Camera Module: Common Quality Issues and Their Countermeasures

Camera is a core part on the devices such as mobile phones and dashcam. So how can you ensure the quality of a camera module that will eventually become part of your product? The best way is tracking back to its manufacturing process.

In this post we conclude some common issues that may occur in camera module manufacturing process. So you will have better idea of what areas to pay more attention to.

Before we start, let’s take a simple review of the manufacturing process.

There are mainly 6 steps:

1) SMT (surface mount technology);

2) Cleaning and segmentation;

3) VCM (voice coil motor) assembly;

4) Lens assembly;

5) Whole module assembly and

6) Lens inspection and focusing.

Now let’s turn to the question: what are the common problems in camera module manufacturing process and how you can fix them?

1. Blurred image

Possible causes:

• Inaccurate focus.
• Loose lens or inaccurate glue dispensing.
• Lens abnormality.

Countermeasures:

• Strict control on focus procedure. Spot check to prevent defective products entering next procedure.
• Make sure the torsion of lens material is in the required range. Strict control on glue dispensing procedure.
• Enhance the dust-free environment and lens protection to prevent foreign matters in aperture.

2. Mess image

Possible causes:

• Poor contact among components.
• Defects from the SMT procedure.
• Defects from FPC (flexible printed circuit).

Countermeasures:

• Strict control on the SMT process.
• Check the FPC, especially if there’s any broken circuit or oxidized solder pad.

3. Unbalanced color in image

Possible causes:

• Defective sensor.
• Sensor doesn’t match with lens.

Countermeasures:

• Detailed assessment and confirmation in sampling stage.
• Collaborate with the sensor and lens manufacturers to solve problem.

4. Dark corner in image

Possible causes:

• FOV (field of view) of the lens isn’t compatible with the device.
• Sensor doesn’t match with lens.
• Defects from SMT or FPC.
• Failure in Lens assembly.

Countermeasures:

• Leave a larger window on device for lens or use a smaller lens.
• Change lens or block the dark corner through software.
• Check the material of SMT and FPC as well as the positioning holes and intervals on them.
• In lens assembly process, examine if the lens warps up.

5. Nonstandard size

Possible causes:

• Nonstandard size materials.
• Caused by manufacturing process.

Countermeasures:

• Examine the size of materials and ask suppliers to control the quality.
• Before mass production, carry out a FAI (first article inspection), to ensure the materials of each part comply with the standard.

6. Lens falling

Possible causes:

• Defective epoxy adhesive.
• Defective FPC.
• Defects from baking process.

Countermeasures:

• Take a FAI. Check if there’re blots on FPC that cause the poor adhesion.
• Ensure the baking parameters are correct, including time, temperature, etc.

7. Defective appearance

Possible causes:

• Defective materials.
• Defects from manufacturing process.

Countermeasures:

• Strengthen the examination of the appearance of material.
• Prevent damage to the materials through the production process.

That concludes what we have to say in this post. Feel free to let us know if you’re interested in knowing more about it, or that you have any question about camera module.

Note: We do not own the images used in this post. Feel free to contact us if they belong to you, and we’ll take them down as quickly as we possibly can.