TECHNICAL SPECIFICATION 2D INSPECTION Description

Transcription

1 D INSPECTION Description D inspection (Di) ensures the quality of the print by monitoring the printing process Di determines when a stencil clean or paste dispense is required and if licensed, to warn for bridging, misalignment, stencil smear, stencil blockage and reduced paste volume Di optimizes the cycle time by eliminating unnecessary stencil cleaning and paste dispensing operations To achieve this the system inspects various areas of the board and/or stencil (sites) to detect the following: Blockage Smear Board Present Board Alignment Board Bridging - solder paste remaining inside stencil apertures - solder paste on the underside of the stencil - amount of the pad covered by solder paste, as a % of the aperture size - accuracy of paste positioning compared to the learnt site image - distance between adjacent deposits of paste or between pad and next pad Inspection Options The following types of inspection are available: Basic Board - Presence Advanced Board - Bridging/Alignment/Volume Basic - Blockage Advanced - Smear Inspection of the board and stencil is licensed as separate features for each The license specifies the maximum level of inspection that may be selected, as follows: Present Blockage Bridging Basic Inspection Alignment Advanced Inspection Smear Volume Page 1 Part No

2 D INSPECTION Inspection The vision system carries out various stencil inspections and are shown below: Clean Screen The position and area aperture within the screen site are learnt as a reference Blockage (Basic) Any change to the area of the aperture must be paste, hence the percentage of blockage can be calculated Smear (Advanced) Any change to the area of the stencil must be paste, hence the area of smear can be calculated Board Inspection The vision system carries out various board inspections and are shown below: Board Pad Clean Board The pad on a selected board site is learnt as a reference for comparison with inspected sites Present (Basic) Since the area of the pad is learnt and the area of paste can be recognised, any change in the pad area must be paste Hence the area of paste present can be calculated Y Alignment (Advanced) The centre of the paste is compared to the centre of the pad to produce alignment error information in X and Y X Bridging (Advanced) Since the area of paste can be recognised the distance between two areas of paste (bridging) can be calculated Bridging Distance Page Part No

3 D INSPECTION Volume Prediction Di combines the results of board and stencil inspections and using a propriety formula, calculates the predicted paste volume This is only available while the inspection is set to advanced for both board and stencil Pad on Pad Board In the example shown the aperture is 100% clear The paste on pad value is 100% This can be represented by the following model of the printed paste: Top face equals area of aperture not blocked by paste, ie 100% Bottom face equals area of paste on pad, ie 100% From this information the system predicts the volume of paste, in this case 100% In the following example the aperture has a blockage of 40% Therefore the aperture is 60% clear The 60% is equal to a rectangle of the same size as shown below The paste on pad inspection result is 90% (Blockage) 40% on Pad This is represented by the following model of the printed paste: Top face equals area of aperture not blocked by paste, ie 60% Bottom face equals area of paste on pad, ie 60% From the information the system predicts the volume of paste, in this case 7448% Page 3 Part No

4 D INSPECTION Summary Specification Inspection Maximum Number of Sites Maximum Site Size Automatic Learn Min Single Feature Size Specification 1000 sites 4mm by 65mm (Green/Graphite camera) / 10mm x 75mm (Gold camera) Single Site Rows Columns QFP BGA BGA Frame 50 Microns Inspection Blockage Smear +/- 6% +/- 01mm +/- 005mm Board Inspection on Pad Bridging Alignment +/- 005mm +/- 00mm +/- 00mm +/- 00mm Predictions Volume Programmable Inspection Rate General Inspection Parameters Programmable Action on Alarm +/- 6% All sites inspected every cycle Selected sites inspected every cycle Inspection of sites every n cycles Individual site limits Individual site naming option Each inspection site can be given a unique name to make it traceable Programmable warning and alarm levels for individual sites Reprint after low paste detection Under screen clean after blockage or smear detection Page 4 Part No

5 D INSPECTION Device Type Pitch Green Speed Gold Speed HawkEye 750 HawkEye 1700 Closest Speed Speed Competition QFP mm QFP 08 05mm QFP 56 04mm PLCC 8 17mm TSOR 3 05mm BGA mm BGA 5 15mm BGA mm BGA mm BGA mm The figures quoted above are actual times taken from our printers These are compared against the fastest published claims from the competition DEK Inspection Speed in Area, on board (mm /sec) Green Gold HawkEye 750 HawkEye 1700 Green Camera Gold Camera HawkEye 750 HawkEye mm / sec - 5 mm / sec mm / sec mm / sec Note: Specification data is based on data gathered under experimental conditions, actual results may vary due to variants in production materials Page 5 Part No