ASAP-1 IPS Digital Sample Preparation System

2024-12-20 to 2025-01-02: Reduced Holiday Operations

Dear Birck Research Community,

The Purdue winter recess begins effective Friday afternoon December 20th and concludes Thursday morning, January 2. The university is officially closed during this time. As we have done in past years, the Birck Nanotechnology Center will remain available for research but will be unstaffed and hazardous gasses will be unavailable. Lab work may otherwise proceed, though any fume hood work must be done with someone else present in the same laboratory or cleanroom bay (the "buddy" system). Click the link above to get more detail about equipment conditions and rules.


Refer to the Material and Process Compatibility page for information on materials compatible with this tool.
Equipment Status: Set as UP, PROBLEM, or DOWN, and report the issue date (MM/DD) and a brief description. Italicized fields will be filled in by BNC Staff in response to issues. See Problem Reporting Guide for more info.

StatusUP
Issue Date and Description


Estimated Fix Date and Comment

Responding Staff

iLab Name: C - ASAP-1 IPS Digital Sample Preparation System
iLab Kiosk: BRK Packaging and Assembly Core
FIC:
Walter Leon-Salas
Owner: Mihailo Bradash

Location:
 BRK 2221
Maximum Wafer Size: 
4"/100 mm

Overview

 Click here to expand...

Note: the following is quoted from ULTRA TEC's documentation

General Description

ASAP-1® IPS is a digital sample preparation system for the decapsulation, thinning and polish­ing of packaged wafer-level devices.

Drawing on ULTRA TEC’s market knowledge and long-standing leadership in electronic sample preparation, IPS is ‘device centric’ – designed to meet the non-destructive, high yield and survivability needs of micro-electronic components.

IPS’ Touch Screen OS has been designed from the ground-up to control all aspects of the sample preparation process. Advanced programming drives IPS’s deep sub-micron axes of motion. The machine vision monitor provides an unique ‘always-live’ image of the device, along with key navigational and process information.

The touch-off tool control provides Z-position at pre-defined locations and pressures – enabling package and die tilt to be corrected quickly and accurately. Tool height variations are automatically-calibrated.

Selected area preparation

"Selected Area Preparation (SAP) has long been established as a low damage machining method, with the use of relatively low spindle speeds, in conjunction with the floating head providing very low temperature rises. This is in stark contrast with high speed 'mills' which introduce excess vibration, ultrasonics, and process temperature rises -- generally requiring either a cooling bath to be in position at all time, or even a constant high flow of coolant to avoid device overheating. SAP is almost always a ‘wet process’ . However the coolant required is minimal."

The use of ULTRA TEC’s patented 'float down' head approach has enabled several hundred customers to achieve high quality polished surfaces, ready for analysis. High yields have been shown using analog ASAP-1® equipment for thinning silicon to less than 20 micron target RST. The move to higher accuracy digital systems allows for routine thinning of extremely thin substrates at even low single-digit RST’s. The move to larger flip chips mounted on PCB substrates requires inherent design for 3D sample prep. Sample Preparation developments have been driven by the industry's push for both smaller RST’s – for optimal backside imaging and attenuation – and the need for improved uniformity, to satisfy the latest analytical techniques.

• “A Straightforward Guide to the Sample Preparation of Curved & Warped IC's”; TEC Note #16, 2015 • “Backside Failure Analysis Techniques: What’s The Gain Of Silicon Getting Thinner”; Boit, Schafer et al; ESREF 2014 • “The State of the Art in Backside Sample Prep”; Jim Colvin, EDFA Vol 4, No.2, 2002 • “Packages Have Become the New IC’s”; Jim Colvin, EDFA Volume 16, Issue 4, November 2014

