Underfill film for semiconductor packaging and manufacturing method of semiconductor package using the same.

Abstract

The present invention provides an underfill film for semiconductor packaging and a method for manufacturing a semiconductor package using the same, relating to an underfill film for semiconductor packaging that improves the connection reliability of the package by including an adhesive layer with the lowest melt viscosity, thereby minimizing the generation of pores during semiconductor packaging.

Description

Technical Field

[0001] This invention relates to an underfill film for semiconductor packaging and a method for manufacturing a semiconductor package using the same. More specifically, it relates to an underfill film for semiconductor packaging that can minimize void generation during semiconductor packaging manufacturing and improve package reliability, and a method for manufacturing a semiconductor package using the same. Background Technology

[0002] In recent years, with the miniaturization and increasing density of electronic devices, flip-chip packaging manufacturing methods, which can mount semiconductor components in the smallest possible area, have attracted attention.

[0003] In the manufacture of flip chip packages, underfill is placed in the space between the semiconductor chip and the package substrate. Underfill not only protects the package structure from external influences such as mechanical shock and corrosion at the junctions, but also minimizes stress caused by the difference in thermal expansion coefficients between the chip and the substrate, thereby improving the reliability of the packaged product.

[0004] Such underfill is formed by filling the space between the semiconductor chip and the packaging substrate with liquid underfill resin using a device such as a needle after the solder reflow process, and then allowing it to cure.

[0005] However, the liquid underfill resin filling process requires uniform application of underfill resin across all areas of the space between the semiconductor chip and the packaging substrate. Therefore, sufficient space is needed to allow the needle to move along the side of the semiconductor chip along a specific trajectory, and also ample space is required for needle placement. This results in space loss, which becomes a limiting factor in the miniaturization of products using flip chips.

[0006] Furthermore, during the liquid underfill resin filling process, the diffusion rate of the liquid underfill resin varies due to differences in the circuit patterns of the printed circuit board, the bonding pads, and the solder of the semiconductor chip, resulting in air gaps or voids within the underfill. These air gaps or voids not only reduce the underfill function but also contribute to decreased package reliability due to long-term moisture penetration. Summary of the Invention

[0007] Technical issues

[0008] The purpose of this invention is to provide an underfill film for semiconductor packaging that simplifies the bonding process during semiconductor packaging and minimizes voids to improve connection reliability.

[0009] Another object of the present invention is to provide a method for manufacturing semiconductor packages that utilizes the aforementioned underfill film to simplify the bonding process and improve production efficiency, while also providing excellent connection reliability.

[0010] Methods for solving problems

[0011] To achieve the above-mentioned technical problem, the present invention provides an underfill film for semiconductor packaging, comprising a substrate and an adhesive layer, wherein the adhesive layer is disposed on one side of the substrate and has a minimum melt viscosity of 3000 Pa·s or less at 160 to 170°C.

[0012] Furthermore, the present invention provides a method for manufacturing a semiconductor package, comprising: pressing an adhesive layer of the underfill film onto the bumps of a semiconductor chip having bumps; aligning the bumps of the semiconductor chip with the adhesive layer pressed onto the bonding pads of a package substrate having bonding pads in areas corresponding to the bump positions; melting the bumps of the semiconductor chip to connect the semiconductor chip to the package substrate; and curing the adhesive layer disposed between the connected semiconductor chip and the package substrate.

[0013] Invention Effects

[0014] This invention simplifies the bonding process in semiconductor packaging by including an adhesive layer with the lowest melt viscosity and minimizes porosity, thereby improving the connection reliability of the package. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the underfill film for semiconductor packaging according to a first embodiment of the present invention.

[0016] Figure 2 This is a schematic cross-sectional view of the underfill film for semiconductor packaging according to a second embodiment of the present invention.

[0017] Figures 3 to 6 This is a cross-sectional view used to schematically illustrate the various steps of the semiconductor package manufacturing method of the present invention.

[0018] **Symbol Explanation**

[0019] 10A, 10B: Bottom filler film; 11: Substrate.

[0020] 12: Adhesive layer; 12': Cured adhesive layer.

[0021] 13: Second substrate; 20: Semiconductor chip;

[0022] 21: Bump; 30: Packaging substrate;

[0023] 31: Bonding pads. Detailed Implementation

[0024] The present invention will now be described.

[0025] <Underfill film for semiconductor packaging>

[0026] Figure 1 This is a schematic cross-sectional view showing the underfill film for semiconductor packaging according to a first embodiment of the present invention. Figure 2 This is a schematic cross-sectional view of the underfill film for semiconductor packaging according to a second embodiment of the present invention.

