TempTell. Reflower. Model AT Operating Manual Revision 1.08

Transcription

1 TempTell Reflower Model AT Operating Manual Revision 1.08

2 Table of Contents Description... 3 Set Up... 4 Calibration... 5 Operation... 7 Reflowing...7 Baking...7 Normal Messages...8 Open Thermocouple Message...9 Programming Software Accessories Technical Support.Error! Bookmark not defined. FCC Part 15 Information Warranty Page 2 of 16

3 Description TempTell Reflower is a device that controls a standard toaster oven to perform prototype and small batch surface mount solder reflowing operations. The reflow temperature profile is customizable through its RS-232 interface to fit the user s requirements. TempTell Reflower incorporates two safety features in software. First, if an open thermocouple is detected the Reflower will be shut down and will not operate until the problem is fixed. Second, if TempTell Reflower turns the oven on but does not detect a temperature rise within 60 seconds it will abort the cycle Page 3 of 16

4 Set Up Figure 1 Reflower connector locations. 1) Connect the serial cable: Plug the DB9 serial cable into the J4 connector on the outside of the case. The opposite end of the DB9 cable plugs into your computer s serial port. 2) Plug the toaster oven into the Reflower s outlet. 3) If your Reflower does not already have the thermocouple installed, remove the four cover screws in the face of the Reflower and remove the cover. Put the bare ends of the thermocouple wires through the hole in the case and into the screw terminals marked J3. The yellow thermocouple wire must go into the + (right) terminal. Tighten down both screw terminals. Replace the cover and the four screws. Page 4 of 16

5 4) Plug the Reflower s AC cable into an AC outlet that is rated for 15 amps at 120VAC Calibration Once the Reflower is set up it is necessary to calibrate it to your oven. Calibrating the Reflower consists of an iterative process of adjusting the parameters to achieve the desired temperature profile with minimum overshoot or undershoot. The drying ramp, drying time, drying temperature, reflow ramp, reflow time, reflow temperature, and cooling ramp will be defined by the components used on the board being reflowed and the solder paste being used. Consult the component and solder paste specification sheets to determine the best values to be used. The values pre-programmed at the factory will provide a reasonable starting point. The hysterisis and Kd parameters are the factors that account for the variations in your specific oven. These parameters must be adjusted iteratively until the desired temperature profile is achieved. The first step in calibration is to determine if your oven can attain the desired reflow temperature. Put the thermocouple approximately in the middle of the oven and adjust the wire so that the door can be closed. Plug the oven into the wall outlet temporarily and set its controls to maximum. Ensure that there is sufficient free air space around the oven then turn it and the Reflower on. The oven should attain between 250 and 280 degrees Celsius within 5 minutes. If it cannot reach these temperatures within this time it probably won t perform well as a reflow oven. Unplug the oven from the wall outlet and plug it into the Reflower outlet. Allow the oven to cool a bit before the next step so you don t get burned working in the oven. Place a blank PCB in the oven. Position the thermocouple so that the junction it touching the board roughly in the center. Don t leave it touching a pad with solder, it may end up soldering the thermocouple down! Set up Page 5 of 16

6 HyperTerminal or your favorite terminal program to capture the text from the Reflower in a file. Press the start (down) button on the Reflower to begin a cycle. When the Reflower enters the cooling state abort the cycle by pressing the start button again. The Reflower should return to the standby state. Stop the terminal program s data capture. Open up Excel (or your favorite spreadsheet program) and import the data. It will be comma delimited. The first (left) column of numbers represents the target temperatures. The right column of numbers represents the actual temperatures. There will be about 5 seconds per data sample. Select the 2 columns of numbers and graph the data. In Excel you would click on the Insert menu item and select Chart. In the Chart Wizard dialog box select a Line chart type and Line Chart sub-type, the click Finish. The graph should look something like the one in Figure 2. If it doesn t, try adjusting the Kd and hysterisis parameters and run the cycle again as described above. It may take several iterations to get the temperature profile right. Reflow Profile Temperature (degrees Celsius) Target Temp Actual Temp Time (5 sec. ticks) Figure 2 Reflow Temperature Profile Page 6 of 16

7 Note that the actual reflow ramp is not as steep as the target reflow ramp. The oven used to gather this data does not have enough power to achieve the desired ramp rate, but it still produces excellent reflow results! Also, most ovens will not cool fast enough to achieve the cooling ramp without some intervention. One solution is to use the cooling time. If the cooling time is non-zero the Reflower will simply wait the cooling time then end the cycle. Once the cycle ends you should open the door and wait for the PCB to cool enough to handle. Another solution would be to set the cooling time to zero and experiment with propping the door open a bit to attain the desired cooling ramp. Operation Reflowing Baking To reflow a PCB, first press the preheat (Up) button on the oven to get things warmed up a bit. When the preheat cycle is finished put your boards in the oven and set the thermocouple near one of the large devices, preferably near the center of the board. Be sure not to set the thermocouple in any of the solder paste! Press the start (Down) button. Your board(s) will be done when the Reflower returns to the standby state. If you need to abort the cycle for any reason you can press either of the buttons on the Reflower. The cycle will abort and the Reflower will return to the standby state. Some surface mount components are moisture sensitive. If these components are exposed to moisture or a humid atmosphere for more than their published floor life they require baking before reflowing to avoid damage to the component. Also, PCBs with moisture sensitive components require baking prior to rework. The IPC recommends the following Page 7 of 16

