Views: 0 Author: Site Editor Publish Time: 2025-10-13 Origin: Site
Separated endoscope camera modules, characterized by the independent layout of "lens - DSP board", are widely used in scenarios such as medical minimally invasive procedures and industrial narrow-space inspection. The connection method between the lens and the DSP board directly affects the module’s transmission stability, installation flexibility, and operation & maintenance costs. This article compares the core advantages and disadvantages of two connection solutions "wire bonding and Type-C port connection" based on an endoscope camera module equipped with OmniVision OV9734 sensor, 3.3mm ultra-fine lens, and 6 0201-sized LED fill lights, providing references for scenario-specific selection.
Wire bonding achieves electrical conduction between the lens module and DSP board through metal wires. As a common connection method in miniaturized devices, its advantages and disadvantages are highly associated with the characteristics of this endoscope module:
Ultra-miniaturization to adapt to ultra-fine lens requirements: The lens of this module has a diameter of only 3.3mm, requiring integration of the sensor, LED beads, and connection structure in an extremely small space. Wire bonding has no "bulk volume" of physical interfaces and realizes connection only through micron-level wires, which can further reduce the overall size of the module. This meets the installation needs of medical endoscopes or industrial applications, avoiding scenario adaptation limitations caused by interface space occupation.
Stable signal transmission to ensure real-time imaging: The module uses MIPI signals to transmit raw images. Wire bonding is a direct connection with "no contact gap", which can reduce changes in contact resistance caused by interface plugging/unplugging, lower the risk of reflection and interference of MIPI high-speed differential signals, and avoid image freezes or frame drops. It is particularly suitable for the core requirement of "no-delay presentation of lesion details" in medical diagnosis.
Controllable cost for mass production: The wire bonding process does not require additional procurement of Type-C connectors, supporting cables, and other materials. It can be integrated into automated production lines synchronously with the module’s SMT process and AA process, reducing assembly procedures and lowering material and labor costs for mass production. It is suitable for consumer-grade maintenance or entry-level industrial inspection scenarios sensitive to cost.
Poor maintainability, difficult reuse after failure: Wire bonding is an irreversible connection. If the wires break or have poor contact, professional equipment is required for re-bonding. Moreover, the repair process may easily damage the OmniVision OV9734 sensor or LED beads. In most cases, the entire module needs to be replaced, increasing long-term operation & maintenance costs—it is especially unsuitable for medical equipment scenarios that "require quick recovery after failure".
Low installation flexibility, limiting separated layout: The core value of the separated design is that "the distance between the lens and DSP board can be adjusted as needed". However, the length of wire bonds is fixed (usually ≤ 3cm), making it impossible to flexibly adjust the layout according to actual scenarios. Forcibly extending the wire bonds will cause MIPI signal attenuation and damage the real-time imaging effect.
High process threshold and strict requirements on production precision: This module adopts the AA process to ensure the alignment precision between the lens and sensor. Wire bonding needs to match the precision of the AA process. If wire bonding shifts during production, it may cause signal disconnection or impedance mismatch, increasing the defective rate. The precision requirements for production line equipment are significantly higher than those for interface connection.
Type-C port connection realizes detachable connection between the lens module and DSP board through a standardized Type-C female connector. The module needs to integrate a MIPI signal transmission channel into the Type-C interface. The matching degree of its advantages and disadvantages with scenario needs is as follows:
Flexible installation to release the value of separated design: The separated design of this module needs to adapt to scenarios where "the distance between the lens and DSP board is variable". Type-C cables can support long-distance transmission of MIPI signals and can be replaced with cables of different lengths as needed, without being limited by fixed wires. Meanwhile, the reversible plugging feature of Type-C avoids "interface damage caused by wrong insertion direction" during installation, improving on-site operation efficiency.
Convenient maintenance to reduce long-term costs: If a fault occurs in the connection between the lens and DSP board, only the Type-C cable or connector needs to be replaced, without disassembling the sensor or LED beads inside the module. This allows quick recovery of equipment operation—it is especially suitable for medical equipment scenarios that "require minimal downtime" or industrial scenarios that "need on-site quick maintenance", avoiding the waste of "disposal after failure" in the wire bonding solution.
Multi-function integration to simplify circuit design: The Type-C interface supports multi-dimensional transmission of "signal + power supply + control". This module integrates 6 0201-sized LED fill lights, and can transmit LED control commands through the sideband signals of Type-C, eliminating the need to design independent connecting wires for LEDs and simplifying the module’s circuit layout. Meanwhile, the USB PD protocol of Type-C can assist in powering the module, reducing the number of power interfaces on the DSP board.
Volume occupation compressing miniaturization space: The physical size of the Type-C female connector is much larger than the "no-volume" feature of wire bonding. Although the lens of this module is only 3.3mm, the DSP board needs to reserve installation space for the Type-C interface, which may increase the overall size of the DSP board. This limits its use in scenarios where "the DSP board needs to be embedded in an ultra-small host".
Signal risks depending on interface quality: MIPI signals have high requirements for contact stability. Frequent plugging/unplugging of the Type-C interface may easily cause wear of the interface pins, leading to poor contact. This further causes MIPI signal attenuation, resulting in noise in 720p resolution images or frame rate drop. In addition, unshielded Type-C cables may introduce electromagnetic interference (EMI), requiring additional use of shielded cables and increasing costs.
Higher cost than wire bonding and increased material complexity: The Type-C solution requires additional procurement of connectors and shielded cables that meet MIPI signal transmission requirements, and needs to design interface protection circuits in the module. The overall material cost is 15%-30% higher than that of the wire bonding solution. Meanwhile, the inventory management of cables also increases supply chain complexity.
Combining the advantages and disadvantages of the two solutions and the parameter characteristics of this module, selection must be closely aligned with "core scenario requirements":
For medical minimally invasive diagnosis: Prioritize the wire bonding solution—it leverages miniaturization and signal stability to ensure the 3.3mm lens enters minimally invasively, while avoiding missed diagnosis of lesions caused by MIPI signal interference.
For industrial inspection: Prioritize the Type-C solution—it enables flexible wiring to adapt to inspection distances of different equipment, and maintenance convenience can reduce downtime costs.
For consumer-grade maintenance: Selection can be based on cost needs—the wire bonding solution is suitable for entry-level models oriented to cost-effectiveness, while the Type-C solution is suitable for professional models requiring "frequent disassembly and flexible adjustment".
