Temporary protection film for semiconductor encapsulation molding, lead frame with temporary protection film, encapsulation molded body, and method for manufacturing semiconductor package

Abstract

A temporary protective film for semiconductor encapsulation molding comprises a support film and an adhesive layer, and is used to temporarily protect the surface of a lead frame on the opposite side from a semiconductor element during sealing molding to form a sealing layer that seals the semiconductor element mounted on a die pad of the lead frame. The adhesive layer contains a thermoplastic resin, and at least one specific compound selected from the group consisting of sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, C10-20 aliphatic alcohol glycidyl ethers, glycerol polyglycidyl ether, C2-30 fatty acid polyalkylene glycol esters, C2-20 fatty acid dipentaerythritol esters, polyethylene glycol monoalkyl ether, and polyethylene glycol dialkyl ether.

Description

Technical Field

[0001] The present disclosure relates to a temporary protection film for semiconductor encapsulation molding, a lead frame with a temporary protection film, an encapsulated molded body, and a method for manufacturing a semiconductor package.

Background Art

[0002] In a semiconductor package, a structure may be adopted in which a sealing layer is formed only on the semiconductor element side of the lead frame and the back surface of the lead frame is exposed (Patent Documents 1 and 2). In manufacturing a semiconductor package having this structure, in order to prevent the sealing resin from flowing around the back surface of the lead frame during encapsulation molding, the back surface of the lead frame may be temporarily protected by attaching a temporary protection film. The temporary protection film is peeled off from the lead frame after the sealing layer is formed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An assembly process for manufacturing a semiconductor package may require heating at a high temperature reaching about 400° C. for reflow connection or the like. However, when the temporary protection film attached to the lead frame undergoes such a high-temperature heat history, if the temporary protection film adheres strongly to the lead frame and the sealing layer and cannot be peeled off from the lead frame, or it is difficult to peel off cleanly from the lead frame without leaving residues.

[0005] The present disclosure relates to a temporary protection film for semiconductor encapsulation molding that can be attached to a lead frame with an appropriate adhesive force and can be easily peeled off after receiving a thermal history at a high temperature of about 400°C.

Means for Solving the Problems

[0006] One aspect of the present disclosure provides a temporary protection film including a support film and an adhesive layer provided on one or both sides of the support film. This temporary protection film is used to temporarily protect the surface of the lead frame opposite to the semiconductor element during encapsulation molding for forming an encapsulation layer that encapsulates the semiconductor element mounted on the die pad of the lead frame. In other words, one aspect of the present disclosure provides an application of the temporary protection film for temporarily protecting the surface of the lead frame opposite to the semiconductor element during encapsulation molding for forming an encapsulation layer that encapsulates the semiconductor element mounted on the die pad of the lead frame. The adhesive layer includes a thermoplastic resin and at least one specific compound selected from the group consisting of sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, glycidyl ether of an alkyl alcohol having 10 to 20 carbon atoms, glycerol polyglycidyl ether, polyalkylene glycol ester of a fatty acid having 6 to 24 carbon atoms, dipentaerythritol ester of a fatty acid having 4 to 12 carbon atoms, polyalkylene glycol monoalkyl ether, and polyalkylene glycol dialkyl ether.

[0007] Another aspect of the present disclosure provides a lead frame with a temporary protection film, including a lead frame having a die pad and the above-mentioned temporary protection film for semiconductor encapsulation molding. The temporary protection film is attached to one surface of the lead frame with the adhesive layer of the temporary protection film in contact with the lead frame.

[0008] Yet another aspect of the present disclosure provides a temporarily protected encapsulated molded body including a lead frame having a die pad, a semiconductor element mounted on the die pad on one surface side of the lead frame, an encapsulation layer encapsulating the semiconductor element, and the temporary protection film for semiconductor encapsulation molding. The temporary protection film is attached to the surface of the lead frame opposite to the semiconductor element with the adhesive layer of the temporary protection film in contact with the lead frame.

[0009] Yet another aspect of the present disclosure relates to a method for manufacturing a semiconductor package, which includes the steps of attaching, to one surface of a lead frame having a die pad, the temporary protection film for semiconductor encapsulation molding according to claim 1 or 2 with the adhesive layer thereof in contact with the lead frame; mounting a semiconductor element on the surface of the die pad opposite to the temporary protection film; forming an encapsulation layer for encapsulating the semiconductor element to obtain a temporarily protected encapsulated molded body having the lead frame, the semiconductor element, and the encapsulation layer; and peeling the temporary protection film from the encapsulated molded body, in this order.

Advantages of the Invention

[0010] According to one aspect of the present disclosure, there is provided a temporary protection film for semiconductor encapsulation molding that can be attached to a lead frame with an appropriate adhesive force and can be easily peeled off after receiving a thermal history at a high temperature of about 400°C.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0012] The present invention is not limited to several embodiments exemplified below. The upper limit value and the lower limit value of the numerical range described in this specification can be arbitrarily combined. The numerical values described in the examples can also be used as the upper limit value or the lower limit value of the numerical range.

[0013] Temporary protection film FIG. 1 is a cross-sectional view showing a temporary protection film according to an embodiment. The temporary protection film 10 shown in FIG. 1 is composed of a support film 1 and an adhesive layer 2 provided on one surface of the support film 1. Adhesive layers may be formed on both surfaces of the support film 1. FIG. 2 is also a cross-sectional view showing a temporary protection film according to an embodiment. The temporary protection film 10' in FIG. 2 has a support film 1, an adhesive layer 2 provided on one main surface of the support film 1, and a non-adhesive layer 3 provided on the other main surface of the support film 1. These temporary protection films can be used as a temporary protection film for semiconductor encapsulation molding for temporarily protecting a lead frame during encapsulation molding by being attached to the back surface of the lead frame (the surface opposite to the surface on which the semiconductor element is mounted) in the step of forming an encapsulation layer for encapsulating a semiconductor element mounted on a die pad of the lead frame.

