Training document Introduction: machine and cutting process

Transcription

1 Training document Introduction: machine and cutting process BrickMaster 860 Version_en-00

2 Training document This document was created by Meyer Burger AG on and is covered by copyright. Meyer Burger categorically rejects any claims for liability for amendments to the original document and any damages arising from them directly or indirectly. Meyer Burger AG Schorenstrasse 39 / CH-3645 Gwatt (Thun) Phone +41 (0) / Fax +41 (0) sales@meyerburger.ch / 2

3 Table of contents 1 Learning objectives 2 Introduction 2.1 Show introduction movie Photovoltaic value chain Waferline Overview modules of waferline Machine 3.1 Overview of assemblies Description of assemblies Wire handling cutting principle Operation Cutting times (Recipe) Introduction to the cutting process 4.1 Diamond wire squaring Diamond wire Cutting principle diamond wire

4 5 Performance indicator 5.1 Reduced total cost of ownership (TCO) Uptime Yield Silicon ingots and bricks 6.1 Overview Technical Glossary 4 Training document - Table of contents Version_en-00

5 1 Learning objectives The trainee receives basic information about the machine and its components. He knows the cutting process critical performance parameters like Uptime, Yield and CoO. 5

6 2 Introduction 7

7 2.1 Show introduction movie 2.2 Photovoltaic value chain Mono and multi silicon Silicon blocs / ingot cutting into wafers Solar cells Solar modules Solar systems Key Factors: Fig. 2-1 Photovoltaic value chain 8 Training document - Introduction Version_en-00

8 2.3 Waferline The following graphic shows the differences between mono and multi line including products. Growing a ingot Cropping Cutting a block / ingot Grinding edges & gluing bricks Slicing wafers Wafer pre-cleaning, separation Cleaning wafers Measuring wafers Mono-Si Czochralskiprozess Mono-Si Block-cutting Edge-grinding Brick-grinding Multi-Si Float zone procedure Multi-Si Block-cutting Brick-gluing Fig. 2-2 Overview of waferline Version_en-00 9

9 2.4 Overview modules of waferline Cropping Bricking/Squaring Grinding Gluing Wafering Separating, cleaning and measuring Process control Waferline Fig. 2-3 Overview modules of waferline 10 Training document - Introduction Version_en-00

10 3 Machine 11

11 3.1 Overview of assemblies Fig. 3-1 Overview Legend 1 Electric cabinet (control system) 2 Traversing device (wire tensioning system) 3 Feed unit 4 Cutting yoke 5 Cutting fluid tank 6 Winder (wire tensioning system) with spool 7 Filtering units 8 Air maintenance unit (media module) 9 Operating panel (control system) 10 Pallet with carrier 11 Loading with stacker 12 Training document - Machine Version_en-00

12 3.1.1 Orientation rechts North South links Fig. 3-2 Orientation Version_en-00 13

13 3.2 Description of assemblies Machine stand and feed unit Machine stand as a welded construction with high mechanical and thermal stability Cutting feed unit Cutting feed from top to bottom Mechanical workpiece attachment Cutting yoke A welded construction ensures high mechanical and thermal stability Special suspension for wire deflection roller with sealing air Receptacle for the main drives Receptacle for cutting fluid supply and cutting fluid distribution on workpiece Receptacle for the load cells Wire and media management One wire tensioning unit, with two wire winding spools Horizontal arrangement of the wire winding spools ensures low-vibration operation. It is the basis for constant wire tension and a correspondingly high wafer quality Digital control of the wire pre-tensioning and of the winding process Use of wire spool MB80 Replacement of the wire winding spools by means of a loading device in minimum time The bearing applications are protected against the ingress of cutting fluid by an air overpressure Cutting fluid unit Cutting fluid tank, can be removed with lifting carriage Micro-filtration of the cutting fluid during the cutting process; double filter, switchable Cutting fluid pump with variable delivery rate Cutting fluid supply A cutting fluid supply covering the total surface of the workpiece Cutting fluid flow measured and displayed with a mass flow meter Flow control Control system Siemens SIMATIC S 7 Integrated PC for operation, data storage and data transmission and connection to higher-ranking computer 14 Training document - Machine Version_en-00

