JP2007157792A - Method of manufacturing wafer scale semiconductor package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a wafer scale semiconductor package which can form a pattern of an adhesive layer with a high positional and thickness accuracy and can increase the productivity. <P>SOLUTION: The method of manufacturing a wafer scale semiconductor package having a hollow part 6 inside includes a process of forming the adhesive layer 3 on a semiconductor wafer 1 using an adhesive; process wherein by irradiating light on the adhesive layer 3 via a negative photo mask 4 to expose the adhesive layer 3, the light-irradiated part of the adhesive layer 3 is changed to a pattern of a heat-sensitive adhesive layer 5 in a B-stage state; process of removing by development of the part not irradiated by the light at the time of exposure; process of bonding a sealing plate 2 to the heat-sensitive adhesive layer 5 left over after the development by bringing the plate into contact with the adhesive layer 5 and heating it; and process of dicing the semiconductor wafer 1 and the sealing plate 2 which are bonded together by heating, into individual pieces. These processors are carried out in the order described above. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a semiconductor package having a hollow portion inside, such as an optical semiconductor, a MEMS, and an RF semiconductor, on a wafer scale.

  In optical semiconductors such as image sensors and acceleration sensors, in order to ensure light transmission and movement of internal mechanical parts, a hollow part is provided in the semiconductor package, and a sealing plate made of glass, metal, ceramic, etc. It is necessary to bond with the arranged adhesive (see, for example, Patent Document 1). Conventionally, a method in which a chip obtained by dicing a semiconductor wafer is mounted on another substrate with a cavity, an adhesive layer is provided around the cavity, and a sealing plate is bonded, but in recent years, Aiming at miniaturization and cost reduction, a manufacturing method by so-called wafer scale packaging, in which an extraction electrode is formed on the back surface of the wafer and a sealing plate is attached on the wafer before singulation, is attracting attention. . In image sensors and MEMS, wafer scale packaging, which is a process that may be contaminated by foreign matter such as dicing or assembly, after the sealing plate attachment process, improves the yield. Is highly effective. Many methods have been proposed for the bonding process of the sealing plate in the wafer scale package.

  For example, as shown in FIGS. 2 and 3, an adhesive layer 3 having a lattice pattern is formed on a semiconductor wafer 1, and a sealing plate 2 covering the entire semiconductor wafer 1 is adhered and attached, and then the adhesive is used. The method of dicing into pieces by including singers has many advantages.

  Specifically, FIG. 2 shows an example of a method for manufacturing an image sensor as a semiconductor package. In this method, first, an adhesive layer 3 having a lattice pattern is formed on a silicon wafer as a semiconductor wafer 1 (FIG. 2A), and then transparent glass as a sealing plate 2 is heated to the adhesive layer. After crimping (FIG. 2 (b)), a semiconductor package as shown in FIG. 2 (c) having a hollow portion 6 inside can be obtained by dicing into individual pieces for each lattice.

  On the other hand, FIG. 3 shows an example of a method for manufacturing a three-dimensional acceleration sensor MEMS as a semiconductor package. In this method, first, an acceleration sensor mechanism portion 8 is formed in a plurality of cavities 7 provided on the surface of a silicon wafer that is a semiconductor wafer 1 by a MEMS process, and an adhesive layer 3 is formed at an opening edge of the cavity 7. (FIG. 3A). Next, after the sealing plate 2 is thermocompression bonded to the adhesive layer 3 (FIG. 3 (b)), it is diced for each lattice and separated into individual pieces, so that FIG. A semiconductor package as shown can be obtained. Moreover, it is usually efficient to perform dicing for dividing into pieces including the center of the adhesive layer 3 as shown by broken lines in FIGS.

  In manufacturing the semiconductor package as described above, the pattern accuracy of the adhesive layer is required to be very strict. If the pattern width is too large, the active portion of the semiconductor is covered and a defect occurs. If the pattern width is too small, the bonded portion is chipped after dicing. Also, if the pattern thickness of the adhesive layer varies, part of the adhesive layer can be adhered, but another part will have poor adhesion, and the adhesive part will be chipped after dicing, or reliability will be obtained due to poor adhesion. The problem of not being able to occur.

