Training & Tooling Associates. Appendix C. Passive Component Rework , 0201, 0401 and 0603

Transcription

1 Appendix C Passive Component Rework 01005, 0201, 0401 and 0603 This optional Appendix will be provided upon request, along with software utilities, at no charge. We request that customers gain experience with this tooling and the rework of small components before attempting to rework even smaller passive components. The Appendix will be provided in Adobe pdf format along with the software via e- mail to existing customers. There will be a nominal charge for hard copy requests. TRAINING & TOOLING ASSOCIATES Innovators of Products and Services For Component Rework Solutions Revision 06 1 of 1

2 Passive Component Rework This guide will review the tooling, special sequences and procedures that can be used to rework very small passive components. The focus of this procedure will be the reworking of resistors and capacitors. However, the same techniques can be used for larger passive components. Summit rework systems that have the motorized top heater slide are the easiest to use for this type of rework. Pneumatic heater slide systems can be adapter for this purpose, but it will be slightly more difficult to control heating. This will be explained in this procedure along with ways to adapt the approach for pneumatic top heater systems. The procedure will review how Summit systems are used to rework 01005s, and will then present the specific methods and tools that are used. A thorough understanding of the particular issues associated with reworking 01005s will enable you to interpret any difficulties you may encounter and to take actions to overcome these problems. Rework Process Overview Tooling The tooling used for rework consists of the following MicroNozzle Resource Kit parts. MicroNozzle with Vent Valve, P/N MN mm Heating Tip, P/N MN-010 Universal Pickup Tube, P/N UPT-0020 Luer Tip Adapter, P/N UPT-0021 Micro Pick Needle,.006 (.15 mm) ID (P/N UPT-0055) ESD Lower Pick Pad, P/N MN-0114 T&Ta Rework Sequences The 4 mm heating tip is a compromise between maximizing heating efficiency, minimizing airflow velocity to prevent part movement during placement and reflow, and minimizing the reflow of adjacent components. The ESD pick pad is useful in cushioning 01005s during pick and placement. The bright blue color also enhances viewing of dark 01005s during alignment for pick. Pick needles for passive components are designed to maximize pick vacuum and to provide a good contact surface for heat transfer. The x- ray image shows the internal shape that is designed to provide the small (.006 inch, 0.15 mm) inside diameter needed to pick 01005s. It quickly opens up to a larger internal diameter (.025 inch, 0.64 mm) to 2 of 2

3 provide a strong vacuum pick force. The large stainless steel needle body diameter (.050 inch, 1.27 mm) provides strength and mass for storing heat to melt metallized end solder. Recommended Summit Upgrades There are three upgrades that are recommended for reworking 01005s on Summit systems. These upgrades are available directly from VJ ElectroniX and include. 1. Hitachi CCD Camera for Leica Optics 2. Hitachi CCD Side Viewing Camera 3. Auxilliary Side Viewing Magnetic Light The Hitachi CCD camera upgrade provides am improved video image during alignment of 01005s to site pads. It is such an improvement that you will find less intense lighting will be required when reworking standard parts. You will also see a big improvement in the ease of reticle alignment for calibration of Summit prism optics. This will be valuable in maintaining your alignment to the highest standards when reworking small parts like 01005s. The Hitachi CCD side viewing camera comes with a magnetic base and Navitar zoom lens. The side viewing capability is invaluable for live viewing of the pick, place and reflow process and the assessment of rework difficulties. Sequences are designed to use the side viewing capability by enabling automatic switching between Leica Viewing and side viewing during the sequence. You can also manually switch between the Leica alignment camera and side-viewing camera by selecting Camera 1 or Camera 2 buttons that are displayed during rework. Additional information on this sequence feature will provided later in this Appendix. Summit system video cards are fully capable of supporting multiple video inputs and installation is easy to perform without needing additional system modifications. The two camera buttons shown here will be displayed in all sequences. The Cam2 button will only work if the second camera is installed. This camera view can be useful when troubleshooting problems such as missed pick attempts or inadequate heating to reflow solder. The auxiliary side viewing light is provided with a magnetic base. This provides the light required for live side viewing during rework. It is available from VJ Electronix in different voltages for different regional voltage standards. 3 of 3

