JP6226596B2 - Support separator - Google Patents

Description

  The present invention relates to a support separating apparatus for separating a support from a laminate.

  In recent years, electronic devices such as IC cards and mobile phones have been required to be thinner, smaller and lighter. In order to satisfy these requirements, a thin semiconductor chip must be used as a semiconductor chip to be incorporated. For this reason, the thickness (film thickness) of the wafer substrate on which the semiconductor chip is based is currently 125 μm to 150 μm, but it is said that it must be 25 μm to 50 μm for the next generation chip. Therefore, in order to obtain a wafer substrate having the above film thickness, a wafer substrate thinning step is indispensable.

  Since the strength of the wafer substrate is reduced due to the thin plate, in order to prevent damage to the thinned wafer substrate, a circuit is placed on the wafer substrate while automatically supporting the support plate on the wafer substrate during the manufacturing process. Etc. are mounted. Then, after the manufacturing process, the wafer substrate is separated from the support plate. Therefore, it is preferable that the wafer substrate and the support plate are firmly bonded during the manufacturing process, but it is preferable that the wafer substrate can be smoothly separated from the support plate after the manufacturing process.

  When the wafer substrate and the support plate are firmly bonded, depending on the adhesive material, it is difficult to separate the support plate from the wafer substrate without damaging the structure mounted on the wafer substrate. Therefore, it is a very difficult temporary fixing technology that realizes strong adhesion between the wafer substrate and the support plate during the manufacturing process and separates the elements mounted on the wafer substrate without damaging them after the manufacturing process. Development is required.

  Examples of the temporary fixing technique include a technique in which a separation layer that is altered by irradiating light is provided in advance between an adhesive layer that bonds the wafer substrate and the support plate and the support plate. Specifically, the support plate is bonded and the back surface of the semiconductor wafer thinned by the thinning process described above is fixed on a dicing tape held on a dicing frame on a holding stage. In this state, the support plate that covers the circuit formation surface of the semiconductor wafer is peeled off by irradiating the separation layer with laser light to alter the separation layer. Thereafter, the support plate and the wafer substrate can be separated by applying a force to the laminated body in which the wafer substrate and the support plate are bonded.

  Here, Patent Document 1 describes a holding device that holds a substrate to which a support film is bonded.

JP 2012-59994 A (published March 22, 2012)

  However, the above-described technique has a problem in that when the laser beam is irradiated to the holding stage when the laminated body held on the holding stage is irradiated with the laser beam, the holding stage is deteriorated by the laser beam irradiation. .

  On the other hand, if the laser beam irradiation is performed so that the holding layer does not protrude from the substrate in consideration of the deterioration of the holding stage, the laser beam is not irradiated to the peripheral edge of the substrate. The separation layer at the peripheral end portion remains untreated. For this reason, there exists a problem that a board | substrate cannot be isolate | separated stably from a laminated body. Therefore, it is required to prevent the holding stage from being deteriorated by laser light irradiation.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a support separating apparatus that can prevent the quality of a holding stage from being deteriorated by laser light irradiation.

  In order to solve the above-described problems, the support separating apparatus according to the present invention irradiates light to a laminate formed by laminating a substrate, an adhesive layer, a separation layer, and a support in this order. In the support separating apparatus for separating the support by the above, a holding stage for holding the laminated body is provided, and the holding stage includes a white ceramic.

  According to the present invention, there is an effect that alteration of the holding stage due to laser light irradiation can be prevented.

It is a side view explaining the schematic structure of the support body separation apparatus which concerns on one Embodiment of this invention.

  The support separating apparatus according to the present invention is a support separating method in which a support is separated by irradiating light to a laminate formed by laminating a substrate, an adhesive layer, a separation layer, and a support in this order. The apparatus includes a holding stage for holding the laminate, and the holding stage includes a white ceramic.

  According to the above configuration, since the holding stage includes white ceramic, absorption of laser light to the holding stage can be reduced. For this reason, it is possible to prevent deterioration of the holding stage due to laser light irradiation. Therefore, the laser beam can be sufficiently irradiated not only inside the peripheral edge of the substrate held on the holding stage but also outside the peripheral edge of the substrate. Therefore, the entire surface including the peripheral edge of the separation layer can be sufficiently altered by laser light irradiation, and the support can be stably separated from the laminate.

