JP2008251572A - Equipment and method for affixing substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide equipment and a method for readily affixing a first substrate and a second substrate for supporting the first substrate with a holding agent. <P>SOLUTION: The equipment 1 for sticking substrates comprises a first holding device 10 for holding a first substrate, i.e., a wafer 4, and a second holding device 20 for holding the support substrate 6 of a second substrate to be stuck to the first substrate, opposite to the first substrate (the wafer 4) held on the first substrate 10. An irradiation device 31 for irradiating a wafer-holding agent 7, arranged on the substrate in order to stick the substrate with radioactive rays and for melting the wafer holding agent is also provided. The wafer 4 and the support substrate 6 are stuck, by making the wafer holding agent 7 melt by means of the irradiation device 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate bonding apparatus for bonding two substrates using a holding agent.

  In electronic circuit substrates such as silicon wafers, silicon nitride wafers, glass wafers, ceramic wafers, glass epoxy substrates and polyimide substrates, it is necessary to perform mechanical and chemical processing and processing on the substrates in order to form electronic circuits. is there. Here, in addition to processing and processing performed on the substrate itself, processing and processing on the substrate itself include processing and processing on a metal layer, metal oxide layer, organic material layer, ceramic layer, etc. include.

  Typical examples of processing and processing performed to form an electronic circuit on a substrate include CVD, sputtering, vapor deposition, electroless plating, electrolytic plating, spin coating, exposure, development, etching, resist stripping, CMP, Various things such as RIE and dicing can be mentioned. In addition, as necessary, the pre-processing and post-processes associated with the processing and processing listed above include washing with water, various solutions and solvents, drying associated with washing, and heat treatment such as annealing and sintering. Is called.

  In recent years, processing and processing technologies for substrates such as those exemplified above are micromachines that produce minute actuators and optical elements on wafers, and MEMS (Micro Electro Mechanical Systems) that combine micromachines and electrical circuits. It is applied to the so-called field. Many of the processes and processes applied to a substrate are difficult to classify simply as mechanical processes, chemical processes, etc., but regardless of the type of process or process applied to the substrate, A method of sticking a substrate to a support substrate is used as a countermeasure when a large thermal and mechanical stress is applied and damage is caused, or when it is difficult to handle the substrate alone (for example, Patent Document 1).

  As a specific example of the method for fixing the substrate to the supporting substrate, for example, a method using an adhesive tape is known in dicing, which is an operation of individually cutting out IC chips made on a silicon wafer. Recently, there has been proposed a method utilizing the fact that a certain kind of organic substance (hereinafter referred to as a wafer holding agent) has a characteristic that crystals melt in a temperature range of about 50 ° C. to 300 ° C.

  In the method using the above-mentioned wafer holding agent, generally, a hot press apparatus that can apply a wafer holding agent to a support substrate or a bonding surface of a wafer with a thickness of several μm to a hundred μm and heat the press surface to room temperature or higher. set. After that, the temperature of the press surface is raised and heated above the melting point of the wafer holding agent to melt the wafer holding agent, and when it is in a fluid state, the wafer and the support substrate are overlapped, and the temperature of the pressing surface is lowered and cooled. Then, a method is used in which the wafer holding agent is solidified and the support substrate and the wafer are bonded to each other.

  The press surface of the hot press used in this method is usually equipped with a plate made of a material with good thermal conductivity such as aluminum, iron, copper, etc., and a heat source such as nichrome wire, sheath heater or the like is heated in the plate. There is a flow path for water and oil, and the plate is maintained at a temperature higher than room temperature, so that heat energy can be transferred to the object in contact with the plate by heat conduction and the object can be heated. It has become.

  Such adhesive tapes and wafer holding agents are used to facilitate reinforcement and handling during the required series of processing and processing on the substrate, and once the required processing and processing are complete. The substrate is peeled off from the support plate, washed as necessary, and used so that no residue of adhesive tape or wafer retainer remains on the product.

JP 2005-51055 A

  However, in the method using a wafer holding agent, the method of controlling the melting and solidification of the wafer holding agent by changing the temperature of the hot plate has a problem that it takes time to heat and cool the hot plate and the throughput is not increased. is there. In addition, since both the heating means and the cooling means are incorporated in the hot plate, the structure of the hot plate is complicated, and a cooling system is required, which increases the size of the apparatus itself. Furthermore, as a matter of course, in order to change the temperature of not only the substrate but also the entire hot plate, a large amount of heat energy is thrown away every time it is pasted, causing problems such as energy loss. is there.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate bonding apparatus capable of bonding a first substrate and a second substrate supporting the first substrate in a short time using a holding agent while being simple and small, and the same It is in providing the board | substrate bonding method using this.