4 Heating The process of heating and pick or placement is different from that used for standard parts. Resistors and capacitors require different temperature ramp rates. Resistors can be heated as fast as they are capable of being heated. Capacitors can be thermally sensitive and may require limiting temperature ramp rate to no greater than 2 o C per second. This creates an unavoidably lengthy rework cycle. This ramp rate may be needed for placements but faster ramp rates can be used for removals when you are not concerned with damaging or reusing the removed Two different sequences are provided for capacitors one for removal and one for placement. The Removal sequence has a short cycle time and the placement sequence has a longer, gentler cycle to obtain the slow ramp rate that is required. Resistors can be reworked with the more aggressive heating cycle for both Removal and Replacement. Heating 01005s is performed differently than for standard parts. Heating is primarily accomplished by thermal conduction from a preheated pick needle, rather than by hot air convection heating. This is accomplished by preheating the Universal Pickup Tube, luer tip adapter and pick needle while the assembly and MicroNozzle is in the Home position. The assembly is raised to a temperature of approximately 270 o C, at which point it is lowered to the circuit board to remove an When placing parts, the is picked from the Lower Nest, heated in the Home position, and then lowered to the site to place and reflow the residual site solder. The pad picture shows locating lines drawn on the pad. This makes it easier to quickly find small parts placed in the center of the pad. Lower Nest with Blue ESD Pad When placing or removing 01005s, two heating tricks are used. Firstly, the Universal Pickup Tube and MicroNozzle travel is nested. Nesting refers to concurrent motion at the same speed of the pickup tube and top heater. This eliminates any opportunity for the pick needle and/or part to cool when the pick needle is lowered to the circuit board site. Secondly, bottom heating is not used and all top heating of the pickup tip is performed with the prism shuttle in the pick position. Blocking top heater air with the prism shuttle and keeping it from heating the circuit board site is done in order to avoid post alignment heating of the circuit board and site. During the development of the rework process it was Prism Shuttle Blocking Airflow found that heating the circuit board after alignment of the to the site pads can cause the alignment to change. This was attributed to thermal 4 of 4

5 expansion of the circuit board that caused the position of site pads to shift after the alignment of to the site. This is the reason no bottom heating is used for rework of these components. When the pick needle is lowered to the site for placement or removal, heat is transferred from the preheated needle to the and solder. This happens very quickly on the order of 3 seconds after contact. Site Solder rework with Summit systems is limited to using a pin dip method for augmenting residual site solder for reattaching replacement 01005s. For pin dip transfer of paste to site pads, we recommend using no-clean Heraeus Type 6 solder paste. This very fine paste can be added to site pads using a transfer pin and 4 mm Heating Tip and.006 ID Needle stereo microscope for application. This Type 6 paste has been specifically developed for reliable pin transfer of solder paste. Contact T&Ta for additional information on pin design and paste specifications. One alternative for 0201, 0402 and 0603 parts is to use the solder paste stencils provided with the MicroNozzle Resource Kit and discussed in the Users Manual, Section 8.5. It can be difficult to withdraw 01005s and 0201s from the upper nests after solder paste has been applied. The upper nest can also be carefully removed before attempting to pick parts, which can make extraction and picking of pasted parts more reliable. Another alternative for 01005s is to tin the metallized ends of 01005s with additional solder. This will provide additional solder volume for reattachment. Multiple 01005s can be processed this way by printing several shorts strips of solder paste on ceramic plates by using an optional stencil. The stencil is hinged to the ceramic plate with a strip of tape. The hinge prevents the solder paste strips from smearing when the stencil is lifted s are then placed on the solder paste strips in order to contact one metallized end to each strip and reflow the paste. The placement of a flat metal plate on top of several positioned 01005s during reflow may help keep the metalized ends flat for easier pick and place during rework. The Summit system can be used with a large standard nozzle to reflow many 01005s at a time for this purpose. The optional stencils, ceramic plate and flat top plate are available from T&Ta. Alignment Height When placing or removing 01005s, the pick needle will move to the alignment height position in order for you to align the part or needle tip to the site. When the pickup tube moves to the alignment height position, you may find that the pick needle hits the inside hub of the MicroNozzle heating tip. Whether your system does this will depend upon how the Home positions were set up on your Summit system. 5 of 5

