Method for manufacturing semiconductor devices

Abstract

One aspect of the present invention relates to a method for manufacturing a semiconductor device, which includes a step of processing a semiconductor component temporarily fixed to a support substrate, and provides a method for easily separating the processed semiconductor component from the support substrate. [Solution] A method for manufacturing a semiconductor device is disclosed, comprising the steps of processing a semiconductor component temporarily fixed to a support substrate, and irradiating a temporary fixing laminate with light from the back side of the support substrate, thereby separating the semiconductor component from the support substrate. The light is sequentially irradiated onto a plurality of irradiated regions, each irradiated region including a part of the back surface. When viewed from a direction perpendicular to the back surface, adjacent irradiated regions partially overlap, and the combined region of the plurality of irradiated regions includes the entire back surface.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor device.

Background Art

[0002] In the field of semiconductor devices, in recent years, technology related to a package called SIP (System in Package) in which a plurality of semiconductor elements are stacked has been growing significantly. In an SIP-type package, since a large number of semiconductor elements are stacked, thinning of the semiconductor elements is required. Therefore, after incorporating an integrated circuit into a semiconductor member (for example, a semiconductor wafer), processing such as thinning by grinding the back surface of the semiconductor member and singulating the semiconductor wafer by dicing may be performed. These processing of the semiconductor member is usually performed in a state where the semiconductor member is temporarily fixed to a support substrate by a temporary fixing material layer (for example, see Patent Documents 1 to 3). Patent Documents 2 and 3 disclose a method of separating a semiconductor member by irradiating a laser beam (coherent light) on the temporary fixing material layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present invention relates to a method for manufacturing a semiconductor device including a step of processing a semiconductor member temporarily fixed to a support substrate, and provides a method for easily separating the processed semiconductor member from the support substrate.

Means for Solving the Problems

[0005] One aspect of the present invention is, A step of preparing a temporary fixing laminate comprising a support substrate having a support surface and a back surface on the opposite side thereof, and a temporary fixing material layer provided on the support surface, wherein the temporary fixing material layer has a curable resin layer including at least one outermost surface of the temporary fixing material layer, A step of temporarily fixing the semiconductor component to the support substrate via the temporary fixing material layer, A step of processing the semiconductor member that has been temporarily fixed to the support substrate, The process involves irradiating the temporary fixing laminate with light from the back side, thereby separating the semiconductor member from the support substrate. A method for manufacturing a semiconductor device is provided, comprising the following in this order: Part or all of the temporary fixing layer is a light-absorbing layer that absorbs light and generates heat. The light is sequentially irradiated onto a plurality of irradiated regions, each of which includes a portion of the back surface. When viewed from a direction perpendicular to the back surface, adjacent irradiated regions partially overlap, and the combined region of the plurality of irradiated regions includes the entire back surface. [Effects of the Invention]

[0006] According to one aspect of the present invention, a method for manufacturing a semiconductor device, which includes a step of processing a semiconductor component temporarily fixed to a support substrate, is provided, wherein the processed semiconductor component can be easily separated from the support substrate by a simple process. [Brief explanation of the drawing]

[0007] [Figure 1] (a), (b), and (c) are schematic diagrams illustrating one embodiment of a method for manufacturing a semiconductor device. [Figure 2] (a) and (b) are schematic diagrams illustrating one embodiment of a method for manufacturing a semiconductor device. [Figure 3] (a) and (b) are schematic diagrams illustrating one embodiment of a method for manufacturing a semiconductor device. [Figure 4](a), (b), and (c) are schematic diagrams showing an embodiment of a method for manufacturing a semiconductor device. [Figure 5] It is a plan view showing an example of a plurality of irradiated regions. [Figure 6] It is a plan view showing an example of a plurality of irradiated regions. [Figure 7] It is a plan view showing an example of a plurality of irradiated regions. [Figure 8] It is a plan view showing an example of a plurality of irradiated regions. [Figure 9] It is a plan view showing an example of a plurality of irradiated regions.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0009] The sizes of the components in each figure referred to in this specification are conceptual, and the relative size relationships between the components are not limited to those shown in each figure. Duplicate explanations may be omitted.

[0010] The numerical values and ranges thereof in this specification also do not limit the scope of the present invention. The numerical range indicated by "~" in this specification indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerically described range. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0011] In this specification, (meth)acrylic acid means acrylic acid or its corresponding methacrylic acid. The same applies to other similar expressions such as (meth)acrylate and (meth)acryloyl group.

[0012] To manufacture a semiconductor device, a temporary fixing laminate for temporarily fixing a semiconductor member to a support substrate is prepared while processing the semiconductor member. FIG. 1 is a cross-sectional view showing some embodiments of the temporary fixing laminate. The temporary fixing laminate 1 shown in FIG. 1 has a support substrate 10 having a main surface as a support surface S1 and a back surface S2 on the back side thereof, and a temporary fixing material layer 30 provided on the support surface S1 of the support substrate 10. The temporary fixing material layer 30 has a curable resin layer 31. The curable resin layer 31 includes the outermost surface S3 of the temporary fixing material layer 30 on the side opposite to the support substrate 10. In addition, the temporary fixing material layer 30 has a light absorption layer 32 provided as a layer separate from the curable resin layer 31, or a light absorption layer 31B provided as a part of the curable resin layer 31. The light absorption layers 32 and 31B are layers that absorb light and generate heat.

[0013] The temporary fixing material layer 30 of the temporary fixing laminate 1 shown in FIG. 1(a) has a curable resin layer 31 including the outermost surface S3 on the side opposite to the support substrate 10 and a light absorption layer 32 provided as a layer separate from the curable resin layer 31. In other words, the light absorption layer 32 and the curable resin layer 31 are laminated in this order on the support surface S1 which is one of the main surfaces of the support substrate 10.