[0027] The bottom filler films 10A and 10B of the present invention are non-conductive adhesive films used to alleviate the stress applied to the connection between the bumps of the semiconductor chip and the bonding pads of the packaging substrate during semiconductor packaging. Figure 1 and Figure 2 As illustrated, the substrate includes a substrate 11 and an adhesive layer 12 disposed on one side of the substrate. Optionally, another substrate (hereinafter referred to as "second substrate") 13 disposed on the other side of the adhesive layer may be further included (see figure). Figure 2 ).

[0028] The following is for reference Figure 1 The following describes the bottom filling film 10A for semiconductor packaging according to the first embodiment of the present invention.

[0029] 1) Substrate

[0030] In the bottom filler film of the present invention, the substrate 11 is the part that supports the adhesive layer while protecting the surface of the adhesive layer, and is peeled off and removed when the bottom filler film is used.

[0031] As such a substrate 11, any plastic film that can be peeled off as commonly known in the art can be used without limitation, and release paper can also be used.

[0032] Non-limiting examples of usable plastic films include polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; polyethylene films; polypropylene films; cellophane; diacetyl cellulose films; triacetyl cellulose films; acetyl cellulose butyrate films; polyvinyl chloride films; polyvinyl alcohol films; ethylene-vinyl acetate copolymer films; polystyrene films; polycarbonate films; polymethylpentene films; polysulfone films; polyetheretherketone films; polyethersulfone films; polyetherimide films; polyimide films; fluoropolymer films; polyamide films; acrylic resin films; norbornene resin films; and cycloolefin resin films. Such plastic films can be transparent or translucent, and can also be colored or uncolored. As one example, substrate 11 can be polyethylene terephthalate (PET). As another example, substrate 11 can be polyimide (PI).

[0033] A release layer can be provided on such a plastic film. The release layer allows for easy separation of the substrate 11 from the adhesive layer 12 while maintaining the shape of the adhesive layer without damaging it. Here, the release layer can be a release material of a commonly used film type.

[0034] The composition of the release agent used in the release layer is not particularly limited, and commonly known release agent components in the art can be used. As non-limiting examples, epoxy-based release agents, release agents composed of fluoropolymers, silicone-based release agents, alkyd resin-based release agents, water-soluble polymers, etc., can be included. Furthermore, powdered fillers, such as silicon or silica, can be included as components of the release layer as needed. In this case, two types of particulate powder fillers can be mixed, and their average particle size can be appropriately selected considering the resulting surface roughness.

[0035] The thickness of such a release layer can be appropriately adjusted within the range known in the art.

[0036] In this invention, the thickness of the substrate 11 is not particularly limited and can be adjusted within the usual range known in the art, for example, it can be about 25 to 150 μm, specifically about 30 to 100 μm, and more specifically about 30 to 50 μm.

[0037] There is no particular limitation on the release force of such substrates; for example, it can be from about 1 to 500 gf / inch, specifically from about 10 to 100 gf / inch.

[0038] There are no particular limitations on the method for forming the release layer; known methods such as hot pressing, hot roller lamination, extrusion lamination, coating with a coating liquid, and drying can be used.

[0039] (2) Adhesive layer

[0040] In the underfill film of the present invention, the adhesive layer 12 is disposed on one side of the substrate 11. In semiconductor packaging, when the semiconductor chip is aligned with the packaging substrate, the semiconductor chip can be bonded to the packaging substrate. As an underfill, the stress and deformation caused by the difference in the coefficient of thermal expansion between the semiconductor chip and the packaging substrate can be redistributed.

[0041] The adhesive layer 12 of the present invention is in a semi-cured state and has a minimum melt viscosity of about 3000 Pa·s at about 160 to 170°C. When such an adhesive layer 12 is placed between a semiconductor chip with bumps and a package substrate with bonding pads and they are pressed together at about 200°C, about 30 to 100 N, and about 1 to 3 seconds, the adhesive layer has a porosity of less than 1%.

[0042] Specifically, the adhesive layer 12 of the present invention has a minimum melt viscosity of about 3000 Pa·s or less, preferably about 100 to 1000 Pa·s, at about 160 to 170°C. Therefore, it easily melts and has fluidity even when pressed at about 200°C, 50 N, and for about 1 to 3 seconds. Thus, when pre-bonding the bumps of a semiconductor chip to the bonding pads of a package substrate, the adhesive layer 12 is placed between the bumps of the semiconductor chip and the bonding pads of the package substrate. This adhesive layer 12 can melt during pre-bonding and fill the space between the bumps and the bonding pads. In particular, due to the high fluidity of the adhesive layer, it can also fill small spaces with fine pitch. Furthermore, the adhesive layer of the present invention not only serves as a bottom filler but also as a flux. Therefore, unlike conventional methods, it is not necessary to apply flux to the bonding pads or wash the flux. Thus, no flux residue or porosity caused by flux washing solvent occurs. Thus, the adhesive layer of the present invention exhibits excellent gap-filling effect, minimizing the formation of pores. For example, under conditions of approximately 200°C, approximately 30–100 N, and approximately 1–3 seconds, the porosity of the adhesive layer after pressing is less than 1%, and this porosity can be further reduced to less than 0.5% during the subsequent reflow process when the bumps melt.