[0014] The adhesive layer 2 contains a thermoplastic resin and a specific compound selected from epoxy compounds and the like.

[0015] The thermoplastic resin may contain at least one selected from the group consisting of aromatic polyether amideimide, aromatic polyetherimide, aromatic polyether amide, aromatic polyamide, aromatic polyester, aromatic polyimide, aromatic polyamideimide, aromatic polyether, and aromatic polyesterimide. From the viewpoints of heat resistance and adhesiveness, the thermoplastic resin may be at least one selected from the group consisting of aromatic polyether amideimide, aromatic polyetherimide, and aromatic polyether amide, and may be aromatic polyether amideimide.

[0016] The aromatic polyether amideimide is a polycondensate formed from an acid component containing an aromatic tricarboxylic acid or a reactive derivative thereof and an amine component containing an aromatic diamine, and can be a polycondensate containing a compound in which at least one of the aromatic tricarboxylic acid or the aromatic diamine has a plurality of aromatic groups and an oxy group bonding the aromatic groups to each other. The aromatic polyetherimide is a polycondensate formed from an acid component containing an aromatic tetracarboxylic acid or a reactive derivative thereof and an amine component containing an aromatic diamine, and can be a polycondensate containing a compound in which at least one of the aromatic tetracarboxylic acid or the aromatic diamine has a plurality of aromatic groups and an oxy bonding the aromatic groups to each other. The aromatic polyether amide is a polycondensate formed from an acid component containing an aromatic dicarboxylic acid or a reactive derivative thereof and an amine component containing an aromatic diamine, and can be a polycondensate containing a compound in which at least one of the aromatic dicarboxylic acid or the aromatic diamine has a plurality of aromatic groups and an oxy bonding the aromatic groups to each other. The reactive derivative of the carboxylic acid may be, for example, an acid anhydride or an acid chloride.

[0017] Aromatic polyether amide imide and aromatic polyamide imide may contain structural units derived from trimellitic acid or its reactive derivatives. Aromatic polyimide and aromatic polyether imide may contain structural units derived from pyromellitic acid, polynuclear aromatic tetracarboxylic acid, or reactive derivatives thereof. Examples of polynuclear aromatic tetracarboxylic acids include bisphenol A bistrimellitate and oxydiphthalic acid. Aromatic polyamide may contain structural units derived from terephthalic acid, isophthalic acid, or reactive derivatives thereof.

[0018] Aromatic polyether amide imide, aromatic polyether imide, and aromatic polyether amide may contain, for example, structural units derived from aromatic diamines having an oxy group selected from 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4'-diaminodiphenyl ether, bis[4-(4-aminophenoxy)phenyl]ether, and 2,2-bis[4-(4-aminophenoxy)]hexafluoropropane. Aromatic polyether amide imide, aromatic polyether imide, and aromatic polyether amide may further contain structural units derived from other diamines selected from aromatic diamines having no oxy group (e.g., 4,4'-methylenebis(2-isopropylaniline)), siloxane diamines (e.g., 1,3-bis(3-aminopropyl)tetramethyldisiloxane), and α,ω-diaminoalkanes (e.g., 1,12-diaminododecane, 1,6-diaminohexane).

[0019] In aromatic polyetherimides, aromatic polyetheramideimides and aromatic polyetheramides, the proportion of the structural units derived from aromatic diamines having an oxy group may be 40 to 100 mol%, or 50 to 97 mol%, based on the total amount of the structural units derived from the diamine component. In aromatic polyetherimides, aromatic polyetheramideimides and aromatic polyetheramides, based on the total amount of the structural units derived from the diamine component, the proportion of the structural units derived from aromatic diamines having an oxy group is 60 to 89 mol%, or 68 to 82 mol%, the proportion of the structural units derived from siloxane diamine is 1 to 10 mol%, or 3 to 7 mol%, and the proportion of the structural units derived from α,ω-diaminoalkane is 10 to 30 mol%, or 15 to 25 mol%. In aromatic polyetherimides, aromatic polyetheramideimides and aromatic polyetheramides, based on the total amount of the structural units derived from the diamine component, the proportion of the structural units derived from aromatic diamines having an oxy group is 90 to 99 mol%, or 93 to 97 mol%, and the proportion of the structural units derived from siloxane diamine is 1 to 10 mol%, or 3 to 7 mol%. In aromatic polyetherimides, aromatic polyetheramideimides and aromatic polyetheramides, based on the total amount of the structural units derived from the diamine component, the proportion of the structural units derived from aromatic diamines having an oxy group is 40 to 70 mol%, or 45 to 60 mol%, and the proportion of the structural units derived from aromatic diamines having no oxy group is 30 to 60 mol%, or 40 to 55 mol%.

[0020] The specific compound may be an epoxy compound (epoxy resin) having one or more epoxy groups (or glycidyl ether groups). The number of epoxy groups in the epoxy compound may be 5 or less. The adhesive layer 2 may contain at least one epoxy compound selected from the group consisting of sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, glycidyl ethers of aliphatic alcohols having 10 to 20 carbon atoms, and glycerol polyglycidyl ether. From the viewpoint of peelability from the lead frame after receiving a heat history at 400°C, the epoxy compound may be sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, or a combination thereof. The adhesive layer 2 may further contain epoxy compounds other than these.

