FS bonder

FS bonder

Essentials
Full name	F&S Bondtec 5630
Manufacturer	F&S Bondtec
Description	Semi-automatic bonder
Location	1st floor lab (03.1.111)
Responsibility
Primary	Harry
Secondary	Nader

F/S Bondtec 5630 is a semi-automatic bonder. Users typically use it to bond semiconductor substrates to PCB daughterboards. It uses a 25 um aluminum wire, bonded at room temperature.

The bonder shares the flow hood and PC monitor with the Lynx EVO stereomicroscope.

The source PC can be switched by pressing Scroll Lock, Scroll Lock, Enter on the keyboard.

Standard operating procedure

This is a standard operating procedure describing the use of F&S 5630 bonder on the first floor lab.

Preparation

1. Turn on the light on top of the laminar air flow bench. Set the flow to 5.
2. Open the sash.
3. Start the 5630 program.
   1. Do you want to move home? Yes
   2. Do you want to open the last bonding program? No
   3. File > Load: Load your preferable bondprogramme.
4. Choose the appropriate block for your daughterboard from the first drawer. There are four different blocks corresponding to different daughterboards:
   1. Copenhagen (large and small block)
   2. QBoard II
   3. Sydney
   4. transmon
   5. QCage
5. Remove the dummy daughterboard from the block.
6. Screw your PCB onto the block.
7. Mount your chip to the board following the procedure you learnt from your group.
   1. Wait a few minutes for the chip to dry.
8. Mount the block on the bonder stage.
9. Connect the grounding cable to the block.
10. Use an ESD anti-static wrist strap.
11. Press F1 on the side key panel to bring up the bonding dialog.

Bonding

1. In Bond1:
   1. Find one of the bonding pads of your daughterboard.
   2. Adjust light settings and focus.
   3. Store trace - 6 to register the height and xy-coordinates.
2. Press Right - 2 or click on Bond2. Note that the head might leave a small mark where it touches down.
3. In Bond2:
   1. Find one of the bonding pads of your chip. Preferably choose a spare if you have any available.
   2. Adjust light settings and focus on the chip.
   3. Store trace - 6 to store chip height. Note that the head might leave a small mark where it touches down.
4. Now you are ready to bond!
   1. It is always a good idea to start with a test bond on spare pads to test the success and the profile of your wirebond. Adjust the bonding parameters if necessary.
   2. Once you find the optimal bonding parameters. Drag and drop Bond1 and Bond2 on the desired positions and then press F1 to bond.

Notes

• Arrows left/right move between Bond1 and Bond2.
• Pressing F1 bond on Bond1 moves to Bond2 position.
• Pressing F1 bond on Bond2 bonds.
• Pressing 0 home | escape homes the stage, turns off the light and turns off the camera.

Clean-up

1. Close the bonding dialog. Save the bond program by selecting File > Save if you would like to save your changes.
2. Close the 5630 program.
3. Wait until the sample stage moves to the home position.
4. Unscrew the block from the stage.
5. You can move the block Under the Lynx Microscope to take some images of your final bonding result.
6. Unscrew your bonded chip/daughterboard from the block.
7. Check that all of the fuzz buttons are present. If not, replace.
8. Screw a dummy board in place.
9. Fill in the sheet-log. Required fields are name, date and comments/problems, if there are any.
10. Close the sash.
11. Turn down the air flow to 1.
12. Turn off the light.

Common issues

DLC flatline

If you see a DLC curve flatline near 0 (usually accompanied by a failed bond) it is likely the bond wire has come out of the wedge or clamp and needs rethreading. Try Wire Feed -# to check if you can see the wire tail first.

The wedge may be clogged

1. Check the thread.
2. Press Feed # to feed the wire. If the wire does not come out of the wedge, you need to rethread.
3. Release the right clamp by rotating it 90 degrees clockwise.
4. Use the scissors to cut the damaged part of the wire.
5. Use the designated tweezers for rethreading.
6. If the wire doesn't pass through the wedge hole:
   1. Press Test on the ultrasonic generator while touching the wedge close to the tip with your metallic tweezers.
   2. Try rethreading again and repeat the process if you don't succeed by your first attempt.
   3. As a last resort, you can try rethreading in the opposite direction. This will verify that your wedge is clogged (or not).
   4. Once you verify that the wedge is clogged, contact one of the tool administrators and they will replace the wedge.
7. Do not attempt to replace the wedge by yourself.

Z motor error

Can happen "randomly" but most common after a failed bond.

1. Check to see if the red sensor light on the left-hand side of the bond head is ON.
2. If it is on, gently rotate the mushroom shaped wheel clockwise until the red light goes off.
3. Restart 5630 software (save? Yes) and carry on bonding as before.

