JP2012059748A - Holding jig for substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a practical holding jig for a substrate capable of simply adhering to a substrate by smoothly flowing air, and controlling adhesiveness to the substrate.SOLUTION: In this jig, an adhesion layer 2 is integrated with a heat resistant plate 1 having a larger flexibility than that of a thin and fragile semiconductor wafer W so that the adhesion layer 2 holds the thin and fragile semiconductor wafer W. A plurality of holding protrusions 3 for the semiconductor wafer W stand on a surface of the adhesion layer 2, and spacing 4 for flowing the air is formed between the plural holding protrusions 3. Each holding protrusion 3 is formed into a column shape, and its tip is made into a flat adhesion face 5. A surface peripheral edge of the adhesion layer 2 is provided with a peripheral wall 6 positioned at a part outer than a peripheral edge of the semiconductor wafer W and surrounding the holding protrusions 3. A plurality of supporting comb teeth 7 supporting the peripheral edge of the semiconductor wafer W are aligned on the peripheral wall 6, so as to form air flowing space between the adjacent comb teeth 7.

Description

  The present invention relates to a holding jig for a substrate used when processing or transporting a substrate such as a thin and fragile semiconductor wafer.

  From the viewpoint of adapting to a thin semiconductor package, a semiconductor wafer is thinned to 100 μm or less (in some cases 50 μm or less) by back grinding and used for a solder reflow process, a dicing process, etc. Since it is brittle and easily warped, there is a high risk of damage if processed or transported as it is. Therefore, conventionally, a holding jig for a substrate is used in order to ensure the rigidity of a thin and fragile semiconductor wafer and prevent damage (see Patent Documents 1, 2, and 3).

  Although not shown, this type of substrate holding jig includes an inner ring and an outer ring that can be fitted and removed from each other, and a peripheral edge of a flexible adhesive layer between the inner ring and the outer ring. A thin and fragile semiconductor wafer is detachably adhered to and integrated with the surface of the adhesive layer.

JP 2010-153410 A JP 2010-28031 A JP 2009-187969 A

  The conventional substrate holding jig is configured as described above, and when the entire surface of the semiconductor wafer is adhered to the adhesive layer without any gap, air does not flow out quickly between the adhesive layer and the semiconductor wafer. Therefore, there is a problem that the adhesion work of the semiconductor wafer is delayed or complicated. In recent years, it has been required to change the adhesiveness of the adhesive layer according to the characteristics of the semiconductor wafer, in other words, to control the adhesiveness. However, the adhesiveness is controlled by changing the material of the adhesive layer. Actually, it is not easy to do, and there is a risk of impeding practicality.

  The present invention has been made in view of the above, and it is possible to easily adhere the substrate by allowing air to flow out smoothly, and to control the adhesiveness to the substrate without changing the material. The object is to provide a holding jig for a substrate.

In the present invention, in order to solve the above-mentioned problem, a holding jig for providing a pressure-sensitive adhesive layer on a flexible heat-resistant plate larger than a thin and fragile substrate and holding the substrate detachably on the pressure-sensitive adhesive layer,
A plurality of holding projections for the substrate are erected on the surface of the adhesive layer, a gap for air circulation is defined between the plurality of holding projections, each holding projection is formed in a substantially column shape, and the tip thereof is formed. A flat adhesive surface,
A peripheral wall located outside the peripheral edge of the substrate and surrounding the plurality of holding projections is provided around the peripheral edge of the adhesive layer, and a plurality of supporting peripheral edges of the substrate are provided on the inner peripheral surface of the peripheral wall. A feature is that support comb teeth are arranged and an air circulation space is defined between adjacent support comb teeth.

Note that a thin and brittle substrate can be a back-ground thin semiconductor wafer.
Further, the heat-resistant plate can be made of glass epoxy resin in which an epoxy resin is infiltrated into glass fiber, and the adhesive layer can be made of silicone rubber, and these heat-resistant plate and adhesive layer can be integrally formed.
Also, the plurality of holding protrusions, the peripheral wall, and the plurality of supporting comb teeth can be made substantially the same height, and each supporting comb tooth can be extended longer than the width of the holding protrusion and directed toward the central portion of the adhesive layer.