[0014] The temporary fixing material layer 30 of the temporary fixing laminate 1 shown in FIG. 1(b) consists of a curable resin layer 31 including a light absorption layer 31B as a part thereof. The curable resin layer 31 here has a light absorption layer 31B including the outermost surface S3 and a substantially non-heat-generating curable resin layer 31A provided on the support substrate 10 side of the light absorption layer 31B.

[0015] In the case of the temporary fixing material layer 30 of the temporary fixing laminate 1 shown in FIG. 1(c), in addition to the light absorption layer 31B similar to that in FIG. 1(b), a light absorption layer 32 is further provided as a layer separate from the curable resin layer 31. Instead of the light absorption layer 32 provided as a layer separate from the curable resin layer 31, a light absorption layer constituting a part of the curable resin layer 31 may be further provided between the curable resin layer 31A and the support substrate 10.

[0016] The temporary fixing laminate 1 can be obtained, for example, by sequentially forming each layer on a support substrate 10. Alternatively, a laminated film having a curable resin layer and a light-absorbing layer may be prepared and laminated on the support substrate 10.

[0017] Figures 2, 3, and 4 are process diagrams illustrating one embodiment of a method for manufacturing a semiconductor device using a temporary fixing laminate. Here, the method using the temporary fixing laminate 1 shown in Figure 1(a) is illustrated, but semiconductor devices can be manufactured similarly using temporary fixing laminates of other configurations. The method shown in Figures 2 to 4 comprises, in this order, the steps of: temporarily fixing the semiconductor member 45 to the support substrate 10 via a temporary fixing material layer 30 (Figure 2); processing the semiconductor member 45 that has been temporarily fixed to the support substrate 10 (Figure 3(a)); forming a sealing layer 50 to seal the processed semiconductor member 45 (Figure 3(b)); and irradiating the temporary fixing laminate 1 with light hν from the support substrate 10 side, thereby separating the semiconductor member 45 from the support substrate 10 (Figure 4(b)). The semiconductor member 45 has a semiconductor substrate 40 and a redistribution layer 41 provided on one side of the semiconductor substrate 40. The semiconductor component 45 may be placed on the curable resin layer 31 in an orientation such that the redistribution layer 41 is located on the curable resin layer 31 side.

[0018] The support substrate 10 is a plate-like body with high transmittance that can withstand the loads applied during the processing of the semiconductor component 45. Examples of the support substrate 10 include an inorganic glass substrate and a transparent resin substrate.

[0019] The thickness of the support substrate 10 may be, for example, 0.1 to 2.0 mm. If the thickness of the support substrate 10 is 0.1 mm or more, handling tends to be easier. If the thickness of the support substrate 10 is 2.0 mm or less, material costs tend to be reduced.

[0020] The outermost surface S3 of the temporary fixing material layer 30 on the side to which the semiconductor member 45 is temporarily fixed is the surface of the curable resin layer 31. For example, by curing the curable resin layer 31 with the semiconductor member 45 placed on it, the semiconductor member 45 can be temporarily fixed to the support substrate 10. In other words, the semiconductor member 45 can be temporarily bonded to the support substrate 10 via the temporary fixing material layer 30 having the cured curable resin layer 31c.

[0021] The curable resin layer 31 is a layer containing a curable resin composition that hardens by heat or light. Before hardening, the curable resin layer 31 has sufficient adhesiveness (or adhesiveness) to allow the semiconductor member 45 to be attached by pressure or the like. The hardened curable resin layer 31c holds the semiconductor member 45 to be processed. In this specification, all components other than the conductive particles constituting the curable resin layer 31 are considered to be components of the curable resin composition.

[0022] The thickness of the curable resin layer 31 may be, for example, 2000 μm or less, 500 μm or less, or 200 μm or less, or it may be 0.1 μm or more, or 1 μm or more, from the viewpoint of stress relaxation.

[0023] The storage modulus of the cured curable resin layer 31c at 25°C may be 5 to 100 MPa. If the storage modulus of the cured curable resin layer 31c at 25°C is 5 MPa or higher, the support substrate 10 is more likely to hold the semiconductor member 45 without bending. Also, when the semiconductor member 45 is separated from the support substrate, the curable resin layer 31c tends to leave less residue on the semiconductor member 45. If the storage modulus of the cured curable resin layer 31c at 25°C is 100 MPa or lower, the displacement of the semiconductor member 45 tends to be reduced. From a similar viewpoint, the storage modulus of the cured curable resin layer 31c at 25°C may be 5.5 MPa or higher, 6.0 MPa or higher, or 6.3 MPa or higher, and may be 90 MPa or lower, 80 MPa or lower, 70 MPa or lower, or 65 MPa or lower. In this specification, the storage modulus of the cured curable resin layer 31c refers to the value obtained by viscoelastic measurement under the conditions of a heating rate of 5°C / min, a frequency of 1 Hz, and tensile mode.

[0024] The storage modulus of the cured curable resin layer 31c at 25°C can be increased, for example, by increasing the content of the hydrocarbon resin described later, by using a hydrocarbon resin with a high Tg, or by adding an insulating filler to the curable resin composition.

[0025] The storage modulus of the cured curable resin layer 31c at 250°C may be 0.70 MPa or higher, 0.80 MPa or higher, 0.85 MPa or higher, or 0.90 MPa or higher, and may be 2.00 MPa or lower, 1.90 MPa or lower, 1.80 MPa or lower, or 1.75 MPa or lower.