Generally, the following three methods are used as a method for forming a lattice pattern of an adhesive on a semiconductor wafer. That is, the first method is to apply a liquid adhesive in a desired shape using a dispenser, and the second method is to print the liquid adhesive through a mask having a desired shape pattern. In addition, the third method is to cut and paste a sheet-like adhesive into a desired shape pattern.
JP-A-3-179765

  However, the above three methods for forming a grid pattern of adhesive have the following problems.

  In other words, the adhesive pattern formation method using the dispenser method (the first method) is easy and widely used, but each line pattern must be formed one after another, so that Inferiority / Unable to form a pattern with high position accuracy / Uniform thickness control is difficult, especially where the intersection of the lines is raised / Limited to low-viscosity liquid adhesives Yes.

  In addition, the adhesive pattern forming method using the printing method (the second method) can form many patterns at a time, so it is excellent in productivity, but in terms of position accuracy and thickness accuracy. In addition to having the same problems as the dispenser method, it requires the properties of a liquid adhesive that can be printed (does not cause sagging or blurring), and the applicable thickness is limited due to the construction method. .

  Further, in the method of using the last sheet-like adhesive by cutting it into a desired shape (the third method), it is possible to cut with high productivity if punching or the like is used, but the pattern is finely complicated or has a thickness. However, in applications that are not sufficient, it is difficult to handle in the process of attaching to the sealing plate in the next stage, and the productivity is not high. Furthermore, it is difficult to ensure the positional accuracy in the attaching process, and there is a problem that foreign matter generated during punching may be mixed into the hollow portion or the like.

  The present invention has been made in view of the above points, and provides a method for manufacturing a wafer-scale semiconductor package that can form a pattern of an adhesive layer with high positional accuracy and thickness accuracy and can achieve high productivity. It is intended to provide.

  The method for manufacturing a wafer scale semiconductor package according to claim 1 of the present invention is a method for manufacturing a wafer scale semiconductor package having a hollow portion 6 therein, and the adhesive layer 3 is formed on the semiconductor wafer 1 using an adhesive. A step of irradiating the adhesive layer 3 with light through the negative photomask 4 and exposing it, thereby changing the irradiated portion to a pattern of the heat-sensitive adhesive layer 5 in a B-stage state; A step of removing by developing a portion that was not irradiated with light at the time of exposure, a step of bringing the sealing plate 2 into contact with the heat-sensitive adhesive layer 5 remaining after the development, and heating to bond, and heating. The bonded semiconductor wafer 1 and the sealing plate 2 are diced into individual pieces and are sequentially processed.

  The invention according to claim 2 is characterized in that, in claim 1, the degree of B-staging of the heat-sensitive adhesive layer 5 is adjusted by heat-aging the adhesive layer 3 before developing after exposure. It is what.

  The invention according to claim 3 is characterized in that, in claim 1 or 2, the temperature during exposure is 50 ° C. or less.

  The invention according to claim 4 is characterized in that in any one of claims 1 to 3, a liquid or sheet-like material containing a cationically polymerizable resin and a photocationic polymerization initiator is used as the adhesive. It is.

  According to the method for manufacturing a wafer-scale semiconductor package according to claim 1 of the present invention, the pattern of the heat-sensitive adhesive layer in the B-stage state is applied to the surface of the semiconductor wafer by using the photolithography method. In addition, since the heat-sensitive adhesive layer is in a B-stage state, the adhesiveness between the semiconductor wafer and the sealing plate can be increased. Thus, a highly reliable wafer scale semiconductor package can be manufactured with a high yield.

  According to the invention which concerns on Claim 2, reaction can be advanced to such an extent that it can develop easily, staying at the reaction degree of the grade which can be heat-bonded later.

  According to the invention which concerns on Claim 3, acceleration of the B-stage formation by heat can be suppressed.

  According to the invention which concerns on Claim 4, the heat sensitive adhesive layer of the B stage state which does not melt | dissolve in a developing solution can be formed easily.

  Embodiments of the present invention will be described below.

  The method for manufacturing a wafer scale semiconductor package according to the present invention is a method for manufacturing a wafer scale semiconductor package such as an optical semiconductor, a MEMS, and an RF semiconductor having a hollow portion 6 therein. An example of this is shown in FIG.