6 If you find that this occurs on your system, you must adjust the top heater Home position to allow the pick needle to go to the proper alignment height position. This adjustment requires you to consider two system requirements 1. The Tip of the pick needle must not enter the top heater chimney tube. When the pickup tube searches for Home position, it travels above Home and then lowers to the Home position. This over travel above Home position must not draw the tip of the pick needle into the chimney. If this is allowed to happen when you rework larger parts, the parts will be dropped when the pickup tube tries to pull the part into the small diameter chimney. 2. The Tip of the pick needle must exit the tip of the MicroNozzle heating tip when going to alignment height position, but not hit the inside of the heating tip hub. If the pick needle hits the inside of the 4 mm heating tip hub, it will shift the position of the pick needle tip. This will result in misaligned metallized ends to site pads. Enabling the needle tip to extend just beyond the end of the heating tip allows for light to illuminate the end of the needle. Exposure of the tip to light is required to adequately see 01005s and needle tips for alignment. The easiest way of achieving the requirements of Condition 1 is to replace the standard top heater chimney with a shortened version available from T&Ta. The easiest way of achieving Condition 2 is to use the largest MicroNozzle hating tip, 7 mm. The needle can pass through the large heating tip with interference when the pickup tube is properly centered. However, the larger heating tip may reflow a larger area of the circuit board and more parts. If you chose to use the 4 mm heating tip, the following instructions will let you achieve the requirements of Condition 2. Short Length Use T&Ta optional P/N RPN-4518 to change to the short chimney. This short length chimney increases the clearance for the pickup to travel upward without entering the chimney before seeking Home position. Standard Length NOTE: You can adjust your system without using this shorter chimney. However, the short chimney makes it easier to meet both Condition 1 and 2 requirements with a minimum of trial and error. The reduced length chimney is designed to just enter the nozzle mounting plate, but no Standard Length Reduced Length 6 of 6

7 further. It has no effect on thermal processes. It is shown below when used with the T&Ta Adjustable Nozzle. The shorter length is usually adequate to provide the extra amount of upward movement required to satisfy Condition 1. The Home position must now be lowered to meet the requirements of Condition 2. Adjustments of top heater Home position can be made in the following manner. The top heater slide and home position switches are shown for a Summit The top heater Home stop is shown for a Summit 1100 Pneumatic slide system. NOTE: Summit 1100 systems are not recommended for 01005/0201 rework. The pneumatic top heater slide is not capable of moving in tandem with the pickup tube for best control of heating. Summit 1800 Switches Summit 1100 Stop Loosen the four hex cap screws that lock the Summit 1800 switches shown in the photo. Lower the position of the two switches to lower the Home position. Tighten the hex cap screws before checking that alignment height position can be achieved with the MicroNozzle, 4 mm heating tip and Universal Pickup Tube and pick needle (condition 2 discussed on the prior page). Then check Pickup Tube tip position to make sure it does not enter the chimney when homing the pickup Tube (condition 1 discussed on the prior page). You can do this using the pickup tube commands available in the Video page of SierraMate. Repeat the switch adjustment process until both conditions are satisfied. With pneumatic top heater slides, the same adjustment approach can be used. Loosen the four hex cap screws that position the top heater stop shown in the photo. Lower the stop position and then check pickup tube position for satisfying conditions 1 and 2 previously discussed. 7 of 7

8 Adjusting the top heater Home position will require modifying System Setup Z-datum values. These values are used to calculate near place positions of the top heater. Access the System Setup / Calculate Z-Datum screen as shown. You will be prompted for a password, which is VJE, upper case. Follow screen prompts to perform calibrations and consult your Summit manuals for additional guidance on this procedure. System Settings Another change to your SierraMate settings should include minimum part size. This can be changed by accessing the Configuration File Manager. Reduce min part size to.0005 inch or the metric equivalent for reworking parts. Adjust breakaway force for the Universal Pickup Tube, luer adapter and pick needle assembly to the lowest possible level without obtaining false breakaway signals when the pickup tube lowers. This is needed to prevent crushing 01005s during pick and place. You should be able to achieve a breakaway force of grams. When you switch to heavier Universal Pickup Tube assemblies, e.g. ¼ or 3/16, you will realize higher, but acceptable, breakaway forces due to the slightly increased weight of these assemblies. Sequences and Thermal Profiles The rework sequences control the order of steps the Summit machine uses in order to perform a rework process. For rework, the sequences that were developed use a number of capabilities not normally found in other sequences. These capabilities include: 1. Multi CCD camera inputs for alternating between Leica vision alignment and optional side viewing. 2. Top heater and pickup tube motor speed control using Visual Basic (VB) script in sequences 3. Heating of the Pickup Tube tip occurs in the Home position while blocking heated air from blowing onto the circuit board. This blocking is performed by moving the prism shuttle to the pick position. 4. Positive Flow (pressure in the pickup tube) and short move relative commands are used to improve part release reliability when picking and discarding parts. 5. VB script is used to engage "nested" travel of 0.95 inch (24 mm) as sequence specific, and does not affect other sequences. 6. An 01005_Abort.mac file is used as a macro to reset motor speeds upon early sequence exit. It also ensures that the pickup homes before the top heater in order to prevent a collision between the pickup tip and small inside diameters of MicroNozzle heating tips. 8 of 8

