resin leakage by improving the effect of increasing adhesive strength in a high-temperature environment, the content of phenolic hydroxyl groups in the adhesive composition is 0.45 to 2.85% by mass. More preferably, 0.50 to 2.85% by mass, 1 to 2.85% by mass, 1.20 to 2.85% by mass, 1.50 to 2.85% by mass, 1.70 to 2.85% by mass %, 1.90 to 2.85% by weight, 2.20 to 2.85% by weight, or 2.50 to 2.85% by weight are more preferred.
• the content of phenolic hydroxyl groups in the adhesive composition is set to 0.20 to More preferably 2.60% by mass, 0.20 to 2.55% by mass, 0.20 to 2.10% by mass, 0.20 to 1.80% by mass, 0.20 to 1.30% by mass, 0 .20 to 1.00% by mass, or 0.20 to 0.60% by mass are more preferred.
• the content of phenolic hydroxyl groups in the adhesive composition is a value calculated using the following calculation formula 1.
• An alkenyl group-containing arylol compound is a compound having at least one alkenyl group and one or more phenolic hydroxyl group in the molecule.
• alkenyl group-containing arylol compounds include compounds of the following formulas (1) to (3).
• Ar is an aryl group, preferably a phenyl group or a naphthyl group, more preferably a phenyl group.
• R 1 is a direct bond (sigma bond) or a hydrocarbon chain (the number of carbon atoms is , for example, 1 to 14), preferably a direct bond (sigma bond) or a carbon number of 1 to 6 (more preferably 1 to 4, still more preferably 1 to 3, even more preferably 1 to 2). It is an alkylene group.
• R 2 is a hydrocarbon chain that may or may not have a double bond between the carbon atoms constituting the main chain (the number of carbon atoms is, for example, 1 to 14). ), and is preferably an alkylene group having 1 to 8 carbon atoms (more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms).
• alkenyl group-containing arylol compounds include vinylphenols such as 2-vinylphenol, 3-vinylphenol, 4-vinylphenol, and 2-methoxy-4-vinylphenol; 2-allylphenol, 4-allylphenol; , 4-methyl-2-allylphenol, 6-methyl-2-allylphenol, eugenol, and other allylphenols; 2-(1-propenyl)phenol, isoeugenol, and other propenylphenols; 2-(3-butenyl)phenol; Butenylphenols such as 2-(1-ethyl-3-butenyl)phenol; Long chain alkenylphenols such as cardanol; Allyloxyphenols such as 2-(allyloxy)phenol and 4-(allyloxy)phenol; 2-allyl-1 Examples include allylnaphthols such as -naphthol and 3-allyl-1-naphthol, and these can be used alone or in combination of two or more. Among these,
• the molar ratio [(C)/ ⁇ (A)+(B) ⁇ ] of the group (C) is preferably 0.5 to 3.0. From the viewpoint of improving the cohesive force due to the crosslinking density of the cured silicone product and increasing the adhesive residue suppression effect, the molar ratio is more preferably 0.8 to 3.0, still more preferably 1.0 to 3.0, 1.1 to 3.0, or 1.2 to 3.0.
• the molar ratio is more preferably 0. .5 to 2.0, more preferably 0.5 to 1.5, even more preferably 0.5 to 1.28, 0.5 to 1.26, 0.5 to 1.24, 0.5 to 1 .22, or 0.5 to 1.20.
• additives may or may not be added as appropriate to the pressure-sensitive adhesive composition for the purpose of improving properties.
• additives include organic/inorganic particles, colorants, silicone oil, silicone resin, silane coupling agents, antioxidants, and the like.
• the cured silicone product having a phenolic hydroxyl group is an adhesive containing the above-mentioned adhesive composition (a silicone composition component of an addition-curing silicone adhesive, an alkenyl group-containing arylol compound serving as a source of a phenolic hydroxyl group, and a crosslinking agent). agent composition) by addition reaction.
• the SiH group contained in the crosslinking agent undergoes an addition reaction with the alkenyl group in the alkenyl group-containing diorganopolysiloxane, and at the same time also undergoes an addition reaction with the alkenyl group in the alkenyl group-containing arylol compound.
