Everyone knows how to prevent PCB bending and board warping from going through the reflow furnace. The following is an explanation for everyone:

1. Reduce the influence of temperature on PCB board stress

Tunda “zazzabi” shine babban tushen damuwa na jirgin, idan dai yanayin zafi na tanda ya ragu ko kuma yawan dumama da sanyaya na jirgi a cikin tanda ya ragu, abin da ya faru na lankwasa faranti da warpage na iya zama mai girma. rage. Koyaya, wasu illolin na iya faruwa, kamar gajeriyar kewayawa.

2. Yin amfani da babban Tg takardar

Tg shine yanayin canjin gilashin, wato, yanayin zafin da kayan ke canzawa daga yanayin gilashin zuwa yanayin roba. Ƙarƙashin ƙimar Tg na kayan, da sauri jirgin ya fara yin laushi bayan shigar da tanda mai sake dawowa, da kuma lokacin da ake ɗauka don zama yanayin roba mai laushi Haka nan zai yi tsayi, kuma lalacewar allon zai zama mafi tsanani. . Yin amfani da farantin Tg mafi girma zai iya ƙara ƙarfinsa don tsayayya da damuwa da lalacewa, amma farashin kayan yana da girma.

3. Ƙara kauri na allon kewayawa

In order to achieve the purpose of lighter and thinner for many electronic products, the thickness of the board has left 1.0mm, 0.8mm, and even a thickness of 0.6mm. It is really difficult for such a thickness to keep the board from deforming after the reflow furnace. It is recommended that if there is no requirement for lightness and thinness, the board* can use a thickness of 1.6mm, which can greatly reduce the risk of bending and deformation of the board.

4. Reduce the size of the circuit board and reduce the number of puzzles

Since most of the reflow furnaces use chains to drive the circuit board forward, the larger the size of the circuit board will be due to its own weight, dent and deformation in the reflow furnace, so try to put the long side of the circuit board as the edge of the board. On the chain of the reflow furnace, the depression and deformation caused by the weight of the circuit board can be reduced. The reduction in the number of panels is also based on this reason. Low dent deformation.

5. Amfani da tire na murhu

If the above methods are difficult to achieve, *reflow carrier/template is used to reduce the amount of deformation. The reason why the reflow carrier/template can reduce the bending of the plate is because it is hoped whether it is thermal expansion or cold contraction. The tray can hold the circuit board and wait until the temperature of the circuit board is lower than the Tg value and start to harden again, and can also maintain the size of the garden.

Idan pallet mai Layer guda ɗaya ba zai iya rage nakasar allon kewayawa ba, dole ne a ƙara murfi don matsa allon kewayawa tare da manyan pallets na sama da na ƙasa. Wannan na iya rage matsalar nakasar allon da’ira ta wutar tanderun da aka sake fitarwa. Koyaya, tiren tanda yana da tsada sosai, kuma dole ne a sanya shi da hannu kuma a sake sarrafa shi.

6. Yi amfani da na’ura mai ba da hanya tsakanin hanyoyin sadarwa maimakon V-Cut don amfani da ƙaramin allo
Tun da V-Cut zai lalata ƙarfin tsarin tsarin panel tsakanin allunan da’irar, yi ƙoƙarin kada ku yi amfani da ƙaramin allo na V-Cut ko rage zurfin V-Cut.