[Laminate 10]
First, the schematic structure of the laminated body 10 separated by the support separating apparatus 100 according to an embodiment of the present invention will be described. In FIG. 1, a laminated body 10 from which a support plate (support) 4 is separated by a support separating apparatus 100 is a substrate 1, an adhesive layer 2 containing, for example, a thermoplastic resin, and a separation that is altered by absorbing light. The layer 3 and the support plate 4 that supports the substrate are stacked in this order.

  Here, the forming method and forming apparatus for forming the laminate 10, that is, the method for forming the adhesive layer 2 and the adhesive layer forming apparatus, and the method for superimposing the substrate and the support plate and the apparatus for superposing them are particularly limited. Instead, various methods and apparatuses can be employed. The laminated body 10 may be formed by laminating the substrate 1, the adhesive layer 2, the separation layer 3, and the support plate 4 in this order when a pressing force is applied by the sticking device.

(Substrate 1)
The substrate 1 is subjected to processes such as thinning, conveyance, and mounting while being supported (attached) to the support plate 4. The substrate is not limited to a wafer substrate, and may be any substrate such as a ceramic substrate, a thin film substrate, or a flexible substrate that needs to be supported by a support plate.

(Support plate 4)
The support plate 4 is a support that supports the substrate 1 and is attached to the substrate via the adhesive layer 2. Therefore, the support plate 4 only needs to have a strength necessary for preventing damage or deformation of the substrate 1 during processes such as thinning, transporting, and mounting of the substrate 1, and is desirably lighter. From the above viewpoint, the support plate 4 is more preferably made of glass, silicon, acrylic resin, ceramics, a silicon wafer, or the like.

(Adhesive layer 2)
The adhesive which comprises the contact bonding layer 2 should just contain the thermoplastic resin which heat-fluidity improves by heating as an adhesive material, for example. Examples of the thermoplastic resin include acrylic resins, styrene resins, maleimide resins, hydrocarbon resins, and elastomers.

  The method for forming the adhesive layer 2, that is, the method for applying the adhesive to the substrate 1 or the support plate 4, or the method for forming the adhesive tape by applying the adhesive to the substrate is not particularly limited. However, examples of the method for applying the adhesive include a spin coating method, a dipping method, a roller blade method, a doctor blade method, a spray method, and a coating method using a slit nozzle.

  The thickness of the adhesive layer 2 may be appropriately set according to the types of the substrate 1 and the support plate 4 to be attached, the treatment applied to the substrate 1 after being attached, and the like, but is 10 μm or more and 150 μm or less. Is preferably in the range of 15 μm or more and 100 μm or less.

(Separation layer 3)
The separation layer 3 is a layer that is altered by irradiation with light. The separation layer 3 is formed between the substrate 1 and the support plate 4. Therefore, the substrate 1 and the support plate 4 can be easily separated by irradiating the separation layer 3 with light after processes such as thinning, transporting and mounting of the substrate 1.

  In this specification, the “deterioration” of the separation layer 3 refers to a phenomenon in which the separation layer 3 can be broken by receiving a slight external force, or a state in which the adhesive force with the layer in contact with the separation layer 3 is reduced. means. The alteration of the separation layer 3 includes decomposition (exothermic or non-exothermic) due to absorbed light energy, cross-linking, configuration change or dissociation of functional groups (and curing or desorption of the separation layer 3 due to these). Gas, contraction or expansion) and the like.

  Further, as the separation layer 3, an inorganic film or an organic film formed by a plasma CVD method may be used. For example, a metal film can be used as the inorganic film. As the organic film, a fluorocarbon film can be used. Such a reaction film can be formed on the support plate 4 by a plasma CVD method, for example.