  The present inventors have found that substrates can be easily bonded by a substrate bonding apparatus provided with a radiation irradiation device for irradiating and melting a holding agent disposed on a substrate to melt the above-mentioned problem It came to know that it can solve. That is, according to the present invention, the following substrate bonding apparatus and substrate bonding method are provided.

[1] A first holding device that holds the first substrate, and a second substrate that is provided with a gap at a position facing the first holding device and is scheduled to be bonded to the first substrate. A heat incorporated in at least one of the second holding device that holds the first substrate held by the first holding device in opposition to the first substrate, and the first holding device and the second holding device. A substrate heating device that maintains a temperature of at least one of the first substrate and the second substrate at room temperature or higher by conduction, and is disposed on a facing surface of at least one of the first substrate and the second substrate. A radiation irradiation device for irradiating a holding agent having a melting point of 50 ° C. or more and 300 ° C. or less to melt the holding agent, and the first holding device and the second after the holding agent is melted by radiation. Less with holding device Also drives the one holding device, a substrate bonding device and a holding device driving means for bonding by the holding agent the first substrate and the second substrate.

[2] Using the substrate bonding apparatus according to [1], the substrate on which the retaining agent is disposed is set to a temperature that is higher than a softening temperature of the retaining agent and lower than a melting temperature by the substrate heating device. A substrate bonding method in which radiation is irradiated by the radiation irradiation apparatus to melt the holding agent, and the first substrate and the second substrate are bonded together by the holding agent.

[3] The substrate bonding method according to [2], wherein a crystalline material is used as the retaining agent.

  Further, the radiation irradiation apparatus includes irradiation device driving means that can be driven in a gap between the first holding device and the second holding device, and the radiation irradiation device includes the first holding device and the second holding device. The holding agent disposed on the opposite surface of at least one of the first substrate and the second substrate is melted, and after the holding agent is melted, the irradiation device driving means causes the radiation to move. The irradiation apparatus may be retracted so that the first substrate and the second substrate are bonded to each other. And the moving direction of the said radiation irradiation apparatus can be comprised so that it may orthogonally cross with the moving direction of the said holding | maintenance apparatus.

  On the other hand, the radiation irradiating device is provided outside the gap between the first holding device and the second holding device, and irradiates the opposing surface of the substrate on which the holding agent is disposed from an oblique direction. It can also be configured as follows.

  Alternatively, the radiation irradiation device is provided in at least one of the first holding device and the second holding device, and is a surface opposite to the facing surface of the substrate on which the holding agent is disposed. It can also comprise so that a radiation may be irradiated.

  The holding device may be configured to include a vacuum chuck or an electrostatic chuck that holds the substrate with a suction force generated by decompression.

  Further, in the substrate bonding method, the substrate on which the retaining agent is disposed is set to a temperature lower by 10 to 100 ° C. than the melting temperature of the retaining agent by the substrate heating device, and then the radiation is irradiated by the radiation irradiating device. Irradiation can melt the retaining agent, and the first substrate and the second substrate can be bonded together by the retaining agent.

  According to the substrate bonding apparatus of the present invention, the bonding step can be performed in a short time because the holding agent is melted by radiation to bond the first substrate and the second substrate. In addition, after the substrate is heated to a temperature not lower than the melting temperature and higher than the softening temperature of the holding agent by the substrate heating device, it is possible to prevent problems due to thermal expansion or the like by irradiating the radiation with the radiation irradiation device and melting the holding agent. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be added without departing from the scope of the invention.

(Embodiment 1)
FIG. 1 shows a first embodiment of a substrate bonding apparatus 1 according to the present invention. Here, as a substrate to be bonded, a relatively well-known silicon wafer (hereinafter simply referred to as a wafer) is used, and various holding agents can be used. In order to show that the agent is used, the retention agent may be referred to as “wafer retention agent”, but this is for ease of explanation and does not limit the scope of the present invention. The substrate bonding apparatus 1 includes a first holding device 10 that holds a wafer 4 that is a first substrate, and a support substrate 6 that is a second substrate that is scheduled to be bonded to the first substrate. And a second holding device 20 that holds the first substrate (wafer 4) held by the second substrate 10 facing the first substrate. The first holding device 10 and the second holding device 20 are provided to face each other with a gap.