• a cured silicone product having the following properties is obtained.
• the reaction conditions for obtaining the cured product include, for example, 160 to 200°C, preferably 170 to 190°C, more preferably 175 to 185°C, for example, 0.5 to 5 minutes, preferably 1 to 3 minutes. It will be done.
• the adhesive force of the adhesive layer of the heat-resistant adhesive film of the present invention is low when attached to a lead frame at room temperature, and takes a short time (for example, 2 .5 minutes to 5.5 minutes, preferably 4.5 to 5.5 minutes), the adhesive strength increases to a level that prevents resin leakage.Furthermore, as a post-mold cure after sealing, the adhesive strength increases for several hours (for example, It is preferable that the adhesive strength does not increase significantly even when subjected to high temperature treatment for 1.2 to 3.5 hours, preferably 1.2 to 2.5 hours, and that the adhesive can be easily peeled off.
• the adhesive strength of the adhesive layer of the heat-resistant adhesive film of the present invention at room temperature makes it possible to attach it to a lead frame without applying pressure due to the self-adhesive strength of the silicone adhesive layer with good wettability. Since it is easy and has excellent reworkability, the heat-resistant adhesive film is attached to copper foil and the heat-resistant adhesive film is peeled off at a peeling angle of 180° and a peeling speed of 300 mm/min.
• the peeling force is preferably in the range of 50 to 500 mN/25 mm, more preferably in the range of 90 to 350 mN/25 mm.
• the adhesive strength of the adhesive layer of the heat-resistant adhesive film of the present invention during short-term heating is determined by pasting the heat-resistant adhesive film on copper foil, from the viewpoint of improving the resin leakage suppressing property in the sealing process.
• the peeling force against the copper foil is preferably 900 mN when the heat-resistant adhesive film is heated at 175°C for 3 minutes and peeled off at a peeling angle of 90° and a peeling speed of 300 mm/min after 3 minutes at 175°C. /25 mm or more, more preferably 1000 mN/25 mm or more.
• the peel angle at this time is measured at a peel angle of 90°, assuming that the resin pressure (peel force) applied to the heat-resistant adhesive film during sealing is perpendicular to the adhesion surface. Further, 3 minutes at 175° C. is a typical process temperature in a transfer mold for semiconductor encapsulation, and a typical time from when the lead frame is mounted on the mold to when resin encapsulation is started.
• the adhesive strength after heating and pressing of the adhesive layer of the heat-resistant adhesive film of the present invention is determined by the ease of peeling the heat-resistant adhesive film after resin sealing and/or the ability to suppress adhesive residue of the adhesive layer.
• a heat-resistant adhesive film was pasted on copper foil, heat-treated at 175°C for 5 minutes, then a pressure of 670 kgf/m 2 was applied to the heat-resistant adhesive film, heat-treated at 175°C for 90 minutes, and then heated at room temperature.
• the peeling force against the copper foil when the heat-resistant adhesive film is peeled off at a peeling angle of 180° and a peeling speed of 300 mm/min is preferably 3500 mN/25 mm or less, more preferably 2600 mN/25 mm or less. .
• the pressurization and heat treatment conditions at this time are typical treatment conditions for post-mold curing after sealing.
• the various adhesive strengths of the adhesive layer of the heat-resistant adhesive film of the present invention are determined by at least one of the following conditions: the molecular weight and crosslinking density of silicone rubber in the adhesive composition used for the adhesive layer, and the ratio of MQ resin. You can control it by changing it.
• the thickness of the silicone adhesive layer of the present invention is not particularly limited, but may be, for example, 2 to 50 ⁇ m.
• the lower limit of the film thickness range (2 to 50 ⁇ m) is preferably 5 ⁇ m or more, from the viewpoint of improving adhesion to the surface of the lead frame by improving the ability to follow irregularities on the surface of the lead frame, which is the adherend. More preferably, it may be 10 ⁇ m or more, 15 ⁇ m or more, 20 ⁇ m or more, or 25 ⁇ m or more, and the upper limit of the film thickness range (2 to 50 ⁇ m) is determined by the clamping pressure to fix the lead frame during resin sealing, etc.