  In the steps shown in FIGS. 1A and 1B, first, an adhesive layer 3 is formed on the surface of the semiconductor wafer 1 using an adhesive. Here, as the semiconductor wafer 1, for example, a silicon wafer can be used. The adhesive is not particularly limited as long as it has negative photosensitivity, can be developed in a B-stage state, and can be thermally bonded. Details of such an adhesive will be described later. Further, the form of the adhesive is not particularly limited, and a liquid or sheet (film) adhesive can be used. When a liquid adhesive is used, the adhesive layer 3 can be formed on the surface of the semiconductor wafer 1 by using a spin coating method, a printing method, or the like. On the other hand, when a sheet-like adhesive is used, the adhesive layer 3 can be formed on the surface of the semiconductor wafer 1 using a laminating method or the like. Thus, in the step shown in FIG. 1B, the adhesive layer 3 can be formed on the entire surface of the semiconductor wafer 1. In the case of the semiconductor wafer 1 having a cavity as shown in FIG. 3, it is preferable to use a sheet-like adhesive.

Next, in the step shown in FIG. 1C, the adhesive layer 3 is irradiated with light such as ultraviolet rays (indicated by arrows) through a negative photomask 4 having a desired mask pattern (such as a lattice pattern). To expose. As a result, a chemical reaction occurs in a portion exposed to light, and no reaction occurs in a portion not exposed to light. In this manner, the portion of the adhesive layer 3 irradiated with light is changed to the pattern of the heat-sensitive adhesive layer 5 in the B stage state. The exposure amount is not particularly limited, but is preferably in the range of 0.1 to 10 J / cm ² .

  Next, in the step shown in FIG. 1D, light is blocked by the negative photomask 4 at the time of the previous exposure, and the portion of the adhesive layer 3 that is not irradiated with light is removed by development. Depending on the presence or absence of the chemical reaction described above, the developer resistance differs between the exposed part and the non-exposed part. Therefore, by selecting an appropriate developer / development condition, as shown in FIG. Only the part of the adhesive layer 3 exposed to light remains as the heat-sensitive adhesive layer 5 in the B stage state, and the other part of the adhesive layer 3 is removed. This series of processes is so-called “photolithography” and is a method that has been used in many fields for a long time. In the present invention, the adhesive layer 3 remaining as a pattern here is in a B-stage state. There are some features.

  Next, in the step shown in FIG. 1E, the sealing plate 2 is brought into contact with the heat-sensitive adhesive layer 5 remaining after development and heated. Then, the heat-sensitive adhesive layer 5 shifts from the B-stage state to the C-stage state, so that the semiconductor wafer 1 and the sealing plate 2 can be bonded. Here, it does not specifically limit as the sealing plate 2, For example, a glass plate, a metal plate, etc. can be used.

  In the last step, the semiconductor wafer 1 and the sealing plate 2 obtained in the previous step shown in FIG. 1E are bonded to each other by dicing into a plurality of pieces as indicated by broken lines. Then, the wafer scale semiconductor package which has the hollow part 6 inside as shown in FIG.1 (f) can be obtained. A wafer-scale semiconductor package can be obtained by dicing the center of the line of the heat-sensitive adhesive layer 5 (indicated by a broken line in FIG. 1E) into individual pieces, but the heat-sensitive adhesive layer 5 Dicing between the lines of the two heat-sensitive adhesive layers 5 without cutting the line portion may be allowed.

  If the above-described series of steps are sequentially performed, the following effects can be obtained. That is, since the photolithography method is used, the pattern of the heat-sensitive adhesive layer 5 in the B stage state can be formed on the semiconductor wafer 1 with high positional accuracy and thickness accuracy, and high productivity can be obtained. Is. More specifically, since the pattern formation of the heat-sensitive adhesive layer 55 is performed using a photolithography method, it is possible to obtain high positional accuracy, and the pattern formation is performed in a lump. Further, productivity can be increased, and the thickness of the adhesive layer 3 can be determined at an initial stage shown in FIG. Further, since the heat-sensitive adhesive layer 5 is in a B-stage state, high adhesion between the semiconductor wafer 1 and the sealing plate 2 can be obtained, and a highly reliable wafer scale semiconductor package is manufactured with high yield. Is something that can be done. Moreover, since the photolithographic method is used, even if the pattern of the heat-sensitive adhesive layer 5 has a fine and complicated shape, it can be easily formed. Further, according to the present invention, since the adhesive application accuracy is high, it is possible to obtain a wafer scale semiconductor package free from bleed, chipping, poor adhesion, etc. of the bonded portion compared to the conventional method described above. is there.