  The substrate bonding apparatus 1 further includes a radiation irradiation device 31 that irradiates and melts the wafer holding agent 7 for bonding the first substrate and the second substrate. The radiation irradiation device 31 is provided at the distal end of the arm 32, and is configured to be movable in and out of the gap between the first holding device 10 and the second holding device 20 by the arm 32. The purpose of this radiation irradiation apparatus is to heat and melt the holding agent without mechanically contacting the holding agent or the second substrate coated with the holding agent. It should be selected according to the characteristics of the retaining agent. For example, in the case where a crystalline organic substance is used for the holding agent, in many cases, it is preferable to use an infrared irradiation device. In addition, since the radiation irradiation apparatus does not require a metal plate having a large heat capacity, it has the advantage that it can be heated with less energy than the hot plate and can be quickly cooled.

  Further, in the second holding device 20, after the wafer holding agent 7 is melted by radiation, the second holding device 20 is driven and the first substrate and the support substrate 6 are bonded together by the wafer holding agent 7. A motor 28 is provided as a driving means.

  The first holding device 10 is configured such that a press heater 12 is connected to an upper plate 11 with a heat insulating material 15 interposed therebetween. The press heater 12 has a vacuum chuck 13 on the lower surface for adsorbing and holding the substrate by decompression, and includes a sheath heater 14 as a heating device for heating the substrate. The press heater 12 can be maintained at a required temperature in the range of room temperature to 300 ° C. In addition, an electrostatic chuck or the like can be used for the holding mechanism of the first substrate.

  Similarly to the first holding device 10, the second holding device 20 is configured such that a press heater 22 is connected to a lower plate 21 with a heat insulating material 25 interposed therebetween. The press heater 22 has an upper surface serving as a vacuum chuck 23 for adsorbing and holding the substrate under reduced pressure, and includes a sheath heater 24 as a heating device for heating the substrate. The press heater 22 can be maintained at a required temperature in the range of room temperature to about 300 ° C. In addition to this second substrate holding mechanism, an electrostatic chuck or the like may be used.

  The press heater 12 and the press heater 22 are a press surface of a press device that is paired up and down, and the second holding device 20 moves up and down to close the press, and the wafer 4 that is the first substrate. The support substrate 6 as the second substrate can be bonded to each other. When the press (the first holding device 10 and the second holding device 20) is closed, the wafer holding agent 7 has fluidity in a molten state, so that an excessive pressing pressure is not required, but the parallelism and interval of the press Is preferably one that can be controlled with an accuracy of at least a micron. In the present embodiment, a method of securing the accuracy of the press interval by attaching the spacer 27 to the press is shown. In order to bond the wafer 4 and the support substrate 6 with a predetermined positional relationship with high accuracy, although not shown, the positional relationship between the wafer 4 and the support substrate 6 is adjusted, and then the press heater 12 or The press heater 22 has a mechanism for setting, or the press heater 12 or the press heater 22 slides back and forth, right and left, and in the rotational direction within the press surface to adjust the positional relationship between the wafer 4 and the support substrate 6. It preferably has a function.

  The radiation irradiation device 31 is attached to the tip of the arm 32, and is configured to be able to enter and retreat out of the gap between the first holding device 10 and the second holding device 20 by operation of the arm 32. . The second holding device 20 is configured to move in the vertical direction, and the moving direction of the radiation irradiation device 31 is configured to be orthogonal to the moving direction of the second holding device 20. In this embodiment, when the wafer holding agent 7 is melted, the radiation irradiation device 31 is moved between the upper and lower press heaters 12 and 22, and the support substrate 6 placed on the lower press heater 22. The wafer holding agent 7 coated on the substrate is irradiated with radiation. Further, when the press (the first holding device 10 and the second holding device 20) is closed and the wafer 4 and the support substrate 6 are overlapped, the radiation irradiation device 31 is configured to move out of the press.

  Specific examples of the first substrate held by the first holding device 10 include electronic circuit substrates such as a silicon wafer, a silicon nitride wafer, a glass wafer, a ceramic wafer, a glass epoxy substrate, and a polyimide substrate.

  As the support substrate 6 as the second substrate held by the second holding device 20, it is preferable to select the support substrate 6 that is substantially the same size and shape as the first substrate and is the same material as the wafer 4 from the viewpoint of thermal expansion. However, when a structure such as a grip or positioning hole is required for handling or alignment, a substrate larger than the first substrate or a substrate having a different shape from the first substrate may be used as necessary. Also, the material is not particularly limited, and ceramic, metal, and resin materials can be used as long as they can withstand the processing and processing conditions performed on the first substrate.