[0021] Sorbitol polyglycidyl ether is a compound having a residue of sorbitol and two or more glycidyl ether groups bonded thereto, and may be a mixture of two or more components having different numbers of glycidyl ether groups. The epoxy equivalent of sorbitol polyglycidyl ether may be, for example, 150 to 200 g / eq.

[0022] The epoxy equivalent of polyethylene glycol diglycidyl ether may be, for example, 200 to 400 g / eq., or 250 to 350 g / eq.

[0023] Glycidyl ethers of aliphatic alcohols having 10 to 20 carbon atoms are compounds having an aliphatic group having 10 to 20 carbon atoms (for example, a linear alkyl group) and a glycidyl ether group bonded thereto. The glycidyl ether of the aliphatic alcohol may be a mixture of two or more components having different numbers of carbon atoms in the aliphatic group. The epoxy equivalent of the glycidyl ether of the aliphatic alcohol may be, for example, 200 to 400 g / eq.

[0024] Glycerol polyglycidyl ether is a compound having a residue of glycerol and two or more glycidyl ether groups bonded thereto, and may be a mixture of two or more components having different numbers of glycidyl ether groups. The epoxy equivalent of the glycerol polyglycidyl ether may be, for example, 120 to 160 g / eq.

[0025] The specific compound may be a polyalkylene glycol ester of a fatty acid having 2 to 30 carbon atoms, a dipentaerythritol ester of a fatty acid having 2 to 20 carbon atoms, a polyethylene glycol monoalkyl ether, a polyethylene glycol dialkyl ether, or a combination thereof.

[0026] The polyalkylene glycol ester of a fatty acid having 2 to 30 carbon atoms is an ester compound formed from one or two fatty acids having 2 to 30 carbon atoms (e.g., aliphatic saturated monobasic acids) and one molecule of polyalkylene glycol. The number of carbon atoms of the fatty acid may be 4 to 24, or 6 to 20.

[0027] The dipentaerythritol ester of a fatty acid having 2 to 20 carbon atoms is an ester compound formed from one to six fatty acids having 2 to 20 carbon atoms (e.g., aliphatic saturated monobasic acids) and one molecule of dipentaerythritol. The number of carbon atoms of the fatty acid may be 4 to 16, or 6 to 12. Examples of the dipentaerythritol ester of a fatty acid having 2 to 20 carbon atoms include dipentaerythritol aliphatic saturated monobasic acid (having 4 to 12 carbon atoms) hexaester.

[0028] Polyethylene glycol monoalkyl ether and polyethylene glycol dialkyl ether are ether compounds formed from one molecule of polyethylene glycol and one or two molecules of alkyl alcohol. The number of carbon atoms of the alkyl alcohol may be 2 to 30, 4 to 24, 6 to 20, or 8 to 16. The alkyl alcohol may be a secondary alcohol. Examples of polyethylene glycol monoalkyl ether and polyethylene glycol dialkyl ether include polyoxyethylene(9) secondary alkyl (11 to 15 carbon atoms) ether.

[0029] From the perspective of peelability from the lead frame after receiving a heat history at 400 °C, the content of the specific compound may be 5 to 30 parts by mass, 5 to 25 parts by mass, 5 to 20 parts by mass, 5 to 15 parts by mass, or 7 to 15 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin. From the same perspective, the content of sorbitol polyglycidyl ether may be 5 to 20 parts by mass, or 5 to 12 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin, and the content of polyethylene glycol diglycidyl ether may be 5 to 20 parts by mass, or 7 to 15 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin.

[0030] The adhesive layer may further contain one or more coupling agents. The coupling agent may be a silane coupling agent. The silane coupling agent may be a compound represented by the following formula (I):

Chemical formula

[0031] R 1 , R 2 or R 3Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group. R 1 、R 2 or R 3 Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, and a hexyl group. R 1 、R 2 or R 3 Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group.

[0032] The reactive functional group that X has may be, for example, an amino group, an isocyanate group, an amide group, or an epoxy group. X may be the following formula (IIa), (IIb), (IIc), (IId), or (IIe):

Chemical formula

[0033] Examples of the silane coupling agent in which X is a group represented by the formula (IIa) include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-phenylaminopropyltriethoxysilane, 3-phenylaminopropylmethyldimethoxysilane, 3-phenylaminopropylmethyldiethoxysilane, 3-methylaminopropyltrimethoxysilane, 3-methylaminopropyltriethoxysilane, 3-ethylaminopropyltrimethoxysilane, and 3-ethylaminopropyltriethoxysilane.

[0034] Examples of the silane coupling agent in which X is a group represented by the formula (IIb) include 3-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-(2-phenylaminoethyl)-3-aminopropyltrimethoxysilane, 3-(2-phenylaminoethyl)-3-aminopropyltriethoxysilane, 3-(2-phenylaminoethyl)-3-aminopropylmethyldimethoxysilane, 3-(2-methylaminoethyl)-3-aminopropyltrimethoxysilane, 3-(2-methylaminoethyl)-3-aminopropyltriethoxysilane, 3-(2-ethylaminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-ethylaminoethyl)-3-aminopropyltriethoxysilane.

[0035] Examples of the silane coupling agent in which X is a group represented by the formula (IIc) include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-isocyanatopropylmethyldiethoxysilane.