14 3.2.7 Operation Colour flat screen for displaying and monitoring process data Pre-selection of profiles for wire pre-tensioning, cutting feed, wire movement and cutting fluid flow to optimise the machining process Safety The machine meets the requirements of current safety standards The machine is CE compliant Options Note If options are described in the operating manual, they are clearly identified as an option (or optional). Version_en-00 15

15 3.3 Wire handling cutting principle Fig. 3-3 Wire handling cutting principle Legend Roller number left Roller number right MB number Designation Winder (wire spool) Traversing device roller Dancing roller 13, Load cell roller 15, Drive roller 14, 16, 17, 23, 25, 26, 28, Deflection roller 16 Training document - Machine Version_en-00

16 3.3.1 Designation of the rollers in yoke 156 mm Fig. 3-4 Legend Designation of rollers in yoke 156 mm Roller number Designation 80, 81, 82, 95, 96, 97 Drive roller 84, 85, 86, 90, 91, 92, 93 Load cell roller 87, 89 Deflection roller 40, 41, 42, 43, 44, 45, 46 60, 61, 62, 63, 64, 65, 66 50, 51, 52, 53, 54, 55, 56 70, 71, 72, 73, 74, 75, 76 Guide roller (shaft) upper layer Guide roller (shaft) lower layer Version_en-00 17

17 Cutting of multi-crystalline ingot G5 Install spacer A B C Fig. 3-5 Wire spacer for G5 ingot cut A B C Wire of lower level Wire of upper level Wire spacer MB no (with deflection roller) Why a spacer is required With a G5 ingot the wire between the rollers no. 40 and 60 is not used. The bowing effect of the lower wires would cause problems. 18 Training document - Machine Version_en-00

18 3.3.2 Designation of the rollers in yoke 125 mm Fig. 3-6 Legend Designation of rollers in yoke 125 mm Roller number Designation 80, 81, 82, 83, 95, 96, 97, 98 Drive roller 84, 85, 86, 87, 90, 91, 92, 93, 94 Load cell roller 88, 89 Deflection roller 40, 41, 42, 43, 44, 45, 46, 47, 48 60, 61, 62, 63, 64, 65, 66, 67, 68 50, 51, 52, 53, 54, 55, 56, 57, 58 70, 71, 72, 73, 74, 75, 76, 77, 78 Guide roller (shaft) upper layer Guide roller (shaft) lower layer Version_en-00 19

19 3.4 Operation Operation consists of: Switching on Main switch Referencing Left traversing device Right traversing device Left dancer Right dancer Feed: Referencing successful Feed 20 Training document - Machine Version_en-00

20 Setup Check cutting yoke (unit) Install wire spools Wind the web Connect and check coolant supply Version_en-00 21

21 Load machine With workpiece carrier and ingot W A1 A2 A3 A4 A5 A6 B1 B2 B3 B4 B5 B6 C1 C2 C3 C4 C5 C6 D1 D2 D3 D4 D5 D6 E1 E2 E3 E4 E5 E6 F1 F2 F3 F4 F5 F6 N Workpiece identification S E Check before cut Wire in the correct groove 22 Training document - Machine Version_en-00

22 Cutting profile and parameters Start Start automatic with green hardware key Check during cut process The winding and unwinding of the spools Noises (abnorm) t db Version_en-00 23

23 Wire: in good conditions (gold instead of red) 24 Training document - Machine Version_en-00

24 After cut Unload workpiece carrier Verify Enough wire for next cut Pulleys in limit of operating hours of cuts Version_en-00 25

25 Collant status 26 Training document - Machine Version_en-00

26 3.5 Cutting times (Recipe) Cut Profile Feed rate -> Cutting Time Wire speed-> Wire Consumption Coolant flow Wire tension Fig. 3-7 Sample of standard recipe Version_en-00 27

27 4 Introduction to the cutting process 29

28 4.1 Diamond wire squaring B 1 C A D Fig. 4-1 Main elements / slurry wafer slicings Legend 1 Silicon ingot A Wire pitch mm B Brick width mm C Wire diameter 420 µm D Kerf loss 430 µm 30 Training document - Introduction to the cutting process Version_en-00