[0043] Furthermore, the onset temperature on the differential scanning calorimeter (DSC) of the adhesive layer 12 ranges from approximately 160 to 220°C. Therefore, the adhesive layer exhibits stable curing properties at high temperatures. Here, the onset temperature refers to the temperature at which the slope of the DSC curve begins to increase due to heating during DSC measurement.

[0044] Furthermore, the thickness of the adhesive layer is adjusted taking into account factors such as the minimum melt viscosity of the adhesive layer. As an example, the thickness of the adhesive layer can be in the range of 80% to 120% of the spacing between the semiconductor chip and the packaging substrate.

[0045] This adhesive layer 12 is composed of a semi-cured adhesive resin composition comprising (a) an epoxy resin containing liquid epoxy resin, phenoxy resin and multifunctional epoxy resin; (b) an anhydride curing agent; (c) a nitrogen (N) heterocyclic compound; and (d) a filler.

[0046] In the above-described adhesive resin composition, the epoxy resin comprises liquid epoxy resin, phenoxy resin, and multifunctional epoxy resin. In this case, the usage ratio (mixing ratio) between the liquid epoxy resin, phenoxy resin, and multifunctional epoxy resin can be 1:1 to 3:1 to 3 by weight. Under these conditions, the minimum melt viscosity of the adhesive layer of the present invention is as low as approximately 3000 Pa·s or less, thus exhibiting excellent adhesion and filling effect, thereby ensuring reliable encapsulation.

[0047] In the above-mentioned adhesive resin composition, the liquid epoxy resin, which is a thermosetting resin and is liquid at 25±5℃, imparts adhesiveness and curing properties to the adhesive resin composition, and also imparts uniform curing to the cured adhesive layer.

[0048] Non-limiting examples of liquid epoxy resins that can be used in this invention include liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid naphthalene type epoxy resin, liquid aminophenol type epoxy resin, liquid hydrogenated bisphenol type epoxy resin, liquid alicyclic epoxy resin, liquid alcohol ether type epoxy resin, liquid cyclic aliphatic type epoxy resin, liquid fluorene type epoxy resin, and liquid siloxane-based epoxy resin. Among these, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, and liquid naphthalene type epoxy resin are suitable in terms of adhesion, curing properties, durability, and heat resistance. They can be used alone or in mixtures of two or more.

[0049] Specifically, products made from liquid epoxy resins include Nippon Steel Chemical's bisphenol F type epoxy resin (product name: YDF8170), DIC's bisphenol A type epoxy resin (product name: EXA-850CRP), Nippon Steel Chemical's bisphenol F type epoxy resin (product name: YDF870GS), DIC's naphthalene type epoxy resin (product name: HP4032D), Mitsubishi Chemical's aminophenol type epoxy resin (grades: JER630, JER630LSD), Momentive Advanced Materials' siloxane-based epoxy resin (product name: TSL9906), and Nippon Steel Chemical Co., Ltd.'s 1,4-cyclohexanediethanol diglycidyl ether (product name: ZX1658GS), but are not limited to these.

[0050] In the above-described adhesive resin composition, the phenoxy resin is a thermoplastic polymer containing at least one epoxy group at the end. The equivalent of the intramolecular epoxy group relative to the molecular weight is very low, thus it can impart fluidity at high temperatures even though it participates in curing. Due to this phenoxy resin, the adhesive layer of the present invention can be formed into a film in a semi-cured (B-stage) state at room temperature (approximately 25±5°C).

[0051] The phenoxy resin that can be used in this invention is not particularly limited as long as it is a polymer containing a phenoxy group in its polymer chain and an epoxy group at at least one end.

[0052] For example, phenoxy resin can be a compound represented by the following chemical formula 1, but is not limited to this.

[0053] [Chemical Formula 1]

[0054]

[0055] (In the above chemical formula 1,

[0056] a and b are integers from 1 to 4.