  The separation layer 3 may include a light absorber that is decomposed by light or the like, for example. Examples of the light absorber include graphite powder, fine metal powder such as iron, aluminum, copper, nickel, cobalt, manganese, chromium, zinc, tellurium, metal oxide powder such as black titanium oxide, carbon black, or aromatic. Dyes or pigments such as diamino metal complexes, aliphatic diamine metal complexes, aromatic dithiol metal complexes, mercaptophenol metal complexes, squarylium compounds, cyanine dyes, methine dyes, naphthoquinone dyes, anthraquinone dyes Can be used. Such a separation layer 3 can be formed by, for example, mixing with a binder resin and applying the mixture on the support plate 4. A resin having a light absorbing group can also be used as the separation layer 3.

(Dicing tape 5)
The dicing tape 5 is bonded to one side of the substrate 1 in order to reinforce the strength of the substrate 1. In this embodiment, the board | substrate 1 in the laminated body 10 is affixed on the dicing tape 5 by which the dicing frame 6 was attached to the outer periphery.

  As the dicing tape 5, for example, a dicing tape having a configuration in which an adhesive layer is formed on a base film can be used. As the base film, for example, a resin film such as PVC (polyvinyl chloride), polyolefin, or polypropylene can be used. The outer diameter of the dicing tape 5 is larger than the outer diameter of the substrate 1. When these are bonded together, a part of the dicing tape 5 is exposed at the outer edge portion of the substrate 1.

(Dicing frame 6)
A dicing frame 6 for preventing bending of the dicing tape 5 is attached to the outer periphery of the exposed surface of the dicing tape 5. That is, the dicing frame 6 is exposed at the outer edge portion of the dicing tape 5. Examples of the dicing frame 6 include a metal dicing frame such as aluminum, an alloy dicing frame such as stainless steel (SUS), and a resin dicing frame. Examples of the resin dicing frame include a resin dicing frame manufactured by Shin-Etsu Polymer Co., Ltd. or DISCO Corporation.

  If a dicing frame made of metal or alloy is used as the dicing frame 6, it is rigid, hard to be distorted and inexpensive, but it is heavy compared to a resin dicing frame, so it burdens the operator or the transport robot during transport. It takes. In recent years, a flat and rigid resin dicing frame has been developed, and has an advantage of being lighter than a metal or alloy dicing frame that has been widely used. The resin-made dicing frame is light in weight so that it can be easily transported, and further has an advantage that dust generation due to friction is small when it is taken in and out of a metal frame cassette.

<Support Separator 100>
Next, the support body separating apparatus 100 is demonstrated using FIG. FIG. 1 is a side view illustrating a schematic configuration of a support separating apparatus 100 according to an embodiment of the present invention.

  As shown in FIG. 1, the support separating apparatus 100 transmits light to a laminated body 10 in which a substrate 1, an adhesive layer 2, a separating layer 3, and a support plate (supporting body) 4 are laminated in this order. It is an apparatus that separates the support plate 4 by irradiation, and includes a holding stage 11 that holds the laminated body 10, and the holding stage 11 includes white ceramic.

  Here, the support body separating apparatus 100 includes a holding stage 11 including a porous portion 11a including a white ceramic and an outer peripheral portion 11b, and a laser unit 12. Further, as shown in FIG. 1, the outer peripheral portion 11 b of the holding stage 11 may be provided with a ground (antistatic means) 13, and an ionizer (static elimination means) 14 is provided in the unit of the support separating apparatus 100. You may have.

[Holding stage 11]
The porous portion 11 a is a porous body that includes a through hole provided in the holding stage 11. The laminated body 10 having the dicing tape 5 attached thereto is placed on the holding stage 11 so that the laminated body 10 is positioned on the porous portion 11a. Here, the laminated body 10 is sucked into the holding stage 11 by sucking out the gas between the holding stage 11 and the surface of the laminated body 10 on which the dicing tape 5 is adhered through the through hole. Thereby, the stacked body 10 is held by the holding stage 11.

