Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/0058—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material
  • B28D5/0076—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material for removing dust, e.g. by spraying liquids; for lubricating, cooling or cleaning tool or work

Definitions

• the invention relates to a device and a method for separating materials, in particular single crystals.
• FIG. 1 is a schematic representation of the inner hole cutting in a plan view seen in the direction of the central longitudinal axis M of a single crystal 1.
• the single crystal 1 which is substantially cylindrical with a central longitudinal axis M, is on a not shown Mounted bracket and together with this movable in a direction perpendicular to the central longitudinal axis M via a feed device, not shown.
• a cutting disc 2 For cutting or cutting the wafers, a cutting disc 2 is provided, which consists of a core sheet 2a having a concentric inner hole, the edge 3 of which surrounds the inner hole is occupied by diamond grains and thus forms a cutting edge.
• the width of the core Sheet between its outer edge and its inner edge is larger than the diameter of the single crystal, which is why only the inner edge is shown schematically in the figure.
• the cutting disc 2 can be rotated about its central axis R via a drive in the direction A shown in FIG. 1.
• the cutting disc and the single crystal are arranged with respect to one another such that the axis of rotation R of the cutting disc 2 and the central longitudinal axis M of the single crystal 1 run parallel to one another at a distance.
• the single crystal 1 can be moved by means of the feed device perpendicular to its central longitudinal axis M in the direction of the cutting disc 2 so that the cutting disc completely rotates through the single crystal 1 in a plane perpendicular to its central longitudinal axis M, and away from the cutting disc 2 into a position movable in which a separated wafer can be removed.
• a coolant-lubricant supply device 4 for supplying coolant-lubricant to the cutting edge intended.
• a second supply device for cooling lubricants is provided in the direction of rotation A after the position P2 of the exit of the cutting disc from the single crystal 1, hereinafter referred to as the exit side.
• the cooling lubricant is applied to the cutting edge or the cutting disc 2 via the feed device 4, which is then transported by the rotation of the cutting disc 2 into the separation gap formed during the cutting.
• cooling lubricant is again applied by the second feed device 5. brings, so that the cleaning and removal of removed material is ensured through the separation gap. Additives are added to the cooling lubricant, which reduce the surface tension and thus improve the wetting of the cutting disc.
• the known device also has a device for interval flushing of the core sheet and the clamping system.
• the known device has the problem that effective cleaning and the removal of the removed material during the cut requires so much cooling lubricant that the separation gap is filled with cooling lubricant and removed material. This can lead to contact between the core plate of the cutting disc 2 and the wafer section in the case of narrow separation gaps. The wafer section is pulled onto the core sheet by adhesion, and the quality of the separated wafer is adversely affected. With large contact areas, the wafer can tear away. If, on the other hand, the amount of coolant lubricant is too low, the cleaning and transport effect is no longer sufficient. In addition, surface-relaxing additives lead to better wetting of the core sheet, which promotes the evaporation and drying of the sawing sludge on the core sheet.
• the device according to the invention and the method according to the invention have the particular advantage that less cooling lubricant is required during the separation process than in the known device. This creates a high quality cut.
• Figure 1 is a schematic representation seen in plan view in the direction of a single crystal longitudinal axis of a known device.
• Figure 2 is a schematic representation of an embodiment of the device according to the invention seen in plan view in the direction of the single crystal central longitudinal axis.
• FIG. 3 shows a schematic illustration of the cooling step of the method according to the invention
• Fig. 4 is a schematic representation of a step of
• Fig. 6 is a schematic representation of the cleaning step in the method according to the invention.
• the device according to the invention has, in a known manner, the holder and the feed device for the single crystal 1, as well as the cutting disc 2 with the core sheet 2a and the diamond-grained edge 3 of the inner hole of the cutting disc.
• the device according to the invention has a first supply device 10 for supplying cooling lubricant to the edge 3 of the inner hole and to the cutting disc 2, which seen in the direction of rotation of the cutting disc 2 on the outlet side at position P2 after passing through the Single crystal 1 is provided.
• the first supply device 10 for cooling lubricants is designed, for example, as a nozzle.
• a second feed device 11 for cleaning agents is provided on the outlet side in the region of the inner hole.
• a device 12 for supplying a gaseous medium, in particular compressed air, to the cutting disc 2 and in particular the edge 3 is also provided on the outlet side.
• FIGS. 3 to 6 The operation of the device according to the invention and the method according to the invention can be seen from FIGS. 3 to 6.
• the cutting disc 2 and the single crystal 1 are separated from one another before the cutting or cutting process.
• the single crystal 1 is moved relative to the cutting disc 2 and this enters the material of the single crystal 1 in a rotating manner for cutting.
• cooling lubricant with a low volume flow ie at low speed v and low pressure p
• a cooling lubricant with an additive is used as the cooling lubricant, which increases the surface tension ⁇ of the cooling lubricant and thus worsens the wetting of the core sheet 2a.
• the core sheet 2a of the cutting disc 2 is poorly wetted, and droplets 20 of the cooling lubricant form on the surface of the core sheet 2a.
• compressed air is blown onto the edge 3 via the compressed air source 12, whereby the poor wetting is compensated for.
• the compressed air further contributes to the formation and distribution of droplets 20.
• FIG. 5 during the cutting process, the cutting disc 2 with the edge 3 and the droplets 20 of the cooling lubricant formed on the surface of the core sheet 2a penetrate into the single crystal 1 in order to separate a wafer section 1a. Air and coolant lubricant of low pressure p are constantly supplied.
• the droplets 20 of the cooling lubricant on the core sheet 2a absorb the removed material for the time of the cut and distribute it on the core sheet without the wafer drying up or being touched.
• the single crystal 1 and the separated wafer are moved away from the cutting disc 2 via the feed device, so that the cutting disc and the single crystal or the separated wafer are separated from one another, as shown in FIG. 6.
• the cleaning and the removal of the material accumulated on the core sheet and enclosed in the droplets 20 is carried out by supplying compressed air at high pressure p via the feed device 12 and at the same time supplying detergent in sufficient quantity and at a higher speed v via the feed device 11 ,
• the method according to the invention is a two-stage method, in which during the cutting process the cooling of the cutting tool, the swirling of the coolant, the inclusion of the removed material in the coolant-lubricant droplets and the distribution and storage of the coolant-lubricant droplets with the removed material under the influence of the Centrifugal force.
• the removed material is removed and removed using high air pressure and a sufficient supply of coolant and lubricant.
• the cleaning agent used in the second stage can be identical to the cooling lubricant, but it can also be another substance, such as water. Cooling lubricants and cleaning agents can therefore have different properties.
• cooling lubricant is required for cooling and lubricating than for cleaning and removing the removed material.
• a high quality cut can only be made with such a small amount of coolant and lubricant.
• the amount of cooling lubricant is set to the minimum required to guarantee cooling and lubrication.
• the separation gap is free and contact between the core sheet and the wafer section is avoided.
• a container 30 is provided for supplying cooling lubricant to the supply device 10, which dispenses the small amount of cooling lubricant during the separation process, and is in a constant position in the working position Distance is located above the feed device 10 and which is connected to it via a line 31.
• cooling lubricant which is fed to the feed device 10 via the line only under the influence of gravity or the hydrostatic pressure. Air bubbles in the line are discharged upwards. This ensures that a constant and bubble-free supply is ensured even with small quantities of coolant to be supplied.
• the invention is suitable for cutting a wide variety of materials, e.g. for optical glasses, plastics and others.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Auxiliary Devices For Machine Tools (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Grinding-Machine Dressing And Accessory Apparatuses (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (3)