  In the present invention, the degree of B-staging of the heat-sensitive adhesive layer 5 can be adjusted by subjecting the adhesive layer 3 to heat aging before development after exposure. That is, the control of advancing the reaction to such an extent that it can be easily developed while keeping the reaction level so that it can be thermally bonded later can be performed by heat aging. The process temperature is not particularly limited, but the heat aging temperature is preferably about 50 to 130 ° C., and the sealing plate 2 adhesion temperature is preferably 150 to 250 ° C. If the heating aging temperature is lower than 50 ° C., there is a possibility that a sufficient change cannot be expected compared to the degree of reaction due to exposure. Conversely, if the heating aging temperature is higher than 130 ° C., the reaction proceeds too much. Therefore, there is a risk that sufficient heat adhesion cannot be obtained.

  In the present invention, the temperature during exposure (working temperature) is preferably 50 ° C. or lower (the practical lower limit is room temperature). This is because if the temperature at the time of exposure is higher than 50 ° C., not only photoreaction but also acceleration of B-stage formation by heat may occur, which may make control difficult. The exposure time means from the start of exposure to the end of exposure.

  Next, an adhesive that can be suitably used for the method of manufacturing a wafer scale semiconductor package according to the present invention will be described. The adhesive is not particularly limited as long as it can be developed in the B-stage state and can be thermally bonded. For example, a group that undergoes a photodimerization reaction and a thermosetting property. An adhesive having the functions of both reactive groups can be used. When such an adhesive is used, it is possible to use a method in which developability is realized by photodimerization and then adhesion is performed with the other reactive group. Specific examples of such an adhesive include an oligomer having a cinnamic acid terminal as a component that causes a reaction capable of photodimerization, and further, a thermal cationic polymerization initiator and an epoxy resin, or a thermal radical initiator and an acrylic oligomer. And a composition containing a monomer and a monomer at the same time. Other examples include liquid or sheet-like (film-like) adhesives containing a cationically polymerizable resin and a photocationic polymerization initiator. In the present invention, such adhesives are used. Is preferred. By using such an adhesive, it is possible to easily form the heat-sensitive adhesive layer 5 in the B stage state that does not dissolve in the developer.

  Here, examples of the cationically polymerizable resin include an epoxy resin, a vinyl ether resin, an oxetane resin, and a furan resin. However, in terms of curability and control of B-stage formation, the cationically polymerizable resin is It is preferable that the compound has a cyclic structure containing an oxygen atom and is cured by ring-opening polymerization. Specific examples of such cationically polymerizable resins include epoxy resins, oxetane resins, furan resins and the like, and most preferred are epoxy resins. Compositions containing acrylic oligomers and monomers containing photoradical initiators that are commonly used in applications that form patterns with light (for dry film and solder resist applications) are suitable for use as adhesives in the present invention. Absent. This is because radicals generated by light are chain-polymerized even at low temperatures, so that it is difficult to control the degree of reactivity that can withstand development and can be thermally bonded.

  The epoxy resin is not particularly limited as long as it has a plurality of epoxy groups in one molecule, and a commercially available liquid epoxy resin or solid epoxy resin can be appropriately used. Specific examples of the epoxy resin include alicyclic epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin having biphenyl skeleton, naphthalene ring-containing epoxy resin, dicyclopentadiene Dicyclopentadiene type epoxy resin having a skeleton, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenylmethane type epoxy resin, bromine-containing epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate, etc. These can be used alone or in combination of two or more. In addition to the epoxy resin, other cationic polymerizable resins such as an oxetane resin can be used in combination.

