MT6573钢网开孔建议

一、MT6573理论计算1、根据IPC7525标准，模板厚度与开口尺寸基本要求宽厚比A:开口宽度(W)/模板厚度(T)＞1.5面积比B:开口面积(W×L)/孔壁面积[2×(L+W)×T]＞0.662、合金粉末颗粒直径选择原则C方形开口时，焊料颗粒最大直径≤模板最小开口宽度的1/5D模板开口厚度（垂直）方向，最大颗粒数应≥3个①开口宽度为：0.25mm方形导0.075圆角面积：开口面积0.1*0.1+4*0.1*0.075+3.14*0.075*0.075=0.0577孔壁面积(4*(0.25-0.15)+3.14*0.15)*T(钢网厚度)=0.871TTYPE4锡膏:颗粒20-38umTYPE5锡膏:颗粒10-30um项目钢网厚度0.08mm0.09mm0.10mm0.12mmOK值项目钢网厚度0.08mm0.09mm0.10mm0.12mmOK值A3.1252.7782.5002.0831.5A3.1252.7782.5002.0831.5B0.8280.7360.6620.5520.66B0.8280.7360.6620.5520.66C0.1520.1520.1520.152≤0.2C0.1200.1200.1200.120≤0.2D2.1052.3682.6323.157≥3D2.6673.0003.3334.000≥3判断NGNGNGNG判断NGOKNGNG②开孔为∮0.25mm时;面积：开口面积3.14*0.125*0.125=0.049孔壁面积2*3.14*0.125*T=0.785TC圆形开口时，焊料颗粒最大直径≤开口直径的1/8。MT6573钢网开孔建议TYPE4锡膏:颗粒20-38umTYPE5锡膏:颗粒10-30um项目钢网厚度0.08mm0.09mm0.10mm0.12mmOK值项目钢网厚度0.08mm0.09mm0.10mm0.12mmOK值A3.1252.7782.5002.0831.5A3.1252.7782.5002.0831.5B0.7810.6940.6250.5210.66B0.7810.6940.6250.5210.66C0.1520.1520.1520.152≤0.125C0.1200.1200.1200.120≤0.125D2.1052.3682.6323.157≥3D2.6673.0003.3334.000≥3判断NGNGNGNG判断NGOKNGNG二、结论因MT6573采用0.4Pitch，多行多列矩阵，根据上诉理论值，只有钢网厚度为0.09mm，考虑钢网加工和下锡量，我们采用0.25方形导0.075圆角，使用5号粉可以满足稳定生产。以上