Precision PCB Fabrication, High Frequency PCB, High Speed PCB, Standard PCB, Multilayer PCB and PCB Assembly.
The most reliable PCB custom service factory.
PCBA Tech
Common defects of SMT patch in front of furnace
PCBA Tech
Common defects of SMT patch in front of furnace

Common defects of SMT patch in front of furnace

2021-11-05
View:31
Author:Downs

SMT patch production line

1. Missing (solder paste without placed footprint)—Missing (solder paste without placed footprint)

a. The component pickup is too biased and unstable. According to the program, find out which machine they are mounted on. From the operation screen, check whether the pickup status of the component is biased. If so, check the Shape data- Process- Do auto offset setting For components smaller than 30mm, it is recommended to set Yes. For components larger than 30mm, it is recommended to set No.

b.Feeder: The feeder is faulty, the feeding position is not accurate, replace the feeder; There is debris in the positioning slot, which causes the feeder to be not installed in place, take it out and check.

c. Insufficient vacuum: Whether the reading of the machine's vacuum gauge is normal, clean the 0.7/1.0 nozzle with a jig and an air gun

d. Vacuum tube: Check whether the vacuum tube installation position under the turret is correct and whether it is damaged

e. Check the gap between the cylinders of the 10 stations and the descending stroke of Clutch. If the impact of the chip working head is too large, it may cause the material to fall during transportation

f. The error range of the material suction in the component data: the relative value does not exceed 20% of the body, and the absolute value does not exceed 1mm

2. Drain components (with traces pasted)—Missing with placed footprinter

pcb board

a. The suction components are too biased and unstable. According to the program, find out which machine they are mounted on. From the operation screen, check whether the suction status of the components is biased. If so, check Shape data- Process- Do auto offset Setting. For components smaller than 30mm, it is recommended to set Yes. For components larger than 30mm, it is recommended to set No.

b.Feeder: The feeder is faulty, the feeding position is not accurate, replace the feeder; There is debris in the positioning slot, which causes the feeder to be not installed in place, take it out and check.

c. Insufficient vacuum: Whether the reading of the machine's vacuum gauge is normal, clean the 0.7/1.0 nozzle with a jig and an air gun

d. Vacuum tube: Check whether the vacuum tube installation position under the turret is correct and whether it is damaged

e. Adjustment of vacuum failure of mechanical valve at 11 stations

3. The component is skewed (Skew in Q direction)

a. The thickness of the PCB component is set incorrectly (larger than the actual thickness)

b. Improper use of the nozzle size, select the appropriate size of the nozzle

c. The Q angle tolerance in the component data is set too large (Shape data-process-pickup-tolerance check-offset Q)

d. If the nozzle is worn or damaged, take it out and check it with a magnifying glass. You can check with the Director-Tool-Line report-Line monintor heand nozzle report

e. The hole of the Holder nozzle is too dirty, causing the nozzle to move unsmoothly, and the cushioning ability is not good when placing the parts

f. SMD working shaft is damaged: whether the Holder, coupling, and wave spring washer are damaged

g. Whether the Joint parts of the 11 stations are damaged and whether the related adjustment items are within the specification range

h. There is no support board or the PCB is not flat due to poor installation

i. X/Y worktable is not level

4. Component shift (Misalignment along X or Y direction)

a. If the entire board is often shifted as a whole, the lens of the fiducial camera needs to be replaced

b. The tolerance of X and Y in PD is too large (Shape data- Body- length/Width tolerance)

c. Inconsistent spacing between small and medium boards (Block) in PCB jigsaw

d. The coordinates of the component need to be corrected

5. Flying parts (scattered components scattered on the PCB)

a. Check whether the height of the support plate is correct and whether there is a problem with the installation

b. The component thickness is set incorrectly, please refer to the file for related component data

c. Poor viscosity of solder paste

d. Check whether there are special or large components around it. It may be affected by the placement of them. At the same time, check the placement order

6. Component flip (Invert)

a. The components are loose in the material belt and are shaken over during the feeding process. Evidence and improvement suggestions should be provided for this problem and submitted to CQE. Temporary measures: You can choose a suitable Feida special

b. The incoming material has been turned (the probability is very small)

7. Chip components cracked (Mechanically damaged)

a. The component thickness is set incorrectly (smaller than the actual value)

b. Check if the component data has a placement offset (z offset)

c. The incoming material is already damaged.