[0057] Multiple R1s and multiple R2s may be the same or different from each other, and each is independently chosen from hydrogen, halogens, and C1 to C2. 10 Alkyl groups, C3-C 20 cycloalkyl, C5-C 20 The group consisting of aryl and nitro groups, specifically, each independently selected from hydrogen, halogen, C1-C5 alkyl, C3-C4 alkyl, and C5-C6 alkyl groups. 10 cycloalkyl, C5-C 10 The group composed of aryl and nitro groups;

[0058] R3 to R8 may be the same as or different from each other, and each is independently hydrogen or hydroxyl, wherein at least one of R3 to R8 is hydroxyl;

[0059] X1 is a single bond or C1~C 10Alkylenes, specifically single-bonded or C1-C5 alkylenes,

[0060] Y1 and Y2 may be the same as or different from each other, and each is independently hydrogen, hydroxyl or epoxy group, wherein at least one of Y1 and Y2 is epoxy group.

[0061] n is an integer between 30 and 400.

[0062] The multifunctional epoxy resins used in this invention are epoxy resins containing two or more epoxy groups. Such multifunctional epoxy resins impart electrical insulation, heat resistance, chemical stability, toughness, and moldability to the adhesive layer.

[0063] As for the multifunctional epoxy resin that can be used in this invention, there is no particular limitation as long as it contains 2 or more, specifically 2 to 5, epoxy groups per molecule (monomer).

[0064] Non-limiting examples of multifunctional epoxy resins include epoxy resins obtained by epoxidation of condensates of phenol or alkylphenols with hydroxybenzaldehyde, phenol-phenolic varnish type epoxy resins, cresol-phenolic varnish type epoxy resins, phenol-aralkyl type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, epoxy resins containing spirocyclic rings, XYLOK type epoxy resins, multifunctional epoxy resins, naphthol-phenolic varnish type epoxy resins, phenolic varnish type epoxy resins of bisphenol A / bisphenol F / bisphenol AD, glycidyl ether epoxy resins of bisphenol A / bisphenol F / bisphenol AD, dihydroxybiphenyl-based epoxy resins, dicyclopentadiene-based epoxy resins, and naphthyl-based epoxy resins. Among these, multifunctional epoxy resins that are non-liquid at 25±5°C are preferred. Here, "non-liquid at 25±5℃" refers to epoxy resin that is semi-solid or solid at 25±5℃, and also includes near-solid epoxy resin.

[0065] The above-mentioned adhesive resin composition contains an anhydride-based curing agent. The anhydride-based curing agent can cure at least one of liquid epoxy resin, phenoxy resin and multifunctional epoxy resin, and can perform flux properties.

[0066] Non-limiting examples of such anhydride-based curing agents include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexenedicarboxylic anhydride, phthalic anhydride, maleic anhydride, and pyromellitic anhydride, which can be used alone or in combination of two or more.

[0067] In addition to the aforementioned anhydride-based curing agents, the adhesive resin composition may further include one or more curing agents known in the art as components for curing epoxy resins. Examples include aromatic amine curing agents such as m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenyl sulfone; aliphatic amine curing agents such as diethylenetriamine and triethylenetetramine; phenolic curing agents such as phenol aralkyl type phenolic resins, phenolic varnish type phenolic resins, XYLOK type phenolic resins, cresol phenolic varnish type phenolic resins, naphthol type phenolic resins, terpene type phenolic resins, polyfunctional phenolic resins, dicyclopentadiene type phenolic resins, naphthol type phenolic resins, and phenolic varnish type phenolic resins synthesized from bisphenol A and resol; and latent curing agents such as dicyandiamide. These can be used alone or in combination of two or more.

[0068] The aforementioned adhesive resin composition contains a nitrogen-containing (N) heterocyclic compound. As a curing catalyst that promotes curing, the N-containing heterocyclic compound not only regulates the curing speed but also ensures the high-temperature stability of the adhesive layer.

[0069] Such nitrogen-containing (N) heterocyclic compounds can be selected from one or more compounds in the group consisting of compounds represented by chemical formula 2 and compounds represented by chemical formula 3.

[0070] [Chemical Formula 2]

[0071]

[0072] [Chemical Formula 3]

[0073]

[0074] In the above chemical formulas 2 and 3,

[0075] n1 is 1 or 2.

[0076] n2 is an integer from 0 to 2.

[0077] X1 to X6 may be the same as or different from each other, and each is independently N or C(R1), wherein more than one of X1 to X6 is N.

[0078] Y1 to Y6 may be the same as or different from each other, and each can be independently N(R2) or C(R3)(R4), wherein more than one of Y1 to Y6 is N(R2).

[0079] At this point, multiple C(R1) may be the same or different from each other, multiple N(R2) may be the same or different from each other, and multiple C(R3)(R4) may be the same or different from each other.