  The wafer holding agent 7 preferably has a solidification temperature of 50 ° C. or higher and is chemically stable, and the solidification temperature is 300 ° C. or lower in order not to overheat the wafer to be processed. Is preferred. It is known that various resins can be used as such a retaining agent (for example, see JP-A-2005-191550). However, since the resin has a large change in physical properties, particularly viscosity, due to temperature and there is a concern that the substrate and the supporting substrate may be shifted due to the temperature and force applied to the substrate during processing, a material having crystallinity is more preferable.

  Examples of such crystalline materials, that is, crystalline compounds, include nitro compounds such as 1,3,5-trinitrobenzene, 2,3,6-trinitrophenol, and 2,4,5-trinitrotoluene. However, from the viewpoints of high safety in handling, excellent heat resistance during melting, and little coloring, an organic compound composed only of C, H, and O elements not containing N element is preferable. For example, an alicyclic compound or a material having a steroid skeleton can be preferably used. Specific examples include aromatic compounds, aliphatic compounds, and alicyclic compounds as exemplified below.

  Examples of the aromatic compound include 9H-xanthene, benzofuran-3 (2H) -one, 1,5-diphenyl-2,4-pentadien-1-one, di-2-naphthyl ether, cis-1,8. -Terpine, 2,3-dimethylnaphthalene, 1,2-naphthalenediol, di-1-naphthylmethane, biphenyl-2,2'-diol, di-1-naphthyl ether, bis (diphenylmethyl) ether, 9,10 -Dihydroanthracene, 2,3,5,6-tetramethyl-p-benzoquinone, 2,6-dimethylnaphthalene, syringaldehyde, vanillyl alcohol, 1,3-diphenylisobenzofuran, 2,3'-dihydroxybenzophenone, Isohydrobenzoin, 4,4′-dimethylbiphenyl, 1,3-naphthalenediol, 4 Phenanthrol, 3,3-diphenylphthalide, pentamethylphenol, hexaethylbenzene, 3,4-dihydroxybenzophenone, 2,4-dihydroxybenzaldehyde, p-hydroxybenzophenone, 4,5,9,10-tetrahydropyrene, 2, 3,4-trihydroxybenzophenone, hematoxylin, 2-isopropyl-5-methylhydroquinone, 1,9-diphenyl-1,3,6,8-nonatetraen-5-one, 9-phenylfluorene, 1,4,5- Naphthalenetriol, 1-anthrol, 1,4-diphenyl-1,3-butadiene, galvinoxyl, pyrene, 9-phenylanthracene, triphenylmethanol, 1,1′-binaphthyl, m-xylene-2,4,6- Triol, 4,4'-methylene Phenol, hexamethylbenzene, dibenzo-18-crown-6, diphenoquinone, biphenyl-4-ol, 1H-phenalene, 10-hydroxyanthrone, flavonol, benzoanthrone, 9H-xanthen-9-one, tetraphenylfuran, 2- Methyl anthraquinone, 4-hydroxy-1-naphthaldehyde, 1,7-naphthalenediol, 2,5-diethoxy-p-benzoquinone, curcumin, 2,2′-binaphthyl, 1,8-dihydroxyanthraquinone, 1,4-naphthalene Diol, 1-hydroxyanthraquinone, 3,4-dihydroxyanthrone, p-terphenyl, 4,4′-dihydroxybenzophenone, anthracene, 2,4,6-trihydroxyacetophenone, 1,8-anthracenediol, te Traphenylethylene, 1,7-dihydroxy-9-xanthenone, 2,7-dimethylanthracene, epicatechin, naringenin, 2-anthrol, 1,5-naphthalenediol, benzylidenephthalide, 2-phenylnaphthalene, cis-decahydro 2-naphthol (cisoid), (2R, 3R) -2,3-bis (diphenylphosphino) butane, trans-1,2-dibenzoylethylene, trans-1,4-diphenyl-2-butene-1, 4-dione, bis (2-hydroxyethyl) terephthalate, fluoranthene, biphenylene, isovanillin, fluorene, 9-anthrol, p-phenylene diacetate, trans-stilbene, biphenyl-3,3'-diol, 2,5- Dihydroxybenzophenone, P Aldehyde, benzoin, hydrobenzoin, 1,2-bis (diphenylphosphino) ethane, 2,4-dihydroxybenzophenone, 1,8-naphthalenediol, 1,2-naphthoquinone, 2,4′-dihydroxybenzophenone, 5-hydroxy -1,4-naphthoquinone, 1-phenanthrol, anthrone, 9-fluorenol, triphenylphosphine oxide, benzo [a] anthracene, 1,2-anthracenediol, 2,3-naphthalenediol, 2,4,6-tri Hydroxybenzophenone, di-2-naphthyl ketone, 3,3′-dihydroxybenzophenone, arbutin, 1,2,3,5-benzenetetraol, diphenylquinomethane, 2-phenanthrol, 2,3,4-trihydroxyacetophenone , Mosquito Santin, 1,3,5-triphenylbenzene, 3,4,5-trihydroxybenzophenone, benzo [a] pyrene, triphenylmethyl peroxide, hexestrol, 1,1,2,2-tetraphenyl-1, 2-ethanediol, 1,8-dihydroxy-3-methylanthraquinone, camphorquinone, 2,2 ′, 5,6′-tetrahydroxybenzophenone, esculin, 3,4′-dihydroxybenzophenone, 2,4,5-tri Hydroxyacetophenone, 9,10-phenanthrenequinone, 1,1,2,2-tetraphenylethane, rutin, (-)-hesperetin, 2,3 ', 4,4', 6-pentahydroxybenzophenone, 7-hydroxycoumarin , Dl-Hesperetin, Ninhydrin, Triptycene, Fluorescin, Qu Examples include lysine, diethylstilbestrol, dibenzo [a, h] anthracene, pentacene, 1,6-dihydroxyanthraquinone, 3,4 ', 5,7-tetrahydroxyflavone, 2,6-anthracenediol, and genistein.