  The porous part 11a contains white ceramic. Thereby, even when laser light irradiation is performed, the porous part 11a reflects without absorbing the laser light. For this reason, the porous part 11a can prevent alterations such as alteration due to laser light irradiation, generation of contaminants due to peeling of the discolored part, and generation of irregularities on the surface of the porous part 11a. Therefore, by using white ceramic for the porous portion 11a, it is possible to prevent the laminate 10 from being contaminated by contaminants generated by laser irradiation, and the adsorption power of the porous portion 11a is reduced by unevenness generated by laser irradiation. Can be prevented.

  The white ceramic preferably contains aluminum oxide. Since the white ceramic contains aluminum oxide, the porous portion 11a can suitably reflect the laser beam. Therefore, alteration due to laser light irradiation can be suitably prevented. The porous portion 11a may be formed only from aluminum oxide. In addition, the porous part 11a can prevent the quality change by a laser beam suitably by including a white ceramic. For this reason, it is not necessary to perform the coating process for preventing the alteration of the porous portion 11a in advance.

  The porous part 11a may contain a conductive material. By containing the conductive material, it is possible to prevent static electricity generated when the support plate 4 is separated from the laminate 10. Thereby, it is possible to prevent the element mounted on the substrate 1 from being damaged by static electricity.

  The porous part 11a of the holding stage 11 includes a through hole penetrating in the thickness direction. The size of the through hole is preferably 40 μm or more and 80 μm or less, and most preferably 50 μm or more and 70 μm or less. Moreover, it is preferable that the through-hole of the porous part 11a is provided in the porous part 11a with a porosity of 40% or more and 45% or less. By providing such a through hole, the porous portion 11a can more preferably reflect the laser beam and hold the laminate 10 with sufficient suction force.

  The size of the planar portion of the porous portion 11a is larger than that of the stacked body 10, and is 0.2 cm or more and 1.0 cm or less, more preferably 0 from the peripheral edge of the substrate 1 when the stacked body 10 is held. .2 cm or more and 0.5 cm or less, and most preferably, it is a size capable of providing an excess portion with a width within a range of 0.2 cm or more and 0.4 cm or less. By setting the size of the porous portion 11a to a size that allows the surplus portion to have a width within the above range from the peripheral end portion of the substrate 1 of the laminate 10, the peripheral end portion of the substrate 1 of the laminate 10 It is possible to perform laser light irradiation widely from the outside to the outside. Further, when the laminated body 10 is held on the holding stage 11, it is not necessary to increase the alignment accuracy of the position where the laminated body 10 is held, and a margin can be provided for the alignment. For this reason, since the high precision is not requested | required also for the alignment of the apparatus which conveys the laminated body 10, it becomes possible to give allowance for position alignment. Therefore, it becomes possible to convey the laminated body 10 using the conveying apparatus which can set an alignment simply.

  The outer peripheral portion 11b is a member that supports the porous portion 11a, and can be formed of, for example, ceramic, conductive ceramic, or a conductive material containing metal such as stainless steel and aluminum. Here, the outer peripheral portion 11b is preferably formed of a conductive ceramic or a conductive material including a metal. By forming the outer peripheral part 11b with a conductive material, it becomes easy to reduce the electrostatic charge to the porous part 11a.

  The outer peripheral part 11b may be connected to a decompression means (not shown) for bringing a suction force to the porous part 11a.

(Laser unit 12)
The laser unit 12 changes the quality of the separation layer 3 by irradiating the separation layer 3 of the laminate 10 with laser light. Since the porous portion 11a is formed of a material that is not altered by laser light irradiation and is formed larger than the stacked body 10 so that an excess portion is generated at the peripheral end of the substrate 1, it has a width wider than the width of the stacked body 10. Irradiation with laser light is possible. Accordingly, the laser unit 12 may irradiate the laser beam all at once over a wider area than the stacked body 10 so that the entire surface of the stacked body 10 is irradiated with laser. The entire surface of the laminate 10 may be irradiated with laser light so that the laser unit 12 scans the laminate 10 held by the holding stage 11. As a result, the laser beam can be sufficiently irradiated to the peripheral edge of the substrate 1 of the laminate 10.