[0026] The curable resin composition constituting the curable resin layer 31 may contain a thermosetting resin and a hydrocarbon resin. The hydrocarbon resin is a resin whose main skeleton is composed of hydrocarbons. When the curable resin composition contains a hydrocarbon resin, the semiconductor member 45 is easily attached to the curable resin layer 31 at low temperatures.

[0027] From the viewpoint of the adhesive properties of the curable resin layer 31 at low temperatures, the glass transition temperature (Tg) of the hydrocarbon resin may be 50°C or lower. From the viewpoint of good peelability of the curable resin layer 31, the Tg of the hydrocarbon resin may be -100°C or higher, or -50°C or higher.

[0028] The Tg of hydrocarbon resins is the midpoint glass transition temperature value obtained by differential scanning calorimetry (DSC). Specifically, the Tg of hydrocarbon resins is the midpoint glass transition temperature calculated by measuring the change in heat quantity under conditions of a heating rate of 10°C / min and a measurement temperature of -80 to 80°C, using a method compliant with JIS K 7121.

[0029] The hydrocarbon resin includes, for example, at least one selected from the group consisting of ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-propylene-1-butene copolymer elastomer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-styrene copolymer, ethylene-norbornene copolymer, propylene-1-butene copolymer, ethylene-propylene-unconjugated diene copolymer, ethylene-1-butene-unconjugated diene copolymer, ethylene-propylene-1-butene-unconjugated diene copolymer, polyisoprene, polybutadiene, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), and hydrogenated versions thereof. These hydrocarbon resins may have carboxyl groups. Carboxyl groups are introduced, for example, by modification using maleic anhydride. The hydrocarbon resin may also contain a styrene-based resin that includes monomer units derived from styrene. The styrene-based resin may be a styrene-ethylene-butylene-styrene block copolymer (SEBS).

[0030] The weight-average molecular weight (Mw) of the hydrocarbon resin may be between 10,000 and 5,000,000 or between 100,000 and 2,000,000. A weight-average molecular weight of 10,000 or more tends to make it easier to ensure the heat resistance of the temporary fixing layer 30. A weight-average molecular weight of 5,000,000 or less tends to make it easier to suppress the decrease in flow and adhesion of the temporary fixing layer 30. The weight-average molecular weight here is the polystyrene equivalent value using a calibration curve with standard polystyrene by gel permeation chromatography (GPC).

[0031] The hydrocarbon resin content may be 40 parts by mass or more, 50 parts by mass or more, or 60 parts by mass or more, or 90 parts by mass or less, 85 parts by mass or less, or 80 parts by mass or less, based on 100 parts by mass of the total mass of the curable resin composition constituting the curable resin layer 31. When the hydrocarbon resin content is within these numerical ranges, it tends to be easier to form a thin, flat curable resin layer 31. In addition, the curable resin layer 31 tends to have good pressure-sensitive adhesion at low temperatures and an appropriate storage modulus after curing.

[0032] Thermosetting resins are components that cure curable resin compositions through a thermosetting reaction. The thermosetting reaction can be a reaction between the thermosetting resin and a curing agent, self-polymerization of the thermosetting resin, or a combination thereof. Examples of thermosetting resins include epoxy resins, acrylic resins, silicone resins, phenolic resins, thermosetting polyimide resins, polyurethane resins, melamine resins, and urea resins. These may be used individually or in combination of two or more. Thermosetting resins may also contain epoxy resins due to their superior heat resistance, workability, and reliability.

[0033] An epoxy resin is a compound having one or more epoxy groups. An epoxy resin may have two or more epoxy groups. Examples of epoxy resins having two or more epoxy groups include bisphenol A type epoxy resins, novolac type epoxy resins (such as phenol novolac type epoxy resins), glycidylamine type epoxy resins, heterocyclic epoxy resins, and alicyclic epoxy resins.

[0034] The curable resin composition may contain a thermosetting resin and its curing agent. The total content of the thermosetting resin and its curing agent may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more, and may be 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, based on 100 parts by mass of the total mass of the curable resin composition. When the total content of the thermosetting resin and its curing agent is within these ranges, there is a tendency for a thin, flat curable resin layer to be easily formed, and the heat resistance of the cured curable resin layer 31c tends to be better.

[0035] When epoxy resin is used as the thermosetting resin, the curable resin composition may contain a curing agent for the epoxy resin. The curing agent for the epoxy resin is not particularly limited, but examples include amines, polyamides, acid anhydrides, polysulfides, boron trifluoride, bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), and phenol resins (phenol novolac resins, bisphenol A novolac resins, cresol novolac resins, phenol aralkyl resins, etc.).

[0036] The thermosetting resin composition may further contain a curing accelerator that promotes the curing reaction of the thermosetting resin, such as an epoxy resin. Examples of curing accelerators include imidazole compounds, dicyandiamides, dicarboxylic acid dihydrazides, triphenylphosphines, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole-tetraphenylborate, and 1,8-diazabicyclo[5,4,0]undecene-7-tetraphenylborate. These may be used individually or in combination of two or more.

[0037] The content of the curing accelerator may be 0.01 to 5 parts by mass per 100 parts by mass of the total amount of thermosetting resin and curing agent. When the content of the curing accelerator is within this range, the curability of the curable resin layer and the heat resistance after curing tend to be better.

[0038] The curable resin composition constituting the curable resin layer 31 may contain a polymerizable monomer having a polymerizable unsaturated group and a polymerization initiator. In this case as well, the curable resin composition may further contain the hydrocarbon resin described above.