  Examples of the aliphatic compound include ribitol, D-arabitol, furyl, γ-carotene, β-carotene, cantharidin, pentaerythritol, trans, trans-1,4-diacetoxybutadiene, D-glucitol, D-mannitol, Idose, decanal, α-carotene, 2,4,6-trimethylphloroglucinol, galactitol, echrin, echilenin, trans-1,2-cyclobentanediol, manol, 1-heptadecanol, 1-octadecanol, Examples thereof include 1-icosanol, dihydroxyacetone, γ-terpineol, 1-hexacosanol, 1-hentriacontanol and stearone.

  Examples of the alicyclic compound include coprostanol, timosterol, ergocalciferol, β-sitosterol, lanosterol, 11-deoxycorticosterone, cholestanol, cholesterol, testosterone, ergosterol, stigmasterol, estradiol, cortisyl Costerone, epicholestanol, androsterone, 17α-hydroxy-11-deoxycorticosterone, gitoxigenin, epicoprostanol, calciferol, progesterone, dehydroepiandrosterone, 7-dehydrocholesterol, agnosterol, 11-dehydrocorticostero , Prednisolone, digitoxigenin, estrone, β-estradiol, cortisone, D-fructose (α form), D-lyx Source (α form), D-lyxose (β form), isomaltose, D-talose (β form), D-talose (α form), D-allose (β form), D-mannose (β form), D-mannose (α form), D-xylose (α form), D-galactose (β form), L-fucose (α form), D-glucose (α form), 2-deoxy-D-glucose, maltotri Aose, D-altro-heptulose, L-arabinose (pyranose α form), D-arabinose, cafe stall, L-arabinose (pyranose β form), D-galactose (α form), lycopene, aucubin, sucrose, freederin, cis -1,3,5-cyclohexanetriol, D-inositol, lutein, diosgenin, tigogenin, zeaxanthin, myo-inositol, cellobiose, Berelin A3, hematein, betulin, D-fructose (β form), D-altrose (β form), dibenzo-24-crown-8, methyl-D-glucopyranoside (β form), D-digitalose, salinomycin, methyl- D-galactopyranoside (α form), α, α-trehalose, bixin (all trans forms), palatinose, trans-1,4-terpine, D-quinobose (α form), D-glycero-D-galacto- Heptose, D-fucose (α form), D-glucose (β form), D-manno-heptulose, D-glycero-D-gluco-heptose, sophorose, salsasapogenin, L-sorbose, D-altro-3- Heptulose, twistin, (+)-borneol, inositol, (-)-isoborneo , L-arabinose (furanose form), L-galactose (alpha form), alpha-santonin, methyl-D-galactopyranoside (beta form), cyclopentadecanone, delta-valerolactone, cis-2- Examples include methylcyclohexanol and compounds represented by the following chemical formulas (1) to (8).