8. Component side stand (Billboard)

a. The dimensional tolerance of the body in the component data is too large, it is recommended that the relative value is less than 20%, and the absolute value does not exceed 2mm

b. The feeder is faulty and the feed is inaccurate, replace the feeder

1. Drain component —Missing with placed footprinter

a. Check whether the suction nozzle is suitable. If the size of the suction nozzle is the same as the component size, it may cause the machine to only suck the material without placing the material

b. The picking component is too biased, and the error range of the component data picking is too large

c. Hand-held components to check vacuum

d. If the nozzle head is sticky, it must be cleaned

2. Component Skew (Skew)

a. The component thickness is set incorrectly, which is larger than the actual thickness

b. The module splint is not working properly and the PCB is not clamped. This kind of failure occurs from time to time

c. Confirm that there is no bad nozzle, and the background part of the nozzle does not interfere with each other

d. Improper use of the nozzle size, select the appropriate size of the nozzle

e. Hold the component to check the vacuum, if it is not enough, check and clean the nozzle, nozzle head, vacuum tube and vacuum generator

f. Lightly touch the front end of the nozzle to check whether the activity is normal. The reason is that the hole of the Holder nozzle is too dirty, or the wrong spring is used, which causes the nozzle to have a poor cushioning ability when placing parts

g. The PCB surface is not flat due to no support board or poor installation

3. Misalignment

a. The tolerance of X and Y in PD is too large (Shape data- Body- length/Width tolerance)

b. Inconsistent spacing between small and medium boards (Block) in PCB jigsaw

c. The coordinates of the component need to be corrected

4. Chip components cracked (Mechanically damaged)

a. The component thickness is set incorrectly (smaller than the actual value)

b. Check if the component data has a placement offset (z offset)

c. The incoming material is already damaged.

SMT patch common defect analysis (NXT)

1. Missing (solder paste without placed footprint)—Missing (solder paste without placed footprint)

a. The component pickup is too biased and unstable. According to the program, find out which module they are mounted on, and check whether the pickup status of the component is biased from the operation screen. If so, check the Shape data- Process- Do auto offset setting For components smaller than 30mm, it is recommended to set Yes. For components larger than 30mm, it is recommended to set No.

b. The feeder is faulty and the feeding position is incorrect, replace the feeder

c. There is debris in the positioning slot, which causes the feeder to be not installed in place, take it out and check it.

d. The vacuum filter is too dirty, remove it for replacement or clean it.

e. The vacuum is not enough, check whether the reading of the module vacuum detection amplifier is normal and whether the parameters are set correctly

f. For some major or heavier components, it is necessary to confirm whether the transport speed (X, Y) is appropriate

2. Drain components (with traces pasted)—Missing with placed footprinter

a. There is a sticky substance on the tip of the nozzle (the inspection method is the same as above), remove it and clean it with alcohol

b. There is no support plate or the installation is not good, resulting in flying parts

3. The component is skewed (Skew in Q direction)

a. The component thickness is set incorrectly (larger than the actual thickness)

b.Improper use of the nozzle size, select the appropriate size of the nozzle.

c. The working shaft (Syringe) of the H08/04 placement head is not flexible up and down, so it is lubricated by T&D

d. The Q angle tolerance in the component data is set too large (Shape data-process-pickup-tolerance check-offset Q)

e. If the nozzle is worn or damaged, take it out and inspect it with a magnifying glass. You can check with the Director-Tool-Line report-Line monintor heand nozzle report.

f. Component rotation setting: Prerotation, and must confirm whether the transport speed (Q) is appropriate

g. Poor nozzle elasticity, lightly touch the front end of the nozzle to check, some nozzles have poor elasticity due to dirt in their moving parts, and some are caused by the buffer spring in the working shaft (Syringe).

h. Check whether the height setting of the components is not in line with the actual situation, causing the vacuum to close prematurely

i. There is no support board or the PCB board is not flat due to poor installation