[0080] R1, R2, R3, and R4 are each independently chosen from hydrogen, deuterium (D), halogen, cyano, nitro, and C1-C4. 20 Alkyl groups, C2-C 20 alkenyl and C2~C 20 The group composed of alkynyl groups.

[0081] Specifically, in the above chemical formula 2, one or two of X1 to X6 can be N, and the rest can be C(R1).

[0082] In addition, in the above chemical formula 3, one or two of Y1 to Y6 can be N(R2), and the rest can be C(R3)(R4).

[0083] Furthermore, in the aforementioned chemical formulas 2 and 3, R1, R2, R3, and R4 can each be independently chosen from hydrogen, deuterium (D), halogen, cyano, nitro, C1-C4. 12 Alkyl groups, C2-C 12 alkenyl and C2~C 12 The group composed of alkynyl groups.

[0084] Examples of compounds represented by the above chemical formula 2 include pyrazine-based compounds and pyridine-based compounds, but are not limited thereto. Specifically, non-limiting examples of compounds represented by the above chemical formula 2 may include compounds represented by the following chemical formula 2a, etc.

[0085] [Chemical Formula 2a]

[0086]

[0087] Examples of compounds represented by the above chemical formula 3 include piperazine-based compounds, but are not limited thereto. Specifically, non-limiting examples of compounds represented by the above chemical formula 3 may include compounds represented by chemical formula 3a, compounds represented by chemical formula 3b, etc.

[0088] [Chemical Formula 3a]

[0089]

[0090] [Chemical Formula 3b]

[0091]

[0092] As an example, N-containing heterocyclic compounds may include one or more compounds selected from the group consisting of pyrazine-based compounds, pyridine-based compounds, and piperazine-based compounds.

[0093] In the adhesive resin composition of the present invention, the content of the N-containing heterocyclic compound is preferably adjusted by considering the overall content or usage ratio of the liquid epoxy resin, phenoxy resin, and multifunctional epoxy resin, as well as the type and content of the anhydride-based curing agent. As an example, in the adhesive resin composition of the present invention, the content of epoxy resin (i.e., the overall content of the liquid epoxy resin, phenoxy resin, and multifunctional epoxy resin) based on the total amount of the resin composition can be in the range of about 40 to 80% by weight, the content of the anhydride-based curing agent based on the total amount of the resin composition can be in the range of about 5 to 20% by weight, and the content of the N-containing heterocyclic compound based on the total amount of the resin composition can be in the range of about 0.01 to 5% by weight. In this case, the usage ratio (mixing ratio) between the liquid epoxy resin, phenoxy resin, and multifunctional epoxy resin can be a weight ratio of 1:1 to 3:1 to 3.

[0094] In this case, the adhesive layer of the present invention is easy to operate, has excellent adhesion, and has a minimum melt viscosity of about 3000 Pa·s at about 160 to 170°C, which minimizes the formation of pores, thus providing excellent filling properties and improving connection reliability.

[0095] The above-mentioned adhesive resin composition contains a filler. The filler can not only exhibit thixotropic properties to adjust the melt viscosity, but also improve adhesion and reduce the coefficient of thermal expansion.

[0096] Such fillers can be organic or inorganic. Specifically, inorganic fillers include metallic components such as gold powder, silver powder, copper powder, and nickel powder; and non-metallic components such as alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, aluminum nitride, silicon dioxide, boron nitride, titanium dioxide, glass, iron oxide, and ceramics. Organic fillers include carbon, rubber-based fillers, and polymer-based fillers, but are not limited to these. They can be used alone or in combination of two or more.

[0097] There are no particular restrictions on the shape and size of the filler. For example, the filler can be polyhedral, spherical, etc., and the average particle size can be in the range of about 10 to 100 nm. If the average particle size of the filler is within the above range, the mechanical properties of the cured product can be further improved. As an example, the filler can be silica with an average particle size of about 10 to 100 nm.

[0098] The content of such filler is not particularly limited. For example, it can be a margin adjusted to make the total amount of the adhesive resin composition reach 100% by weight. Specifically, based on the total amount of the adhesive resin composition, it can be about 10 to 50% by weight. If the content of filler is within the above range, an adhesive layer with a low coefficient of thermal expansion (CTE) will be formed. Therefore, the difference in the coefficient of thermal expansion between the substrate and the semiconductor device is small, which can minimize the occurrence of warpage or crack.

[0099] In addition to the above-mentioned components, the adhesive resin composition of the present invention may selectively include additives generally known in the art, depending on the intended use and environment of the composition. Examples include solvents such as acetone, methyl ethyl ketone, toluene, and ethyl acetate; tackifiers; coupling agents; antistatic agents; adhesion enhancers; wettability enhancers; and leveling enhancers, but are not limited thereto.