In addition, as light which the laser unit 12 irradiates to the above-mentioned separation layer 3, according to the wavelength which the separation layer 3 can absorb, for example, YAG laser, Libby laser, glass laser, YVO ₄ laser, LD laser, fiber laser, etc. A laser beam such as a solid state laser, a liquid laser such as a dye laser, a gas laser such as a CO ₂ laser, an excimer laser, an Ar laser, or a He—Ne laser, a semiconductor laser, or a free electron laser may be appropriately selected. Further, if the separation layer 3 can be altered, non-laser light may be irradiated. The wavelength of the light applied to the separation layer 3 is not limited to this, but may be, for example, light having a wavelength of 600 nm or less. Further, the laser output and the pulse frequency may be appropriately adjusted according to conditions such as the type of separation layer, thickness, type of substrate, and the like.

[Earth 13]
As shown in FIG. 1, the holding stage 11 includes a ground (antistatic member) 13. Here, if the outer peripheral part 11b of the holding stage 11 is formed of a conductive material, the ground 13 may be connected to the outer peripheral part 11b.

  Thereby, it is possible to suitably prevent static electricity from being charged to the porous portion 11a. Therefore, damage to the element mounted on the substrate 1 due to static electricity can be prevented. Although different depending on the type of the substrate 1 separated from the laminated body 10, it is preferable that the porous portion 11a is prevented from being charged so that the electrostatic charge amount in the porous portion 11a is ± 100 V or less. As a result, damage to the element mounted on the substrate 1 due to static electricity spark can be prevented.

[Ionizer 14]
As shown in FIG. 1, the support separating apparatus 100 further includes an ionizer (static eliminating means) 14 that neutralizes static electricity charged in the holding stage 11.

  By neutralizing the static electricity charged in the porous portion 11a by the ions supplied from the ionizer 14, the charge amount of the porous portion 11a can be reduced. Thereby, the damage by the static electricity of the element mounted in the board | substrate 1 can be prevented.

  The ionizer 14 is installed inside the unit of the support separating apparatus 100 so that ions can be supplied to the porous portion 11a.

  Examples of the ionizer 14 include corona discharge methods such as an AC method, a DC method, a pulse AC method, a pulse DC method, and a high frequency method, or ionizers such as a plasma method, a soft X-ray method, and an ultraviolet method. Here, the ionizer 14 is preferably a blower-type or bar-type ionizer from the viewpoint of ion balance, static elimination time, ion generation amount, and the like.

  The ionizer 14 may supply ions to the porous portion 11a using Coulomb force that attracts ions of different charges, or may supply ions to the porous portion 11a by a fan or air blow. Here, from the viewpoint of the installation distance, the ionizer 14 more preferably supplies ions to the porous portion 11a by a fan or air blow.

[Operation of Support Separator 100]
First, before the support plate 4 is separated from the laminated body 10 by the support separating apparatus 100, the exposed surface of the substrate 1 is ground by a grinder in the thinning process. Thus, the substrate 1 is thinned to a desired thickness.

  Thereafter, the thinned substrate 1 side surface of the laminate 10 is attached to the dicing tape 5 held by the dicing frame 6. Next, as shown in FIG. 1, the laminated body 10 is adsorbed by the porous portion 11 a of the holding stage 11 from the side where the dicing tape 5 is adhered. Thereby, the stacked body 10 is held on the holding stage 11. At this point, the laminated body 10 is maintained in a state that allows the separation layer 3 to be irradiated with laser light through the support plate 4.

  The laser unit 12 irradiates a laser beam selected according to the type of the separation layer 3. Here, the laser unit 12 sufficiently irradiates the laser beam not only inside the peripheral end of the substrate of the laminate 10 but also outside the peripheral end of the substrate 1. This operation is possible because the porous portion 11a provided on the holding stage 11 can prevent deterioration due to laser light irradiation.

  Thereafter, the support separating apparatus 100 fixes the support plate 4 by suction means (not shown) and pulls it up in the vertical direction while maintaining the state in which the substrate 1 of the laminated body 10 is held by the suction force of the porous portion 11a. . At this time, the entire surface of the laminated body 10 including the peripheral end portion of the separation layer 3 is sufficiently altered by the laser beam irradiation. For this reason, the support body separating apparatus 100 can stably separate the support plate 4 from the laminated body 10 without applying excessive force to the laminated body 10.

