In PCBA processing, systematic identification and resolution of faults can improve product reliability and reduce production costs.
I. Common types of failure
1. Welding defects
Soldering defects are the most common problems in PCBA processing, including false soldering, cold soldering, solder bridges and missing solder joints. False soldering is manifested in poor contact with the solder joints, resulting in unstable electrical signal transmission. Solder bridge refers to the flow of solder to the area should not be connected to form a short circuit. Missing solder joints refers to the solder joints are not fully formed, resulting in open-circuit problems.
2. Open circuit board
Open-circuit problem refers to some lines on the circuit board or solder joints do not form a reliable electrical connection, common causes include poor soldering, PCB substrate damage and design errors.
3. Short circuit problem
Short-circuit problem refers to the circuit board on the two or more should not be connected to the circuit part of the accidental contact, resulting in an abnormal flow of current, which may damage the circuit board or components. Common causes include solder overflow, shorted copper wires or accidental contact caused by contaminants.
II. Failure analysis methods
1. Visual Inspection
Check the solder joints: Observe the shape and connection status of the solder joints to confirm the presence of false or cold soldering.
Check the lines: Check whether the lines on the circuit board are intact and whether there are any open or short circuit problems.
Implementation strategy: Conduct regular visual inspections, find and record problems, and take timely repair measures.
2. Electrical test
Function test: Conduct function test after the assembly is completed to confirm whether the circuit board is working properly according to the design requirements.
Continuity test: use a multimeter to test the circuit board’s various connection points, check whether there are open-circuit problems.
Insulation Test: Test the insulation of the board to ensure that there are no accidental short circuits in various parts of the board.
Implementation strategy: conduct systematic electrical testing during and after the completion of the production process to identify and solve problems in a timely manner.
3. X-Ray Inspection
Inspection of solder joints: X-ray inspection to check the soldering quality of BGA solder joints, to confirm the existence of false soldering or solder bridges.
Inspection of internal structure: Check the internal structure of the PCB to identify possible short-circuit or open-circuit problems.
Implementation Strategy: Configure X-ray inspection equipment to conduct regular and random internal inspections to ensure solder quality.
III. Troubleshooting strategy
1. Resoldering
Clean the surface: Before re-welding, clean the welding surface to remove oxides and contaminants.
Adjust welding parameters: Adjust temperature, time and amount of solder according to welding requirements to ensure welding quality.
Implementation strategy: for welding defects, re-welding and check the welded joints to ensure that the welding quality meets the standards.
2. Replace damaged parts
Identify damaged parts: Identify damaged parts through electrical testing and visual inspection.
Replacement: Replace damaged parts, reweld and function test.
Implementation strategy: Replace damaged parts and ensure that the quality of new parts meets the requirements.
3. Repair PCB substrate
Repair line: use conductive adhesive or conductive line to repair the damaged line.
Reinforcement of the substrate: Reinforcement of the substrate to reduce the risk of physical damage.
Implementation strategy: PCB substrate repair, and ensure that the repaired substrate meets the requirements of use.
Company Profile
Zhejiang NeoDen Technology Co., Ltd. has been manufacturing and exporting various small pick and place machines since 2010. Taking advantage of our own rich experienced R&D, well trained production, NeoDen wins great reputation from the world wide customers.
with global presence in over 130 countries, the excellent performance, high accuracy and reliability of NeoDen PNP machines make them perfect for R&D, professional prototyping and small to medium batch production. We provide professional solution of one stop SMT equipment.
In our global Ecosystem, we collaborate with our best partners to deliver a more closing sales service, high professional and efficient technical support.
Post time: Aug-06-2024