The bond is in the wrong place, even though the Bond1 Bond2 positions were correctly set

If you use Bond - F1 to switch between the tabs "Bond1 > Bond2 > BOND" make sure the stage has finished moving before pressing F1 to advance.

The bonder appears to read the stage instantaneous position as you switch tabs, rather than use the stored bond position.

After power loss, if the ultrasound generator lights are red

Check the blue ultrasound generator software and reset the errors in each tab

Other errors

Most other problems can be resolved by saving and restarting the 5630 program. But please take a screenshot and report the problem to the cleanroom staff: cleanroom@nbi.ku.dk.

Bondprogramme setup

First-time bondprogramme setup

1. 1. "Create Program Dialog" box appears.
   2. Data source: Create from default value: 25 um
2. Use the joystick to move to the bonding pads on the daughterboard (not your chip): It should be at least 5 mm away from any screws or connectors.
3. "Global Camera setting": Adjust Gain and Shutter to make the daughter board visible.
4. Adjust head height to see the PCB in focus: press button on joystick, tilt joystick down slowly
5. Next
6. Store trace - 6 to set "Workheight1"
7. Store trace - 6 to set "Workheight2"
8. Bring the bonding head halfway down (no closer than 5 mm above the highest point of any screws)
9. Store trace - 6 to set "Joystick Limit"
10. Store trace - 6 to set "max z position"
    1. The head will touch down on the PCB and adjust the height. Note that the head might leave a small mark where it touches down.
    2. In all of these four states you don’t need to move the stage or change the height of the head (except height for "joystick limit").
11. Next
12. File > Save as... to save your bonding program.
    1. Please make a folder for yourself in the users folder.

Bonding parameter suggestions

• Bond force: 30
• US power: 60
• Total bond time: 30
• Other parameters default

You can change these parameters later ant any point before/during/after bonding.

You are encouraged to look up parameters that previous users have used on similar surfaces.

Reuse a bondprogramme (single wire mode)

1. Load selected program "File > Open"

   Warning: It is usually safe to load any program written for the specific sample holder you are using (standard thickness brass block is 10mm). If you have a PCB with additional features e.g. capacitors or extra tall connectors beware when loading programs, the last bond position (to which the bonder will drive directly when you open the bonding dialog) may be INSIDE one of your tall features. It is safest to load the program first, open the bonding dialog, and check the bond head position and height and then go to "Home position" to load your sample/PCB. If in doubt, ask an experienced user or a member of staff.

2. If required select "Single Wire" mode.
3. Press Bond - F1 to bring up the Bonding Dialog...
4. It is very strongly recommended that you perform a touch down to verify the height of your chip and PCB before you start bonding. If you don't and you are unlucky you may damage your chip and/or bend the bondhead! You have been warned!
   1. Adjust Bond1 focus and light settings until you can see the PC in reasonably sharp focus.
   2. Drag and drop the Bond1 position to a suitable touchdown location (e.g. Bond pad at least 5mm away from any connectors - remember the rear of the wedge.)
   3. Click to place the cursor in the "Height" box
   4. Press Store Trace - 6, bondhead will now touch down and update both the bond height and the focus height for Bond1.
   5. Switch to Bond2 tab and repeat steps 2-4. Note the touch down will probably leave a small mark so select a location (e.g. Off-mesa/blank space) where you do not actually want to bond.
5. Drag and drop the bond end points and Bond - F1 as normal.

Maintenance

Weight calibration

Procedure

1. Place a digital weighing scale on the bonder sample holder. You will need a scale with a range over 200 g.
2. Make a new bond program for the height of the scale.
3. Bonder software: Mode > Head calibration
4. In BW-Calib tab:
   1. Weight point 1: Store trace - 6
      1. Wedge comes down and presses on the scale.
      2. Update weight point 1.
   2. Weight point 2: Store trace - 6
      1. Wedge comes down and presses on the scale.
      2. Update weight point 2.
   3. Repeat until both weights are accurate within 1 g.

Calibration test

1. Open the bond program for the scale.
2. F1 to open the bonding window.
3. Click on Bond1.
4. Set the bonding force to e.g. 25 g and US power to 0.
5. Change to step mode with F2.
6. F1 to go through the bonding steps until the head presses on the scale.
7. Verify that the weight is within 1 g, otherwise repeat the procedure.

Cleaning of clogged wedges

1. 15 min Acetonce sonication at 35°C, 37kHz and 50% power (in a glass beaker)
2. 5 min IPA sonication at 35°C, 37kHz and 50% power
3. 5 min IPA
4. Blow dry with N2 gun
5. Blow dry with hot air
6. Optical inspection of the wedges at the microscope located on the left side of the bonder

20 Aug 2024: Nader, Harry out of approx 35 wedges, only 4 were clogged after cleaning.