Specifications

  • Suits all sizes of die - package, wafer and board-level
  • Real Time Video Monitor with system parameter
  • Touchscreen control with physical joystick & controls
  • Rigidized Table Assembly and closed-loop, high-torque, motor control enhances the machining of tough and hard materials
  • X, Y and Z axes all have deep sub-micron accuracy
  • Accurately decaps, then thins substrate and polishes
  • Patented Floating Head provides a true polishing action -- yields polishing quality & high survivability
  • Intuitive menus provide a powerful, easy to use, system
  • USB Flash Driveinterface for preparation recipe storage
  • Short set-up and process times
  • Accurate die-tilt adjustment ‘on the fly’
  • Bench-top & Quiet in Operation
Z-Vertical Direction Precision0.04 microns (40 nanometers)
Table Precision (X& Y Travel)0.2 microns (200 nanometers)
Table Travel Amplitude100mm x 100mm
Polishing MethodPatented ASAP-1 Float-down head, with Z-lock, enhanced with electronic sensors and tool patterns
VideoReal-time machine vision with 6.5 inch video monitor. External Video Output (NTSC)
Programming Input MethodTouchscreen with joystick and 3 physical rotary encoders 
Machine VisionReal-time Video of overlaid with stage and process variables.
Tilt ControlComputer-aided 2-circle tilt control, ULTRACOLLIMATOR Measurement (option) 
Force Control1000grams (max) with 1 gram precision. Overall accuracy +/- 10 grams
Recipe Load & SaveUSB Port, for removable flash drive (up to 2Gb)
Z Position Touch-off MethodMechanical Positioning with Force-feedback (option) sensors.
X & Y PositionLASER Targeting
Power Consumption300 Watts Maximum in use
Power RequirementsUniversal: 100-120VAC;  200-240VAC
Footprint19 inches (480mm) Width x 25 inches (635 mm) Depth x 22 Inches (560mm) Height

Tool Overview

InstructionsGraphics

Operator Controls

  1. Floating polishing head assembly.
  2. Floating head lock knob.
  3. USB Slot for storing recipes
  4. Real time camera view
  5. Operator input screen. (Touch Sensitive)
  6. Emergency OFF button
  7. XYZ control joystick
  8. Dual purpose input knob
    1. X axis manual/micro move
    2. Manual table speed adjust
  9. Dual purpose input knob
    1. Y axis manual/micro move
    2. Manual tool speed adjust
  10. Z axis micro move
  11. Power button
  12. spindle shown with tool inserted


Operator Input Screens

InstructionsGraphics

Screen Title: ASAP - 1 Initialization Screen

Menu Label: NA

  • Displays during initial power up routine. Touch screen with stylus to exit.


Screen Title: Menu

Menu Label: NA

  • To access this menu, press located in the upper left corner of
    any operator screen.

Screen Title: Load/Save Recipes

Menu Label: Load-Save and Tool Dia

  • This screen loads after power ON initialization screen is touched.
  • This displays machine default settings loaded on power up.
  • This screen displays current machine settings after changes.

Screen Title: Load-Save and Tool Diameter Select

Menu Label: Not directly accessible from the menu

  • To access this screen, first navigate to Load/Save Recipes screen shown
    above. Then click .
  • This screen is used only to select tool diameter.

Screen Title: Set Scan Start/Endpoints

Menu Label: Start/Endpoints

  • This screen is primarily used to define the area to be thinned/polished.
  • is essentially the same as pressing Run on the Run screen
  • allows the user to interrupt the system while it is running,
    and will allow table moves and resetting of Start/End points.
  • are temporary coordinate holders. You can store X,Y
    positions of interest to return to later.

Screen Title: 3D

Menu Label: 3D/Tilt

  • This screen is used to manage auto tilt and curvature parameters.

Screen Title:

Menu Label: Illumination/Cam Mode/Text

  • Text overlay contrast on real time camera view can be adjusted.
  • Control of camera mode is achieved on this screen.
  • This screen is used to manage power to the laser indicator.
  • This screen also controls the display of the text overlay on the
    real time camera display

Screen Title: Table Travel Pattern Select

Menu Label: Patterns

  • Pattern selection defines the motion of the polishing tool over the area to
    be thinned/polished.

Screen Title: Run

Menu Label: Run Process

  • This screen is used to control the process start and stop.
  • Checking the Timer box will force the process to stop when the timer has
    reached 0 remaining seconds.
  • Checking the Trip box will ...?
  • Checking the Zstop box will ....?
  • Vac En is not used on this tool

Screen Title:

Menu Label: Z Force Feedback

Screen Title: Keypad

Menu Label: Keypad

  • This screen is used to enter numerical values directly into parameters
  • Can be used to move the stage to absolute coordinates
    • Press , then enter coordinate, then press
      axis label / /
  • Can be used to move the stage using reletive coordinates
      • Press , then enter coordinate, then press
        axis label / /


Safety Precautions

This device produces visible laser radiation. To prevent injury to your eyes, never look directly into the laser.


Sample Requirements and Preparation

 Click here to expand...

The Automated Selected Area Polisher (ASAP-1-IPS) is designed to thin and polish small selected areas (windows) in electronic packages and wafer-level dies. The resultant thinned component is transparent to infra-red light, thus enabling backside failure analysis to be carried out on the (front side) circuitry in the device.

Typical Applications

Mechanical Decapuslation

Wafer ThinningFailure Analysis
Images from http://www.ultratecusa.com

Standard Operating Procedure

 Click here to expand...