  Here, the substrate in the claims includes semiconductor wafers made of silicon wafers of φ200, 300, and 450 mm, silicon for solar cells, and the like. Examples of the method for providing the pressure-sensitive adhesive layer on the heat-resistant plate include a method of laminating and bonding the pressure-sensitive adhesive layer to the heat-resistant plate with an adhesive or the like, a method of integrally forming the heat-resistant plate and the pressure-sensitive adhesive layer, and the like. The holding protrusion is formed in a cylindrical shape, a prism shape, a truncated cone shape, a truncated pyramid shape, or the like having a flat adhesive surface at the tip.

  According to the present invention, when holding a thin and fragile substrate on a holding jig, a plurality of holding projections of the holding jig are gradually adhered to the substrate from the end, and the peripheral edge of the substrate is supported by a plurality of supporting comb teeth. If it is made, rigidity can be given to a board | substrate and it can hold | maintain safely. At this time, the air between the substrate and the adhesive layer flows out from the gap for air circulation to the outside via the air circulation space, so that it is less likely to stay and can adhere to the substrate more easily than before. it can.

  Also, when processing the substrate held by the holding jig, fix the substrate to various tables and devices, and gradually hold the heat-resistant plate and adhesive layer of the holding jig from the end. If it peels, a holding jig can be peeled from a board | substrate and a predetermined process can be given to a board | substrate. At this time, since air flows from the outside of the holding jig into the internal gap via the air circulation space, the substrate can be quickly peeled off.

  According to the present invention, air can flow out smoothly and the substrate can be easily adhered, and the adhesiveness to the substrate can be easily controlled without changing the material of the adhesive layer. is there. In addition, a practical substrate holding jig can be provided with a simple configuration.

  According to the second aspect of the present invention, since the plurality of holding projections, the peripheral wall, and the plurality of supporting comb teeth have substantially the same height, the posture can be stabilized by holding the substrate horizontally without tilting. it can. In addition, since the peripheral edge of the substrate is supported by the support comb teeth longer than the width of the holding protrusion, the peripheral edge of the substrate does not protrude outside the holding protrusion, and the entire peripheral edge of the substrate is safely supported. It becomes possible to suppress damage to the peripheral edge of the substrate. Furthermore, since each support comb tooth is not inclined and directed in the circumferential direction of the adhesive layer or the like, but is directed in the center portion direction, it is possible to reliably support the entire peripheral edge portion of the substrate.

It is a section explanatory view showing typically the use state in the embodiment of the holding jig for substrates concerning the present invention. It is a section explanatory view showing typically the holding state of the semiconductor wafer in the embodiment of the holding jig for substrates concerning the present invention. It is a plane explanatory view showing typically an embodiment of a holding jig for substrates concerning the present invention. It is bottom explanatory drawing which shows typically embodiment of the holding jig for substrates which concerns on this invention. It is front explanatory drawing which shows typically embodiment of the holding jig for substrates which concerns on this invention. It is side surface explanatory drawing which shows typically embodiment of the holding jig for substrates which concerns on this invention. It is principal part expansion plan explanatory drawing which shows typically the some holding | maintenance protrusion and support comb tooth in embodiment of the holding jig for substrates which concerns on this invention. It is a fragmentary sectional view showing typically the holding state of the semiconductor wafer in the embodiment of the holding jig for substrates concerning the present invention. It is another partial cross-section explanatory drawing which shows typically the holding state of the semiconductor wafer in embodiment of the holding jig for substrates which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A holding jig for a substrate in the present embodiment includes a heat-resistant plate 1 and an adhesive layer that are larger than a semiconductor wafer W, as shown in FIGS. 2 and a jig for detachably holding a thin and fragile semiconductor wafer W on the adhesive layer 2. A plurality of holding projections 3 and a peripheral wall 6 are disposed on the surface of the adhesive layer 2. A plurality of support comb teeth 7 are formed.

  The semiconductor wafer W is not particularly limited. For example, the semiconductor wafer W is formed of a silicon wafer having a diameter of 200 mm that is thinned to 100 μm or less by back grinding of a back grinding apparatus. This semiconductor wafer W has a feature that it is very thin and fragile and easily warps, and in particular, its peripheral edge portion is easily chipped.

