Технология PCB - защита от проблем орошения при производстве панелей PCB

Board bending and доска warping are prone to occur when the печатная плата проходящая печь, so how to prevent the печатная плата доска from going through the reflow furnace from bending and plate warping, the following is a detailed explanation for everyone:
1. Reduce the influence of temperature on плата печатная плата stress
Since "temperature" is the main source of печатная плата доска stress, только при понижении температуры в реторте или при понижении скорости нагрева и охлаждения в реторте печатная плата board production in the reflow furnace is slowed, the bending and warpage of the board can be greatly reduced. произойти. However, могут возникнуть другие побочные эффекты, such as short circuits.
2. печатная плата with панель высокого Tg
Tg температура стеклования, that is, температура материала из стекла в резиновое состояние. The lower the Tg value of the material, Чем быстрее печатная плата board starts to soften after entering the reflow furnace, and it becomes soft rubber state The time will also be longer, и панель печатная плата will of course be more serious. The use of a higher Tg board can increase its ability to withstand stress and deformation, но материалы для производства относительно высокие печатная плата правление is also relatively high.
три. Increase the thickness of the плата печатная плата
In order to achieve the purpose of lighter and thinner for many electronic products, the thickness of the печатная плата board has left 1.0mm, 0.8 мм, or even 0.6 мм. Such a thickness must keep the панель печатная плата from deforming after the reflow furnace, Это действительно немного затруднительно для других. It is recommended that if there is no requirement for lightness and thinness, использовать толщину% 1.6mm for the печатная плата board, which can greatly reduce the risk of bending and deformation of the board.

4. Reduce the size of the печатная плата board and reduce the number of puzzles
Since most of the reflow furnaces use chains to drive the печатная плата board forward, the larger the проектирование печатная плата size, the печатная плата board will dent and deform in the reflow furnace due to its own weight, Итак, попробуйте лечить тело на длинной стороне печатная плата доска как край доски. Putting it on the chain of the reflow furnace can reduce the depression and deformation caused by the weight of the circuit board itself. сокращение числа распределительных щитов также обусловлено этим. Reach the lowest amount of depression deformation.
5. Used furnace tray fixture
If the above methods are difficult to achieve, Наконец, использование печи для уменьшения деформации. The furnace tray can reduce the bending and warpage of the board because whether it is thermal expansion or cold contraction, надеюсь, лоток исправит эту проблему панель печатная плата. After the temperature of the печатная плата board is lower than the Tg value and starts to harden again, the size of the garden can be maintained.
Если одноярусный лоток не может уменьшить изменения в лотке панель печатная плата, a cover must be added to clamp the печатная плата board with the upper and lower pallets. This can greatly reduce the problem of панель печатная плата deformation through the reflow furnace. However, эта плита очень дорогая, and manual labor is required to place and recycle the trays.
6. Use Router instead of V-Cut to use the sub-board
Since V-Cut will destroy the structural strength of the panel between the печатная плата boards, try not to use the V-Cut sub-board or reduce the depth of the V-Cut.