[0039] Polymerizable monomers are compounds having polymerizable unsaturated groups such as ethylenically unsaturated groups. Polymerizable monomers may be monofunctional, difunctional, or trifunctional or more, but from the viewpoint of obtaining sufficient curability, polymerizable monomers with two or more functions may be used. Examples of polymerizable monomers include (meth)acrylates, vinylidene halides, vinyl ethers, vinyl esters, vinylpyridines, vinyl amides, and arylated vinyls. Polymerizable monomers may also be (meth)acrylates or (meth)acrylic acid. (Meth)acrylates may be monofunctional (meth)acrylates, difunctional (meth)acrylates, polyfunctional (meth)acrylates with three or more functions, or combinations thereof.

[0040] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, and decyl (meth)acrylate. 2-Hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, 3-Chloro-2-Hydroxypropyl (meth)acrylate, 2-Hydroxybutyl (meth)acrylate, Methoxypolyethylene glycol (meth)acrylate, Ethoxypolyethylene glycol (meth)acrylate, Methoxypolypropylene glycol (meth)acrylate, Ethoxypolypropylene glycol (meth)acrylate, and mono(2-(meth)acryloyloxyethyl) succinate, etc. Aliphatic (meth)acrylates; as well as benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthoxyethyl (meth)acrylate, 2-naphthoxyethyl (meth)acrylate, phenoxypolyethylene glycol Aromatic (meth)acrylates such as (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, phenoxypolypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl (meth)acrylate, and 2-hydroxy-3-(2-naphthoxy)propyl (meth)acrylate are examples.

[0041] Examples of difunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 2-butyl-2-ethyl-1,3-propane Aliphatic (meth)acrylates such as diol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, glycerin di(meth)acrylate, tricyclodecanedimethanol (meth)acrylate, and ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate; as well as ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, Examples of aromatic (meth)acrylates include ethoxylated propoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol F di(meth)acrylate, propoxylated bisphenol F di(meth)acrylate, ethoxylated propoxylated bisphenol F di(meth)acrylate, ethoxylated fluorene-type di(meth)acrylate, propoxylated fluorene-type di(meth)acrylate, and ethoxylated propoxylated fluorene-type di(meth)acrylate.

[0042] Examples of polyfunctional (meth)acrylates with three or more functions include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, ethoxylated propoxylated pentaerythritol tri(meth)acrylate, penta Examples include aliphatic (meth)acrylates such as erythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated propoxylated pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetraacrylate, and dipentaerythritol hexa(meth)acrylate; and aromatic epoxy (meth)acrylates such as phenol novolac type epoxy (meth)acrylate and cresol novolac type epoxy (meth)acrylate.

[0043] These (meth)acrylates may be used individually or in combination of two or more. These (meth)acrylates may also be combined with other polymerizable monomers.

[0044] The polymerizable monomer content may be 10 to 60 parts by mass per 100 parts by mass of the curable resin composition constituting the curable resin layer 31.

[0045] A polymerization initiator is a compound that initiates the polymerization reaction of a polymerizable monomer by heating or irradiation with ultraviolet light or the like. For example, if the polymerizable monomer is a compound having an ethylenically unsaturated group, the polymerization initiator may be a thermal radical polymerization initiator, a photoradical polymerization initiator, or a combination thereof.

[0046] Examples of thermal radical polymerization initiators include diacyl peroxides such as octanoyl peroxide, lauroyl peroxide, stearyl peroxide, and benzoyl peroxide; t-butyl peroxypivalate, t-hexyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, t-hexyl peroxyisopropyl monocarbonate, and t-butyl peroxyisopropyl monocarbonate. Examples include peroxyesters such as -oxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurylate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, and t-butyl peroxyacetate; and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2'-dimethylvaleronitrile).

[0047] Examples of photoradical polymerization initiators include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-hydroxy ketones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one; and phosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

[0048] These thermal and photoradical polymerization initiators may be used individually or in combination of two or more.

[0049] The content of the polymerization initiator may be 0.01 to 5 parts by mass per 100 parts by mass of the total amount of polymerizable monomers.

[0050] The curable resin composition constituting the curable resin layer 31 may further contain other components such as insulating fillers, sensitizers, and antioxidants.

[0051] Insulating fillers are added to curable resin compositions to impart low thermal expansion and low hygroscopicity. Examples of insulating fillers include non-metallic inorganic fillers such as silica, alumina, boron nitride, titania, glass, and ceramics. These insulating fillers may be used individually or in combination of two or more types.

[0052] The amount of insulating filler may be 5 to 20 parts by mass per 100 parts by mass of the total mass of the curable resin composition constituting the curable resin layer 31. When the amount of insulating filler is within this range, the cured curable resin layer 31c tends to have excellent heat resistance and good peelability.

[0053] Examples of sensitizers include anthracene, phenanthrene, chrysene, benzopyrene, fluorantene, rubrene, pyrene, xanthon, indanthrene, thioxanthene-9-one, 2-isopropyl-9H-thioxanthene-9-one, 4-isopropyl-9H-thioxanthene-9-one, and 1-chloro-4-propoxythioxanthone. The sensitizer content may be 0.01 to 10 parts by mass per 100 parts by mass of the total mass of the curable resin composition constituting the curable resin layer 31.

[0054] Examples of antioxidants include quinone derivatives such as benzoquinone and hydroquinone, phenol derivatives such as 4-methoxyphenol and 4-t-butylcatechol, aminoxyl derivatives such as 2,2,6,6-tetramethylpiperidine-1-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and hindered amine derivatives such as tetramethylpiperidyl methacrylate. The antioxidant content may be 0.1 to 10 parts by mass per 100 parts by mass of the total mass of the curable resin composition constituting the curable resin layer 31.