The cationic photopolymerization initiator is not particularly limited as long as it generates a Lewis acid or a Bronsted acid by light. Specific examples thereof include PF ₆ ⁻ , AsF ₆ ⁻ as anions. , SbF ₆ ⁻ , SbCl ₆ ²⁻ , BF ₄ ⁻ , SnCl ₆ ⁻ , FeCl ₄ ⁻ , BiCl ₅ ^{2−, and the} like, and as anions, PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , SbCl ₆ ²⁻ , BF ₄ ⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , FSO ₃ ⁻ , F ₂ PO ₂ ⁻ , B (C ₆ F ₅ ) ₄ ^{− and the} like, diaryl iodonium salts, triaryl sulfonium salts , triarylselenonium salt, as an ^{_{anion, PF 6 -, AsF 6 -}} , SbF 6 - Jiarukirufu with like Nasylsulfonium salts, dialkyl-4-hydroxyphenylsulfonium salts, and sulfonic acids such as α-hydroxymethylbenzoin sulfonate, N-hydroxyimide sulfonate, α-sulfonyloxy ketone and β-sulfonyloxy ketone An ester, an iron allene compound, a silanol-aluminum complex, o-nitrobenzyl-triphenylsilyl ether, etc. can be mentioned, and only one kind may be used, or a plurality of initiators may be used in combination. Good. Among these cationic photopolymerization initiators, triallylsulfonium salt or diallyl iodonium salt is most preferable because of its cation generation efficiency and stability. In addition, the addition amount of a photocationic polymerization initiator is although it does not specifically limit, It is preferable that it is the range of 0.1-10PHR.

  Photocationic polymerization initiators generate cationically active species efficiently by light irradiation, but unlike radical systems, some heating is required for the cationic polymerization reaction of epoxy resins and the like to proceed due to the generated cations. In the stage where the cation active species are generated at a low temperature, the resin chain reaction does not occur so much, and the degree of the reaction can be easily controlled by the heating temperature and time. As a result of finding out this point by the present inventor, the present invention has been completed.

  Moreover, in this invention, it is preferable to contain the thermal cationic polymerization initiator which generate | occur | produces a cation by heating in addition to the photocationic polymerization initiator for generating a cation by a light irradiation process. Thereby, the amount of cationic active species can be further increased in the B-staging and heat bonding processes. In addition, although the addition amount of a thermal cationic polymerization initiator is not specifically limited, It is preferable that it is the range of 0.1-5 PHR.

  Moreover, in order to generate a cation efficiently by an initiator, a so-called sensitizer can be used in combination. Specific examples include benzophenone, acridine orange, perylene, anthracene, phenothiazine, 2,4-diethylthioxanthone, and the like.

  In the cationic curing system, a chain transfer agent can be used in combination for the purpose of increasing the polymerization rate and preventing unreacted epoxy resin from being left behind. In general, polyfunctional alcohols are used, and examples thereof include ethylene glycol, butanediol, trimethylolpropane triol, pentaerythritol, and polyvinyl alcohol.

  Furthermore, a coupling agent for increasing the adhesive property of the adhesive, for example, various silane coupling agents, titanate coupling agents, and aluminate coupling agents may be used. It is also possible to use additives such as fillers, pigments and dyes as long as they do not inhibit the generation of cations by light irradiation.

  In the present invention, at least one of phenoxy resin, butyral resin, and epoxidized polybutadiene having a hydroxyl group can be added to the adhesive. These improve the film formability in the varnish coating process when forming the adhesive into a sheet, reduce the tackiness of the sheet adhesive after drying, reduce the brittleness It has the effect of imparting the effect of expressing flexibility and the effect of reducing pattern chipping when pattern exposure / development is performed after a sheet-like adhesive is applied. Moreover, since it has a hydroxyl group in a molecule | numerator, it has a chain transfer effect in a cation hardening system, and can raise a polymerization rate (curing rate). Liquid adhesives are also effective in improving developability and curability.

  Hereinafter, the present invention will be specifically described by way of examples.

  First, raw materials used for manufacturing the adhesive will be described.

  As the bisphenol type epoxy resin, “Epicoat 1006” which is solid at room temperature (epoxy equivalent 1100, manufactured by Japan Epoxy Resin Co., Ltd.), “YDF175S” which is liquid at room temperature (Bisphenol F type manufactured by Toto Kasei Co., Ltd.), liquid at room temperature “840S” (Dainippon Ink Industries, Ltd., bisphenol A type) was used.

