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LENS: A precisely engineered plastic or glass-plastic combination lens that receives the light signal and focuses it onto the photosensitive element.

Voice coil motor (VCM): A device that controls lens movement and the autofocus function by changing the DC current of a motor coil in a permanent magnetic field to control the position at which the spring is extended.

IR Filter: A filter device that blocks the near-infrared portion of the spectrum detected by the image sensor, avoiding red-tinted images.

Sensor: A core component of an imaging module that converts external light into electricity, converts the image signal obtained through an on-chip analog converter into a digital signal, and performs a series of processes such as analyzing light sensitivity, restoring color, and removing noise. Mainly includes CCD and CMOS.

Flexible Circuit Board (FPC): A device for connecting devices to other circuits.

2. Introduction of camera module mounting technology

Common encapsulation technologies for imaging head modules include CSP (chip scale package), COB (chip on board), COF (chip on flex), FC (flip chip), etc. Among them, COB and CSP are two mainstream electronic component technologies, which are often used by mobile phone camera module manufacturers in particular. Simply put, COB is fashionable and elegant, and is a method of bonding the photosensitive chip to the substrate with gold wire, and then gluing the lens and support to the substrate. CSP is powerful and has a samurai spirit. The photosensitive chip is fixed to the substrate by SMT, and the lens and support are also fixed to the substrate. FC technology is like Ouyang sealing, which is a very special operation. Currently, it is only used by Apple, which uses the chip upside down, the electrical engineering side down, and the gold hooks are used, and the gold wire is omitted to greatly reduce the thickness of the module.

Advantages and disadvantages of COB encapsulation

Advantages: COB has better image quality, smaller module space, lower packaging costs, and can be directly used by downstream assembly plants, since the upstream packaging plant handles everything.

Disadvantages: COB encapsulation is quite delicate, requires a lot of environmental requirements and process equipment, and there is a trade-off between process time and success rate. If the process time is shortened, the technical difficulty of the module will increase significantly and the success rate will decrease.

Advantages and Disadvantages of CSP Encapsulation

Advantages: CSP is a method in which a photosensitive chip is covered with a protective glass and then manufactured underneath. The process environment and equipment requirements are not high, but the process time and yield are quite good.

Disadvantages: Due to its low light transmittance and large module space requirements, it is often used in low-end products and is currently somewhat stagnant.

Difference between COB and CSP

The biggest difference between COB and CSP is that COB encapsulates the chip bare, while CSP encapsulates after covering it with protective glass. Although CSP can save module space compared to COB, COB encapsulation has high requirements for production environment and process equipment, and the performance is not very good. Therefore, some manufacturers continue to use CSP encapsulation technology to guarantee the performance.