JP2010245462A - Auxiliary sheet for dicing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary film for dicing never diced together with an adherent such as a semiconductor wafer or the like in a dicing process using a laser. <P>SOLUTION: The auxiliary film 2 for dicing is constituted to have an inorganic pigment charged layer 11 containing an inorganic pigment and a binder resin, preferably constituted such that the inorganic pigment charged layer 11 constitutes a biaxial oriented plastic film charged with the inorganic pigment, preferably constituted to have an adhesion layer 12 on the inorganic pigment charged layer 11, and preferably constituted to use a silica and/or a calcium carbide as the inorganic pigment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an auxiliary sheet for dicing used for dicing semiconductor wafers, semiconductor packages, glass, ceramics and the like made of silicon, gallium arsenide, or the like.

  A semiconductor wafer made of silicon, germanium, gallium-arsenic, or the like is manufactured in a large diameter state, and then back-ground (back-ground) to a predetermined thickness, and further, back-surface treatment ( A semiconductor chip is manufactured by performing etching (polishing, etc.) and cutting (dicing).

  In more detail, an auxiliary sheet for dicing is installed on the back surface of the semiconductor wafer (mounting process), and is cut and separated into element pieces (chips) (dicing process), followed by the cleaning process, the expanding process, and the picking process. After that, it is made into a chip. Here, when the semiconductor wafer is cut and separated (dicing step), it is possible to suppress chipping (chipping) or chip scattering by fixing with an auxiliary sheet for dicing, and also to prevent damage to the semiconductor wafer. can do. During the dicing process, a blade is used to cut the semiconductor wafer. In addition, there are two types of dicing processes, scribing (half cut) and full cut (complete cutting).

  As an auxiliary sheet for dicing, a sheet having a structure in which an adhesive layer having a thickness of about 1 to 50 μm is laminated by applying and drying an acrylic pressure-sensitive adhesive on a base material layer made of a plastic film or the like is mainstream ( Patent Document 1).

Japanese Patent Laid-Open No. 2-187478

  In many dicing processes, blades are used for cutting semiconductor wafers, and conventional auxiliary sheets for dicing do not cause any particular trouble.

  However, in recent years, laser processing (YAG laser, ruby laser) has been used as a means for cutting a semiconductor wafer, and when performing full cut (complete cutting) as a dicing method, an auxiliary sheet for dicing in addition to the semiconductor wafer by the laser. The device itself was also cut, resulting in a problem that productivity was lowered.

  Then, an object of this invention is to provide the auxiliary sheet | seat for dicing which is not cut | disconnected in the case of the dicing process using a laser.

  The auxiliary sheet for dicing of the present invention that solves the above-mentioned problems is characterized by having an inorganic pigment-filled layer containing an inorganic pigment and a binder resin.

  The auxiliary sheet for dicing according to the present invention is preferably characterized in that the inorganic pigment-filled layer is a biaxially stretched plastic film filled with an inorganic pigment.

  Moreover, the auxiliary sheet for dicing according to the present invention preferably has an adhesive layer on the inorganic pigment-filled layer.

  Moreover, the auxiliary sheet for dicing according to the present invention is preferably characterized in that the inorganic pigment-filled layer has adhesiveness.

  The auxiliary sheet for dicing according to the present invention is preferably characterized in that the inorganic pigment is silica and / or calcium carbonate.

  Since the auxiliary sheet for dicing of the present invention is not cut together with an adherend such as a semiconductor wafer even in a dicing process using a laser, the workability of dicing can be improved.

Sectional drawing which shows one Example of the auxiliary sheet | seat for dicing of this invention Sectional drawing which shows the other Example of the auxiliary sheet | seat for dicing of this invention Sectional drawing which shows the other Example of the auxiliary sheet | seat for dicing of this invention Sectional drawing which shows the other Example of the auxiliary sheet | seat for dicing of this invention

  The auxiliary sheet for dicing according to the present invention has an inorganic pigment-filled layer containing an inorganic pigment and a binder. Hereinafter, embodiments of each component will be described.

  1-4 is sectional drawing which shows embodiment of the auxiliary sheet | seat 2 for dicing of this invention. The dicing auxiliary sheet 2 of the present invention comprises a single layer of an inorganic pigment-filled layer 11 as shown in FIG. 1, has an adhesive layer 12 on the inorganic pigment-filled layer 11 as shown in FIG. 2, and as shown in FIG. Examples thereof include those having the inorganic pigment filling layer 11 and the adhesive layer 12 on the transparent plastic film 13, and those having the inorganic pigment filling layer 11 on the transparent plastic film 13 as shown in FIG.