[0036] Examples of the silane coupling agent in which X is a group represented by the formula (IId) include 3-ureidopropyltrimethoxysilane, 3-ureidopropylmethyldimethoxysilane, 3-ureidopropyltriethoxysilane, 3-ureidopropylmethyldiethoxysilane, 3-(3-phenylureido)propyltriethoxysilane, 3-(3-methylureido)propyltriethoxysilane, 3-(3-ethylureido)propyltriethoxysilane, 3-(3-propylureido)propyltriethoxysilane, 3-(3-butylureido)propyltriethoxysilane, 3-(3-hexylureido)propyltriethoxysilane, 3-(3-phenylureido)propyltrimethoxysilane, 3-(3-methylureido)propyltrimethoxysilane, 3-(3-ethylureido)propyltrimethoxysilane, 3-(3-propylureido)propyltrimethoxysilane, 3-(3-butylureido)propyltrimethoxysilane, and 3-(3-hexylureido)propyltrimethoxysilane.

[0037] Examples of the silane coupling agent in which X is a group represented by the formula (IIe) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane.

[0038] The content of the coupling agent may be 1 to 40 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin. When the content of the silane coupling agent is 1% by mass or more, the peelability from the lead frame after heat treatment tends to be more improved. When the content of the coupling agent is 40% by mass or less, gelation, viscosity reduction, etc. of the varnish for forming the adhesive layer 2 are less likely to occur, and the temporary protective film can be manufactured more easily. From the same viewpoint, the content of the coupling agent may be 1 to 35 parts by mass, 2 to 35 parts by mass, 3 to 30 parts by mass, more than 5 parts by mass and 35 parts by mass or less, more than 5 parts by mass and 30% by mass or less, or more than 5 parts by mass and 20 parts by mass or less with respect to 100 parts by mass of the content of the thermoplastic resin.

[0039] The adhesive layer 2 may further contain a filler. Examples of the filler include ceramic powder, glass powder, silver powder, copper powder, resin particles, and rubber particles. The content of the filler may be 0 to 30 parts by mass, 1 to 30 parts by mass, or 5 to 15 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin.

[0040] In the adhesive layer 2, the total content of the thermoplastic resin, the specific compound (such as an epoxy compound), and the coupling agent, or the total content of the thermoplastic resin, the specific compound (such as an epoxy compound), the coupling agent, and the filler may be 90 to 100% by mass based on the mass of the adhesive layer 2.

[0041] From the viewpoint of further suppressing the curl of the temporary protection film, the thickness of the adhesive layer 2 may be 20 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, 10 μm or less, 9 μm or less, or 8 μm or less. The thickness of the adhesive layer 2 may be 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, or 8 μm or more.

[0042] The support film 1 may be, for example, a film of at least one polymer selected from the group consisting of aromatic polyimide, aromatic polyamide, aromatic polyamideimide, aromatic polysulfone, aromatic polyethersulfone, polyphenylene sulfide, aromatic polyether ketone, polyarylate, aromatic polyether ether ketone, and polyethylene naphthalate. The support film 1 may be a film of copper, aluminum, stainless steel, or nickel in a film form. When the support film 1 is a polymer film, its surface may be surface-treated by methods such as alkali treatment, chemical treatment such as silane coupling treatment, physical treatment such as sand mat treatment, plasma treatment, and corona treatment.

[0043] The thickness of the support film 1 may be, for example, 5 to 100 μm, or 5 to 50 μm or less. The ratio T2 / T1 of the thickness T2 of the adhesive layer to the thickness T1 of the support film may be 0.5 or less, 0.3 or less, or 0.2 or less.

[0044] The non-adhesive layer 3 is a resin layer that substantially has no adhesiveness (or pressure-sensitive adhesiveness) to the lead frame at 0 to 270°C. The non-adhesive layer may be a resin layer that is difficult to soften at high temperatures. For example, a resin layer having a high glass transition temperature can function as the non-adhesive layer.

[0045] The resin layer as the non-adhesive layer 3 includes a resin that is a thermoplastic resin, a thermosetting resin (cured product), or a combination thereof. The thermoplastic resin may have an amide group, an ester group, an imide group, an oxy group, or a sulfonyl group. The thermosetting resin may be, for example, an epoxy resin, a phenol resin, or a bismaleimide resin. When combining a thermoplastic resin and a thermosetting resin, the amount of the thermosetting resin may be 5 to 100 parts by mass, or 20 to 70 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin.

[0046] The non-adhesive layer 3 may contain a filler (for example, ceramic powder, glass powder, silver powder, copper powder, resin particles, rubber particles), a coupling agent, etc. The content of the filler in the non-adhesive layer 3 may be 1 to 30 parts by mass, or 5 to 15 parts by mass with respect to 100 parts by mass of the content of the resin. The content of the coupling agent may be 1 to 20 parts by mass, or 2 to 15 parts by mass with respect to 100 parts by mass of the content of the resin.

[0047] The 90-degree peel strength of the non-adhesive layer 3 against a copper mold may be less than 5 N / m, or 1 N / m or less at 25°C. This peel strength is measured after pressing the non-adhesive layer 3 against a copper mold at a temperature of 250°C and a pressure of 8 MPa for 10 seconds.

[0048] The thickness of the non-adhesive layer 3 may be, for example, 10 μm or less, 9 μm or less, 8 μm or less, or 7 μm or less. The thickness of the non-adhesive layer may be, for example, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, or 6 μm or more. The thickness of the non-adhesive layer is not particularly limited, but may be, for example, 1 to 10 μm, or 1 to 8 μm.