  As the alicyclic epoxy resin, “Celoxide 2021P” (abbreviated as “CEL2021P”, manufactured by Daicel Chemical Industries, Ltd.), which is liquid at room temperature, was used.

  As the phenoxy resin, “YP50” (manufactured by Toto Kasei Co., Ltd.) was used.

  As a photocationic polymerization initiator, “SP-170” (manufactured by Asahi Denka Kogyo Co., Ltd.) was used.

  As a solvent, anone (cyclohexanone), toluene, 2-butanone, and propylene glycol (industrial reagent) as a chain transfer additive were used.

(Formulation examples 1 and 2)
The liquid adhesive was produced in the amount (parts by weight) shown in Formulation Example 1 in [Table 1] below. Specifically, raw materials other than the cationic photopolymerization initiator were weighed, heated to 100 ° C. and mixed with stirring, then cooled to room temperature, added with the cationic photopolymerization initiator, and mixed with stirring. After heating to 80 ° C. and stirring and mixing, the mixture was allowed to cool to room temperature, filtered through a membrane filter having a pore size of 3 μm, and degassed under reduced pressure to obtain a liquid adhesive.

  The sheet-like adhesive was manufactured in the amount (parts by weight) shown in Formulation Example 2 in [Table 1] below. Specifically, the resin and solvent other than the cationic photopolymerization initiator are weighed, heated to 80 ° C. and mixed with stirring, then cooled to room temperature, added with the cationic photopolymerization initiator, and mixed with stirring. The varnish was prepared by filtering through a 3 μm membrane filter and degassing under reduced pressure. Subsequently, a sheet-like adhesive was produced using this varnish as follows. A varnish is applied to a 25 μm thick PET film (base film) with a bar coater, followed by primary drying at 80 ° C. for 10 minutes, followed by secondary drying at 120 ° C. for 10 minutes to obtain a sheet-like adhesive. It was. This sheet-like adhesive had no tackiness and the thickness of the coating film was 80 μm.

  Next, examples and comparative examples of a method for manufacturing a wafer scale semiconductor package using the liquid and sheet adhesives obtained as described above will be described.

Example 1
Using the liquid adhesive shown in Formulation Example 1, printing was performed on a 4-inch silicon wafer to a thickness of 20 μm (see FIG. 1B). This was subjected to UV exposure through a mask using a normal high-pressure mercury lamp type parallel exposure machine (see FIG. 1C). The mask used was a 2 mm wide line-shaped pattern arranged in a grid at 2 mm intervals. The exposure was completed at a stage where energy (exposure amount) of ² J / cm ² was applied. The workpiece temperature at that time was 40 ° C. At this stage, no tack was observed on the surface of the irradiated product. Further, the irradiated product was subjected to a heat aging treatment at 100 ° C. for 10 minutes, followed by development treatment with a mixed solvent of isopropyl alcohol and acetone in a volume ratio of 7: 3 in an ultrasonic bath, and then solvent drying at 80 ° C. for 5 minutes ( (Refer FIG.1 (d)).

  Then, when the state of the formed heat-sensitive adhesive layer was observed with a microscope, pattern formation as in the mask was observed, no pattern chipping or development residue was observed, there was no peeling of the heat-sensitive adhesive layer, and good resistance It had developability / pattern formability. That is, it was confirmed that the pattern formability was excellent.

  In addition, a 1 mm thick, 10 cmφ disk-shaped glass plate is overlaid on the B-staging pattern obtained as described above, and a 0.5 kg weight is placed on the glass plate. It heat-processed for minutes (refer FIG.1 (e)). After cooling at room temperature, the glass plate was firmly bonded. That is, it was confirmed that the glass plate adhesion was excellent.

  Next, the sample to which the glass plate was bonded was diced at the center of the line along the line of the heat-sensitive adhesive layer to obtain 340 pieces of 4 mm square packages (see FIG. 1 (f)). For each package, cracks / chips in the peripheral portion and adhesion failure of the glass sealing plate were confirmed. As a result, the number of defective products (number of inspection failures after separation) was zero.