  Further, the earth 13 and the ionizer 14 prevent static electricity generated when the support plate 4 is separated from the laminate 10 from being charged to the porous portion 11a. For this reason, it is possible to prevent the element mounted on the substrate 1 from being damaged by static electricity.

  Thereafter, the residue of the adhesive layer 2 and the separation layer 3 is removed by cleaning, and the substrate 1 is divided into chips by a dicing apparatus.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

[Evaluation of damage to the holding stage by laser light irradiation]
As Example 1, a holding stage using aluminum oxide as a white ceramic in a porous portion was produced. Similarly, as Comparative Example 1, a holding stage using gray ceramic in the porous portion was produced. In Example 1 and Comparative Example 1, damage to each holding stage due to laser light irradiation was evaluated.

(Production of laminate)
The laminated body used for an Example was produced as follows. First, under the conditions of a flow rate of 400 sccm, a pressure of 700 mTorr, a high frequency power of 2500 W, and a film forming temperature of 240 ° C., a fluorocarbon film (thickness 1 μm) as a separation layer is supported by a CVD method using C ₄ F ₈ as a reaction gas. Formed on body (12 inch glass support plate, thickness 700 μm). Next, TZNR (registered trademark) -A3007t (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is an adhesive composition, is spin-coated on a 12-inch silicon wafer and heated at 100 ° C., 160 ° C., and 200 ° C. for 3 minutes each. An adhesive layer was formed (film thickness 50 μm). Then, the silicon wafer and the support plate were bonded to each other through the adhesive layer and the separation layer for 3 minutes under a condition of 220 ° C. and 4000 Kg under vacuum to produce a laminate.

(Laser irradiation)
The process of holding the laminated body produced as described above on the holding stage of Example 1 and irradiating the laser beam to the outside of the peripheral edge of the 12-inch silicon wafer is performed three times by changing the laminated body every time. It was. For Comparative Example 1, the same operation as in Example 1 was performed.

  For the laser beam irradiation, a pulse laser with a wavelength of 532 nm was irradiated under the condition of a pulse frequency of 40 KHz. The scanning speed of the laser beam was set to 6500 mm / second, and the irradiation scan pitch was set to 180 μm. The irradiation range was set to φ = 309 mm in order to irradiate the laser beam to the outside of the peripheral edge of the 12-inch silicon wafer.

(Damage evaluation)
After the above operation, changes in appearance between the holding stage of Example 1 and the holding stage of Comparative Example 1 were visually evaluated. In the holding stage of Example 1, no change in appearance due to three times of laser light irradiation was observed. On the other hand, in the holding stage of Comparative Example 1, reddish brown discoloration was observed at the peripheral end portion of the porous portion using gray ceramic by three times of laser light irradiation.

  The support separating apparatus according to the present invention can be widely used, for example, in a manufacturing process of a miniaturized semiconductor device.

1 Substrate 2 Adhesive layer 3 Separation layer 4 Support plate (support)
10 Laminated body 11 Holding stage 11a Porous part (holding stage)
11b Outer peripheral part (holding stage)
13 Earth (Antistatic member)
14 Ionizer (static elimination means)
100 Support Separator

Claims (4)

Laser light is emitted from the side of the support that does not have the separation layer to a laminate formed by laminating a substrate, an adhesive layer, a separation layer that is altered by irradiation with light, and a support in this order. In a support separating apparatus that separates a support by irradiation,
A holding stage that includes a white ceramic and holds the laminate by sucking a side of the laminate having the substrate ;
A support separating apparatus, comprising: a laser unit that irradiates a laser beam from a side of the laminated body that does not have the separation layer of the support.   The said white ceramic contains the aluminum oxide, The support body separation apparatus of Claim 1 characterized by the above-mentioned.   3. The support separating apparatus according to claim 1, wherein the holding stage includes an antistatic member.   The support separating apparatus according to any one of claims 1 to 3, further comprising a static eliminating unit that neutralizes static electricity charged on the holding stage.

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