[0049] The temporary protection film can be manufactured by a method including a step of applying a varnish containing, for example, a thermoplastic resin, a specific compound (such as an epoxy compound) and a solvent to a support film and removing the solvent from the coating film to form an adhesive layer. The non-adhesive layer can also be formed in the same manner.

[0050] Method for manufacturing a semiconductor package Using the temporary protection film according to the embodiments exemplified above, a semiconductor package can be manufactured. The manufactured semiconductor package may be, for example, a Non Lead Type Package having a lead frame and a semiconductor element mounted thereon, and a sealing layer for sealing the semiconductor element on the semiconductor element side of the lead frame, with the back surface of the lead frame exposed for external connection. Specific examples thereof include QFN (Quad Flat Non-leaded Package) and SON (Small Outline Non-leaded Package).

[0051] FIGS. 3 and 4 are cross-sectional views showing an embodiment of a method for manufacturing a semiconductor package. FIG. 5 is a cross-sectional view showing an embodiment of a semiconductor package obtained by the manufacturing method of FIGS. 3 and 4. Hereinafter, each step will be described with reference to the respective drawings as necessary.

[0052] The method shown in FIGS. 3 and 4 includes a step of attaching the temporary protection film 10 to the back surface, which is one surface of the lead frame 11 having the die pad 11a and the inner lead 11b, in such a direction that its adhesive layer is in contact with the lead frame 11; a step of mounting the semiconductor element 14 on the surface of the die pad 11a opposite to the temporary protection film 10; a step of providing a wire 12 for connecting the semiconductor element 14 and the inner lead 11b; a step of forming a sealing layer 13 for sealing the semiconductor element 14 and the wire 12 to obtain a temporarily protected sealed molded body 20 having the lead frame 11, the semiconductor element 14, and the sealing layer 13; and a step of peeling the temporary protection film 10 from the sealed molded body 20, in this order. The temporarily protected sealed molded body is composed of the sealed molded body 20 and the temporary protection film 10.

[0053] The step of attaching the temporary protection film 10 to the lead frame 11 may include heating and pressing the temporary protection film 10 disposed on the lead frame 11. The heating temperature may be 150 °C or higher, 180 °C or higher, or 200 °C or higher, and may also be 400 °C or lower. The pressure may be 0.5 - 30 MPa, 1 - 20 MPa, or 3 - 15 MPa. The time for heating and pressing may be 0.1 - 60 seconds, 1 - 30 seconds, or 3 - 20 seconds.

[0054] The lead frame 11 may be formed of, for example, an iron-based alloy such as 42 alloy, copper, or a copper-based alloy. The lead frame 11 may have a molded body formed of copper or a copper-based alloy and a coating layer such as palladium, gold, or silver covering its surface.

[0055] The semiconductor element 14 is usually adhered to the die pad 11a via an adhesive (e.g., silver paste). After adhering the semiconductor element 14 to the die pad 11a, reflow connection (such as CuClip connection) may be performed under the conditions of a maximum temperature of 250 - 440 °C, or 250 - 400 °C, and for 1 - 30 minutes.

[0056] The wire 12 is not particularly limited, and may be, for example, a gold wire, a copper wire, or a palladium-coated copper wire. For example, it may be heated at 200 - 260 °C, or 350 - 260 °C for 3 - 60 minutes, and the semiconductor element 14 and the inner lead 11b may be joined to the wire 12 using ultrasonic waves and pressing pressure.

[0057] The sealing layer 13 is formed by sealing molding using a sealing material. By sealing molding, a sealed molded body 20 having a plurality of semiconductor elements 14 and a sealing layer 13 that collectively seals them may be obtained. During the sealing molding, since the temporary protection film 10 is provided, it is possible to suppress the sealing material from flowing around to the back side of the lead frame 11.

[0058] The temperature during the formation of the sealing layer 13 (the temperature of the sealing material) may be 140 to 200 °C, or 160 to 180 °C. The pressure during the formation of the sealing layer may be 6 to 15 MPa, or 7 to 10 MPa. The time for sealing molding may be 1 to 5 minutes, or 2 to 3 minutes.

[0059] The formed sealing layer 13 may be heat-cured as necessary. The heating temperature for curing the sealing layer 13 may be 150 to 200 °C, or 160 to 180 °C. The heating time for curing the sealing layer 13 may be 4 to 7 hours, or 5 to 6 hours.

[0060] The sealing material may contain, for example, epoxy resins such as cresol novolac epoxy resin, phenol novolac epoxy resin, biphenyl diepoxy resin, and naphthol novolac epoxy resin. The sealing material may contain a filler, a flame retardant substance such as a bromine compound, a wax component, and the like.

[0061] After the sealing molding for forming the sealing layer 13, the temporary protective film 10 is peeled off from the lead frame 11 and the sealing layer 13 of the obtained sealing molded body 20. When curing the sealing layer 13, the temporary protective film 10 may be peeled off at any time before or after the curing of the sealing layer 13.

[0062] The temperature for peeling the temporary protective film 10 from the sealing molded body 20 may be 0 to 250 °C, 100 to 200 °C, or 150 to 250 °C.

[0063] After peeling the temporary protective film 10 from the lead frame 11, if a part of the adhesive layer remains on the lead frame 11 and the sealing layer 13, this may be removed. The remaining adhesive layer may be removed by mechanical brushing or with a solvent. The solvent may be, for example, N-methyl-2-pyrrolidone, dimethylacetamide, diethylene glycol dimethyl ether, tetrahydrofuran, cyclohexanone, methyl ethyl ketone, or dimethylformamide.