29 4.2 Diamond wire Quality results using diamond wire: Flatter wafers Resulting in possible improved cell performance Roadmap for thinner wafers Holistic approach to cutting Improved wafer quality (TTV, saw marks, etc.) Excellent cutting accuracy Fig. 4-2 MB80 spool with diamond wire Maintenance and environment friendly: Elimination of slurry management No PEG and SiC hazardous waste management Fewer wire spool changes Cleaner and faster process Potential for Si recycling process Ecological use of all substances and media Machine Wire Post-Cut Processing Wafer Quality Stable Process Ingot Preparation Process Recipes Water quality Fig. 4-3 Process using diamond wire Version_en-00 31

30 4.3 Cutting principle diamond wire Moving wire cutting zone Silicon Fig. 4-4 Cutting principle diamond wire Diamonds are coated on the wire to generate a true cutting action 2 body erosion Grits slide over silicon Grits speed equal to wire speed Theoretically doubling of removal rate in comparison to loose abrasive process Nominal wire size mm Kerf size mm Application Silicon wafering Sapphire wafering Sapphire wafering Cropping and squaring Cropping and squaring Cropping and squaring.140 mm.155 mm.200 mm.250 mm.300 mm.310 mm.380 mm Fig. 4-5 Diamond wire 32 Training document - Introduction to the cutting process Version_en-00

31 4.3.1 Different types of diamond wire At the moment there are several diamond wire production technologies used. The technologies differ mainly in the way the diamonds are fixed on the core wire. Diamond wire + low costs + absorb forces - lifetime Resin wire Nickel plating + high wire performance + hardness + lifetime ALMT Electroless plating (chemical plating) Electroplating Asahi, Eyetech Direct nickel plating JFS, READ Diamond attach and nickel plating DMT Fig. 4-6 Wire manufacturing processes Diamond wire (DMT) Plating and diamond attach technology Core wire Cu coating Ni coating Diamond Fig. 4-7 Diamond attach and plating process Fig. 4-8 Diamond wire DMT Version_en-00 33

32 Chemical nickel plated wire: Asahi, JFS, others Full plating technology Diamond Core wire Ni coating Fig. 4-9 Chemical plated diamond wire Fig Chemical plated diamond wire (Asahi) 34 Training document - Introduction to the cutting process Version_en-00

33 5 Performance indicator 35

34 5.1 Reduced total cost of ownership (TCO) Faster cut times: 2 x faster than slurry on average Increased capacity without increasing capital expenditures Faster ROI due to reduced initial capital investment Roadmap to lower cost/watt: Lower cost/watt resulting from reduced TCO Less expensive secondary process costs Re-use of wire Reduced utilities Less plant complexity: No slurry mixing or supply and recovery systems required Reduced running costs such as electricity and cooling water Slurry versus Diamond Wire Parameter Slurry Diamond wire Format 156mm Loading: Wafer: Wire/Core: Pitch: Capacity: Wafers/run Wafers/year: MW/year: Wafers/kg: Time: 1000mm 180µm 120µm Mio Min. 1000mm 180µm 120µm Mio Min. Note Depending on consumables/process 36 Training document - Performance indicator Version_en-00

35 5.2 Uptime Planned running time of machine: 8760 h (365 x 24; depending on customer specific situation) Target Uptime (95%): 8322 h Effective Uptime (measured by PQMS) Technical fault No Operator available WGR exchange No spare parts available No service technician available No material available (e.g. cutting fluid, bricks) Rebuild / upgrade No consumables available (e.g. pulleys) Fig. 5-1 Availability - uptime of machines Version_en-00 37

36 5.3 Yield =Input (max. No. of wafers) Total brick length Usable brick length =usable input (max. No. of good wafers) Defect areas =usable input =usable output (inspec. wafers) wire saw related off spec. wafers broken wafers and other issues Fig. 5-2 Yield Definition: Parameter Formula Example max. No. of wafers = total brick length [mm] WGR pitch [mm] 500 mm = = mm 1408 wafers max. No. of good wafers = usable brick length [mm] WGR pitch [mm] = 494 mm = mm 1391 wafers Yield calculations Parameter Formula Example Yield of measured wafers = no. of inspec wafers no. of measured wafers 1338 wafers = = 97 % 1380 wafers Wire saw yield = 1 no. out of spec wafers* 42 wafers = = 97 % max. no. of wafers 1391 wafers Wafer line yield = no. of inspec wafers max. no. of wafers 1338 wafers = = 95 % 1408 wafers 38 Training document - Performance indicator Version_en-00

