What are the common faults of solder paste printing?

I. Diagnosis and treatment of tin lap

1. Description of the phenomenon: a small amount of solder paste between the two solder pads overlap. In high-temperature welding is often pulled back by the main tin body on each pad, once you can not pull back, will cause a short circuit of the tin ball or circuit, resulting in poor welding.

2. Tin ride diagnosis: low amount of tin powder, tin powder viscosity bottom, tin powder particle size, high room temperature, printing is too thick, placed under high pressure.

3. Tin ride processing:

a. Increase the proportion of metal components in the paste to increase the viscosity of the paste

b. Reduce the particle size of tin powder; reduce the ambient temperature

c. Reduce the thickness of the printed solder paste

d. Enhance the precision of printing solder paste

e. Adjust the various construction parameters of the solder paste

f. Reduce the pressure exerted by the parts

g. Adjust the temperature profile of preheating and soldering.

II. Diagnosis and treatment of tin bleeding

1. Phenomenon Description: After printing, there are burrs or excess solder paste near the solder paste.

2. Diagnosis of tin bleed: insufficient squeegee pressure, squeegee angle is too small, stencil opening is too large, PCB and PAD size is too small, printing is not aligned, the printer parameter settings are wrong, stencil and PCB is not tightly adhered to the paste viscosity is not enough, PCB or the bottom of the stencil is not clean, and so on.

3. Tin bleed treatment:

a. Adjust the parameters of the solder paste printing machine

b. Cleaning or replacement of the template

c. Cleaning or replacement of PCB

d. Improve the accuracy of the printing machine

e. Increase the viscosity of the solder paste

III. Paste collapse paste powdered diagnosis and treatment

1. Description of the phenomenon: poor molding of the solder paste on the PCB, the printing height is not the same, the solder paste into powder.

2. Solder paste collapsed solder paste pulverization diagnosis: too much solvent in the paste, too much solvent when wiping the bottom of the stencil, the paste dissolved in the solvent, the wiping paper does not rotate, the quality of the solder paste is poor, PCB printing is completed in the air placed in the air for too long, the PCB temperature is too high.

3. Solder paste collapse solder paste pulverization processing:

a. Increase the proportion of metal components in the solder paste; increase the viscosity of the solder paste

b. Reduce the particle size of tin powder; reduce the ambient temperature

c. Reduce the thickness of the printed solder paste; strengthen the accuracy of the printed paste

d. Adjust the various construction parameters of the solder paste

e. Reduce the pressure exerted by the placement of parts

f. Avoid the solder paste and printing PCB after a long time in the wet air

g. Reduce the flux activity in the solder paste

h. Reduce the lead content in the metal.

IV. Paste pull the tip of the diagnosis and treatment

1. Description of the phenomenon: solder paste on the PCB molding is poor, smear area is too large, the pitch of the solder joints is too small.

2. Paste pull tip diagnosis: stencil open hole is not smooth, stencil open hole size is too small, mold speed is unreasonable, PCB solder joints are contaminated, solder paste quality is abnormal, stencil wipe is not clean.

3. Paste pull tip processing:

a. Clean or replace the stencil

b. Cleaning or replacement of PCB

c. Adjust the printing parameters

d. Replacement of better quality solder paste

Features of NeoDen NeoDen Y600 Full Automatic Printer

Specification