| | Hello. | | 1 Could anyone tell me the range of temperature | | to solder MI components? The process eng is using 400~500 | | degrees Celcius!! For standard 0805/0603 chips & TH components & | | also to touch up on ICs. What is the consequence? | | 2.I am currently routing a pcb for RF circuits. Any | | thing I should keep in mind? | | 3. Is there any newsletter on SMT related where I can subscribe. | | Preferbably free. | You most definately got your units mixed up! At 400-500 degrees C (752,932 degrees F respectively) you would have done more than delaminate a PCB. Your control module is more than likely set at reflow for 400-500 degrees F and the actual temperature of the assembly would depend on belt speed, air flow, thermal absorption properties of the assembly and many other factors. I solder with setpoint (reflow) at 500 F but assembly only reaches 210-220 for approximately 30-45 seconds. You must have a thermocouple or profiler if you plan to continue soldering. Also keep in mind I am only talking about a single zone in your oven! There are likely more zones that must be adjusted to achieve the proper curve (preheat,soak,reflow and cooldown). Ask you solder manufacturer to provide you with the recommended profile for the alloy you are using. Make your oven fit this profile. If the profile is not right for your part then you are using the wrong paste. For R/F designs many still are not using appropriate design rules for manufacturing - especiall concerning solderability. DFM must be considered first or excessive touch up, repair, and failure will be effected. Use standard, for the most part, design rules for chip device types as neck downs or? Be sure the R/F magicians are included in the design process so they adequately recalculate what neck downs, as an example, to to high speeds, impedance, and the like. Earl Moon
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