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• 2000
  • 2000-11-08 DE DE10055286A patent/DE10055286A1/de not_active Withdrawn
• 2001
  • 2001-10-17 EP EP01984580A patent/EP1224067B1/de not_active Expired - Lifetime
  • 2001-10-17 DE DE50102989T patent/DE50102989D1/de not_active Expired - Fee Related
  • 2001-10-17 WO PCT/EP2001/012032 patent/WO2002038349A1/de not_active Ceased
  • 2001-10-17 US US10/181,099 patent/US20030005919A1/en not_active Abandoned
  • 2001-10-17 JP JP2002540914A patent/JP4302979B2/ja not_active Expired - Fee Related
  • 2001-10-17 CZ CZ20022365A patent/CZ301194B6/cs not_active IP Right Cessation
  • 2001-10-17 CN CNB018034896A patent/CN100396460C/zh not_active Expired - Fee Related
  • 2001-10-17 AT AT01984580T patent/ATE271962T1/de not_active IP Right Cessation
  • 2001-10-17 RU RU2002118120/03A patent/RU2271927C2/ru not_active IP Right Cessation
  • 2001-10-17 CN CNA2007101065817A patent/CN101066616A/zh active Pending
  • 2001-10-17 SK SK978-2002A patent/SK286415B6/sk not_active IP Right Cessation
  • 2001-11-02 TW TW090127230A patent/TW590842B/zh not_active IP Right Cessation
• 2007
  • 2007-10-03 JP JP2007260189A patent/JP2008135712A/ja not_active Withdrawn

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Non-Patent Citations (2)

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