  The inorganic pigment-filled layer is a layer containing at least an inorganic pigment and a binder resin. The presence of such an inorganic pigment-filled layer can make it difficult to cut the dicing auxiliary sheet itself even if a laser (YAG laser, ruby laser) is used as a cutting means during the dicing process. When resin beads are used instead of inorganic pigments, laser cutting cannot be prevented.

  As the inorganic pigment, silica and calcium carbonate are preferably used. Examples of other inorganic pigments include barium sulfate and titanium oxide.

  As binder resins, polyester resins, acrylic resins, acrylic urethane resins, polyester acrylate resins, polyurethane acrylate resins, epoxy acrylate resins, urethane resins, epoxy resins, polycarbonate resins, cellulose resins, acetals Resin, vinyl resin, polyethylene resin, polystyrene resin, polypropylene resin, polyamide resin, polyimide resin, melamine resin, phenolic resin, silicone resin, fluorine resin, and other thermoplastic resins, thermosetting An ionizing radiation curable resin or the like can be used.

  Moreover, if resin which expresses adhesiveness is used among these resin, adherends, such as a semiconductor wafer, can be fixed with the auxiliary sheet | seat for dicing, without apply | coating an adhesive agent separately. As the resin exhibiting adhesiveness, a resin similar to the resin exemplified in the adhesive layer described later can be used.

  The form of the inorganic pigment-filled layer is not particularly limited, but is preferably a biaxially stretched plastic film filled with an inorganic pigment from the viewpoints of dimensional stability, strength, and laser resistance. As the biaxially stretched plastic film, a biaxially stretched polyester film is preferable.

  The inorganic pigment filling layer may be not only one layer but also two or more layers. For example, the auxiliary sheet for dicing of the present invention is constituted by two layers of inorganic pigment filling layers, or has an inorganic pigment filling layer on both sides of a plastic film (biaxially stretched plastic film filled with inorganic pigment or transparent plastic film). It may be a configuration.

  In the inorganic pigment filled layer, the average particle diameter of the inorganic pigment is 0.1 to 20 μm, the content of the inorganic pigment is 0.1 to 1000 parts by weight with respect to 100 parts by weight of the binder, and the thickness of the inorganic pigment filled layer is 1 to 300 μm. Design appropriately according to the degree.

  The inorganic pigment-filled layer is preferably formed on the substrate when the strength alone is not sufficient. Examples of such base materials include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polypropylene, polyethylene, polyvinyl chloride, polystyrene, various transparent plastic films made of (meth) acrylate resin, fluorine-based resin, paper, etc. Can be given.

  Moreover, it is preferable to have an adhesive layer on the inorganic pigment-filled layer for easy fixation of the adherend. For the adhesive layer, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive, an adhesive such as a hot melt adhesive, a thermocompression-bondable thermoplastic resin film, or the like can be used. In addition, adhesives that have pressure-sensitive adhesive properties at room temperature and whose adhesive strength decreases due to crosslinking by heating or irradiation with ionizing radiation are excellent in fixing adherends in the process (such as dicing), and after completion of the process This is preferable in that the adherend can be easily peeled off from the dicing auxiliary sheet.

  When using a pressure-sensitive adhesive, it is preferable to attach a separator on the adhesive layer (or an inorganic pigment-filled layer using a pressure-sensitive adhesive as a binder resin) so as not to impair the handleability. As the separator, those obtained by subjecting various plastic films to a mold release treatment can be used.

  In the adhesive layer, the thickness of the layer is appropriately designed to be about 1 to 50 μm.

  You may add additives, such as a leveling agent, in the inorganic pigment filling layer and adhesive layer mentioned above.

  In order to form the inorganic pigment-filled layer and the adhesive layer as described above, the material constituting each layer is appropriately adjusted as a coating solution by adding an additive or a diluting solvent as necessary, and the coating solution is conventionally used. Examples thereof include a method of applying and drying by a known coating method, a method of melting a resin component constituting an inorganic pigment-filled layer and an adhesive layer, and adding this to other necessary components (inorganic pigment, etc.) to form a sheet. .

  The method for dicing an adherend using the dicing auxiliary sheet of the present invention will be described in the case where a semiconductor wafer is used as the adherend.

  A series of steps for dicing the semiconductor wafer includes a mounting step, a dicing step, and a pickup step. The mounting step is a step of bonding the semiconductor wafer and the auxiliary sheet for dicing together. When the auxiliary sheet for dicing has adhesiveness, the surface having adhesiveness and the adherend can be bonded to each other. When the auxiliary sheet for dicing does not have adhesiveness, the adhesive is applied to at least a part of the auxiliary sheet for dicing and bonded, or the auxiliary sheet for dicing and the adherend are fixed by a tape or other fixing member. Can do.