9 Sequences have been given the following names to distinguish them from other Micro_ and standard sequences P&P.act simple Pick and Place from the lower nest Remove.act aggressive thermal cycle for removing resistors or capacitors PRP Capacitor.act Pick, Reflow, Place Two separate heating options are available for resistors and capacitors. Pick part from lower nest, align part to site, preheat part in Home position, Place part and reflow the solder PRP Resistor.act Preheat cycle for resistors is 45 seconds to reach a top heater setpoint of 375 o C. This results in a peak resistor temperature of approximately 260 o C during placement. Preheat cycle for capacitors uses a 2.5 o C per second ramp rate to reach a top heater 375 o C setpoint. This results in a peak capacitor temperature of approximately 250 o C during placement _Abort.mac A special abort macro that performs several functions. This macro makes sure that the pickup tube homes before the top heater to prevent a collision with small MicroNozzle heating tips. It also resets camera settings to Camera 1, the main Leica viewing camera. It resets motor speeds to default system settings and resets interference travel. This guide will review new features of these sequences so that you will be able to modify sequence commands as needed. The Remove.act sequence and file will be used to describe typical sequence features. The sequence text begins by describing the rework approach. This text is preceded by an asterix (*) that is used to ignore the text as a sequence command. The text commands shown in the red box are used to enable the use of Visual Basic script commands (referred to as VB script). 9 of 9

10 The three.vbs commands enable the use of CAM1 and CAM2 selection buttons and the use of VB script motor commands for motor speed control. Motor speed control to very slow speeds is required to gently pick and place components. Using VB script in sequences enables this control specific to the sequence so that other standard sequence speeds will remain unaffected. This VB script approach also permits the use of any number of different speeds for different sequence steps. You are no longer limited to merely Fast and Slow settings but any range of speed within the capability of the stepper motor controller for both top heater and pickup tube travel. There are separate VB script files for each command as shown in the red box. These script files must be added to SierraMate in order for these sequences to work properly. The method of loading these files will be described later in this Appendix. There are two items worth mentioning about the first steps in this sequence. You will first notice the camera=1 command. This commands the system to use the main Leica camera for the alignment step. Later in the sequence you will see the Camera=2 command. This tells the system to switch to the side-viewing camera, when available, when picking or placing the When the pickup tube seeks alignment height, the sequence uses the following commands. The Pickup Move Relative command is used to locate the tip of the pickup needle to the best position for viewing and aligning the tip to a on the Lower Nest. This was needed because the assembled length of the Universal Pickup Tube, Luer adapter and needle is a bit shorter than a standard pickup tube. The relative movement adjusts for this difference in length and the calculated alignment height of the system. Adjust the value for this distance as required on your system for optimum focus and lighting of the pick needle tip. The *InchToSystem parameter automatically adjusts the.140 inch distance to metric for metric machines. You will notice a similar command approach is used elsewhere for English/Metric velocity units. Wait=0.5 seconds, and similar Wait= commands used elsewhere, are commonly used to make sure the system has 10 of 10

