How to test CIS chip?

Smart home 、 Intelligent city and intelligent manufacturing together form the intelligent environment we live in . As life patterns become more and more data , Image sensor becomes the key to connect the real world and data network .CIS yes CMOS image sensor （CMOS Image Sensor） Abbreviation , Small size 、 High sensitivity 、 Highly integrated 、 Low power consumption 、 Fast imaging 、 Low cost, many advantages ,CIS Chip is the core component of camera , And the camera is an important part of all intelligent technologies . At present ,CIS Chips have been widely used in mobile phones 、 The camera 、 Automotive electronics 、 Security and other fields .

Under the impact of the epidemic, life and work modes are forced to accelerate digitization , Smart life has become the new normal . video conferencing 、 Online learning 、 Disinfection and cleaning robot 、 Unmanned transport aircraft, etc , This new way of life makes the world CIS（CMOS image sensor ） Demand has exploded , according to IC Insights The latest report ,2021 In the world CIS The market size recovered strongly and increased to 228 Billion dollars , Expect to 2025 In the world CIS The market scale is 336 Billion dollars . among , Mobile phone is CIS The segment with the largest application scale , Expect to 2025 reach 157 Billion dollars , And automobile is the fastest growing segment , Is expected in the future 5 The compound growth rate of the industry in was as high as 33.8%, Scale up to 51 Billion dollars . Security surveillance camera 、 Industrial robot 、 The growth of Internet of things and other fields also followed .

Mobile applications are increasingly using multi camera and fingerprint scanning camera technology for user authentication . With the increasing complexity of chip design , The test time required is also increasing . Besides , Automotive applications are also facing the impact of low temperature and high temperature testing in package chip testing , Multi channel tests at different temperatures also significantly increased the number of tests . As image sensors become more and more complex , Continue to design more new functions ,CIS Test requirements are also diversified .

Two 、CIS Test requirements

（ One ）、DC&Function Tests

DC Common tests are OS、 voltage 、 Current, etc ;Function Common tests are DFT and BITS Related tests .

（ Two ）、 Light source and control

because CMOS Inherent device structure characteristics of image sensor , Each pixel and each column of pixels have independent amplifiers , A small mismatch or deviation in the amplifier will produce fixed mode noise of the image sensor . So in CMOS The image sensor needs to be calibrated before it is put into use CMOS Calibrate the image sensor .CMOS Incandescent lamps are commonly used for calibrating light sources of image sensors 、 Tungsten halogen lamp 、LED The lamp . Incandescent lamps and halogen tungsten lamps have low luminous efficiency 、 Large power consumption and many other problems . Compared to the first two ,LED Lamps and lanterns can save energy 、 Environmental protection 、 long life 、 Small volume 、 Low power consumption and other characteristics , So we use LED As CMOS Calibration light source of image sensor .

at present ,LED Common dimming methods for light sources are 2 Kind of , One is PWM Dimming , One is DC Dimming ; because PWM Dimming ,LED The light source will have stroboscopic problems , Now most of them use DC Dimming . Control different color temperature by controller LED The light source , Satisfy CIS sensor Test requirements .

（ 3、 ... and ）、Image Image test

1、 Image acquisition （ Need support CPHY/DPHY Interface protocol ）

In recent years, with the CMOS Image sensor is developing towards the trend of high frame rate and high pixel , The amount of data transmitted by the camera continues to jump . In order to carry out signal transmission effectively , Usually use MIPI D-PHY And MIPI C-PHY Two types of transmission interfaces , D-PHY Separate clock synchronization line is adopted + data Lane Transmission structure , Every one of them Lane By 2 A difference line forms , Strong anti-interference ability and driving ability ; and C-PHY There is no independent clock 3 A complex transmission structure composed of voltage driven leads , Weak anti-interference and driving ability , So right. IC Design ability has higher requirements . but MIPI C-PHY As a result of 5 Binary transmission , Can provide higher throughput , be better than D-PHY Binary system , Its transmission capacity is 2.28 times , Most of them are used by high-end mobile phone platforms .

2、 Image test

Common image tests are Blemish Test、Black Test、White Test And other test items . Recognize and judge the image by algorithm .