[0064] When the lead frame includes a plurality of patterns having die pads and inner leads, if necessary, the encapsulation molded body 20 can be divided to obtain a plurality of semiconductor packages 100 as shown in FIG. 5 each having one semiconductor element. That is, when the lead frame 11 has a plurality of die pads 11a and semiconductor elements 14 are mounted on each of the plurality of die pads 11a, the manufacturing method according to one embodiment may further include a step of dividing the encapsulation molded body 20 after peeling the temporary protection film 10 (or 10') from the encapsulation molded body 20 to obtain a semiconductor package 100 having one die pad 11a and one semiconductor element 14.

[0065] A long temporary protection film may be wound around a winding core, and a semiconductor package may be manufactured while unwinding the temporary protection film from the obtained reel body. The reel body in this case has a winding core and the temporary protection film according to the above-described embodiment wound around the winding core.

[0066] FIG. 6 is a perspective view showing an embodiment of a reel body. The reel body 30 shown in FIG. 6 includes a winding core 31, a temporary protection film 10 wound around the winding core 31, and side plates 32. The widths (lengths in a direction orthogonal to the winding direction) of the winding core 31 and the temporary protection film 10 may be, for example, 0.001 cm or more, 0.005 cm or more, or 0.008 cm or more, and may be 0.03 cm or less. The widths (lengths in a direction orthogonal to the winding direction) of the winding core 31 and the temporary protection film 10 may be, for example, 0.001 cm or more and 0.03 cm or less, 0.005 cm and 0.03 cm or less, or 0.008 cm or more and 0.03 cm or less.

[0067] The temporary protection film according to the above-described embodiment may be provided as a package body in which the reel body is housed in a packaging bag. FIG. 7 shows an embodiment of the package body. As shown in FIG. 7, the package body 50 includes a reel body 30 and a packaging bag 40 that houses the reel body 30. The reel body 30 is usually individually housed in a packaging bag, but a plurality (for example, 2 to 3) of reel bodies 30 may be housed in one packaging bag 40.

[0068] The packaging bag 40 may be formed from a resin film or may be formed from a composite film which is a resin film having an aluminum layer. Specific examples of the packaging bag 40 include a plastic bag coated with aluminum. Examples of the material of the resin film include plastics such as polyethylene, polyester, vinyl chloride, and polyethylene terephthalate. The reel body 30 may be, for example, accommodated in the packaging bag in a vacuum-packed state. The package 50 is not limited to being vacuum-packed.

[0069] The packaging bag 40 may accommodate a desiccant together with the reel body 30. Examples of the desiccant include silica gel. The package 50 may further have a cushioning material that wraps the packaging bag 40 containing the reel body 30.

[0070] The package 50 may be provided as a packaged item accommodated in a packing box. FIG. 8 shows an embodiment of the packaged item. As shown in FIG. 8, the packaged item 70 includes the package 50 and a packing box 60 that houses the package 50. One or a plurality of packages 50 are accommodated in the packing box 60. As the packing box 60, for example, cardboard can be used.

[0071] A semiconductor package manufactured using the provisional protection film according to an embodiment is excellent in terms of high density, small area, thinness, etc., and can be suitably used for electronic devices such as mobile phones, smartphones, personal computers, and tablets.

Examples

[0072] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[0073] 1. Production of provisional protection film Example 1 270.9 g (0.63 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 67.0 g (0.27 mol) of 1,3-bis(3-aminopropyl)-tetramethyldisiloxane were used to prepare an aromatic polyether amide imide which is a polycondensate formed with 187.3 g (0.89 mol) of trimellitic anhydride chloride. 100 parts by mass of this aromatic polyether amide imide, 7 parts by mass of sorbitol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name: EX-614B, epoxy equivalent: 173 g / eq.), and 3 parts by mass of 3-glycidoxypropyltrimethoxysilane (manufactured by Toray Dow Corning Silicone Co., Ltd., trade name: SH6040) were dissolved in N-methylpyrrolidone to obtain a varnish for forming an adhesive layer. The obtained varnish was applied onto one surface of a support film. As the support film, a polyimide film (thickness: 25 μm, manufactured by Ube Industries, Ltd., trade name: Upilex SGA) having a chemically treated surface was used. The coating film on the support film was dried by heating at 100 °C for 10 minutes and at 200 °C for 10 minutes to form an adhesive layer with a thickness of 6 μm, and a temporary protective film of Example 1 having the support film and the adhesive layer was obtained.

[0074] Example 2 An adhesive layer-forming varnish and a temporary protective film were obtained in the same manner as in Example 1, except that the amount of sorbitol polyglycidyl ether was changed to 10 parts by mass with respect to 100 parts by mass of the aromatic polyether amide imide.

[0075] Example 3 An adhesive layer-forming varnish and a temporary protective film were obtained in the same manner as in Example 1, except that polyethylene glycol diglycidyl ether (manufactured by Kyoei Chemical Co., Ltd., trade name: Epolite 400E, epoxy equivalent: 264 - 290 g / eq.) was used instead of sorbitol polyglycidyl ether, and the amount thereof was 10 parts by mass with respect to 100 parts by mass of the aromatic polyether amide imide.

