Screen Printer - Simon Fraser University · o Activate F5 o Close the cover and start a printing run by pressing the Foot-Switch o Press F6 when the printing table is in printing

4D LABS, Simon Fraser University 8888 University Drive, Burnaby, B.C. V5A 1S6

E [email protected] 778.782.8084 F 778.782.3765 W www.4dlabs.ca

Screen Printer

Standard Operating Procedure

Revision: 1.0 — Last Updated: Jun.24/2014, Revised by Nathanael Sieb

Overview

This document will provide a detailed operation procedure of the Ekra X1 Screen Printer. Formal

Training is required for all users prior to using the system.

Revision History

# Revised by: Date Modification

1 Nathanael Sieb 2014-06-24 Initial Release

2

3

4

5

Document No. 4DSOP000X

2



Table of Contents

General Information ................................................................................................................................. 3

Operation ................................................................................................................................................ 4

1. Startup ............................................................................................................................................ 4

2. Software Operation .......................................................................................................................... 5

3. Screen Installation ............................................................................................................................ 6

4. Flooding Bar and Squeegee Installation ............................................................................................ 7

5. Print Settings ................................................................................................................................... 9

6. Printing .......................................................................................................................................... 10

7. Clean-up ........................................................................................................................................ 11

8. Alignment system (optional) ........................................................................................................... 12

References and Files ............................................................................................................................... 14

Contact Information ............................................................................................................................... 14

3



General Information

The Ekra X1 is an automated screen printing system. It has the following features:

flexible and rigid substrates up to 460 x 460 mm can be printed

screen and stencil holder for common screen/stencil sizes up to 740 x 740 mm

motor driven print table with high repeatability

alignment accuracy: ± 10 um

manual optical positioning system

The basic operation involves loading a screen and substrate, manually depositing the ink on the

screen, automatically spreading the ink across the screen, and automatically printing the ink through the

screen.

4



Operation

1. Startup

Before using the machine, all workspace and tools must be cleaned, including flooding bar, print-

ing squeegee, printing table, and screens

o Always wear gloves and change gloves frequently

o Use isopropanol as the cleaning solution and use white lint-free wipes

Switch on machine using the main switch at the bottom-left of the system

The computer turns on automatically and does not require a login password

After logging into Windows, the Ekra operating software will automatically start

Follow the instructions in the software to initialize the machine

5



Press F2 to switch on the machine

Now the last used Printing settings are shown.

2. Software Operation

The left-side buttons can be activated by the trackball or by using the F-keys on the keyboard.

Green indicated the function is active, grey indicates it is off.

F2 – Switch machine on/off

F3 – Access printing settings

F4 – Access camera settings

F5 – Squeegee up/down: If it is active, the squeegee stays up all time. This function is important

for installing and leveling the printing squeegee and flooding bar.

F6 – Squeegee stop: The squeegee stops when this button is activated. Usually it is used to stop

the process and control a specific printing position.

6



F7 – Squeegee Stop in front: The standard print mode 1 is printing – transport – flooding

transport. When this function is active, it changes to flooding - transport - printing – transport. If

the flooding is directly before printing, the danger of clogging the screen with paste is minimized.

F8 – Lock Stencil: If it is active, the screen is fixed in its position.

F9 – PCB Lock: If it is active, the vacuum is activated on the printing table.

F11 – Fix camera: If it is active, the camera positions are fixed.

F12 – Activate cameras: If it is active, the alignment system is on.

Load/Save Printing settings:

At tab “File” you can load or save your printing and camera settings.

At tab “settings” you can influence some alignment parameters.

3. Screen Installation

Open the cover and press F8 to unlock the screen.

Remove the adapter frame from the system.

Connect the screen to the mother/adapter frame.

Take care that the printing pattern is facing down that the bolts are in the same direction as the

picture below.

Open the cover and insert adapter frame + screen into the slots.

7



Press F8 to lock the screen.

Check for correct position of the screen (usually not necessary):

o Activate F5

o Close the cover and start a printing run by pressing the Foot-Switch

o Press F6 when the printing table is in printing position

o Check if position of the printing pattern matches the wafer area on the printing table

o Contact a staff member if there is a problem

o STAFF ONLY: Readjust screen position if necessary at the back. You are only able to

change the position in x-direction.

4. Flooding Bar and Squeegee Installation

Install the printing squeegee in the back and the flooding bar in the front.

8



Be careful to not drop anything on the screen. It may damage the screen.