Separately, using a mask having a 2 mm square opening, a 2 mm square B-staging pattern is formed by the same process, and a 2 mm square silicon chip is formed thereon using a flip chip bonder at 180 ° C., 30 ° C. Pressurized for 2 seconds. After the sample was further cured at 180 ° C. in an oven, the shear bond strength was measured by a bond tester and found to be 2.94 MPa (30 kgf / cm ² ).

(Example 2)
In Example 1, the pattern formation and glass plate adhesion were evaluated in exactly the same manner as in Example 1 except that the exposure dose was extended to 5 J / cm ² and no post-exposure after exposure was performed. Then, the number of defective inspections after singulation was counted and the shear bond strength was measured. These results are shown in [Table 2] below.

(Example 3)
In Example 1, except that a spot-type high-pressure mercury lamp was used as an exposure machine, the pattern formability and the glass plate adhesion were evaluated in exactly the same manner as in Example 1, and the number of inspection defects after singulation was determined. While counting, the shear bond strength was measured. These results are shown in [Table 2] below. However, in Example 3, the workpiece temperature at the start of exposure was room temperature (25 ° C.), but the workpiece temperature at the end of exposure increased to 75 ° C.

Example 4
Instead of the liquid adhesive of Example 1, the adhesive layer was formed by the vacuum laminating method instead of the printing method using the sheet-like adhesive having a resin thickness of 80 μm manufactured in the above-described process. Except for the above, in the same manner as in Example 1, the pattern formability and the glass plate adhesiveness were evaluated, the number of defective inspections after counting was counted, and the shear adhesive strength was measured. These results are shown in [Table 2] below.

  Further, FIG. 4 shows an enlarged micrograph of a sample formed in a lattice pattern on a silicon wafer and bonded to a glass plate. Good developability can be confirmed.

  (* 1) Pattern formability was determined based on the following criteria.

  “A”: Pattern formation as observed in the mask is observed, and pattern chipping and development residue are not observed.

  “◯”: A pattern is formed, but a development residue appears in portions to be removed.

  “△”: Some of the pattern lines are missing.

  “X”: A pattern does not appear even after development, and the film remains.

  “XX”: All that was eluted during development.

  (* 2) Glass plate adhesion was evaluated based on the following criteria.

  “◎”: A material that is firmly bonded, does not peel off, and breaks the glass if it is forcibly removed.

  "○": Can be peeled off, but requires considerable force.

  “×”: A material that can be easily peeled off when a little force is applied.

  “XX”: Not thermally bonded.

An example of embodiment of this invention is shown and (a)-(f) is sectional drawing. An example of a prior art is shown and (a)-(c) is sectional drawing. Another example of a prior art is shown, (a)-(c) is sectional drawing. It is an enlarged micrograph which shows the sample which pattern-formed in the shape of a lattice on the silicon wafer, and bonded together with the glass plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Sealing plate 3 Adhesive layer 4 Negative photomask 5 Heat-sensitive adhesive layer 6 Hollow part

Claims (4)

  In a method of manufacturing a wafer scale semiconductor package having a hollow portion therein, a step of forming an adhesive layer using an adhesive on a semiconductor wafer, and exposing the adhesive layer to light through a negative photomask for exposure Thus, the step of changing the portion irradiated with light to the pattern of the heat-sensitive adhesive layer in the B stage state, the step of removing the portion not exposed to light during exposure by developing, and the remaining after development A step of bringing a sealing plate into contact with the heat-sensitive adhesive layer and heating it and a step of dicing the semiconductor wafer and the sealing plate bonded by heating into pieces are sequentially performed. A method of manufacturing a wafer scale semiconductor package characterized by the above.   2. The method of manufacturing a wafer scale semiconductor package according to claim 1, wherein the degree of B-staging of the heat-sensitive adhesive layer is adjusted by subjecting the adhesive layer to heat aging after exposure and before development. .   The method for producing a wafer scale semiconductor package according to claim 1 or 2, wherein the temperature during exposure is 50 ° C or lower.   The method for producing a wafer scale semiconductor package according to any one of claims 1 to 3, wherein a liquid or sheet-like one containing a cationically polymerizable resin and a photocationic polymerization initiator is used as the adhesive.