[0076] Example 4 Instead of sorbitol polyglycidyl ether, a mixture of glycidyl ether of C12 alkyl alcohol and glycidyl ether of C13 alkyl alcohol (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Epolite M-1230, epoxy equivalent: 295 - 320 g / eq.) was used. The amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protection film were obtained.

[0077] Example 5 Instead of sorbitol polyglycidyl ether, glycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name: EX-313, epoxy equivalent: 141 g / eq.) was used. The amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protection film were obtained.

[0078] Example 6 Instead of sorbitol polyglycidyl ether, dipentaerythritol aliphatic saturated monobasic acid (C4 - C12) hexaester (manufactured by ADEKA Corporation, trade name: Adeka Sizer UL-6) was used. The amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protection film were obtained.

[0079] Example 7 Instead of sorbitol polyglycidyl ether, dipentaerythritol aliphatic saturated monobasic acid (C4 - C12) hexaester (manufactured by ADEKA Corporation, trade name: Adeka Sizer UL-6) was used. The amount was 20 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protection film were obtained.

[0080] Example 8 Instead of sorbitol polyglycidyl ether, polyoxyalkylene mono- or di-fatty acid (C6-C24) esters (manufactured by ADEKA CORPORATION, trade name: Adeka Sizer RS-700) were used. An adhesive varnish for forming an adhesive layer and a temporary protective film were obtained in the same manner as in Example 1, except that the amount was 10 parts by mass with respect to 100 parts by mass of the aromatic polyether amide imide.

[0081] Example 9 Instead of sorbitol polyglycidyl ether, polyoxyalkylene mono- or di-fatty acid (C6-C24) esters (manufactured by ADEKA CORPORATION, trade name: Adeka Sizer RS-700) were used. An adhesive varnish for forming an adhesive layer and a temporary protective film were obtained in the same manner as in Example 1, except that the amount was 20 parts by mass with respect to 100 parts by mass of the aromatic polyether amide imide.

[0082] Example 10 Instead of sorbitol polyglycidyl ether, polyoxyethylene(9) secondary alkyl (C11-C15) ether (manufactured by Kao Corporation, trade name: Emulgen 709) was used. An adhesive varnish for forming an adhesive layer and a temporary protective film were obtained in the same manner as in Example 1, except that the amount was 10 parts by mass with respect to 100 parts by mass of the aromatic polyether amide imide.

[0083] Example 11 Instead of sorbitol polyglycidyl ether, polyoxyethylene(9) secondary alkyl (C11-C15) ether (manufactured by Kao Corporation, trade name: Emulgen 709) was used. An adhesive varnish for forming an adhesive layer and a temporary protective film were obtained in the same manner as in Example 1, except that the amount was 20 parts by mass with respect to 100 parts by mass of the aromatic polyether amide imide.

[0084] Comparative Example 1 Instead of sorbitol polyglycidyl ether, glycidyl ether of lauryl alcohol ethylene oxide adduct (manufactured by Nagase ChemteX Corporation, trade name: EX-171, epoxy equivalent: 971 g / eq.) was used, and the amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protective film were obtained, except that the amount was 10 parts by mass.

[0085] Comparative Example 2 Instead of sorbitol polyglycidyl ether, 1,6-hexanediol diglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name: EX-212, epoxy equivalent: 151 g / eq.) was used, and the amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protective film were obtained, except that the amount was 10 parts by mass.

[0086] Comparative Example 3 Instead of sorbitol polyglycidyl ether, ethylene glycol diglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name: EX-810, epoxy equivalent: 113 g / eq.) was used, and the amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protective film were obtained, except that the amount was 10 parts by mass.

[0087] Comparative Example 4 Instead of sorbitol polyglycidyl ether, polyglycidyl ether of aliphatic polyol (manufactured by Nagase ChemteX Corporation, epoxy equivalent: 164 g / eq.) was used, and the amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amide imide. In the same manner as in Example 1, a varnish for forming an adhesive layer and a temporary protective film were obtained, except that the amount was 10 parts by mass.

[0088] Comparative Example 5 Instead of sorbitol polyglycidyl ether, polypropylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Epolite 400P, epoxy equivalent: 264 - 290 g / eq.) was used, and the amount was 10 parts by mass with respect to 100 parts by mass of aromatic polyether amideimide. In the same manner as in Example 1 except for this, a varnish for forming an adhesive layer and a temporary protection film were obtained.

[0089] Comparative Example 6 An adhesive layer-forming varnish and a temporary protection film were obtained in the same manner as in Example 1 except that sorbitol polyglycidyl ether was not used.

[0090] 2. Peel Strength (1) After Attachment The temporary protection film was attached to a copper plate for a lead frame (size: 50 mm × 200 mm, processed from "EFTEC64T" manufactured by Shinko Electric Industries Co., Ltd. and Furukawa Electric Co., Ltd., plasma irradiation-treated) under the conditions of a temperature of 235 °C, a pressure of 6 MPa, and a time of 10 seconds, with the adhesive layer facing the copper plate. Next, the 90-degree peel strength between the adhesive layer and the copper plate at 25 °C was measured under the condition of a peeling rate of 300 mm per minute. (2) After Heat Treatment The temporary protection film was attached to a copper plate for a lead frame (size: 50 mm × 200 mm, processed from "EFTEC64T" manufactured by Shinko Electric Industries Co., Ltd. and Furukawa Electric Co., Ltd., plasma irradiation-treated) under the conditions of a temperature of 235 °C, a pressure of 6 MPa, and a time of 10 seconds, with the adhesive layer facing the copper plate. Next, the copper plate and the temporary protection film attached thereto were subjected to heat treatment by heating at 180 °C for 1 hour and then at 400 °C for 2 minutes. After the heat treatment, the 90-degree peel strength between the adhesive layer and the copper plate at 200 °C was measured under the condition of a peeling rate of 300 mm per minute.