  Among the above compounds, from the viewpoint of tablet processability, cholesterol, coprostanol, timosterol, ergocalciferol, β-sitosterol, lanosterol, 11-deoxycorticosterone, cholestanol, testosterone, ergosterol, stigmasterol, Estradiol, corticosterone, epicholestanol, androsterone, 17α-hydroxy-11-deoxycorticosterone, gitoxigenin, epicoprostanol, calciferol, progesterone, dehydroepiandrosterone, 7-dehydrocholesterol, agnosterol, 11- Dehydrocorticosterone, prednisolone, digitoxigenin, estrone, β-estradiol, cortisone and the above chemical formulas (1) to 8) a compound having a steroid skeleton such as the compound represented by 8), trans-1,2-cyclobentanediol, manool, 1-heptadecanol, 1-octadecanol, 1-icosanol, γ-terpineol, 1-hexa Hydroxyl-containing compounds such as cosanol and 1-hentriacontanol and derivatives thereof are particularly preferable. However, ester derivatives are not preferable because they have a low melting point and may become acidic when thermally decomposed and may erode the adhesive surface.

  The said crystalline compound may be used independently and may mix and use 2 or more types. The crystalline compound is used so that the content in the adhesive composition is 70% by weight or more, preferably 80% by weight or more, particularly preferably 90% by weight or more. When the content is lower than the above range, the melting temperature may not be sharp and the melt viscosity may be increased.

  Next, the bonding process of the wafer 4 and the support substrate 6 by the substrate bonding apparatus 1 shown in the embodiment of FIG. 1 will be described with reference to FIG.

  During standby, the presses (the first holding device 10 and the second holding device 20) are open, and the press heater 12 and the press heater 22 are maintained at a predetermined temperature. The radiation emitting device 31 is usually outside the press.

  First, the wafer 4 and the support substrate 6 are set. When the press is closed, the support substrate 6 and the wafer 4 are aligned so that they are accurately overlapped, and the wafer 4 is applied to the upper press heater 12 and the wafer holding agent 7 is applied to the lower press heater 22 capable of irradiating radiation. The support substrate 6 is adsorbed.

  As the wafer holding agent 7, a material having a melting point of 50 ° C. or more and having crystallinity may be used. Then, the support substrate 6 coated with the wafer holding agent 7 is set to a temperature not lower than the softening temperature of the wafer holding agent 7 and lower than the melting temperature by the lower press heater 22 which is a substrate heating device. At this time, more preferably, the temperature is lower by about 10 to 100 ° C. than the melting temperature of the wafer holding agent 7.

  Next, the wafer holding agent 7 is melted. Specifically, the radiation irradiation device 31 is moved between the upper press heater 12 and the lower press heater 22 by operating the arm 32 to irradiate the support substrate 6 with radiation. As a result, the temperature of the wafer holding agent 7 applied to the support substrate 6 becomes higher than the temperature of the press heater 22, usually about 10 to several tens of seconds, at the earliest several seconds to several hundreds of seconds at most. When the temperature reaches the melting point or higher, the wafer holding agent 7 is melted. After the wafer holding agent 7 is melted, radiation irradiation is stopped, and the radiation irradiation device 31 is moved out of the press by operating the arm 32.

  Subsequently, the press is closed, the wafer 4 and the support substrate 6 are overlapped, and the wafer 4 and the support substrate 6 are bonded together. At this time, it is preferable to accurately control the parallelism and interval between the wafer 4 and the support substrate 6.

  Since the press heater 12 and the press heater 22 are kept at a temperature lower than the melting point of the wafer holding agent 7, the temperature of the wafer holding agent 7 quickly decreases and solidifies in about several tens of seconds to several hundred seconds. Thereby, the wafer 4 and the support substrate 6 are bonded to each other.

  The press is opened, and the wafer 4 and the support substrate 6 that have been bonded together are taken out of the press. After the bonded wafer 4 and support substrate 6 are taken out, the apparatus enters a standby state.

  Although the description has been given here assuming that the wafer holding agent 7 is applied to the support substrate 6, the wafer holding agent 7 may be applied to the wafer 4. For example, when the wafer 4 has large unevenness, better results can be obtained by applying a sufficient amount of the wafer holding agent 7 to fill the unevenness. At this time, the wafer 4 is set in a press heater on the side where radiation can be irradiated. Further, the wafer holding agent 7 does not necessarily have to be applied to a uniform thickness, and may be placed so as to rise in the center of the wafer 4 or the support substrate 6.

  When the cushioning property is required for the layer of the wafer holding agent 7, the wafer holding agent 7 is applied to both the wafer 4 and the support substrate 6, and the wafer holding agent 7 layer when bonded is thickened to about several hundred μm. It is also possible to do. Even when the wafer holding agent 7 is applied to both the wafer 4 and the support substrate 6, it is sufficient to melt the wafer holding agent 7 only in either the wafer 4 or the support substrate 6. At this time, as a matter of course, the layer of the wafer holding agent 7 that is not heated and melted needs to have sufficient thickness accuracy over the entire region to be bonded.