If necessary, adjust the squeegee angle before installing the printing squeegee.

The flooding bar and squeegee must be leveled:

o Do a single printing run with F5 and F7 activated. Wait until print run is completed.

o Open cover and move squeegee holder manually to the middle of the screen.

o Get sure that your down-stops are at the lowest level

o Deactivate F5/Lowers flooding bar

o Adjust level and height of the flooding bar. The flooding bar should slightly touch the

screen over the whole length of the bar.

9



o Check the correct position by using a paper and pull it slowly away. You should have to

use the same force at each corner

o Activate F5 and close cover

o Follow the same procedure for the printing squeegee but do a single print run only with F5

activated. After reactivating F5, turn the down-stop up.

5. Print Settings

Squeegee speed forward: Speed of the printing squeegee. Influence on deposition.

Squeegee speed backward: Speed of the flooding bar. Usually stays at the same value.

Squeegee position in front: Depends on the size of the printing pattern.

Squeegee position in back: Depends on the size of the printing pattern.

Print mode: There 5 different print modes.

o 3: Transport-print-print-transport

o 3a: like 3, but both squeegees are lowered in park position

o 4: Transport-print-transport (alternates front and back for each run)

o 4a: like 2, but both squeegees are depressurised in parking position

o 1: Transport-print-flood-transport

Squeegee pressure: Has to be manually adjusted on the front of the machine. Able to calculate the

corresponding Newton value by entering the value for the pressure.

PCB-thickness: Thickness of the wafer. Usually around 200µm.

Snap off: Determines the distance between substrate and screen.

Separation speed: Determines the velocity of the separation.

10



6. Printing

Prepare the paste/ink to be used. Mix it well and check that the viscosity is as desired.

Put a test substrate (e.g., aluminum foil) on the vacuum chuck.

Adjust the PCB thickness to 0.4mm.

Do a single printing run with F5 and F7 activated.

Mix the paste/ink a final time and place it on the screen in front of the pattern.

Move flooding bar manually in position and lower it (Press F5)

Move the flooding bar manually with a constant speed to fill up the printing area

11



Press F5 again

Do a print run. Only F5 is activated. Wait until print run is completed.

Lower squeegee

Perform the first real print run.

Check the result.

Press F7 (to avoid clogging)

Print a few times on the test foil to get the paste moving uniformly through the screen. Readjust

the print settings if necessary.

Change the test substrate to the real substrate. Readjust PCB-thickness as needed.

Do the first 3-5 runs on dummy substrates and monitor the printing results.

When the results are consistent, begin the real printing.

7. Clean-up

Use the scraper to remove excess paste/ink from the screen

Use isopropanol and lint-free wipes to clean the screen, squeegees, and any dirty surfaces

Place a paper towel under the screen to collect any drips from the cleaning process

Continue cleaning the screen until all pores are clear

12



8. Alignment system (optional)

The positioning of the wafer can be aligned to the printing pattern. It is necessary if the printing

area has to hit a certain structure on the wafer. This system uses an adjustable printing table with a wafer

chuck on top. The screen is in a fixed position. The position of the wafer is determined by two cameras. To

change the wafer position, the table has 3 knobs. The angle and the perpendicular direction are controlled

by knob 1 and 2, vertical by knob 3. You are able to align using the wafer edges, fiducials or any structures

with a high contrast. The alignment itself works manually.

13



To set up the alignment, us the following steps:

Move the camera to the reference point and fix them (F11).

The blue square determines the reference point.

Pressing F12 to teach the image to the alignment software.

The accuracy can be changed in the menu “settings” (password: 6090).

Define a virtual square around your reference point and set a value for the quality factor.

When trying to align the wafer, the alignment software will show a virtual green image, which re-

fers to your image taught to the software during the first step.

The blue square is still the reference position.

Try to get the blue and green squares to overlap by turning the adjustment knobs. The three cir-

cles at the center of the screen advise in which direction the knobs should be turned.

The virtual crosses in the upper part of the screen give a live feedback of the accuracy and quality

factor.

14



References and Files

Ekra X1 Manual and training notes.

Contact Information

Questions or comments in regard to this document should be directed towards Nathanael Sieb

([email protected]) in 4D LABS at Simon Fraser University, Burnaby, BC, Canada.

Documents

Screen Printer - Simon Fraser University · o Activate F5 o Close the cover and start a printing run by pressing the Foot-Switch o Press F6 when the printing table is in printing