When the PCBA board undergoes reflow soldering and wave soldering,the PCBA board will be deformed due to the influence of various factors,resulting in poor PCBA welding,which has become a headache for production personnel.Next,we will analyze the causes of PCBA board deformation.
1.PCBA board passing temperature
Each circuit board will have a maximum TG value.When the reflow soldering temperature is too high and is higher than the maximum TG value of the circuit board,it will cause the board to soften and cause deformation.
2.PCB board
With the popularity of lead-free technology,the furnace temperature is higher than that with lead,and the requirements for plates are getting higher and higher.The lower the TG value of the circuit board,the easier it is to deform during the furnace process,but the higher the TG value,the more expensive the price.
3.PCBA board thickness
With the development of electronic products in the direction of small and thin,the thickness of circuit boards is becoming increasingly thinner.The thinner the circuit board,the more likely it will be deformed due to high temperature during reflow soldering.
4.PCBA board size and number of panels
When circuit boards are reflow soldered,they are generally placed on chains for transportation.The chains on both sides serve as support points.If the size of the circuit board is too large or there are too many panels,it is easy for the circuit board to dent toward the middle point,causing deformation.
5.The depth of V-Cut
V-Cut will destroy the board structure.V-Cut cuts grooves in the original large sheet.If the V-Cut line is too deep,it will cause the PCBA board to deform.
6.The copper area on the PCBA board is uneven
Generally,circuit boards are designed with a large area of copper foil for grounding purposes.Sometimes the Vcc layer is also designed with a large area of copper foil.When these large area copper foils cannot be evenly distributed on the same circuit board When it is installed,it will cause the problem of uneven heat absorption and heat dissipation speed.Of course,the circuit board will also expand with heat and shrink with cold.If the expansion and contraction cannot occur at the same time,it will cause different stresses and deformation.At this time,if the temperature of the board has reached At the upper limit of the TG value,the board will begin to soften,causing permanent deformation.
7.Connection points of each layer on the PCBA board
Today's circuit boards are mostly multi-layer boards with many drilled connection points.These connection points are divided into through holes,blind holes,and buried holes.These connection points will limit the thermal expansion and contraction of the circuit board,thus Causes deformation of the board.
When the PCBA board undergoes reflow soldering and wave soldering,the PCBA board will be deformed due to the influence of various factors,resulting in poor PCBA welding,which has become a headache for production personnel.Next,we will analyze the causes of PCBA board deformation.
1.PCBA board passing temperature
Each circuit board will have a maximum TG value.When the reflow soldering temperature is too high and is higher than the maximum TG value of the circuit board,it will cause the board to soften and cause deformation.
2.PCB board
With the popularity of lead-free technology,the furnace temperature is higher than that with lead,and the requirements for plates are getting higher and higher.The lower the TG value of the circuit board,the easier it is to deform during the furnace process,but the higher the TG value,the more expensive the price.
3.PCBA board thickness
With the development of electronic products in the direction of small and thin,the thickness of circuit boards is becoming increasingly thinner.The thinner the circuit board,the more likely it will be deformed due to high temperature during reflow soldering.
4.PCBA board size and number of panels
When circuit boards are reflow soldered,they are generally placed on chains for transportation.The chains on both sides serve as support points.If the size of the circuit board is too large or there are too many panels,it is easy for the circuit board to dent toward the middle point,causing deformation.
5.The depth of V-Cut
V-Cut will destroy the board structure.V-Cut cuts grooves in the original large sheet.If the V-Cut line is too deep,it will cause the PCBA board to deform.
6.The copper area on the PCBA board is uneven
Generally,circuit boards are designed with a large area of copper foil for grounding purposes.Sometimes the Vcc layer is also designed with a large area of copper foil.When these large area copper foils cannot be evenly distributed on the same circuit board When it is installed,it will cause the problem of uneven heat absorption and heat dissipation speed.Of course,the circuit board will also expand with heat and shrink with cold.If the expansion and contraction cannot occur at the same time,it will cause different stresses and deformation.At this time,if the temperature of the board has reached At the upper limit of the TG value,the board will begin to soften,causing permanent deformation.
7.Connection points of each layer on the PCBA board
Today's circuit boards are mostly multi-layer boards with many drilled connection points.These connection points are divided into through holes,blind holes,and buried holes.These connection points will limit the thermal expansion and contraction of the circuit board,thus Causes deformation of the board.