[0055] The curable resin layer 31 is provided on the light-absorbing layer 32 by, for example, preparing a laminated film having a support film and a curable resin layer formed on the support film in advance and attaching it to the light-absorbing layer 32. The attachment of the laminated film to the light-absorbing layer 32 can be done at room temperature (20°C) or while heating using a roll laminator, vacuum laminator, etc. The laminated film having a support film and a curable resin layer can be obtained, for example, by a method including applying a resin varnish containing a thermosetting resin or polymerizable monomer, an organic solvent, and other components as needed to the support film, and removing the organic solvent from the coating. Alternatively, the curable resin layer 31 may be formed on the light-absorbing layer 32 by directly applying a similar resin varnish to the light-absorbing layer 32 and removing the organic solvent from the coating.

[0056] The light-absorbing layer 32 is a layer that absorbs light and generates heat. An example of the light-absorbing layer 32 is a conductive layer containing a conductor that absorbs light and generates heat. Examples of conductors that constitute the conductive layer as the light-absorbing layer 32 include metals, metal oxides, and conductive carbon materials. The metal may be a single metal such as chromium, copper, titanium, silver, platinum, or gold, or an alloy such as nickel-chromium, stainless steel, or copper-zinc. Examples of metal oxides include indium tin oxide (ITO), zinc oxide, and niobium oxide. These may be used individually or in combination of two or more. The conductor may be chromium, titanium, or a conductive carbon material.

[0057] The light-absorbing layer 32 may be a single layer or a metal layer consisting of multiple layers. For example, the light-absorbing layer 32 may be a metal layer consisting of a copper layer and a titanium layer. The metal layer as the light-absorbing layer 32 may be a layer formed by physical vapor deposition (PVD) such as vacuum deposition and sputtering, chemical vapor deposition (CVD) such as plasma chemical deposition, or a plated layer formed by electroplating or electroless plating. With physical vapor deposition, even if the support substrate 10 has a large area, a metal layer as the light-absorbing layer 32 that covers the surface of the support substrate 10 can be efficiently formed.

[0058] Another example of a light-absorbing layer is a layer containing conductive particles that absorb light and generate heat, and a binder resin in which the conductive particles are dispersed. The conductive particles may be particles containing the conductors described above. The binder resin may be a curable resin composition, in which case the light-absorbing layer constitutes a part of the curable resin layer 31. For example, the light-absorbing layer 31B in the temporary fixing laminate 1 of Figure 1(b) may be a layer containing conductive particles and a curable resin composition. The curable resin composition constituting the light-absorbing layer may contain the same components as the curable resin composition constituting the curable resin layers other than the light-absorbing layer. The curable resin composition constituting the light-absorbing layer may be the same as or different from the curable resin composition constituting the curable resin layers other than the light-absorbing layer. The content of conductive particles in the light-absorbing layer may be 10 to 90 parts by mass per 100 parts by mass of the binder resin or curable resin composition, i.e., the total amount of components other than conductive particles in the light-absorbing layer.

[0059] A light-absorbing layer containing conductive particles and a binder resin can be formed, for example, by a method that includes applying a varnish containing conductive particles, a binder resin, and an organic solvent onto a support substrate or a curable resin layer, and then removing the organic solvent from the coating. A pre-fabricated light-absorbing layer 32 may be laminated onto the support substrate 10 or a curable resin layer. A laminate consisting of a light-absorbing layer and a curable resin layer may be laminated onto the support substrate.

[0060] The thickness of the light-absorbing layer 32 may be 1 to 5000 nm or 100 to 3000 nm from the viewpoint of easy peelability. When the thickness of the light-absorbing layer 32 is 50 to 300 nm, the light-absorbing layer 32 tends to have a sufficiently low transmittance.

[0061] The thickness of the temporary fixing material layer 30 (in the case of Figure 1(a), the total thickness of the light-absorbing layer 32 and the curable resin layer 31) may be 0.1 to 2000 μm or 10 to 500 μm from the viewpoint of stress relaxation.

[0062] After preparing the temporary fixing laminate 1, the semiconductor member 45 before processing is placed on the curable resin layer 31, as shown in Figure 2(a). The semiconductor member 45 has a semiconductor substrate 40 and a redistribution layer 41. The semiconductor member 45 may also have external connection terminals. The semiconductor substrate 40 may be a semiconductor wafer or a semiconductor chip obtained by dividing a semiconductor wafer. In the example of Figure 2(a), multiple semiconductor members 45 are placed on the curable resin layer 31, but the number of semiconductor members may be one. For example, a semiconductor member having one semiconductor wafer as a semiconductor substrate may be placed on the curable resin layer of one temporary fixing laminate.

[0063] The thickness of the semiconductor component 45 may be 1 to 1000 μm, 10 to 500 μm, or 20 to 200 μm, in order to miniaturize and thin the semiconductor device, as well as to suppress cracking during transport, processing, etc.

[0064] The semiconductor component 45 placed on the curable resin layer 31 is pressed against the curable resin layer 31 using, for example, a vacuum press or a vacuum laminator. When using a vacuum press, the pressing conditions can be a pressure of 1 hPa or less, a pressing pressure of 1 MPa, a pressing temperature of 120 to 200°C, and a holding time of 100 to 300 seconds. When using a vacuum laminator, the pressing conditions can be, for example, a pressure of 1 hPa or less, a pressing temperature of 60 to 180°C or 80 to 150°C, a lamination pressure of 0.01 to 0.5 MPa or 0.1 to 0.5 MPa, and a holding time of 1 to 600 seconds or 30 to 300 seconds.