• the thickness is preferably 40 ⁇ m or less, more preferably 35 ⁇ m or less, still more preferably 32 ⁇ m or less, 15 ⁇ m or less, 10 ⁇ m or less, or 7 ⁇ m or less.
• the adhesive composition is uniformly spread on the substrate to a predetermined thickness, either as is or in the form of a coating liquid whose viscosity has been adjusted with a solvent, etc.
• a silicone adhesive layer can be formed by coating, drying the solvent, and further heating to cure the adhesive composition.
• Examples of the coating method for the adhesive composition include a gravure coater, a bar coater, a comma knife coater, and a die coater.
• a separator made of a plastic film is attached to a silicone adhesive layer in order to prevent dirt and foreign matter from adhering to the surface of the silicone adhesive layer before the adhesive film is attached to a lead frame, and to improve the handling of the adhesive film. It is suitable to use it by bonding it to the surface of the agent layer.
• the separator is made of a plastic film with high releasability, and if desired, a plastic film with a release agent formed on its surface can be used as appropriate.
• the heat-resistant adhesive film of the present invention is used by adhering to protect terminal portions when resin-sealing semiconductor components.
• the method for manufacturing a semiconductor package using the heat-resistant adhesive film of the present invention includes the following steps. A wire bonding step for electrically connecting the semiconductor chip and a terminal portion of the lead frame in a lead frame on which a semiconductor chip is mounted; an adhering step of adhering the heat-resistant adhesive film of the present invention to the surface of the lead frame opposite to the surface on which the semiconductor chip is mounted; a sealing step of sealing the semiconductor chip with a sealing resin; and a peeling step of peeling the heat-resistant adhesive film from the lead frame to obtain a semiconductor package.
• the heat-resistant adhesive film of the present invention can increase the adhesiveness to such an extent that resin leakage can be suppressed in a short time during the sealing process.
• no separate heating step is included in between.
• the heat-resistant adhesive film of the present invention has the excellent property of being able to increase adhesiveness in a short time as described above, and also has excellent releasability.
• the method for manufacturing a semiconductor package can include a post-mold curing step using heat and pressure between the sealing step and the peeling step.
• Temperature conditions in the post-mold curing step include, for example, 170 to 180° C.
• heating time includes, for example, 1.2 to 3.5 hours, preferably 1.2 to 2.5 hours.
• Pressure conditions in the post-mold curing step include, for example, 600 to 750 kgf/m 2 , preferably 630 to 720 kgf/m 2 , and more preferably 650 to 700 kgf/m 2 .
• FIG. 2 is a process diagram of an example of a method for manufacturing a semiconductor package using the heat-resistant adhesive film of the present invention.
• the method for manufacturing a semiconductor package includes a step (b) of mounting the semiconductor chip 30 on the lead frame 20, and a wire bonding step (c) electrically connecting the semiconductor chip 30 and the terminal portion 22 of the lead frame 20. ), an adhesion step (d) of adhering the heat-resistant adhesive film 10 to the lead frame 20, a sealing step (e) of sealing the semiconductor chip 30 with the sealing resin 50, and a step (e) of adhering the heat-resistant adhesive film 10 to the lead frame 20;
• the method includes at least a peeling step (f) of peeling off the adhesive film to obtain the QFN unit 60, and a dicing step (g) of dividing the QFN unit 60 to obtain individual QFN packages 70.
• a lead frame 20 having at least a semiconductor chip mounting part 21, a terminal part 22, and an opening part 23 is prepared.
• the lead frame 20 is made of a metal such as copper and has a plurality of QFN terminal patterns engraved thereon, and its electrical contact portions are coated with a material such as silver, nickel, palladium, or gold. (plated) in some cases.
• the thickness of the lead frame 20 is generally 100 to 300 ⁇ m.
• the lead frame 20 has a pattern in which the individual QFNs are regularly arranged in a lattice pattern so that the lead frame 20 can be easily cut into pieces in a dicing process.
• the semiconductor chip mounting step is a step of fixing the semiconductor chip 30 to the semiconductor chip mounting portion 21 of the lead frame 20, as shown in FIG. 2(b).
• a die attach material such as a conductive paste, a thermosetting adhesive, or an adhesive tape is used.