37 6 Silicon ingots and bricks 39

38 6.1 Overview Fig. 6-1 High variations of p-si and ingots Legend 1 Multi-Ingot 2 Mono-Ingot 3 Mono-Brick 4 Mono-Wafers 5 Multi Wafers 6 Multi-Brick Note Type, hardness, quality and contamination define cutting performance at wafering 40 Training document - Silicon ingots and bricks Version_en-00

39 7 Technical Glossary Term Band Saws Brick/Brick line Cropping Fixed Abrasive Saws Explanation A band saw is a machine with tools consisting of a band saw blade, which is welded to a closed circle. In the solar industry, the band saw cuts the large blocks into smaller squares, which are then cut into wafers with a wire saw. In the semiconductor industry, the band saw can be used as a cropping saw. On the one hand, top & tail of the monocrystalline Silicon-Ingot is cut; on the other hand, using a sophisticated control system, test wafers are cut and separated. A brick is a silicon block, already squared. This brick is cut into thin slices of micrometers during the manufacturing process wafer slicing. The brick line reflects the fully automated and integrated manufacturing process of a monocrystalline or multicrystalline silicon brick from surface refinement to cropping and right through to fully automated gluing, for the bricks to be ready for further manufacturing processes using wire saws. Top & tail cutting of a monocrystalline silicon-ingot, or cap-cutting from a multicrystalline silicon-block with a band saw or ID / OD-saw. Saw machines with diamond-coated wires, bands or discs on inner or outer diameter. 41

40 Term Gluing Glycol-(PEG) Grinding ID / OD Saws Ingot Output Photovoltaic SiC Silicon Silicon wafers Slurry Solar Cell Wire saws Yield Explanation Fixing the brick with beam and workpiece holder. Polyethylene glycol; a chemical inert polymer used in the medical, pharmaceutical, cell biological research and industry. Grinding edges and surfaces of ingots/bricks for optimal size with minimum loss of material. ID / OD (inner diameter / outer diameter) saws are suited for cutting of different sizes per cut or for sample wafers, testing and laboratory cuts. OD or ID saws also cut quartz and magnet materials, optical glass as well as ceramic materials. The raw material blocks or silicon bars are referred to as ingots. The structure of these can be monocrystalline (bar structure) or multicrystalline (block structure). The shape of the ingots and therefore the wafers that are produced from them is usually square in the case of solar cells. Monocrystalline solar cells are also available in pseudo square shapes, i.e. with rounded corners that come from a monocrystal bar. Unit of measure for the number of wafers, which can be produced per kilogram of silicon, as well for the number of wafers after a completed production process (yield) Photovoltaic has to do with the conversion of radiation energy, for the most part energy from the sun, into electrical energy and has been in use as a source of energy supply (initially in satellites). Silicon carbide; a chemical composition made of silicon and carbon. Silicon is a metalloid and the second most common element on the earth s surface after oxygen. Silicon is not found in elemental form in nature. It is contained in numerous inorganic minerals, such as quartz (sand), feldspar, mica or tourmaline. Some 90% of the earth s crust consists of silicon compounds. Silicon discs, which are mainly used for manufacturing solar cells. Dispersion made of SiC and PEG used as a cutting suspension (slicing compound) for wire saws. Solar cells are a photovoltaic application; they transform energy from light (typically sun light) into DC by taking advantage of the photovoltaic effect. The classic application of a wire saw is for cutting monocrystalline and multicrystalline silicon bricks into thin square or round wafers for the solar and semiconductor industries. The ratio of the usable products as compared to the number of products produced (with regards to a manufacturing process). If for example from a Brick a total of 100 wafers could be produced and at the effective produced wafers are 88, the yield is 88%. Yield Definition: Wire saw yield = wafers within specification / wafers considered for calculation 42 Training document - Technical Glossary Version_en-00

41 Notes Version_en-00 43

42 44 Training document - Version_en-00