  As shown in FIG. 1 to FIG. 3 and the like, the heat-resistant plate 1 is formed by using a predetermined material into a flat disk with front and back surfaces each having at least flexibility, and is handled by a dedicated robot. Is done. The predetermined material of the heat-resistant plate 1 is not particularly limited, and examples thereof include glass epoxy resin in which an epoxy resin is infiltrated into glass fiber, special glass, and the like.

  Among these, it is preferable to use an inexpensive glass epoxy resin which is excellent in mechanical properties, chemical properties and dimensional accuracy, is easy to bend and is not easily broken. Further, the heat-resistant plate 1 is set together with the semiconductor wafer W in a solder reflow apparatus, and is given heat resistance of at least 250 ° C. or higher because it is exposed to a high-temperature environment.

  The heat-resistant plate 1 is formed with a diameter slightly larger than the semiconductor wafer W by about 1 to 2 mm, preferably about 1 mm. Therefore, when the semiconductor wafer W has a diameter of 200 mm, the heat-resistant plate 1 has a size of 201 to 202 mm. This is because if the heat-resistant plate 1 is not larger than the semiconductor wafer W by about 1 to 2 mm, the handling of the robot will be hindered, and the peripheral portion of the semiconductor wafer W cannot be sufficiently protected. This is because the work of peeling from the end may be difficult. Moreover, even if the heat-resistant plate 1 is made 2 mm or more larger than the semiconductor wafer W, the workability cannot be remarkably improved, and conversely, the material required for the heat-resistant plate 1 is wasted, or an existing robot can be used as it is. Because it disappears.

  The thickness of the heat-resistant plate 1 is determined in consideration of the diameter of the semiconductor wafer W, imparting rigidity to the thin and fragile semiconductor wafer W, and the flexibility of the heat-resistant plate 1. When the semiconductor wafer W is φ200 mm, the heat-resistant plate 1 preferably has a thickness of about 400 μm.

  The adhesive layer 2 is formed into a planar circular thin film using a predetermined material having self-adhesiveness, and is integrated with the entire surface of the heat-resistant plate 1. The predetermined material for the pressure-sensitive adhesive layer 2 is not particularly limited, and examples thereof include silicone rubber and fluorine rubber excellent in heat resistance, weather resistance, flame retardancy, viscosity temperature characteristics, and the like.

  As shown in FIGS. 1 to 3 and FIGS. 7 to 9, a plurality of holding projections 3 for the semiconductor wafer W are erected integrally at a predetermined interval on the surface excluding the peripheral portion of the adhesive layer 2. A gap 4 for air circulation is defined between the plurality of holding projections 3, and this gap 4 functions to facilitate the adhesion work and the peeling work of the semiconductor wafer W by circulating air.

  The pitch between the adjacent holding protrusions 3 is determined in consideration of the adhesiveness to the semiconductor wafer W. That is, when it is desired to improve the adhesiveness to the semiconductor wafer W, the pitch is adjusted narrowly, and when it is desired to reduce the adhesiveness to the semiconductor wafer W, the pitch is adjusted widely. In the case of this embodiment, the pitch between the holding projections 3 and the holding projections 3 is set to about 500 μm.

  Each holding projection 3 is formed in a cylindrical shape, and its tip is formed on a flat adhesive surface 5, and the semiconductor wafer W is detachably adhered to the adhesive surface 5. The holding projections 3 are respectively formed at a height and diameter of about 100 μm, and the height from the adhesive surface 5 to the bottom surface of the adhesive layer 2 is about 250 μm. The height of the holding protrusion 3 is about 100 μm. If the holding protrusion 3 is too high, the holding protrusion 3 is likely to buckle by an external force, and the semiconductor wafer W may be destroyed. This is because.