  Although the lower press heater 22 can irradiate the radiation, one of the upper and lower press heaters can be selected even if the upper press heater 12 is irradiated on the apparatus. Moreover, it is good also as a structure which can irradiate with respect to both upper and lower press heaters.

  Even if the wafer 4 or the supporting substrate 6 coated with the wafer holding agent 7 is set on the upper press heater 12 and the wafer holding agent 7 is heated and melted, the wafer holding agent 7 is usually a thin layer of about several μ to 100 μm. Therefore, there is no fear that the wafer holding agent 7 will drip from the wafer 4 or the support substrate 6.

  The time required for each stage of the bonding process is influenced by the type of wafer holding agent used and the thermal conductivity of the wafer and support substrate, so it cannot be generally stated. With the substrate bonding apparatus 1 configured as described above, one set of bonding can be completed in a time of several minutes to tens of minutes, and the time required for the process is remarkably shortened as compared with a method not using a radiation heater. be able to. In addition, since the substrate bonding apparatus 1 can be used with a constant heater temperature, complicated temperature control is unnecessary, and since the retaining agent is melted by radiation, As the wafer retainer is melted and bonded with fluidity, it can be pressed and bonded with a small pressure, and the bonding accuracy can be determined with machine accuracy. Advantages such as being able to perform pasting with high reproducibility can be given.

(Embodiment 2)
Next, Embodiment 2 will be described with reference to FIGS. 3 and 4. One of the upper press heater 12 and the lower press heater 22 may be a press plate with a built-in radiation irradiating device 31, and the pressing function and the radiation irradiating function may be combined. However, depending on the type of wafer retainer 7, there may be problems such as cracking or inability to stick stably when rapidly cooled, so at least one of the press heaters can easily keep the temperature constant. As a hot plate method, it is preferable to perform temperature control after the wafer 4 and the support substrate 6 are overlapped.

(Embodiment 3)
The third embodiment will be described with reference to FIGS. It is also possible to irradiate the wafer 4 or the support substrate 6 coated with the wafer holding agent 7 while holding the radiation irradiation device 31 outside the press. By adopting such a configuration, a means for moving the radiation irradiation apparatus becomes unnecessary, and at the same time, the wafer 4 or the support substrate 6 coated with the wafer holding agent 7 is irradiated with radiation from a plurality of directions so that more uniform heating can be performed. A plurality of radiation irradiation devices 31 can be installed.

  In this way, the processing and processing as described above can be performed efficiently and with high yield on the wafer 4 fixed to the support substrate 6. When the required processing is completed, the wafer holding agent 7 is melted by heating with a hot plate, the wafer 4 and the support substrate 6 are peeled off, and the wafer 4 is cleaned with a predetermined cleaning solution, so that the desired electronic circuit, minute size can be obtained. Machine elements, a combination of these can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

(Example)
An 8 inch silicon wafer coated with a wafer holding agent with a thickness of 10 μm was prepared as a supporting substrate, and an 8 inch silicon wafer on which nothing was coated was bonded thereto. A wafer holding agent having a melting point of 240 ° C. was used.

  As a substrate bonding apparatus, a hot press manufactured by Applied Power Japan (corresponding to the first holding apparatus 10 and the second holding apparatus 20 described above) was used, the pressing load was set to 50 kg, and the press heaters were set to 210 ° C. on both the upper and lower sides. An infrared heater with an output of 900 W was prepared as an infrared irradiation device, and a method of irradiating from the side of the press (corresponding to the third embodiment described above) was used.

The support substrate was set on the lower press heater and the silicon wafer was set on the upper press heater, and then the wafer holding agent on the support substrate was heated by the infrared heater. Since the wafer holding agent melted in 20 seconds, heating by infrared rays was stopped and the press was closed. The load at this time was 31 N per 1 cm ² of wafer. After maintaining the press in a closed state for 150 seconds, the press was opened, and the bonded wafer and the supporting substrate were taken out. The wafer and the support substrate were adhered well. Separately, when tested with a test piece pasted under the same procedure and conditions, it was confirmed that the adhesive strength measured in the shear direction was 120 N or more in an adhesive area of 4 cm ² and the heat resistance was 210 ° C.

(Comparative Example 1)
The same wafer holding agent and press apparatus as in the example were used. Also, the same wafer and support substrate were prepared, and a wafer holding agent was applied to the support substrate with a thickness of 10 μm. The press heater was set at 250 ° C. on both the upper and lower sides.