Turn Power ON

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InstructionsGraphics

Generally, turning the machine on only requires pressing the Green Power
button on the lower right of the control panel.

  • The Green button will light up
  • The input screen will power on
  • The real time camera view will power on
  • The illumination light will power on
  • The polishing head will move to the top of travel
  • After the tool quits moving and "Wait for RESET Initialization" is no
    longer shown on the real time camera view, use the stylus to touch
    anywhere on the input screen.
  • The input screen now displays the Load/Save Recipes screen and is
    ready for normal use.
  • The tool requires three things for power ON. Two of which are
    normally already in the correct state.
    • Toggle switch on back of tool in the down position
    • Emergency button on front panel released
    • Green power button engaged


Sample mounting

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Your sample needs to be mounted flat and rigid to the sample holder.  Assuming mounting technique meets these two criteria, there is no preferred method.  Below are a couple common mounting techniques used regularly.

  1. Bond small samples to glass slide using Crystal Bond 555-HMP, then use clamps to hold slide in place.
    1. Place glass slide on hot plate and heat to 80 degrees C.
    2. Spread a small amount of Crystal Bond 555-HMP over the area where sample will be mounted.
    3. Press sample firmly down onto Crystal Bond and allow assembly to cool to room temperature.
    4. Place assembly onto sample holder and use mechanical clamps to hold the glass slide in place.
  2. Bond sample directly to the sample holder using Crystal Bond 555-HMP.
    1. Remove the sample holder from the ASAP-1 tool.
    2. Place on hot plate and heat to 80 degrees C.
    3. Spread a small amount of Crystal Bond 555-HMP over the area where sample will be mounted.
    4. Press sample firmly down onto Crystal Bond and allow assembly to cool to room temperature.
    5. Mount sample holder back onto the ASAP-1 tool.
  3. Mechanical Clamps
    1. Using the threaded holes provided in the sample holder, mount clamps in place as needed.  Two options on each side, one closer to the middle, the second further away from center accomodating a wide range of sample widths.
    2. The screw that threads into the clamp is used to adjust the clamp for your sample thickness.  That screw needs to be adjusted so that it sticks our futher than the sample is thick resulting the the front edge of the clamp making contact with the sample.
    3. Tighten the slotted screw until firm.
      1. Be sure to adjust the rear screw on the clamp appropriately based on the sample thickness.  You need to have the edge exerting force on the sample top, not exerting clamping force on the glass slide / sample edge.

      2. Be careful not to exert too much force on the sample.  Clamping introduces stress on the package/wafer that can result in cracking or warping during the thinning process.

_Proper contact angle in this image is exagerated for illustrative purposes.

Typical Sample Mounting Technique Examples

Wax Mount to Glass Slide and Mechanically Clamped

Mechanical Clamping for Decapsulation

Image from http://www.ultratecusa.com

Wax Mounting Direct to Sample Holder

Image from http://www.ultratecusa.com

Selected Area Polish of Wafer Backside Process Example

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Set Processing Parameters

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The parameters needed for backside polishing are directly observable and will not require cross sectioning of a sample as is required with decapuslation.  The tool can only polish a rectangular area with radiused corners, no other geometry is possible.  

  1. Tool rotational speed (2000 rpm recommended starting point)
    1. Minimum: 1600 rpm
    2. Maximum: 2400 rpm
  2. Table speed (3.5 mm/sec recommended starting point)
  3. Geometry
    1. Start Point (μm)
      1. Xstart = - (Length of Area to polish in X axis-Tool Diameter) / 2
      2. Ystart = (Length of Area to polish in Y axis-Tool Diameter) / 2
    2. End Point (μm)
      1. Xend = (Length of Area to polish in X axis-Tool Diameter) / 2
      2. Yend = - (Length of Area to polish in Y axis-Tool Diameter) / 2
    3. Depth of polish in Z axis (μm)
  4. Processing times
    1. As a general rule, the more area to be thinned and polished the longer each step of the process will take, increase processing time accordingly.

Select appropriate tool size and Polishing Force

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Tools can be purchased from the manufacturer at the following link:

https://www.ultratecusa.com/product/sap-tools/

Area to be Polished

* Length x Width

(mm2)

Tool Diameter

(mm)

Suggested Polishing Force

( grams)

Processing factor

(seconds/mm2)

up to 40.4

5

300
4 to 90.715100
9 to 361.03025
36 to 812.010012
81 to 2253.03004.0
225 to 6255.05001.5
625 and up8.0

900

0.5
  • Corner radius need not be taken into consideration for calculating area to be polished.
  • To estimate processing time in seconds, based on the tool diameter selected, select
    the appropriate processing factor and multiply by processing area. Values are typically
    between 5 and 15 minutes.
InstructionsGraphics

Step 1 - Set the processing timer

  • Navigate to Keypad Screen
  • Press , enter appropriate time in seconds then press .