[0065] After the semiconductor member 45 is placed on the curable resin layer 31, the semiconductor member 45 is temporarily fixed to the support substrate 10 via a temporary fixing material layer 30 having a cured curable resin layer 31c by thermal curing or photocuring the curable resin layer 31. The thermal curing conditions may be, for example, 300°C or less or 100-200°C for 1-180 minutes or 1-60 minutes.

[0066] Next, as shown in Figure 3(a), the semiconductor component temporarily fixed to the support substrate 10 is processed. Figure 3(a) shows an example of processing including thinning of the semiconductor substrate. Processing of the semiconductor component is not limited to this and may include, for example, thinning of the semiconductor substrate, dicing of the semiconductor component, formation of through electrodes, etching, plating reflow, sputtering, or a combination thereof.

[0067] Thinning of the semiconductor substrate 40 is performed by grinding the side of the semiconductor substrate 40 opposite to the redistribution layer 41 using a grinder or the like. The thickness of the thinned semiconductor substrate 40 may be, for example, 100 μm or less.

[0068] After processing the semiconductor member 45, a sealing layer 50 may be formed to seal the processed semiconductor member 45, as shown in Figure 3(b). The sealing layer 50 can be formed using a sealing material commonly used for the manufacture of semiconductor devices. For example, the sealing layer 50 may be formed using a thermosetting resin composition. The thermosetting resin composition used for the sealing layer 50 includes epoxy resins such as cresol novolac epoxy resin, phenol novolac epoxy resin, biphenyl diepoxy resin, and naphthol novolac epoxy resin. The sealing layer 50 and the thermosetting resin composition for forming it may also contain additives such as fillers and / or flame retardants.

[0069] The sealing layer 50 is formed using, for example, a solid material, a liquid material, a fine-grained material, or a sealing film. When a sealing film is used, a compression sealing molding machine, a vacuum laminating device, etc., are used. For example, the sealing layer 50 can be formed by covering the semiconductor member 45 with a sealing film that has been heat-melted using these devices at a temperature of 40 to 180°C (or 60 to 150°C), a pressure of 0.1 to 10 MPa (or 0.5 to 8 MPa), and for 0.5 to 10 minutes. The thickness of the sealing film is adjusted so that the sealing layer 50 is greater than or equal to the thickness of the semiconductor member 45 after processing. The thickness of the sealing film may be 50 to 2000 μm, 70 to 1500 μm, or 100 to 1000 μm.

[0070] After forming the sealing layer 50, the sealing layer 50 and the curable resin layer 31c may be divided into multiple parts, each containing one semiconductor member 45, as shown in Figure 4(a).

[0071] As shown in Figure 4(b), light hν is irradiated onto the temporary fixing laminate 1 from the support substrate 10 side, thereby separating the semiconductor member 45 from the support substrate 10. Irradiation with light hν causes the light-absorbing layer 32 to absorb light and instantaneously generate heat. This generated heat can cause, for example, melting of the cured curable resin layer 31c, thermal stress between the support substrate 10 and the semiconductor member 45, and scattering of the light-absorbing layer 32. One or more of these phenomena are the main causes that allow the semiconductor member 45 to easily separate from the support substrate 10. If the curable resin composition constituting the curable resin layer 31 contains a hydrocarbon resin and the storage modulus of the cured curable resin layer at 25°C is 5 to 100 MPa, delamination at the interface between the light-absorbing layer 32 and the cured curable resin layer 31 tends to occur easily. This tendency is due to the energy amount of light hν being 1 to 50 J / cm². 2 This is particularly noticeable in the range of [this]. In order to separate the semiconductor member 45 from the support substrate 10, a small amount of stress may be applied to the semiconductor member 45 along with the irradiation of light hν.

[0072] In one embodiment of the method, light hν is sequentially irradiated onto a plurality of irradiated areas including the back surface S2 of the support substrate 10. Figure 5 is a plan view showing an example of a plurality of irradiated areas. In the embodiment of Figure 5, light hν is irradiated once onto each of the three irradiated areas X1, X2, and X3, each including a part of the back surface S2 and arranged in series along a certain direction. If the light hν is pulsed light, one light irradiation may include one pulse or two or more pulses. The plurality of irradiated areas X1, X2, and X3 are arranged such that, when viewed from a direction perpendicular to the back surface, adjacent irradiated areas partially overlap, and the combined area X of the plurality of irradiated areas X1, X2, and X3 includes the entire back surface S2.

[0073] In the case of Figure 5, the edge of irradiated region X1 including edge Y1 and the edge of irradiated region X2 including edge Y2 overlap. Because the portions of the edges of adjacent irradiated regions that are located directly above the back surface S2 overlap, the portions of the back surface S2 located at the edges of each irradiated region are irradiated with light hν two or more times. As a result, it is thought that the semiconductor member 45 can be easily peeled off the support substrate 10 even when the back surface S2 has a large area. Even when light of substantially uniform intensity is irradiated over the entire irradiated region, the semiconductor member 45 may be difficult to peel off the support substrate 10. The inventors estimate that this is because the energy of the irradiated light is easily diffused at the edges of the irradiated region.

[0074] The width W1 of the overlapping portion of adjacent irradiated areas may be any width that allows the semiconductor material 45 to be properly peeled off, for example, 0.05 cm or more, or 0.1 cm or more, or 1000 cm or less. The ratio of width W1 to width W0 of the irradiated area may be 0.05 or more, or 0.1 or more, or 0.9 or less. Here, widths W0 and W1 refer to the maximum width of the irradiated area and the overlapping portion, respectively, in a direction perpendicular to the outer circumference of the irradiated area.