  A dicing process is a process of manufacturing a semiconductor chip by dividing a semiconductor wafer into individual pieces. Dicing is performed according to a known method using a laser (YAG laser, ruby laser). The laser processing conditions are, for example, wavelength: 266 nm, repetition frequency: 50 kHz, average output: 4 w, condensing spot: elliptical (long axis 200 μm, short axis 10 μm), processing feed rate: 150 mm / sec. Since the auxiliary sheet for dicing of the present invention contains at least an inorganic pigment and a binder resin in the inorganic pigment filling layer, the auxiliary sheet for dicing itself can be made difficult to cut during the dicing process using a laser.

  The semiconductor chip pick-up step is a step of peeling the semiconductor chip that is bonded and fixed to the auxiliary sheet for dicing. The pickup method is not particularly limited, and various conventionally known methods can be employed. For example, there is a method in which individual semiconductor chips are pushed up by a needle from the dicing auxiliary sheet side and the pushed-up semiconductor chips are picked up by a pickup device.

  As mentioned above, although the case where the semiconductor wafer was used as an adherend was demonstrated as an example, the auxiliary sheet | seat for dicing of this invention is not limited to this, It can be used also for dicing of a semiconductor package, glass, ceramics, etc. .

  The following examples further illustrate the present invention. “Parts” and “%” are based on weight unless otherwise specified.

  As an auxiliary sheet for dicing used in Example 1 and Comparative Examples 1 to 10, sheets A having an inorganic pigment filling layer and a to j having no inorganic pigment filling layer were prepared.

  Sheet A (Chemical mat PBU: Kimotosha), Sheet a (Light-up NSH: Kimotosha), Sheet b (Light-up SXE: Kimotosha), Sheet c (Light-up MXE: Kimotosha), Sheet d (Light-up LSE) : Kimotosha), Seat e (Light-up GM2: Kimotosha), Sheet f (Light-up GM3: Kimotosha), Sheet g (Light-up DX2: Kimotosha), Seat h (Lightup UK2: Kimotosha), Seat i (Light-up UK4: Kimoto), sheet j (LE5000: Lintec).

  The sheet A (Example 1) has an inorganic pigment filled layer b containing a binder resin and calcium carbonate on both sides of a biaxially stretched polyester film (inorganic pigment filled layer a) filled with an inorganic pigment (silica). Sheets a to i (Comparative Examples 1 to 9) have a resin bead layer containing a binder resin and resin beads on a transparent plastic film, and a sheet j (Comparative Example 10) is An auxiliary sheet for dicing having an adhesive layer on a transparent plastic film (LE5000: Lintec Corporation, the adhesive layer does not contain inorganic pigments or resin beads).

  Using the double-sided adhesive tape (Nystack: Nichiban Co., Ltd.) on the grinding surface of a 6-inch semiconductor wafer (thickness: 40 μm) subjected to backside grinding of the dicing auxiliary sheet of Example 1 and Comparative Examples 1-9 The outer peripheral part was bonded together. Moreover, the auxiliary sheet | seat for dicing of the comparative example 10 bonded together the said grinding surface and the contact bonding layer. Next, the semiconductor wafer was diced using a YAG laser to obtain a semiconductor chip.

<Dicing conditions>
Wavelength: 266nm
Repeat frequency: 50 kHz
Average output: 4w
Focusing spot: elliptical (long axis 200 μm, short axis 10 μm)
Processing feed rate: 150 mm / sec

  Since the auxiliary sheet for dicing of Example 1 has an inorganic pigment filling layer, the sheet itself was not cut by laser dicing.

  On the other hand, the auxiliary sheets for dicing of Comparative Examples 1 to 9 do not have an inorganic pigment-filled layer and have a resin bead-filled layer, but the sheets themselves are cut by laser dicing. The auxiliary sheet for dicing in Comparative Example 10 has a conventional general structure (adhesive layer on a plastic film), but the sheet itself is cut by laser dicing.

DESCRIPTION OF SYMBOLS 11 ... Inorganic pigment filling layer 12 ... Adhesive layer 13 ... Transparent plastic film 2 ... Dicing auxiliary film

Claims (5)

  An auxiliary sheet for dicing having an inorganic pigment-filled layer containing an inorganic pigment and a binder resin.   The auxiliary sheet for dicing according to claim 1, wherein the inorganic pigment-filled layer is a biaxially stretched plastic film filled with an inorganic pigment.   The auxiliary sheet for dicing according to claim 1, further comprising an adhesive layer on the inorganic pigment-filled layer.   The auxiliary sheet for dicing according to claim 1 or 2, wherein the inorganic pigment-filled layer has adhesiveness.   The auxiliary sheet for dicing according to any one of claims 1 to 4, wherein the inorganic pigment is silica and / or calcium carbonate.

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