Step 2 - Set the table rastering speed (3.5 mm/s recommended)

  • Navigate to Keypad Screen
  • Click , enter desired table speed into the field, then click .

Step 3 - Select polishing pattern

  • Navigate to Table Travel Pattern Select screen
  • Click on the radio button below the desired pattern.
    (ASAP-1 or ASAP-1 X recommended)

Step 4 - Set polishing force

  • Navigate to Keypad Screen
  • Press , enter appropriate force in grams, then press .

Step 5 - Set tool diameter

  • Navigate to Load/Save Recipes screen and press button.
  • Click radio button next to selected tool diameter

Step 6 - Verify above settings are active

  • Navigate to the Load/Save Recipes Screen
  • In the left column review:
    • Time setting
    • Speed setting
    • Selected pattern
    • Force setting
  • In the right column review:
    • Tool Dia: setting

Processing - Four Steps

 Click here to expand Process Overview...

This process recipe should be considered a guide, the procedure can be modified to meet your specific needs.
The following procedure should yield a thinned surface with no scratches in a cavity the size of your choosing.


Tool TypeApplicationCoolant/Slurry

Process Time

(minutes)

Stage 1Fine DiamondSilicon ThinningExtender Fluid

10 per 50 μm

Stage 2XYLEMPre-polishBlue diamond paste and extender fluid10
Stage 3XYLEMIntermediate polishYellow diamond paste and extender fluid10
Stage 4XYBOVEFinal polishColloidal Silica5
* Process times are flexible and you may need to run the polishing steps longer to achieve your desired results.
 Click here to expand Processing Stage 1 - Silicon Thinning

Processing Stage 1 - Silicon Thinning

InstructionsGraphics

Step 1 - Mount the selected diameter Fine Diamond tool into the spindle.

  • Make sure to align the flat on the tool shank with the set screw
    when inserting the tool into the spindle.

Step 2 - Mount the sample to be thinned.

  • Wafer piece mounted backside up onto a glass slide using
    Crystal Bond 555-HMP and then mechanically clamped to the
    sample holder shown.




Step 3 - Apply one to two drops of Extender Fluid to the area to be polished.

Step 4 - Gently lower the head into operating position.
  • Be careful, damageto the tool will occur, and you may be
    held responsible for damages, if you release the locking
    mechanism and allow the polishing head to drop onto the force
    sensor.

Step 5 - Define the Start point of the area to be polished.

  • Navigate to the Set Scan Start/Endpoints screen.
  • Make sure the lower right button is indicating the
    joystick will move the spindle in the Z axis.
    • Z axis will move very slowly
    • Z axis will move quickly
  • Using the joystick, bring the head down until the tool nearly conacts
    the surface of your sample. Force reading should still be ~0.
  • Press button to change to indicating the
    joystick will move the table in the X and Y axis.
  • Use the joystick to move the spindle to the upper left corner of area
    to be polished.
  • Press , then to define the start point of the
    area to be polished.

Step 6 - Define the End point of the area to be polished.

    • Use the joystick to move the spindle to the lower right corner of area
      to be polished.
    • Press , then to define the end point of the
      area to be polished.


Step 7 - Define the center of area to be polished as XY origin (0,0).

  • Press to move the spindle to the center of the start and
    end points previously defined.
    • If is displayed rather than on the
      Set Scan Start/Endpoints screen, press and will
      change to .
  • Press , then to define the center of the
    area to be polished. You should see the X and Y display values
    change to 0.

Step 8 - Define the top surface of the sample as the origin, or zero,
point for the Z axis.

  • Make sure force sensor is on.
  • Make sure is displayed before continuing.If
    is not displayed, click to switch joystick control to the
    Z axis.
  • Using the joystick bring the tool down to the sample surface until
    100 gm is reached. Z motion should stop automatically at 100 gm.
    Displayed on real time camera view.
  • Click to navigate to the Keypad Screen.
  • Click and then . The display on real time camera
    view will update to show Z position as 0.
  • Click , enter 20 into field, then click . The head should
    lift 20 μm off the sample and force should read ~0. This will allow you
    to safely start the 5 point tilt auto generate process.