[0075] The shape of the irradiated area is not particularly limited, but can be a rectangle, for example, as shown in Figure 5. For example, when using a light source (e.g., a lamp) with a light-emitting surface, the area obtained by perpendicularly projecting the light-emitting surface onto a plane including the back surface S2 can be considered as the irradiated area. The light source may be a lamp with a light-emitting surface that supplies light of substantially uniform intensity (energy amount) to the entire irradiated area. For example, the amount of light energy [J / cm²] across the entire light-emitting surface of the lamp can be used. 2 The result may be within ±5.0% of the overall average.

[0076] The area of ​​the back surface S2 of the support substrate 10 is 100 mm². 2 Above, or 400mm 2 It may be greater than or equal to 1,000,000 mm 2 The following is also possible: Even when the area of ​​the back surface S2 of the support substrate 10 is large, the light irradiation method according to this embodiment allows for easy removal of the semiconductor member. Furthermore, damage to the support substrate 10 is suppressed.

[0077] By moving the relative position of the light source with respect to the support substrate 10, multiple irradiated areas can be sequentially irradiated with light hν. The support substrate 10 may be moved while the light source is fixed. Alternatively, the light source may be moved while the support substrate 10 is fixed. In the embodiment shown in Figure 5, the position of the light source with respect to the support substrate 10 is intermittently moved between positions corresponding to the irradiated areas X1, X2, and X3, respectively, and light hν is irradiated while the light source is stopped relative to the support substrate 10. The order in which the irradiated areas are irradiated with light is arbitrary.

[0078] The number, size, and position of the multiple irradiated areas are not limited to the configuration shown in Figure 5. The combined area of ​​the multiple irradiated areas must include the entire back surface S2, and each irradiated area's edge, including the back surface S2, must be irradiated at least twice. Figures 6, 7, and 8 are plan views showing other examples of multiple irradiated areas. In Figure 6, instead of showing the irradiated areas other than the irradiated area X1 to which the first light is irradiated, the centers C1, C2, C3, and C4 of each irradiated area are shown. The arrow Z indicates the direction of movement of the light source relative to the support substrate 10 (i.e., the irradiated area). A similar method of illustration is applied in Figures 7 and 8. In the example in Figure 6, four irradiated areas, including the back surface S2 of the support substrate 10, are irradiated four times sequentially in a clockwise direction. In the example in Figure 7, nine irradiated areas, including the back surface S2 of the support substrate 10, are irradiated nine times sequentially in a clockwise direction. The last irradiated area includes the center of the back surface S2. In the example shown in Figure 8, starting from the first irradiated area X1 which includes the center of the back surface S2, the nine irradiated areas of the support substrate 10, including the back surface S2, are sequentially irradiated nine times in a clockwise direction.

[0079] As shown in the example in Figure 9, the light hν may be sequentially irradiated to multiple irradiated areas by rotating the support substrate while the light source is fixed. In the embodiment of Figure 9, the light hν is irradiated by a light source fixed to the upper part of the circular back surface S2 of the support substrate 10. After irradiating the first irradiated area X1 with light hν, the support substrate 10 is rotated 45° in a clockwise direction CW, and the irradiated areas X2, X3, X4, X5, X6, X7, and X8 are irradiated once each in that order. Each of the eight irradiated areas X1 to X8 includes a part of the back surface S2. The rotation angle of the support substrate 10 is not limited to 45°, but can be changed to any angle such that the combined area of ​​the multiple irradiated areas includes the entire back surface S2. The rotation direction may also be counterclockwise. The method of rotating the support substrate 10 is advantageous in that the distance traveled by the support substrate 10 or the light source is smaller compared to, for example, a method of moving the support substrate 10 or the light source linearly. This method is particularly easy to apply when the back surface S2 of the support substrate 10 is circular.

[0080] The light hν can be incoherent light or coherent light such as laser light. Incoherent light is non-coherent light, and is an electromagnetic wave that has properties such as not generating interference fringes, low coherence, and low directivity. Incoherent light tends to attenuate as the optical path length increases. Laser light is generally coherent light, while sunlight, fluorescent light, etc., are incoherent light. Incoherent light can also be defined as light other than laser light. In the method of this embodiment, even with incoherent light with a relatively low energy level, the processed semiconductor material can be easily separated from the support substrate. By using incoherent light with a low energy level, damage to fine structures such as the redistribution layer of the semiconductor material can be suppressed. The irradiation area of ​​incoherent light is generally overwhelmingly larger than that of coherent light (i.e., laser light), so it is possible to reduce the number of irradiations.

[0081] Light hν may include infrared light. Light hν may also be pulsed light. When light hν is incoherent light, the light source is not particularly limited, but may be a xenon lamp. A xenon lamp is a lamp that utilizes light emission by applying and discharging a discharge tube filled with xenon gas. Because a xenon lamp discharges while repeatedly ionizing and exciting, it stably has a continuous wavelength range from the ultraviolet light region to the infrared light region. Compared to lamps such as metal halide lamps, xenon lamps have a shorter start-up time, which can significantly reduce the time required for the process. Although high heat is instantaneously generated because a high voltage is applied for light emission, xenon lamps are advantageous because they have a short cooling time and allow for continuous operation.

[0082] The irradiation conditions for the xenon lamp include the applied voltage, pulse width, irradiation time, irradiation distance (distance between the light source and the temporary fixing material layer), and irradiation energy, and these can be arbitrarily set according to the number of irradiations, etc.

[0083] A portion of the curable resin layer 31c may adhere to the separated semiconductor member 45 as a residue 31c'. The adhered residue 31c' is removed as shown in Figure 4(c). The residue 31c' is removed, for example, by washing with a solvent. The solvent is not particularly limited, but examples include ethanol, methanol, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, hexane, etc. These may be used individually or in combination of two or more. To remove the residue 31c', the semiconductor member 45 may be immersed in the solvent or ultrasonic cleaning may be performed. The semiconductor member 45 may also be heated at a low temperature of about 100°C or below.

