What’s the PCB board restrict temperature examination? The best way to do? Because the printed solder paste, no solder PCB assembly board can not be fixed thermocouple test conclude, which means you will need to employ the particular soldered items for tests.
take a look at samples shouldn’t be employed continuously, not more than two occasions at most. Typically speaking, providing the take a look at temperature would not exceed the limit temperature, the assembly board examined 1~2 instances can continue to be utilized as the official solution, nonetheless it is absolutely not authorized to make use of the same take a look at sample board consistently for years.
For the reason that following a protracted period of large temperature welding, the colour in the printed board will grow to be darker, as well as turn into burnt yellow-brown. Although the heating technique of the full incredibly hot air oven is mainly convection conduction, but there is also a little volume of radiation conduction, dim brown compared to the typical contemporary light eco-friendly PCB absorbed more heat. Hence, the measured temperature is considerably greater than the precise temperature. If in lead-free soldering, it is very likely to lead to chilly soldering.
Pick take a look at points: In keeping with the complexity of the PCB assembly board as well as the amount of channels of your collector (usually collectors have 3 to 12 check channels), find a minimum of a few or maybe more can replicate the PCB surface area assembly board over the higher (the most well liked place), medium and small (the coldest position) agent temperature test factors.
The highest temperature (hot place) is usually in the middle of the chamber, no components or factors and small elements; the bottom temperature (chilly point) is mostly with the big parts (these types of as PLCC), a substantial space of copper fabric, transmission rails or maybe the fringe of the furnace hall, the placement of the very hot air convection can’t blow.
fastened thermocouple: high-temperature solder (Sn-90Pb, melting level of more than 289 ?? C solder) is going to be various thermocouple test ends are soldered from the test place (solder joints), the initial solder need to be cleared before welding; or high-temperature tape paper will be glued to the take a look at stop of your thermocouple respectively from the PCB temperature test stage locale, in spite of which solution to resolve the thermocouple, are demanded Make certain that the weld, sticky, clamped firmly.
the other end with the thermocouple to the machine desk one, 2.3 … respectively. Plug the opposite end of your thermocouple into your one, two.three…. Number the thermocouples and recall the relative place of each thermocouple about the surface assembly board and history it.
Area the surface PCB assembly board beneath take a look at around the conveyor chain/webbing for the entrance from the reflow welder (if using a collector, spot the collector behind the area PCB assembly board, leaving some distance, approximately 200mm or even more), and begin the KIC temperature profile examination method.
As the PCB runs, draw (show) the real-time curve within the monitor (when the device will come with KIC check software).
once the PCB operates by the cooling zone, pull the thermocouple wire to drag the PCB assembly board back, at this time to accomplish a check system, the complete temperature curve and peak temperature / routine on the display (if your temperature curve collector is used, the PCB and collector from your reflow oven outlet, and afterwards read out the temperature curve and peak temperature schedule as a result of the application). The above mentioned will be the PCB board restrict temperature test, I hope it will aid you.