8 guidelines for baking moisture sensitive components whose floor life has expired before reflowing: Package thickness less than or equal to 1.4 mm bake time ranges from 4 to 14 hours at 125 C, or 5 to 19 days at 40 C. Package thickness less than or equal to 2.0 mm bake time ranges from 18 to 48 hours at 125 C, or 21 to 68 days at 40 C. Package thickness less than or equal to 4.0 mm bake time is 48 hours at 125 C, or 67 or 68 days at 40 C. Remember, high-temperature component trays can be baked at 125 C, while low-temperature trays cannot be baked at temperatures higher than 40 C. You can avoid problems with moisture sensitivity by becoming familiar with the contents of IPC-M-109, Moisture-sensitive Component Standards and Guideline Manual which is available at SMTA recommends that assembled boards be baked prior to rework to avoid damaging moisture sensitive components during localized reflow. The default bake cycle for populated boards is 10 days at 90C. More information about moisture susceptibility can be found at The bake cycle is initiated through the serial interface by issuing the B command. Normal Messages Normally the display alternates between the current temperature at the business end of the thermocouple and the current state. The states are: Page 8 of 16

9 SbY Standby The unit is ready and waiting. PrE Preheat The unit is preheating the oven. Once the preheat temperature is reached it will return to standby state. Dr Drying ramp The unit is controlling the oven to attain the drying temperature at the specified ramp rate. DrY Drying The unit has attained the drying temperature and is waiting for the drying time. rr Reflow ramp - The unit is controlling the oven to attain the reflow temperature at the specified ramp rate. ref Reflow - The unit has attained the reflow temperature and is waiting for the reflow time. Col Cooling The unit is done reflowing and is now controlling the oven temperature to attain the specified cooling rate. bnn - The unit is in a bake cycle. If the number of hours in the bake cycle is greater than 99, nn will show -9. If the number of hours remaining in the bake cycle is less than or equal to 99, nn will show the number of hours remaining in the cycle. Open Thermocouple Message The display will show Err if an open thermocouple is detected. An open thermocouple condition could be caused by several things; A bad thermocouple, not having the thermocouple installed correctly, or a failure on the Reflower circuit board. If you see an open thermocouple display, first check that the thermocouple is installed correctly and the screws on the terminal block are tight. Next, replace the thermocouple with a short length of wire. The display should show ambient temperature. If the display shows ambient temperature the thermocouple is bad, you need to obtain a replacement. If it doesn t show ambient temperature there is probably a problem on the circuit board and the unit will have to be returned for repair. Page 9 of 16

10 Programming The Reflower will accept commands over its RS-232 interface to set its operational parameters. A terminal program like HyperTerminal can be used to communicate with the Reflower, or a custom software application can be written. When the parameters are set through the serial port they are written to non-volatile memory so they will not need to be set again each time the unit is powered up. Note that if you are using a custom software application to communicate with the Reflower you must allow at least one millisecond guard time in between consecutive characters sent to the Reflower. The serial protocol is 9600 baud, 1 start bit, 8 data bits, 1 stop bit, and no parity. The commands are generally one or two alphabetic characters and an optional numeric parameter. AB Abort the cycle that is in process, return to the standby state. BC - start a Bake Cycle. Bnnn set the Bake temperature in degrees Celsius. BTnnn nnn set the Bake Time in hours and days. Hours are required, days are optional. CSnnn set the Cooling Slope in tenths of degrees Celsius per second. CTnnn set the Cooling Time. If cooling time is set to zero the Reflower will try to maintain the cooling slope. If cooling time is non-zero the Reflower will ignore the cooling slope and end the cycle after the cooling time passes. Dnnn set the Drying temperature in degrees Celsius. DSnnn set the Drying Slope in tenths of degrees Celsius per second. Page 10 of 16

11 DTnnn set the Drying Time in seconds. H help. An abbreviated list of commands similar to this is transmitted: AB = ABort cycle in progress BC = start s Bake Cycle Bnnn = Bake temp BTnnn nnn = Bake Time CSnnn = Cooling Slope CTnnn = Cooling Time Dnnn = Drying temp DSnnn = Drying Slope DTnnn = Drying Time H = Help HYnnn = HYsterisis Knnn = Kd On = output on/off Pnnn = Preheat temp PH = start a PreHeat cycle Rnnn = Reflow temp RF = start a ReFlow cycle RSnnn = Reflow Slope RTnnn = Reflow Time S = Settings HYnnn set the system Hysterisis. Target temperatures are attained plus or minus this amount. Knnn nnn set the system Kd. Kd is a multiplicative factor that accounts for variances in power from one oven to the next. Since an oven s temperature gain rate may not be the same as its temperature loss rate, TempTell Reflower uses 2 values for Kd. The first nnn is the heating Kd, the second nnn is the cooling Kd. Page 11 of 16