[0084] By the method illustrated above, a semiconductor element 60 comprising the processed semiconductor member 45 can be obtained. A semiconductor device can be manufactured by connecting the obtained semiconductor element 60 to another semiconductor element or a substrate for mounting semiconductor elements. [Examples]

[0085] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0086] 1. Fabrication of a laminate for temporary fixation 1-1. Curable resin layer A 40% by mass elastomer solution was prepared by dissolving hydrogenated styrene-butadiene elastomer (product name: Dynalon 2324P, JSR Corporation) in toluene. A resin varnish was obtained by mixing the elastomer solution containing 80 parts by mass of hydrogenated styrene-butadiene elastomer with 20 parts by mass of 1,9-nonanediol diacrylate (product name: FA-129AS, Hitachi Chemical Co., Ltd.) and 1 part by mass of peroxyester (product name: Perhexa 25O, NOF Corporation).

[0087] The obtained resin varnish was applied to the release surface of a polyethylene terephthalate (PET) film (Purex A31, Teijin DuPont Films Ltd., thickness: 38 μm) using a precision coating machine. The coating was dried by heating at 80°C for 10 minutes to form a curable resin layer with a thickness of approximately 100 μm.

[0088] 1-2. Light-absorbing layer A rectangular glass slide measuring 110 x 110 mm was prepared as a support substrate. A titanium layer and then a copper layer were formed on the prepared glass slide by sputtering to create a light-absorbing layer consisting of two layers: a titanium layer (thickness: 20 nm) and a copper layer (thickness: 200 nm). In the sputtering process, the titanium and copper layers were formed by RF sputtering after pretreatment by reverse sputtering.

[0089] 1-3. Laminate for temporary fixing A curable resin layer, cut to a size of 100 x 100 mm, was placed on a light-absorbing layer formed on a glass slide. The curable resin layer was adhered to the light-absorbing layer by vacuum lamination to obtain a temporary fixing laminate having a laminated structure of support substrate / light-absorbing layer / curable resin layer.

[0090] 2. Peel test Examples A semiconductor chip (size: 100 mm x 100 mm) was placed on a curable resin layer of a temporary fixing laminate. The curable resin layer was cured by heating at 180°C for 1 hour to obtain a test specimen for peeling tests, which had the semiconductor chip temporarily fixed to the support substrate.

[0091] From the support substrate side of the temporary fixing laminate, pulsed light was irradiated from a xenon lamp onto each of the three irradiated areas, including the back surface of the support substrate. The edges of adjacent irradiated areas overlapped, and the width W1 of the overlapping portion was 0.75 cm. A NovaCentrix PulseForge® 1300 was used as the xenon lamp. This xenon lamp has a light-emitting surface measuring 150 mm × 75 mm that emits substantially uniform light. The wavelength range of the emitted light is 200 nm to 1500 nm. One pulse of light with an applied voltage of 800 V and a pulse width of 250 μs was irradiated onto each irradiated area. The energy of each irradiated pulse was 3.4 J / cm². 2 That was the case.

[0092] By irradiating three areas with light, the semiconductor chip was detached without causing the glass slide to crack.

[0093] Comparative Example From the slide glass side of the temporary fixing laminate similar to that in the example, pulsed light from a xenon lamp was irradiated under the same conditions as in the example to two irradiated areas that were in contact with each other in the center of the back surface of the slide glass, so that their edges did not overlap. After irradiation, it was confirmed that the semiconductor chip had not peeled off in the center of the slide glass. [Explanation of Symbols]

[0094] 1... Laminate for temporary fixing, 10... Support substrate, 30... Temporary fixing material layer, 31, 31A, 31c... Curable resin layer, 31B, 32... Light absorption layer, 40... Semiconductor substrate, 41... Redistribution layer, 45... Semiconductor component, 50... Encapsulation layer, 60... Semiconductor element, hν... Light, S3... Outer surface, S1... Support surface, S2... Back surface, X... Area including irradiated region, X1, X2, X3... Irradiated region.

Claims

1. A step of preparing a temporary fixing laminate comprising a support substrate having a support surface and a back surface on the opposite side thereof, and a temporary fixing material layer provided on the support surface, wherein the temporary fixing material layer has a curable resin layer including at least one outermost surface of the temporary fixing material layer, A step of temporarily fixing the semiconductor component to the support substrate via the temporary fixing material layer, A step of processing the semiconductor member that has been temporarily fixed to the support substrate, The process involves irradiating the temporary fixing laminate with light from the back side, thereby separating the semiconductor member from the support substrate. They are provided in this order, A part or all of the aforementioned temporary fixing layer is a light-absorbing layer that absorbs light and generates heat. The light is sequentially irradiated onto a plurality of irradiated areas, and each of the irradiated areas includes a part of the back surface. When viewed from a direction perpendicular to the back surface, adjacent irradiated regions partially overlap, and the combined region of multiple irradiated regions includes the entire back surface. A method for manufacturing semiconductor devices.

2. The method according to claim 1, wherein the light is incoherent light.

3. The method according to claim 2, wherein the light source of the incoherent light is a xenon lamp.

4. The method according to any one of claims 1 to 3, wherein the temporary fixing material layer has a metal layer provided as a separate layer from the curable resin layer as the light absorbing layer.

5. The method according to any one of claims 1 to 4, wherein the light is sequentially irradiated onto a plurality of irradiated areas by rotating the support substrate while the light source is fixed.

Images