The support substrate was set in the lower press heater and the silicon wafer was set in the upper press heater, and then the press was closed without infrared irradiation. The load at this time was 31 N per 1 cm ² of wafer. After 180 seconds, the press heater was turned off and cooling was started. It cooled, sending a wind to a press heater using a fan. After 25 minutes, the press heater was cooled to 210 ° C., and the wafer and the support substrate were taken out.

(Comparative Example 2)
The test was performed in the same manner as in Comparative Example 1 except that the press heater was set at 210 ° C. and the time during which the press was closed was set to 300 seconds. In this example, the wafer and the support substrate were not attached at all, and the wafer slipped off just by tilting the support substrate.

  When the wafer holding agent on the support substrate is heated by the infrared heater as in the embodiment, the wafer holding agent is melted in 20 seconds, and the wafer is attached to the support substrate by keeping the press closed for 150 seconds. I was able to. That is, the pasting could be performed in a short time. On the other hand, in the case where infrared irradiation is not performed as in Comparative Example 1, the press heater is heated to 240 ° C. or higher of the melting point of the wafer holding agent, but can be attached, but after closing the press, It took 25 minutes for the press heater to cool. In addition, as in Comparative Example 2, when the infrared heater is not irradiated and the press heater is set to 210 ° C., which is a temperature lower than the melting point, the wafer and the support substrate are attached even if the press is closed for a long time I couldn't.

  The present invention can be used as a substrate bonding apparatus for bonding a substrate and a support substrate to support a substrate such as a wafer. According to the present invention, the apparatus itself has advantages such as simple control of the temperature of the hot plate, eliminating the need for a cooler, no need for a large pressing pressure, and miniaturization of the press mechanism itself, and further, The required time can be significantly shortened. In particular, it is suitable as a bonding apparatus for a substrate for an electronic circuit such as a silicon wafer, a silicon nitride wafer, a glass wafer, a ceramic wafer, a glass epoxy substrate, and a polyimide substrate and a support substrate.

  In addition, in this device, by reviewing the operation procedure and operating conditions, an adhesive that is bonded by heating and melting, such as hot melt, or an adhesive that causes a curing reaction by heating, such as an epoxy adhesive, is bonded. It is also possible to perform permanent substrate bonding using an agent.

It is a schematic diagram which shows Embodiment 1 of the board | substrate bonding apparatus of this invention. It is explanatory drawing explaining a bonding process. It is a schematic diagram which shows Embodiment 2 provided with a radiation irradiation apparatus in a lower press heater. It is a schematic diagram which shows Embodiment 2 provided with a radiation irradiation apparatus in an upper side press heater. It is a schematic diagram which shows Embodiment 3 provided with a radiation irradiation apparatus on the outer side of a press. It is a schematic diagram which shows Embodiment 3 provided with several radiation irradiation apparatus on the outer side of a press.

Explanation of symbols

1: substrate bonding apparatus, 4: wafer, 6: support substrate, 7: wafer holding agent, 10: first holding apparatus, 11: upper plate, 12: (upper) press heater, 13: (upper) vacuum chuck, 14: (upper) sheath heater, 15: (upper) insulation, 20: second holding device, 21: lower plate, 22: (lower) press heater, 23: (lower) vacuum chuck, 24: (lower Side) sheath heater, 25: (lower side) heat insulating material, 27: spacer, 28: motor, 29: shaft, 31: radiation irradiation device, 32: arm.

Claims (3)

A first holding device for holding a first substrate;
A second substrate which is provided with a gap at a position facing the first holding device and is scheduled to be bonded to the first substrate; and the first substrate held by the first holding device; A second holding device that holds the opposite,
Substrate heating incorporated in at least one of the first holding device and the second holding device to maintain the temperature of at least one of the first substrate and the second substrate at room temperature or higher by heat conduction Equipment,
A radiation irradiation device for irradiating a holding agent having a melting point of 50 ° C. or more and 300 ° C. or less, which is disposed on an opposing surface of at least one of the first substrate and the second substrate, to melt the holding agent; ,
After the holding agent is melted by radiation, at least one of the first holding device and the second holding device is driven, and the first substrate and the second substrate are bonded together by the holding agent. Holding device driving means;
A substrate bonding apparatus comprising:   Using the substrate bonding apparatus according to claim 1, the radiation irradiating apparatus after the substrate on which the retaining agent is disposed is set to a temperature not lower than the softening temperature of the retaining agent and lower than the melting temperature by the substrate heating device. Therefore, a substrate bonding method in which radiation is irradiated to melt the holding agent, and the first substrate and the second substrate are bonded with the holding agent.   The substrate bonding method according to claim 2, wherein a crystalline material is used as the holding agent.

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