[0100] The amount of such additive is not particularly limited and can be used within the general range known in the art. For example, it can be from about 0.01% to 10% by weight, based on the total amount of the above resin composition.

[0101] The above-described adhesive resin composition can be manufactured by methods commonly known in the art. For example, the adhesive resin composition can be manufactured by mixing and stirring liquid epoxy resin, phenoxy resin, multifunctional epoxy resin, anhydride curing agent, N-containing heterocyclic compound, filler, and selective additives at room temperature and at appropriately heated temperatures using mixing equipment such as ball mills, bead mills, 3-roll mills, basket mills, dynomills, and planetary mills.

[0102] The underfill film of the present invention can be manufactured by methods generally known in the art. For example, the underfill film can be manufactured by diluting the adhesive resin composition obtained by the above method with a dilutable organic solvent as needed, stirring it to a suitable concentration that facilitates the formation of a coating, coating it onto a substrate, and drying it.

[0103] Regarding the above coating and drying methods, there are no particular limitations as long as the method can form a coating film, such as bar coating, gravure coating, corner wheel coating, reverse roller coating, roller knife coating, die coating, or lip die coating.

[0104] The bottom filler film of the present invention has a low minimum melt viscosity, thus minimizing porosity during pre-bonding between the semiconductor chip and the packaging substrate, resulting in excellent filling performance and improved package connection reliability. It can also be applied to fine pitch applications. Furthermore, unlike conventional methods, it simplifies the bonding process and enables mass reflow processes.

[0105] The following is about Figure 2 The bottom filling film 10B of the second embodiment of the present invention, as illustrated in the figure, will be described.

[0106] like Figure 2 As illustrated, the bottom filler film 10B of the present invention may include a substrate (hereinafter referred to as "first substrate") 11, an adhesive layer 12 disposed on one side of the substrate, and another substrate (hereinafter referred to as "second substrate") 13 disposed on the other side of the adhesive layer 12.

[0107] The first substrate 11 and adhesive layer 12 that can be used in this invention are the same as those described in the substrate and adhesive layer portion of the first embodiment, and therefore are omitted.

[0108] In this invention, the second substrate 13 is a portion disposed on the other side of the adhesive layer 12 to support the adhesive layer and protect the surface of the adhesive layer. Since it can be peeled off, it can be peeled off and removed when the film is used.

[0109] The second substrate 13 may be the same as or different from the first substrate. The description of examples of the second substrate is the same as that described in the substrate section of the first embodiment, and therefore is omitted.

[0110] <Semiconductor Packaging Manufacturing Methods>

[0111] On the other hand, the present invention can utilize the aforementioned underfill films 10A and 10B to provide various methods for manufacturing semiconductor packages. In particular, the underfill films 10A and 10B have a minimum melt viscosity of approximately 3000 Pa·s or less at approximately 160–170°C. Therefore, when aligning the semiconductor chip with the package substrate by pressing at approximately 200°C for approximately 1–3 seconds, the underfill films readily possess fluidity and can fill the gap between the semiconductor chip and the package substrate without porosity, thereby improving the connection reliability of the semiconductor package. Therefore, the present invention not only simplifies the semiconductor package manufacturing process by utilizing the aforementioned underfill films but also enables the manufacture of semiconductor packages with excellent connection reliability while improving production efficiency.

[0112] As an example, a semiconductor packaging manufacturing method may include: (a) a step of depositing the adhesive layer of the underfill film onto the bumps of a semiconductor chip having bumps; (b) a step of aligning the bumps of the semiconductor chip having the adhesive layer onto the bonding pads of a packaging substrate having bonding pads in areas corresponding to the bump positions; (c) a step of melting the bumps of the semiconductor chip to connect the semiconductor chip and the packaging substrate to each other; and (d) a step of curing the adhesive layer disposed between the connected semiconductor chip and the packaging substrate. It should be noted that the manufacturing method of the present invention can be implemented by modifying or selectively combining the various process steps as needed.

[0113] The following is for reference Figures 3 to 6 The semiconductor packaging manufacturing method of the present invention is described in detail below, breaking it down into individual process steps.

[0114] (a) Steps for applying an adhesive layer to a semiconductor chip

[0115] like Figure 3 As shown in the figure, the adhesive layer 12 of the bottom filling films 10A and 10B is disposed on the bump 21 of the semiconductor chip 20 having bump 21 (hereinafter referred to as "S100 step").

[0116] Generally, terminals (pads) (not shown) for connecting internal electronic circuits to the outside are formed along the edge of the semiconductor chip 20, and one or two rows can be formed along the center of the chip as needed.