• a conductive paste or a thermosetting adhesive it is generally heated and cured at a temperature of about 150 to 200° C., and the semiconductor chip 30 is fixed and mounted on the semiconductor chip mounting section 21.
• a wire bonding process is performed in which the semiconductor chip 30 and the terminal portion 23 of the lead frame 20 are electrically connected using bonding wires 40.
• bonding wire 40 for example, a gold wire or an aluminum wire is used.
• wires are connected using a combination of vibration energy from ultrasonic waves and compression energy from applied pressure while being heated to 120 to 250°C.
• a suitable method for attaching the heat-resistant adhesive film to the lead frame 20 is a lamination method or the like.
• sealing is performed by transfer molding using a sealing resin 50.
• a sealing resin 50 a conventionally known resin is used, such as a mixture of an epoxy resin and an inorganic filler.
• the heating temperature during resin sealing may be, for example, 170 to 180°C, and the heating time may be several minutes (for example, 2.5 to 5.5 minutes, preferably 4.5 to 5.5 minutes). .
• heat treatment post-mold curing process
• Temperature conditions in the post-mold curing step include, for example, 170 to 180°C, and heating time includes, for example, 1.2 to 3.5 hours, preferably 1.2 to 2.5 hours.
• the heat-resistant adhesive film 10 stuck to the lead frame 20 is peeled off to obtain a QFN unit 60 in which a plurality of QFN packages are arranged.
• the dicing process is a process of cutting the QFN unit 60 into individual QFN packages 70 by dicing it along the outer periphery of each QFN package 50, as shown in FIG. 2(g).
• the heat-resistant pressure-sensitive adhesive film of the present invention will be explained in detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
• Adhesive films of Examples 1 to 12 and Comparative Examples 1 to 3 were prepared by coating with an applicator to the thickness shown in Table 2, and then heating and curing in a gear oven at 180 ° C. for 2 minutes. .
• step (e) in Figure 2 (equivalent to the conditions for the post-mold curing process between the process (f)). After that, it was taken out from the gear oven and left in an environment of 23°C and 50%RH for 5 minutes, and then tested using a tensile tester in accordance with JIS Z0237:2009 in an environment of 23°C and 50%RH. The peeling force when the adhesive film of the copper foil attached sample 1 was peeled off from the rolled copper foil at a peeling angle of 180° and a peeling speed of 300 mm/min was measured, and this measured value was calculated as the adhesive force after heat treatment (mN/25 mm). ). Table 2 shows the measurement results of Examples 1 to 12 and Comparative Examples 1 to 3.
• ⁇ Preparation of lead frame> As a lead frame, one with the following specifications [32QFN (CD194, plated; PD2L+Au) 32LQFNPADSIZE3.0SQMM, manufactured by Shinko Electric Industries Co., Ltd.] was used, in which a nickel plated layer, a palladium plated layer, and a gold plated layer were provided in this order on a copper plate. . (Lead frame specifications) [Dimensions] 55mm x 58mm, [Arrangement] Matrix array of 8 QFN patterns x 8 (total 64), [Package size] 5mm x 5mm, [Number of pins] 32
• the pressure and heat treatment time was set to two levels: 90 minutes or 180 minutes (corresponding to the conditions of the post mold curing step between steps (e) and (f) in FIG. 2).
• the copper foil pasted sample 1 was taken out of the gear oven and left in an environment of 23°C and 50% RH for 5 minutes.
• a peeling angle of 180° and a peeling speed of 500 mm/min the adhesive film of the copper foil pasted sample 1 was peeled from the rolled copper foil, and the surface of the rolled copper foil from which the adhesive film was peeled was visually confirmed, and the following criteria were met. It was evaluated by Table 2 shows the evaluation results of Examples 1 to 12 and Comparative Examples 1 to 3.
• Heat-resistant adhesive film 11 Adhesive layer 12: Base material 20: Lead frame 21: Semiconductor chip mounting part 22: Terminal part 23: Opening part 30: Semiconductor chip 40: Bonding wire 50: Sealing resin 60: QFN unit 70:QFN package

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• 2023
  • 2023-04-10 KR KR1020247023055A patent/KR20250005962A/ko active Pending
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