3、 ... and 、CIS Test plan

How to meet different test requirements , Reduce testing costs 、 Accelerate test time and time to market ？ Accelerate the development of the first domestic 250Mbps The above high-performance digital analog mixed signal testing machine , Using the high-speed distributed communication technology and high-performance algorithm acceleration technology accumulated for many years , Provide a complete set of high-performance and low-cost CIS Test solutions . The solution supports up to 64 star 2.5Gbps MIPI D PHY Interface acquisition meets the growing demand for high-resolution image sensors , Use acceleration technology up to 160Gbps Distributed communication technology realizes high-speed image acquisition , Image function test data and DC Seamless data fusion . Using acceleration technology high performance algorithm acceleration technology can greatly speed up the image algorithm processing time , Greatly improve the overall testing efficiency , It also allows customers to implement customized image testing algorithms to create and protect tests IP.

* take Tester IPC Arrangement CIS Server+ATE Client

CIS Server: be responsible for CIS Overall test business test

ATE Client: be responsible for DC+Function test

*CIS Server

Use IPC Self contained HP card , control Prober or Handlerd The action of

Use USB Line , Control the action of light source

Use the Internet , control ATE Client and IMAGE Client The action of

*IMG Client

Use CIS High speed image acquisition test system (ST8016C), Realize image data acquisition , Accelerate and enable image testing by configuring self-made acceleration board .

Four 、 Accelerate technology CIS Test program advantages

Accelerate technology CIS The test plan has the following advantages .

（ One ） Product advantage

1、 New architecture design ：

1） Adopt the latest advanced communication technology framework , High performance , high reliability , Flexible expansion is guaranteed ;

2） Each test function is modularized , Different test requirements can be achieved by replacing the module ;

3） Integrated design of upper computer and chassis , There is no bottleneck in system performance , The whole is more reliable ;

2、 More powerful ：

1） The communication bandwidth can reach 40Gbps, It can realize high-performance real-time testing and data transmission ;

2） Highly integrated , The board can integrate more functional modules and channels , The system can integrate more channels ;

3） Well designed analog circuit , Ensure that the error of test parameters is less than 0.1%;

4） be based on FPGA To accelerate the technology , Achieve more powerful computing power 、 Real time scheduling and full parallel testing ;

5） Support big Pattern The test application , Maximum Vector Deepth reach 192M That's ok , The loading rate can reach 4.5 minute ;

3、 The test is cost-effective ：

1） Digital and mixed signal architecture design , You can complete the numbers at one time 、 simulation 、 RF signal test ;

2） Optimize the design for customer applications , High test efficiency , Low cost of testing ;

3） Provide different optimized equipment for design companies and factories .

4、 Own intellectual property , The depth of the custom

1） Completely own intellectual property , According to customer needs , Develop custom test plans , Meet the requirements of system packaging （SIP）、 Special craft (CIS/MEMS） Equal demand ;

2） It can be extended in multiple directions , Test module 、PCBA;

3） According to the stable needs of customers , Accelerate the maturity of high-performance digital testing machine platform and high-performance FPGA Development capability , Help customers develop test schemes and ultra-high cost performance test schemes that cannot be achieved by traditional testing machines .

（ Two ） Program advantages

1、 System specifications

• Support 2.5Gbps MIPI D PHY Interface ,

• Support 2.5Gsps ~3.5GspsC PHY （ Custom board ）

• Support customization LVDS Interface

• Support 4~64 Particle parallel measurement

• Support 4 Group 40Gbps High speed communication interface

• Support 250Mbps/500Mbps/1Gbps Digital board

• Support the highest 160 Channel digital power supply

• Support custom lighting

• Match professional SoC Digital board , To achieve a strong SoC Test ability

• Support DC Data and image function test data fusion management

• to open up FPGA Image testing algorithm implemented in

2、 Integrated operation interface

1) Support multiple mode selection switching ;

2) be based on Eclips Of IDE development environment , Support based on C/C++ Development of , Development is easy to learn ;

3) Convenient operation and maintenance .

3、 Algorithm acceleration advantages

The test scheme has high-performance algorithm acceleration technology , It can greatly improve the overall test time , At the same time, it can also meet the requirements of customers to realize customized algorithms .

4、 Stable and reliable

Compare with other testing machine manufacturers , According to the customer's on-site feedback , The equipment operates stably and reliably for a long time ;

（ 3、 ... and ） Service advantages

1、 A more comprehensive turnkey solution

2、 Hands on empowering Services

• Process specification

• Product development services

• In plant service

3、 Learn from the experience of industry experts to quickly optimize the iterative scheme

• In depth understanding of the industry

• Fast optimization iteration

5、 ... and 、 Application scenarios

CIS FT Test connection diagram

CIS CP Test connection diagram

The above is what we will learn today CIS Test requirements and CIS Chip test scheme , Welcome to inquire if you want to know more .