  The diameter of the holding protrusion 3 is determined in consideration of the adhesiveness to the semiconductor wafer W, as in the above pitch. That is, when the adhesiveness to the semiconductor wafer W is desired to be improved, the diameter is increased, and when the adhesiveness to the semiconductor wafer W is desired to be decreased, the diameter is reduced. Also, the height from the adhesive surface 5 of the holding projection 3 to the bottom surface of the adhesive layer 2 is about 250 μm. If it is too high, the thickness of the entire holding jig may increase, and the handling of the semiconductor wafer W may be hindered. This is because, if it is generated and conversely too low, the mechanical strength of the pressure-sensitive adhesive layer 2 may be insufficient.

  As shown in FIG. 3 and FIG. 7, a planar ring-shaped peripheral wall 6 that is located outside the peripheral portion of the semiconductor wafer W and surrounds the plurality of holding protrusions 3 from the outside is provided at the peripheral portion of the surface of the adhesive layer 2. A plurality of support comb teeth 7 are arranged on the inner peripheral surface of the peripheral wall 6 so as to support the peripheral portion where the semiconductor wafer W is easily chipped. An air circulation space 8 communicating with the gap 4 is defined between the adjacent support comb teeth 7 and the support comb teeth 7, and the air circulation space 8 circulates air together with the gap 4 to adhere the semiconductor wafer W. And contribute to peeling.

  Each support comb 7 is formed to extend longer than the diameter of the holding protrusion 3 from the viewpoint of reliably supporting the peripheral edge of the semiconductor wafer W, and its curved tip is directed toward the center of the adhesive layer 2. In the case of this embodiment, each support comb 7 is formed to a length of about 2.5 mm, and the length from the outer peripheral surface of the peripheral wall 6 to the tip is about 4.5 mm.

  The plurality of holding protrusions 3, the peripheral wall 6, and the plurality of support comb teeth 7 are aligned at the same height from the viewpoint of horizontally sticking the semiconductor wafer W. In the case of the present embodiment, the plurality of holding protrusions 3, the peripheral wall 6, and the plurality of support comb teeth 7 are aligned to a height of 100 μm.

  In the above configuration, when manufacturing the holding jig, first, the silicone rubber for the adhesive layer 2 is set in a dedicated stamper, the mold is clamped, and the glass epoxy resin for the heat-resistant plate 1 is filled. Then, the holding jig can be manufactured by punching into a predetermined size and shape.

  Next, when the thin and brittle semiconductor wafer W is held by the holding jig, the semiconductor wafer W is adhered and held on the flat adhesive surfaces 5 of the plurality of holding projections 3, and the semiconductor wafer W is placed on the plurality of supporting comb teeth 7. If the peripheral edge portion of the semiconductor wafer W is supported, the thin and brittle semiconductor wafer W can be given rigidity and can be safely held.

  In addition, when the thin and fragile semiconductor wafer W vacuum-sucked on the suction table 10 shown in FIG. 1 is held by the holding jig, a plurality of holding protrusions 3 of the holding jig bent on the exposed surface of the semiconductor wafer W are end. If the vacuum suction of the suction table 10 is released after the peripheral edge of the semiconductor wafer W is supported by the plurality of support comb teeth 7 and then the suction table 10 is released, the semiconductor wafer W can be given rigidity and can be safely held.

  The suction table 10 is not particularly limited. For example, the suction table 10 includes a porous ceramic disk, and the disk is connected to a vacuum pump through a pipe, and the vacuum pump is driven. By exhausting the air indicated by the arrow, the semiconductor wafer W is adsorbed and held on the surface.

  At the time of the above operation, since the adhesive surface 5 of each holding projection 3 is not curved in a hemispherical shape and is flat and substantially wide in contact area, the holding projection 3 is accurately adhered to the exposed surface of the semiconductor wafer W. be able to. In addition, since the air between the adhesive layer 2 and the semiconductor wafer W flows out of the holding jig through the air circulation space 4 through the air circulation space 8, the semiconductor wafer W can be easily and reliably removed. Can stick. Therefore, it is not necessary to carefully adhere the semiconductor wafer W and the plurality of holding protrusions 3 of the holding jig over time under vacuum using a vacuum apparatus.

