A Brief Talk about Vision of Tesla Infrastructure Project:
From chip design to product, the common test standard of the whole industry chain-quantum efficiency
CMOS Image Sensor
In recent years, as the “visual soul” of electronic devices, image sensors have become the focus of market attention with the popularization of 5G. Tesla, as the leader of unmanned driving technology, announced that they will abandon the radar equipment in the self-driving system Autopilot and FSD last month. Start from this month, the self-driving system of some new cars in Model 3 and Model Y will be changed to full-lens detection. There is no radar sensor, and semi-autonomous driving can be carried out in North America. We can also expect that the markets of CMOS image sensor (CIS) chip and CIS camera module (CCM) will usher in explosive growth.
From image sensor chip design to wafer manufacturing, packaging and testing, and the most downstream system factories such as mobile phones, automobiles, etc. After years of development, the process level of each stage has shown a leap-forward improvement. However, the division of labor in the industry is quite meticulous, and the construction and time costs from the manufacturing are high, which supports the respective technical thresholds of the upstream, midstream, and downstream reaches of the industry.
Take the fingerprint recognition chip under the optical screen of the image sensor as an example. The design is led by the top chip design companies, and then commissioned by TSMC and Caiyu OEMs, and finally passed to the packaging and testing plant for packaging and basic electronics test. Therefore, for chip design engineers, they have to wait three to six months to know whether their own designs can meet the expectations of end customers. To understand end customer needs and to verify the quality of own products effectively in order to achieve the final success and gain the popularity among the market.
SG-A image sensor tester is a standardized image sensor tester developed by Enli Technology, which can provide from image sensor chips to assembled products such as under-screen fingerprint recognition modules, and the key parameters required for high dynamic range for car webcam, such as full-spectrum quantum efficiency QE, overall system gain K, temporal dark noise, signal-to-noise ratio, absolute sensitivity threshold, saturation capacity, dynamic range, DSNU, PRNU, Linearity error, and so on. Even a chip design company can easily get the relevant optoelectronic characteristics report before and after packaging to speed up the delivery of the final product. The test method of the SG-A image sensor tester is optimized on the basis of the EMVA 1288 standard, and it added the main light angle CRA measurement function that cannot be carried out by the traditional method. It overcomes the inspection difficulties of new manufacturing processes, including small pixel (< 1 um), BSI and 3D stacking, micro lens, new Bayer array design, and so on., and it directly assists wafer-level photoelectric characteristics analysis and microlens design verification.
The development of technology has spawned the progress of standards, only if make testing method standardized from upstream to downstream of industry, and it will speed up the verification of design process. We found that the chip design companies in the past were very familiar with the electrical analysis of chips. However, with the explosion of market applications of light sensor products, if we put more attention on the characteristics of light-to-electricity on the chip, it will become a technological breakthrough.
Taking quantum efficiency, an important parameter on image sensors, as an example, using non-destructive optical “reverse translation” technology, the digital image signal generated by the image chip analyzes the quantum efficiency of the micron-level photosensitive element and the system gain of the chip analog circuit, etc. Through the quantum efficiency QE curve of sensor, it can also understand that the performance capability of the sensor in the spectral range.
As can be seen from the above figure, from the QE results, due to the BI structure, the highest EQE value above 85% can be reached at 650nm, and the near-infrared band response values at 850nm and 940nm are also very high, making SONY IMX556 a leader in 3D sensing applications.
- If you specialize in electronic circuit chip design, but are not familiar with optical inspection, and hope to find a partner who is good at optical and spectroscopy inspection….
- If you are an expert in consumer electronics, now you want to step into the back-end module products related to image sensors, but you are not familiar with the inspection methods and methods of image sensor imaging quality…
- If your image sensor chip needs to complete the design and verification of related optical performance in a short time, but needs to complete the deployment of the optical inspection system in an instant, you want to find a reliable partner for…
- If you already have a traditional integrating sphere detection system, but the divergence angle is too large to perform performance tests on precise optical parameters such as the principal angle of light (CRA)…
- For the image sensor chip that has been put into production, you want to be able to verify the quality of the foundry process, and you want to find a non-destructive optical inspection system…
- If you are a back-end camera module manufacturer, you need accurate image sensor chip optical parameters (such as the CRA of the chip plus microlens) to design appropriate lens parameters to complete the design and verification of the overall module…
- If you are developing a back-end ISP (image signal processing chip), and you are looking for an analog light source system that has high light intensity dynamic range modulation capability and covers the UV to NIR wavebands, which can be compared to the application environment of the image sensor chip to assist you in developing ISP algorithms…
Adopting the advanced optical conversion and modulation technology and a full set of test solutions from Enli Technology, without cutting or destructive testing of the chip, the digital signal of the image chip can be “reversely translated” to analyze the quantum efficiency of the micron-level photosensitive element, and the chip analog circuit System gain, dark current noise, saturation, photoelectric response linearity, etc., it will accelerate the time to market of your new products.
- Fingerprint recognition (CIS+Lens, CIS+collimator, TFT-array sensor)
- Micro-lens design of CIS, wafer level optics inspection
- CIS DSP chip algorithm development
- Si TFT sensor panel
- Time-of-Flight camera sensor
- Proximity Sensor (Quantum efficiency, sensitivity, linearity, SNR et al.,)
- d-ToF sensor, i-ToF sensor
- Multi-spectral sensor
- Ambient light sensor (ALS)
- Fingerprint-Under-Display (FoD) sensor
If you are interested in testing technologies such as CIS and CMM quantum efficiency, please contact us for more equipment selection information.