Reflow oven,SMT Reflow Soldering Oven 当前位置: Home >>News>>News
Circuit Board Voids & PCB Delamination

Circuit Board Voids

Circuit Board Voids are cavities or air pockets inside the solder joint formed by gases that are released during reflow or by flux residues that fail to escape from the solder before it solidifies.

 

Process and design-related causes:

• Improper solder volume due to improper land design

• Improper solder volume due to blocked stencil aperture

• Improper solder volume due to improper stencil design

• Paste viscosity too low

• Paste metal content too low

• Bad or expired solder paste

 Ambient humidity too high for solder paste work envelope

Reflow-related causes:

• Preheat too aggressive for flux – adjust to manufacturers recommendations

• Improper profile for solder paste

 

 

PCB Delamination

PCB Delamination is a separation between any of the layers of the base material or between the laminate and the conductive foil, or both.

 

Process and design-related causes:

• Improper fabrication of the PCB

• Improper packaging of PCBs during shipping

• Improper storage of PCBs resulting in excessive absorbed moisture. (Some practitioners pre-bake components and boards to drive out moisture. This is not encouraged and should be a last resort as baking tends to build intermetallics as well as degrade the solderability by increasing oxidation levels. Shipping and storing suspect plastic molded components in nitrogen is preferred.)

Reflow-related causes:

• Preheat portion of profile and rate of heating too aggressive (should not exceed 4K/sec.)

 

SMT pick and place machineSMT MounterChip MounterJUKI Pick and place MachineJUKI Chip ShooterJUKI Chip PlacementJUKI RS-1R pick and place machineJUKI RX-7R pick and place machineRX-6RRX-6BKE-3020VAJM-100,  Samsung Pick and Place MachineHanwha SM481 Plus Pick and Place MachineSMT482PlusSMT 471Plus,Yamaha Pick and Place MachinePanasonic Pick and Place MachineFUJI Pick and Place MachineSiemens Pick and Place Machine.

文章From:http://www.etasmt.com/te_news_bulletin/2021-08-31/23574.chtml