Since the camera module plays an increasingly important role in electronic products, let’s learn more about it so that you can make right decisions concerning camera module of your products.
We’re going to provide some tips and the manufacturing process of camera module in the following content. Hope it helps.
How to choose a proper camera module
In fact, what lens you need is largely dependent on where you want to install your cameras/camera modules. Do you want to install it in your room, your office, your cars, your big factory, your open backyard, your street, or your building? These different places with different observation distance use very different lens, so how to choose the suitable one among hundreds of different lens?
There are many factors to think about when choosing your lens, like focal length, aperture, lens mount, format, FOV, lens construction and optical length, etc, but in this article, I am going to emphasize on ONE factor, the most important factor when choosing lens: The Focal Length
The focal length of the lens is the distance between the lens and the image sensor when the subject is in focus, usually stated in millimeters (e.g., 3.6 mm, 12 mm, or 50 mm). In the case of zoom lenses, both the minimum and maximum focal lengths are stated, for example 2.8mm–12 mm.
The Focal Length is measured in mm. As a guide:
a short focal length (e.g. 2.8mm) = a wide angle of view=short observation distance
a long focal length (e.g. 16mm) = a narrow angle of view=long observation distance
The shorter the focal length, the greater the extent of the scene captured by the lens. On the other hand, the longer the focal length, the smaller the extent captured by the lens. If the same subject is photographed from the same distance, its apparent size will decrease as the focal length gets shorter and increase as the focal length gets longer.
2 different ways to pack the sensor
Before we get down to the manufacturing process of a camera module, it’s important that we get how the sensor is packed clear. Because the way of packaging affects the manufacturing process.
Sensor is a key component in the camera module.
In the manufacturing process of a camera module, there are two ways to pack the sensor: chip scale package (CSP) and chip on board (COB).
Chip scale package (CSP)
CSP means the package of the sensor chip has an area no greater than 1.2 times that of the chip itself. It’s done by the sensor manufacturer, and usually there is a layer of glass covering the chip.
Chip on board (COB)
COB means the sensor chip will be directly bonded to PCB (printed circuit board) or FPC (flexible printed circuit). COB process is part of the camera module production process, thus it’s done by the camera module manufacturer.
Comparing the two packaging options, CSP process is faster, more accurate, more expensive, and may cause poor light transmittance, while COB is more space-saving, cheaper, but the process is longer, the yield problem is larger, and can’t be repaired.
Manufacturing process of a camera module
For camera module using CSP:
1. SMT (surface mount technology): first prepare the FPC, then attach the CSP to FPC. It’s usually done in a large scale.
2. Cleaning and segmentation: clean the large circuit board then cut it into standard pieces.
3. VCM (voice coil motor) assembly: assemble the VCM to the holder using glue, then baker the module. Solder the pin.
4. Lens assembly: assemble the lens to the holder using glue, then bake the module.
5. Whole module assembly: attach the lens module to circuit board through ACF (anisotropic conductive film) bonding machine.
6. Lens inspection and focusing.
7. QC inspection and packaging.
For camera module using COB:
1. SMT: prepare the FPC.
2. Conduct COB process:
Die bonding: bond the sensor chip onto FPC.
Wire bonding: bond extra wire to fix the sensor.
3. Continue to VCM assembly and the rest of the procedures are the same as the CSP module.
This is the end of this post. If you want to know more about OEM camera module, just contact us. We’re glad to hear from you!
Post time: Nov-20-2022