[0117] Such semiconductor chips have bumps 21 formed on their terminals. These bumps are external terminals that electrically connect the substrate and the semiconductor chip during packaging, and can be solder bumps or gold bumps, etc.

[0118] In this invention, such as Figure 3 As illustrated, substrates 11 and 13 are separated from the bottom filler films 10A and 10B, and the adhesive layer 12 is disposed only on the bump 21 side of the semiconductor chip. At this time, the semiconductor chip 20 with bumps 21 can be press-laminated onto the adhesive layer 12 under a pressure of approximately 30 to 100 N. Furthermore, if necessary, the semiconductor chip 20 can be press-laminated at a temperature lower than the onset temperature of the adhesive layer, for example, 50 to 150°C. Thus, the adhesive layer is pressed onto the bumps of the semiconductor chip in a semi-cured state (B-stage). In this case, the adhesive layer not only serves as a bottom filler but also as a flux, thus, unlike conventional methods, this invention eliminates the need to wash the bumps with flux.

[0119] (b) Alignment steps between semiconductor chip and substrate

[0120] The semiconductor chip 20, to which the adhesive layer 12 was pressed in step S100 above, is aligned on the packaging substrate 30 (hereinafter referred to as "step S200").

[0121] The packaging substrate 30 used in this invention is a substrate on which a circuit pattern (not shown) is formed on at least one side, such as a printed circuit board (PCB). Such a packaging substrate 30 has bonding pads 31 formed in the region corresponding to the location of the bump 21 of the semiconductor chip 20.

[0122] In this invention, such as Figure 4 As illustrated, the semiconductor chip 20, with bumps 21 formed thereon, is mounted on the packaging substrate 30 in such a manner that the semiconductor chip 20 is arranged on the bonding pads 31. Specifically, the bumps 21 of the semiconductor chip 20 can be pressed onto the bonding pads 31 of the packaging substrate 30 at approximately 200°C, approximately 30 to 100 N, and for approximately 1 to 3 seconds to pre-bond the packaging substrate 30 and the semiconductor chip 20. At this time, the adhesive layer 12 disposed between the semiconductor chip 20 and the packaging substrate 30 flows due to its low minimum melt viscosity, as described above. Therefore, the porosity of the adhesive layer is approximately 1% or less.

[0123] Furthermore, in this invention, the adhesive layer 12 contains components that function as flux, thus, unlike conventional methods, it is not necessary to apply flux to the bonding pads 31 of the package substrate 30 before step S200. Therefore, the flux application process and flux washing process for the bonding pads can be omitted in this invention.

[0124] (c) Bump melting step

[0125] like Figure 5 As shown in the figure, the bumps 21 of the semiconductor chip 20 are melted to electrically and mechanically connect the semiconductor chip 20 to the packaging substrate 30 (hereinafter referred to as "S300 step").

[0126] Step S300 involves reflowing the bumps in an oven at approximately 150 to 300°C, specifically approximately 170 to 270°C, where the bumps melt and the semiconductor chip 20 and the package substrate 30 are electrically and mechanically connected. During this process, the adhesive layer 12 disposed between the semiconductor chip 20 and the package substrate 30 also melts, further reducing the porosity of the adhesive layer to approximately 0.5% or less. This further improves the connection reliability of the semiconductor package manufactured according to the present invention.

[0127] (d) Curing steps of the adhesive layer

[0128] like Figure 6 As illustrated, the adhesive layer 12 between the semiconductor chip 20 and the package substrate 30 connected in step S300 above is cured (hereinafter referred to as "step S400").

[0129] The adhesive layer 12 of the present invention has an initial temperature of about 160 to 220°C, so step S400 can be performed at a temperature higher than the above-mentioned initial temperature, such as about 170 to 250°C.

[0130] The curing time of the adhesive layer is adjusted according to the curing temperature, for example, it can be about 0.5 to 3 hours.

[0131] The present invention will be specifically described below through embodiments, but the following embodiments and experimental examples are only illustrative of one aspect of the present invention, and the scope of the present invention is not limited to the following embodiments and experimental examples.

[0132] [Examples 1-3 and Comparative Example 1: Manufacturing of the bottom filling film]

[0133] 1-1. Preparation of adhesive resin composition

[0134] The adhesive resin compositions of Examples 1-3 and Comparative Example 1 were prepared by mixing the components according to the composition described in Table 1 below. The content of each component listed in Table 1 is in weight %, based on the total amount of the above resin compositions.

[0135] 1-2. Manufacturing of the bottom filler film

[0136] The various adhesive resin compositions manufactured in Examples 1-1 are molded onto one side of a PET release film (thickness: 38 μm), and then dried to form an adhesive layer (thickness: 18 μm), thereby producing a non-conductive adhesive film.