11 sufficient time to execute a command before proceeding with the sequence. After aligning the on the circuit board to the tip of the pick needle, the pick needle is preheated while the prism shuttle is brought to the part tray position. This blocks heated air from hitting the circuit board. A bottom heater set point of 25 o C is used to avoid bottom heating. The adequacy of a top heater set point of 375 o C and wait of 45 seconds was determined by the following method. A circuit board and high response rate thermocouple (TC) was used to determine heat transfer of the pick needle to the TC junction. This TC is provided with your T&Ta MicroNozzle Resource Kit specifically for this purpose. The following photos show how the TC junction is aligned to the pick needle tip. TCs were also placed on the nozzle body and needle tip. Since it was easier to put a TC on the nozzle body, this method was used after correlating nozzle body and needle tip temperature. Performing a Remove sequence, the needle tip is lowered to the TC junction after heating and the temperature profile at the junction is datalogged. A peak temperature at the junction of 234 o C was obtained along with a ramp rate that transferred heat above the lead-free solder melting point within 3 seconds. Abort or skip through the sequence after you have obtained the datalog to avoid the removal step. Adjust top heater temperature set point and/or dwell time in the sequence to get your desired results. TC on Nozzle Body Up View of needle tip Down view of TC junction Needle Tip Touching TC on Board TC on Needle For the default sequences provided for rework, this approach resulted in the following thermal profile. 11 of 11

12 Needle Contacts TC Junction TC Junction Profile Nozzle Lowers to Board For all removals and placing resistors, this profile produced a peak TC junction temperature of 234 o C. For placing capacitors, a slower heating ramp rate was developed for use with the Pick Reflow Place Capacitor sequence. Ramping the top heater at a rate of 2.5 o C per second to a setpoint of 375 o C was found to produce a needle tip ramp rate of approximately 2 o C per second. This heating cycle produced a peak TC junction temperature of 243 o C. Top Heater 2.5 o C Ramp 12 of 12

13 If you determine that you can use a faster capacitor heating rate, or need a slower ramp rate, the capacitor ramp rate can be changed in the PRP Capacitor.act sequence. Simply change the indicated ramp rate in this sequence where shown. Peak top heater temperature setpoint can also be adjusted just below the Wait= command. Remember to also change the Message= command to indicate any new setpoint you may select. In the next part of the Remove sequence, some additional VB script control methods are used. The first command [ ] engages interference travel for the top heater and pickup tube. This nests the travel of the top heater with the pickup tube when the pickup tube moves down more than 1.2 inches. It does not perform this nested travel when the pickup tube moves up. This approach is not possible with pneumatic heater slides. At best, the pickup can be commanded to lower, wait for a set period, and then the heater can be commanded to lower. This can be timed so the top heater just catches up to the pickup tube when it reaches near place. The Adjustable Heater Downstop must be set at different times in the sequence to the proper height for viewing, placement and heating. The second item [ ] engages the side viewing camera. The third item [ ] is a VB script velocity command. The number 1 defines the axis to control speed. In this case axis 1 is the pickup tube. The velocity is set to a very slow speed of.005 inches per second. The *svinchtosystem text automatically converts units for metric systems. Notice that the syntax for automatic unit conversion is different for script speed commands than for the Move Relative distance commands previously discussed. 13 of 13

14 The discard step of the sequence is kept simple for maximum speed of the process. Wiping the tip of the needle with a cotton swab tip that is soaked in flux cleaner removes picked parts from the needle tip. Flow On and Flow Off commands [ ] pressurizes the pickup tube to help blow the part from the tip and onto the cotton swab. The use of flux cleaner helps dissolve residual part flux for easier part removal. At the end of the sequence the following commands are used. 14 of 14

15 The abort macro resets the Camera view to Camera 1 and resets the interference travel to 10 inches. In this case the pickup tube would have to lower at least 10 inches (254 mm) before the top heater lowers. This travel is reset in case there are sequences that are used where nested travel would be inappropriate. The macro also makes sure that the pickup tube Homes before the top heater in order to prevent a collision between the small nozzle and larger diameter pickup tube. The 01005_Abort macro was mentioned earlier. When a sequence is stopped early, the system goes to this macro to reset cameras, motor speeds and interference travel to default settings. CAUTION If you engage the STOP button more than once, the 01005_Abort macro will be ignored and the system will use the hard coded abort. This can cause a collision between the pickup tube and small MicroNozzle heating tips and may stretch the pickup tube breakaway spring. This can cause loss of breakaway force calibration and may require this force to be recalibrated. If you find that Camera 2 and the side viewing image is active at the start of your next sequence run, you may have failed to let the 01005_Abort macro reset settings at the end of your sequence run. Close the sequence properly and restart the sequence. You should find that camera settings have been restored and Camera 2 is no longer active. Loading Sequences and Files First load the Micro_ sequences that automatically load from the floppy disc provided with the MicroNozzle Resource Kit. A second floppy disc is included with the MicroNozzle Resource Kit that includes the files needed for rework. The files should be manually placed in the correct SierraMate folders according to the following locations. Sequence Folder Files Products Folder Files P&P.act Universal Instruments Folder (and sub folders) Remove.act PRP.act 01005_Abort.mac CameraButtons.vbs CameraControl.vbs MotorCmds.vbs CamSelect.bmp After loading, launch SierraMate and verify that the sequences and parts appear for use. Perform a dry run to make sure that the sequences perform properly before applying them for training or use. Skipping through the sequence can speed up this process. A quick way to skip through sequence steps is to enable the Skip button when running a sequence. 15 of 15

