How to prevent PCB board bending and board warping from going through the reflow furnace?

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

Cum “temperatus” sit principale fons accentus tabulae, dummodo temperatura refluentis clibani deprimatur, vel rate calefactionis et refrigerationis tabulae in clibano refluenti retardatur, eventus laminae inflexionis et staminis multum esse potest. reduci. Sed alia lateris effectus possunt accidere, ut solida brevis circuitus.

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2. Using altum Tg sheet

Tg est temperatura vitrea transitus, id est, temperatura ad quam materiales mutationes a statu vitreo ad statum iuvantis. Inferior Tg valor materiae, quo citius tabula incipit emollire post refluentem in clibanum intrantem, et tempus fit ut mollis Flexilis status fiat etiam longior, et deformatio tabulae utique gravior erit. . Maiori Tg lamina uti facultatem augere potest ut vim ac deformationem sustineat, sed pretium materiae relative altum est.

3. Crassitudo circuli tabulae auge

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 Used fornacem lance fixture

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.

Si grabatus unus iacuit deformationem tabulae circuire minuere non potest, operculum adiciendum est fibulae tabulae circuli cum superioribus et inferioribus grabatis. Hoc problema per refluentem fornacem deformationis tabulae ambitus valde minuere potest. Hoc autem ferculum clibanum admodum pretiosum est, et manuale positum et recyclum esse debet.

6. Utere Router pro V-cut ut sub tabula
Cum V-Cut destruet vires structuras tabulae inter tabulas ambitus, conari non uti V-Cut sub-tabula vel altitudinem V-Cut minuere.