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7 Product File and Machine Optimisation

7.5 Optimise Parameters to Produce Acceptable Quality Prints at Higher Throughputs

Process Foundation DEK Micron-Series 12/2017 53

7.5 Optimise Parameters to Produce Acceptable Quality

Prints at Higher Throughputs

Aim

To optimize the product file and machine set up parameters to be capable of printing twenty

consecutive boards at the stated throughput with zero print defects.

Required throughput: 300 boards/ hour

Step 1

Calculate the required cycle time for the stated throughput ………………..s

Hint: Calculate the cycle time assuming that there will be no under screen cleaning but be

aware that if cleaning becomes necessary it will significantly reduce throughput hence the

cycle time will need to be increased.

Step 2

Estimate the required separation speed ………………..mm/s

Estimate the required separation distance ………………..mm

Hint: Use 10mm/s and 2mm distance if you are unsure of the paste performance.

Step 3

Determine through experimentation what print speed will

achieve the desired cycle time

………………..mm/s

Hint: Cycle a batch of boards through the machine left to right with no squeegees fitted and print

pressure set to 0kg. Vary the print speed until the desired cycle time and throughput is

achieved.

Step 4

Record below any other product file or machine set up parameters that you had to change to

achieve the required cycle time.

Note: Speeding up the cycle time can lead to instability of the process so any changes should

be monitored closely.

7 Product File and Machine Optimisation

7.5 Optimise Parameters to Produce Acceptable Quality Prints at Higher Throughputs

54 Process Foundation DEK Micron-Series 12/2017

Step 5

Determine, through experimentation, the best print parameter settings to successfully achieve the

objective. Record your results in the table over:

Squeegees

Print Speed

Squeegee Pressure

Separation Speed

Separation Distance

USC Program (mode 1)

USC Rate (Mode 1)

USC Program (Mode 2)

USC Rate (Mode 2)

Notes:

………………………………………………………………………………………………………………

8 Troubleshooting and Process Review

8.1 Identify Causes of Print Defects

Process Foundation DEK Micron-Series 12/2017 55

8 Troubleshooting and Process Review

8.1 Identify Causes of Print Defects

It is important that the people responsible for the design and maintenance of the process

understand which areas under their control can have a direct influence on the print quality, how to

identify a defect and to quickly rectify the problem.

Note: This section refers to solder paste related print defects. For other print materials, refer to

the appropriate application modules.

The Perfect Solder Print

Causes:

●

Good Alignment

●

Good Gasket Seal

●

Good Board Support

●

Good Stencil Design

●

Good Print Material

Well Designed Process (speed, pressure, etc.)

Exercise

For each of the print defects shown below, identify the possible design and/ or process

maintenance causes:

Bridging

Causes:

………………………………………………………