Table 1

[0091] Table 1 shows the evaluation results of the peel strength after pasting and after heat treatment. The temporary protection films of each example exhibited an appropriate peel strength after pasting and a sufficiently reduced peel strength after heat treatment. In the measurement of the peel strength after heat treatment of Examples 5 and 10 and Comparative Examples 1 to 5, generation of residues where a part of the adhesive layer remained on the lead frame was observed after peeling. Particularly in the cases of Comparative Examples 1, 2, and 5, since the temporary protection film tore during peeling, it was difficult to peel the temporary protection film cleanly from the copper plate with a single peeling operation. In Examples 6 and 7, generation of thin residues was observed.

Explanation of Signs

[0092] 1…Support film, 2…Adhesive layer, 3…Non-adhesive layer, 10, 10’…Temporary protection film, 11…Lead frame, 11a…Die pad, 11b…Inner lead, 12…Wire, 13…Sealing layer, 14…Semiconductor element, 20…Sealed molded body, 30…Reel body, 31…Spindle, 32…Side plate, 40…Packaging bag, 50…Package, 60…Packing box, 70…Packing material, 100…Semiconductor package.

Claims

1. A temporary protection film for semiconductor encapsulation molding, comprising a support film and an adhesive layer provided on one or both surfaces of the support film, and used for temporarily protecting the surface of the lead frame opposite to the semiconductor element during the encapsulation molding for forming an encapsulation layer that encapsulates the semiconductor element mounted on the die pad of the lead frame, wherein the adhesive layer contains a thermoplastic resin and at least one specific compound selected from the group consisting of sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, glycidyl ether of an aliphatic alcohol having 10 to 20 carbon atoms, glycerol polyglycidyl ether, polyalkylene glycol ester of a fatty acid having 2 to 30 carbon atoms, dipentaerythritol ester of a fatty acid having 2 to 20 carbon atoms, polyethylene glycol monoalkyl ether, and polyethylene glycol dialkyl ether, and the thermoplastic resin contains at least one selected from the group consisting of aromatic polyether amide imide, aromatic polyether imide, aromatic polyether amide, aromatic polyamide, aromatic polyester, aromatic polyimide, aromatic polyamide imide, aromatic polyether, and aromatic polyester imide. A temporary protection film for semiconductor encapsulation molding.

2. A temporary protection film for semiconductor encapsulation molding, comprising a support film and an adhesive layer provided on one or both surfaces of the support film, and used for temporarily protecting the surface of the lead frame opposite to the semiconductor element during the encapsulation molding for forming an encapsulation layer that encapsulates the semiconductor element mounted on the die pad of the lead frame, wherein the adhesive layer contains a thermoplastic resin and at least one specific compound selected from the group consisting of sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, glycidyl ether of an aliphatic alcohol having 10 to 20 carbon atoms, glycerol polyglycidyl ether, polyalkylene glycol ester of a fatty acid having 2 to 30 carbon atoms, dipentaerythritol ester of a fatty acid having 2 to 20 carbon atoms, polyethylene glycol monoalkyl ether, and polyethylene glycol dialkyl ether, and the content of the specific compound is 5 to 30 parts by mass with respect to 100 parts by mass of the content of the thermoplastic resin. A temporary protection film for semiconductor encapsulation molding.

3. The temporary protection film for semiconductor encapsulation molding according to claim 2, wherein the thermoplastic resin contains at least one selected from the group consisting of aromatic polyether amideimide, aromatic polyetherimide, aromatic polyether amide, aromatic polyamide, aromatic polyester, aromatic polyimide, aromatic polyamideimide, aromatic polyether, and aromatic polyesterimide.

4. A lead frame having a die pad, The temporary protection film for semiconductor encapsulation molding according to any one of claims 1 to 3, comprising: A lead frame with a temporary protection film, wherein the temporary protection film is attached to one surface of the lead frame in such a direction that the adhesive layer of the temporary protection film is in contact with the lead frame.

5. A lead frame having a die pad, A semiconductor element mounted on the die pad on one surface side of the lead frame, A sealing layer that seals the semiconductor element, The temporary protection film for semiconductor encapsulation molding according to any one of claims 1 to 3, comprising: A temporarily protected encapsulation molded body, wherein the temporary protection film is attached to the surface of the lead frame opposite to the semiconductor element in such a direction that the adhesive layer of the temporary protection film is in contact with the lead frame.

6. A step of attaching the temporary protection film for semiconductor encapsulation molding according to any one of claims 1 to 3 to one surface of a lead frame having a die pad in such a direction that its adhesive layer is in contact with the lead frame, A step of mounting a semiconductor element on the surface of the die pad opposite to the temporary protection film, A step of forming a sealing layer for sealing the semiconductor element to obtain a temporarily protected encapsulation molded body having the lead frame, the semiconductor element, and the sealing layer, A step of peeling the temporary protection film from the encapsulation molded body, A method for manufacturing a semiconductor package, comprising the above steps in this order.

7. The lead frame has a plurality of the die pads, and the semiconductor elements are mounted on each of the plurality of die pads. The method according to claim 6, further comprising a step of dividing the encapsulation molded body after peeling the temporary protection film from the encapsulation molded body to obtain a semiconductor package having one of the die pads and the semiconductor element.

Images