[0137] [Table 1]

[0138]

[0139] [Experimental Example 1: Physical Property Evaluation]

[0140] The physical properties of the non-conductive adhesive films manufactured in Examples 1 to 3 and Comparative Example 1 were measured respectively, and the measurement results are shown in Table 2 below.

[0141] 1) Onset Temperature

[0142] The initial temperature of the non-conductive adhesive film was determined using differential scanning calorimetry (DSC).

[0143] 2) Melt Viscosity

[0144] The viscosity of a non-conductive adhesive film was measured using a rheometer while the temperature was increased from 50°C to 300°C at a rate of 10°C per minute.

[0145] [Table 2]

[0146] Example 1 Example 2 Example 3 Comparative Example 1 Starting temperature (°C) 171 175 198 140 Melt viscosity (Pa.s) 2775 980 450 4537

Claims

1. An underfill film for semiconductor packaging, comprising a substrate and an adhesive layer, The adhesive layer is disposed on one side of the substrate and has a minimum melt viscosity of 3000 Pa·s at 160 to 170°C. The adhesive layer is a cured product of an adhesive resin composition comprising (a) an epoxy resin containing liquid epoxy resin, phenoxy resin, and multifunctional epoxy resin; (b) an anhydride-based curing agent; (c) a nitrogen-containing heterocyclic compound; and (d) a filler. The nitrogen-containing heterocyclic compound is selected from one or more compounds grouped together with compounds represented by chemical formula 2 and chemical formula 3. [Chemical Formula 2] [Chemical Formula 3] In chemical formulas 2 and 3, n1 is 1 or 2. n2 is an integer from 0 to 2. X1 to X6 may be the same as or different from each other, and each is independently N or C(R1), where, N is one or more of X1 to X6. Y1 to Y6 may be the same as or different from each other, and each can be independently N(R2) or C(R3)(R4), wherein more than one of Y1 to Y6 is N(R2). At this point, multiple C(R1) may be the same or different from each other, multiple N(R2) may be the same or different from each other, and multiple C(R3)(R4) may be the same or different from each other. R1, R2, R3, and R4 are each independently chosen from hydrogen, deuterium (D), halogen, cyano, nitro, and C1-C4. 20 Alkyl groups, C2-C 20 alkenyl and C2~C 20 The group composed of alkynyl groups.

2. The bottom filler film for semiconductor packaging according to claim 1, wherein the adhesive layer is located between a semiconductor chip having bumps and a packaging substrate having bonding pads, and the porosity of the adhesive layer is less than 1% when pressed under conditions of 200°C, 30-100N, and 1-3 seconds.

3. The bottom filler film for semiconductor packaging according to claim 2, wherein the thickness of the adhesive layer is in the range of 80 to 120% of the spacing between the semiconductor chip and the packaging substrate.

4. The bottom filler film for semiconductor packaging according to claim 1, wherein the initial temperature on the differential scanning calorimeter (DSC) is in the range of 160 to 220°C.

5. The underfill film for semiconductor packaging according to claim 1, wherein, based on the total amount of the adhesive resin composition, the adhesive resin composition comprises: 40 to 80% by weight of epoxy resin, 5 to 20% by weight of curing agent, 0.01 to 5% by weight of nitrogen-containing heterocyclic compounds, and 10 to 50% by weight of filler.

6. The underfill film for semiconductor packaging according to claim 1, comprising the liquid epoxy resin, phenoxy resin and multifunctional epoxy resin in a weight ratio of 1:1 to 3:1 to 3.

7. A method for manufacturing a semiconductor package, comprising: The step of pressing the adhesive layer of the bottom filler film according to any one of claims 1 to 6 onto the bumps of a semiconductor chip having bumps; The step of aligning the bumps of a semiconductor chip to which the adhesive layer is pressed in on the bonding pads of a package substrate having bonding pads in the area corresponding to the location of the bumps. The step of connecting the semiconductor chip to the packaging substrate by melting the bumps of the semiconductor chip; as well as The step of curing the adhesive layer disposed between the connected semiconductor chip and the packaging substrate.

8. The semiconductor package manufacturing method according to claim 7, wherein the alignment step between the bump and the bonding pad is performed by pressing under conditions of 200°C, 30–100 N, and 1–3 seconds. After the pressing, the porosity of the adhesive layer is less than 1%.

9. In the semiconductor package manufacturing method according to claim 8, after the melting step of the bump, the porosity of the adhesive layer is less than 0.5%.

10. The semiconductor package manufacturing method according to claim 7, wherein the curing temperature of the adhesive layer is in the range of 170 to 250°C.

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