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Part 1. Dispensing Training Course with Camalot Dispensing Equipment. Presented by Helmut Pawelka Application & Sales Engineer Dispensing / Coating November, 2003. Why do we need Dispensing ?. Dispensing Printing. more flexible > 200 Dots/Board much faster
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Part 1 Dispensing Training Course with Camalot Dispensing Equipment Presented by Helmut Pawelka Application & Sales Engineer Dispensing / Coating November, 2003
Why do we need Dispensing ? Dispensing Printing more flexible > 200 Dots/Board much faster higher volumes less interruptions through changing Paste wider material range more comfortable in cleaning less waste of material faster changeover for products less maintenance smaller Pitch possible Independent vs. existing components (slightly wider process window) process possibilities (underfill, encapsulation,...) paste deposit inspection
Major types of dispensing technologies piston pump time / pressure auger screw
Properties Easy to program, but difficult to control. High Speed pressure pulses causing heating in the material and reduces viscosity. Only needle needs to be cleaned. Closed loop control neccessary to stabilize volume. A linear change of pressure causes exponential rise of volume. time / pressure
Properties Very fast material output. Fast load / reload times. Increasing temperature in the piston through high frictional resistance. Higher costs for consumable parts. Good accuracy through fixed piston travel at pneumatic systems. More time consumptive in cleaning / maintenance. piston pump
Camalot rotary pump technology 24V DC permanent air feed DC Motor • Permanent rotating DC Motor guarantees • the maximum torque at any time. • Motors are available with various gear ratios • for individual materials or optimised throughput. • Electromagnetic clutch connects with a • reaction time from 10 ms to 10 s . • (Parameter defines desired dotsize) • Air is only neccessary to feed the material from • the syringe to the screw. The dotsize is only defined • by the time the screw rotates (clutch connected). • A permanent pressure on the material syringe prevents • temperature rise and viscosity changes in • HighSpeed applications. • Dispensed volume is only defined by screw & needle : • Time of rotation • Angle of gradient • Needle diameter (flow rate) 1:53,2 gear ratio material syringe gear 24V DC as programmed electro magnetic clutch coupling flexible tube screw needle
Camalot XyFlex/Pro Dispense Unit (DU) Air feed Linear Drive Z Encoder Disp. RPM Gear Gear Removable Unit (left) Contains material feeding parts Encoder Fixed Head (right) Contains motion & measuring devices CCD LVDT CCD Laser (optional) Heated Dispense Units (Semicon.) available ( Machine already pre-wired) Standard AugerScrew 635/680 Types For footless and footed needles
5 Steps to set up a stable process... Analyse the range of components and the board itself. Check the viscosity of the desired material. Find out the neccessary needle and parameters. Watch process environment. Start the process.
How to... Analyse the range of components and the board itself. Example Requires Component range: 0805 / 1206 / Melf / SOT23 / SO8 / SO20 2 different needle ID‘s Board material : FR 2 / 1,0 mm Support Board size : 220 mm / 280 mm Support Planarity : +/- 1,50 mm (side to side) footed needles
How to... Check the viscosity of the desired material. Example Requires Material : see data sheet (visco) Low Viscosity Syringe Pressure 0,2 – 0,5 bar Medium Viscosity Syringe Pressure 0,5 – 1,0 bar High Viscosity Syringe Pressure 0,8 – 1,5 bar
How to... Find out the neccessary needle and parameters. Connect a needle to the pump and purge material through the needle. Program a matrix i.e. 10 Dots with 10 ms 10 Dots with 15 ms 10 Dots with 20 ms 10 Dots with 25 ms 10 Dots with 30 ms ... 10 Dots with 100 ms Check the dots for diameter, height and quality. Then define the process window of the needle. If you have good quality between 25 ms and 60 ms, assign the different shotsizes to the matching components. Save the parameters for further programs.
23 Gauge Needle 20 ms 25 ms 35 ms 40 ms 30 ms 1206 0805 SOT23 How to... Find out the neccessary needle and parameters. 21 Gauge Needle 30 ms 40 ms 60 ms 70 ms 50 ms MELF SO 20
How to... Watch process environment. • Make sure that the material is not expired. • Remove material out of the fridge max. 1 hour before you need it. • Let material reach room temperature on a table. Don‘t put it on an oven or hot surface. • Be sure that the material has reached room temperature before you use it (18°C – 23°C). • Purge a little material out of the syringe before you mount it on the pump. • Purge at least 30 sec. Before you continue with the process. • Do not use a syringe what was longer than 24 hours at room temperature or higher temperature. • Whenever possible try to empty a syringe. Check the pot-life of the material. • If you are not sure about the material condition, never put it back in the fridge. • Try to get stable temperatures in the machine (18°C – 25°C). Viscosity drops if temp. rises.
Conclusion... Your process needs Board support dual pump a small needle for 0805 / 1206 / SOT23 21 G 23 G
Conclusion... Your process needs Board support dual pump a small needle for 0805 / 1206 / SOT23 a big needle for MELF / SO 8 / SO 20 23 G 21 G
Conclusion... Your process needs Board support dual pump a small needle for 0805 / 1206 / SOT23 a big needle for MELF / SO 8 / SO 20 Needle Sizes / ID 23 G = 0,32 mm 21 G = 0,52 mm 23 G 21 G 680 Type
Pract • Dispensing with correct Parameters • Shotsize within Process-Window • Upheight matches Adhesive properties • Downheight set to contact (footed needle) • Board planarity in acceptable tolerances
Dispensing with correct Parameters • Clamping System guarantees equal • surface position of each board
Dispensing with correct Parameters • Standard footed Needle used • in combination with • „Camalot Rotary Pump System“
Dispensing with correct Parameters • Downheight = 0.00 mm (contact)
Dispensing with correct Parameters • Dispenstime within Process Window • of Needle inner Diameter / Standoff
Dispensing with correct Parameters • Upheight depends on viscosity and • elasticity of the Material
Dispensing with poor Planarity • Influence of warped Boards • on dispensing result
Dispensing with poor Planarity • Influence of warped Boards • on dispensing result
Dispensing with poor Planarity • Contact at the beginning