  Next, when the semiconductor wafer W held by the holding jig is to be sucked and processed by the suction table 10, the semiconductor wafer W is vacuum-sucked and positioned on the flat surface of the suction table 10, and then the holding jig is used. When the heat-resistant plate 1 and the adhesive layer 2 are gradually folded from both ends and peeled upward (see the upper arrow in FIG. 1), the holding jig is peeled off from the semiconductor wafer W, and the semiconductor wafer W is predetermined. Can be processed. At this time, since air flows into the gap 4 from the outside of the holding jig via the air circulation space 8, the semiconductor wafer W can be quickly peeled off.

  According to the above configuration, when the semiconductor wafer W is adhered to the adhesive layer 2, the gap 4 and the air circulation space 8 can be used so that air can be quickly discharged from between the adhesive layer 2 and the semiconductor wafer W. The adhesion work of the semiconductor wafer W can be significantly smoothed, speeded up, and facilitated. Moreover, if the pitch between the plurality of holding protrusions 3 and the diameter of each holding protrusion 3 are changed, the adhesiveness can be freely controlled without changing the material of the adhesive layer 2, and the practicality can be improved. Can do. Moreover, since the holding jig is substantially the same size as the semiconductor wafer W and does not become extremely thicker than the semiconductor wafer W, it is possible to improve operability and handleability with a simple configuration.

  Further, since the long supporting comb teeth 7 support the fragile peripheral portion of the semiconductor wafer W, damage to the semiconductor wafer W can be effectively prevented. This point will be described in detail. For example, when the holding protrusion 3 supports a very fragile peripheral edge of the semiconductor wafer W, the peripheral edge of the semiconductor wafer W protrudes outside the holding protrusion 3, and the semiconductor wafer W There is often a risk that the entire periphery cannot be safely supported. As a result, the semiconductor wafer W may flutter and its peripheral edge may be easily chipped due to a collision or the like.

  On the other hand, in this embodiment, since the peripheral edge of the semiconductor wafer W is supported by the support comb teeth 7 longer than the diameter of the holding protrusion 3, the fragile peripheral edge of the semiconductor wafer W protrudes outside the holding protrusion 3. There is nothing, and it is possible to safely and appropriately support the entire peripheral edge of the semiconductor wafer W, and to suppress and prevent chipping caused by wobbling.

  Further, since each support comb 7 is directed not in the circumferential direction of the adhesive layer 2 but in the center direction, even if the semiconductor wafer W is a large-diameter type, it is long enough to support the peripheral edge of the semiconductor wafer W. Therefore, reliable support of the entire peripheral edge of the semiconductor wafer W can be greatly expected. Furthermore, since a separate inner ring and outer ring and an adhesive layer as in the prior art are not required, a reduction in the number of parts can be expected.

  The surface excluding the peripheral edge of the adhesive layer 2 and the plurality of holding protrusions 3 may be appropriately colored with chromatic color, black, or the like. Moreover, the support comb teeth 7 may or may not have adhesiveness.

  The holding jig for substrates according to the present invention can be used in the field of manufacturing semiconductors and solar cells.

DESCRIPTION OF SYMBOLS 1 Heat-resistant plate 2 Adhesive layer 3 Holding protrusion 4 Gap 5 Adhesive surface 6 Peripheral wall 7 Supporting comb tooth 8 Air circulation space 10 Suction table W Semiconductor wafer (thin and fragile substrate)

Claims (2)

An adhesive layer is provided on a flexible heat-resistant plate that is larger than a thin and fragile substrate, and the substrate is a holding jig for detachably holding the substrate,
A plurality of holding projections for the substrate are erected on the surface of the adhesive layer, a gap for air circulation is defined between the plurality of holding projections, each holding projection is formed in a substantially column shape, and the tip thereof is formed. A flat adhesive surface,
A peripheral wall located outside the peripheral edge of the substrate and surrounding the plurality of holding projections is provided around the peripheral edge of the adhesive layer, and a plurality of supporting peripheral edges of the substrate are provided on the inner peripheral surface of the peripheral wall. A holding jig for a substrate, wherein support comb teeth are arranged and an air circulation space is defined between adjacent support comb teeth.   2. The substrate according to claim 1, wherein the plurality of holding protrusions, the peripheral wall, and the plurality of supporting comb teeth have substantially the same height, and each supporting comb tooth extends longer than the width of the holding protrusion and is directed toward the center portion of the adhesive layer. Holding jig.

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