Step 9 - Compensate for sample tilt

  • Navigate to the Set Scan Start/End screen
  • Press to change to
  • Press and the tool will proceed automatically touching
    off at 5 points within the selected area to polish.
  • Once completes the tool will move to XY 0 and Z at 5 mm
    above the surface.
  • X and Y tilt values are shown on the real time camera view.
  • Navigate to the 3D/Tilt screen.
  • Press followed by . The motorized tilt stage will move
    and auto align the stage based on tilt measurement just taken.
  • Press followed by to measure sample tilt. The tool will
    proceed through the auto tilt measurement process as before.
  • Once auto tilt measurement completes, X and Y tilt values are shown on
    the real time camera view. The goal is to have these values measure
    at ~0. You may need to repeat this many times to achieve 0 values
    in both axis.
  • If you need to repeat, press followed by . The
    motorized tilt stage will move and auto align the stage based on tilt
    measurement just taken.
  • Press followed by to measure sample tilt and
    verify alignment.

Step 10 - Start the spindle (2000 RPM recommended)

  • From the Keypad screen, click , enter desired rotational speed into
    the field, then click . The spindle will begin rotating at the
    set speed.

Step 11 - Begin the thinning process

  • Navigate to the Run screen
  • You should see your entered timer value in the Timer section
    under Set(Sec).
  • Make sure the Timer box is checked, indicating the tool should stop when
    the Elapsed time equals Set time.
  • Click and the tool will start rastering across the selected
    area.
  • Click to navigate to the Keypad Screen.
  • Click , enter desired depth into field as a negative value,
    then click . It is recommended to remove a maximum of 50 μm
    per processing step.
  • While continuing to raster, the head will slowly move down onto the part
    until the set polishing force is reached. Initially, the tool will try to maintian
    this set force by moving down in Z. Once Z has reached set point, the
    tool will hold Z position and continue processing while the applied force
    fades to zero.
  • The process will stop automatically and position the tool at the end point
    with Z ~50 μm above final Z depth when the set time has past.


Step 12 - Continuing to thin the sample

  • Since our extender fluid will become saturated with ground material,
    if you need to thin your sample by more than 50 μm, you should do so in
    multiple steps.
  • From the Keypad screen click , enter 20 into field,
    then click . The head should lift 20 μm off the sample and
    force should read ~0.
  • Use your hand to gently lift the head to the top of travel. Engage the
    locking handle by rotating the handle clockwise until tight. Make sure
    the head is locked before removing the support of your hand.
  • Wipe up the used extender fluid using a clean wipe and isopropyl
    alcohol.
  • Apply another drop or two of fresh extender fluid.
  • Gently lower the head into operating position.

    • Be careful, if you release the locking mechanism and allow the
      polishing head to drop onto the force sensor, damage to the tool
      will occur.
  • Return to Step 10 above and continue. Repeat steps 10 through 12 until
    the desired thinning has been achieved.


Rasing the head


Lowering the head


 Click here to expand Processing Stage 2 - Pre-polish

Processing Stage 2 - Pre-polish

InstructionsGraphics
Step 1 - Raise the head to allow access to the sample and tool.

Step 2 - Thoroughly clean your sample and realign for pre-polish

  • After the thinning process it is necessary to thoroughly clean your
    sample to remove large particles that would cause scratches that can't be
    removed during the pre-polish step.
  • If the sample was removed for cleaning, you must realign and clamp your
    sample, see these instructions.

Step 3 - Mount the selected diameter Xylem tool into the spindle.

  • Make sure to mount the tool reserved for the blue diamond paste, it will
    be marked with blue paint on the mounting flat.
  • Make sure to align the flat on the tool shank with the set screw
    when inserting the tool into the spindle.

Step 4 - Apply a small amount of Blue Diamond paste to the thinned area.


Step 5 - Apply one to two drops of Extender Fluid to the thinned area
and spread blue diamond paste.

Step 6 - Gently lower the head into operating position.

    • Be careful, if you release the locking mechanism and allow the
      polishing head to drop onto the force sensor, damage to the tool
      will occur.

Step 7 - Define the top surface of the sample as the origin, or zero,
point for the Z axis.

  • Since you have changed tools, we must re establish the Z origin.
  • Make sure force sensor is on.
  • Make sure is displayed before continuing. If
    is not displayed, click to switch joystick control to the
    Z axis.
  • Using the joystick bring the tool down to the sample surface until
    100 gm is reached. Z motion should stop automatically at 100 gm.
    Displayed on real time camera view.
  • Click to navigate to the Keypad Screen.
  • Click and then . The display on real time camera
    view will update to show Z position as 0.
  • Click , enter 50 into field, then click . The head will
    lift 50 μm off the sample and force should read ~0.