12 On Output. O1 turns temperature output on. Temperature data is output through the RS-232 port at a 5 second rate. O0 turns temperature output off. The default is temperature output on. Note - If your Reflower ever appears to be unresponsive try entering an 'O1' command to turn the output on! Pnnn set the Preheat temperature in Celsius. PH start a PreHeat cycle. Rnnn set the Reflow temperature in Celsius. RF - start a ReFlow cycle. RSnnn set the Reflow Slope in tenths of degrees Celsius per second. RTnnn set the Reflow Time in seconds. S settings. Displays a list of the current settings similar to the following: Preheat temp 100 C Drying slope 10 Drying temp 100 C Drying time 120 Reflow slope 40 Reflow temp 212 C Reflow time 60 Cooling slope 10 Cooling Time 0 Bake Temp 125 C Bake Time 10 hours 0 days Hysterisis 5 Kd 90 Page 12 of 16

13 Software The Reflower software allows you to save parameter sets to your computer's disk. The parameter set can reside in 3 places... in a computer file, in the software's memory, and in the Reflower. Parameters in memory must be saved before exiting the software. The buttons at the bottom of the window, 'Set Parameters' and 'Get Parameters' send the params to and retrieve the params from the Reflower. The parameters are displayed on the screen in 4 tabs. Reflow parameters pertain to the reflow profile, and will change with different solder paste and PCB components. Preheat parameters affect the preheat cycle. Bake parameters affect the bake cycle. Oven parameters are the calibration values for your specific oven, and should only change if you change ovens. A fifth tab, Oven Control, allows you to start and abort the cycles. The 'Preheat', 'Reflow' and 'Bake' buttons will start their respective cycles. The 'Abort' button will stop any cycle in process. Accessories Accessories can be purchased by contacting your Reflower distributor. Part Number TC-BJ-1 RS Description 36 Replacement low mass thermocouple 6 replacement RS-232 cable Custom thermocouple types and lengths are available. Call for a quote. Page 13 of 16

14 FCC Part 15 Information This equipment complies with Part 15 of the FCC Rules. The FCC Part 15 label is located on the rear of the control unit. Operation is subject to the following two conditions: (1) This device may not cause harmful interference. (2) This device must accept any interference received, including interference that may cause undesired operation. Changes or modifications to this device not expressly approved by the manufacturer could void the user s authority to operate the device, and will void the warranty. Page 14 of 16

15 Warranty 1. Warrantor: Dealer, Distributor, Retailer, and Manufacturer 2. Warranty and Remedy We believe that this is a high quality product. Although we test all products for proper functionality, we cannot guaranty that there will never be a defective unit, or that a unit will function with all communication equipment in existence. For this reason it must be clear that the Warrantors are not insuring your premises or guaranteeing that there will not be damage to your person or property if you use this product. If this warranty is unacceptable please return the unused product for a full refund. One Year Limited Warranty Articulation LLC warrants its products to be free from defects in material and workmanship under normal use for one year, and is not responsible for consequential damage or installation costs of any nature. In the event that the Product does not conform to this Warranty at any time during the period of one year from the original purchase date, Warrantor will repair the defect and return it to you at no charge. Important: The Warranty is limited to replacement of the Product ONLY. This warranty shall terminate and be of no further effect at the time the product is 1) damaged by extraneous cause such as fire, water, lightning, etc. or not maintained as reasonable and necessary: 2) modified: 3) improperly installed: 4) repaired by someone other than the Warrantor: 5) used in a manner or purpose for which the product was not intended. Warrantors obligation under this warranty is limited to repair or replacement of the product only. This warranty does not cover payment or provide for the reimbursement of payment for incidental or consequential damages. It must be clear that the Warrantors are not insuring your premises or guaranteeing that there will not be damage to your person or property if you use this product. The Warrantors shall not be liable under any Page 15 of 16

16 circumstances for damage to your person or property or some other person or that person s property by reason of the sale or use of this Product, or its failure to operate in the manner in which it was designed. The Warrantor s liability, if any, shall be limited to the original cost of the Product only. Use of this Product is at your own risk. 3. Procedures for obtaining performance for Warranty: In the event that the Product does not conform to this Warranty, the Product should be shipped or delivered freight prepaid to a Warrantor with evidence of original purchase. If in any way you re not comfortable with the product or its Limited Warranty, we encourage you to return it unused for a full refund. Page 16 of 16