16 First select a P&P (Pick and Place) sequence, Universal Instrument circuit board and part. Press GO to begin the sequence. Next, place you cursor just next to the sequence GO button, hold the Shift key on the keyboard and click the left mouse button. This will display the Skip button. Hit the skip button to progress through sequence steps to reach those you wish to check. Some sequence steps cannot be skipped. However, enough steps can be skipped to speed your progress through a sequence to evaluate key steps. Use this method to check out changes you make to a sequence in order to make sure the sequence behaves as you intended. Make changes to sequence commands as needed to achieve what you wanted. All sequences are extensively annotated with comments that show where special steps were used and where changes may be needed. Sequence comments are preceded with an asterix (*) to prevent them from being recognized as sequence commands. These comments will help you quickly identify where process adjustments can be made. You can use the PRP Capacitor.act sequence for Pick, Reflow and Place of either capacitors or resistors. We have provided two heating options with this sequence a fast one for resistors and a slow one for capacitors. The default heating cycle is the slow one for capacitors. This same sequence can be used for resistors and a faster heating cycle as an alternative to selecting the PRP Resistor.act sequence. The fast heating cycle is recommended for resistors and the slow cycle is intended for thermally sensitive capacitors. The capacitor heating cycle is the default cycle. In order to select this cycle, simply select the sequence and GO. In order to select the faster heating resistor cycle, you must enter RES, all upper case, in the User Val 1 field accessed from the Process window of SierraMate. Select the Additional Process Steps button to access the User Val field. Enter RES and select OK. The sequence will now use the faster heating cycle. 16 of 16

17 This appendix should provide you with a good review of the techniques used to rework passive components on Summit 1800 rework systems. The discussion on sequences should enable you to modify rework conditions to suit your needs. TRAINING & TOOLING ASSOCIATES Innovators of Products and Services For Component Rework Solutions 17 of 17

18 01005/0201 Rework Checklist The following checklist has been assembled to help you make sure that you meet all system and tooling requirements for successful rework. Review the requirements of Appendix C and your VJ Manuals for additional guidance. 1. Thoroughly read and understand the requirements for rework as described in the MicroNozzle Resource Kit Users Manual and Appendix C. 2. Load MicroNozzle Resource Kit software utilities and manually load sequences and files in your SierraMate software as describe on page 15 of Appendix C. 3. Install short top heater chimney 4. Adjust Top Heater home switch position as described in Appendix C. 5. Install Universal Pickup Tube, luer tip, pick needle and adjust pickup tube breakaway force as recommended in Appendix C. Consult your VJ Maintenance Manual for guidance. 6. Verify positive airflow pressure in the pickup tube is functioning correctly. Consult your VJ Maintenance Manual for guidance. 7. Install MicroNozzle and verify that alignment height of pick needle can be reached without hitting inside hub of 4 mm heating tip. If it cannot, adjust system settings as described in Appendix C. 8. Perform system z-datum calibrations to record new top heater home position. Consult your VJ Maintenance Manual for guidance. 9. Reduce minimum part size to.005 inch (0.127 mm) in Configuration File Manager. 10. Thoroughly inspect and clean optics for maximum viewing clarity. Consult your VJ Maintenance Manual for guidance. 11. Verify rework system placement accuracy by performing prism precision reticle alignment. Consult your VJ Maintenance Manual for guidance. 12. Perform an pick and place sequence in order to familiarize yourself with how these custom sequences work. Adjust sequence commands as described in Appendix C for optimum performance on your rework system. Make system adjustments as needed. 13. Verify that all system settings are correct and that you are accurately picking and placing parts. Calibrate your rework system as required if problems are uncovered. 14. Perform an remove sequence to see how the heating cycle is performed. 18 of 18