cis testing technology

思衛科技Jetek Technology Corp.

CIS Testing Technology

思衛科技 JemmyMobil Phone:0917866007E-mail:[email protected]


Contents• Basic Introduction

• CIS Function

• CIS Test Item

• CIS Test System

• Production Issue


Basic Introduction

-What is CIS

-CIS Application

-CIS Market


What is CISCIS(CMOS Image Sensor)

Digital camera

CCDCCD

Digital camera

CCDCIS


Note PC

PDA

Mobile Phone

Digital Camera

Video Camera

Fingerprint/Pupil

User AuthenticationCopy

MachineFacsimile/Scanner

Security Camera

In-vehicle Camera

Wristwatch Camera

CCD / CMOS Image Sensor

CIS Application


CIS Market


CIS Function

-System Block


System Block

CMOS Image Sensor

CDSADCAGC

DSP

TimingGenerator

VideoEncoder

Interface

Memory

DVP(Digital Video Port)

MIPI(Mobile Industry

Processor Interface)

NTSC/PAL


Image Sensor Structure


Passive Sensor: Advantage: Simple circuit(one transistor) Large sensor area Disadvantage: Loading is higher Random noise is big

Active Sensor: Advantage: Electron convert voltage directly in each pixel Reduce radon noise Disadvantage: Small sensor area Amplifier character is different in each pixel Fixed pattern noise


Digital Control Logic

•Timing generator• I2C Interface

Exposure control Frame Rate control Gain control Image size control Multi port output --------


CDSCDS(Correlated Double Sampling)

Delay T

Vin Vout

+

_


About Multi Port Output :

Clk limit solution for big area sensor


EnCoderMonochrome:

Color:

1 Hsync

1 Hsync

Chroma

Burst

Sync


DVP Waveform Diagram

FEN: VSyncLEN: HSync


MIPI Waveform Diagram


Output Image:


Output Signal(Internal ADC) :

Respons

e

Pixels


CIS Test Item

• DC/Function Test• ADC Test• Image Test(Dark,Standard Light,Saturation,Color)• Image Processor Library


DC Test• Continuity

• Leakage

• Power Consumption

• I2C Write/Read

• DSP Pattern

Function Test

CIS Test Item

ADC Test• Offset

• Gain

• INL / DNL

• THD

• S / N


Dark Test

• Dark Mean/Std.

• Dark Row/Column Variation

• Dark uniformity

DSNU(Dark Signal non-uniformity)

• Dark Defect Pixel

• Dark Cluster

• Dark Current


Dark Current

(Dark_level1-dark_level2)/(0.255-0.02) Dark_level1 : Exposure:255ms Dark_level2 : Exposure:20ms

Exposure Time(ms)20 255

Respons

e


Defect Test

• Defect Pixel Test

• Adjacent Defect Pixel Test

Wound Pixel

Dead Pixel


Adjacent Defect(Cluster)

Region Define


Cluster Test Algorithm

• Build Convolution Filter

• Build Bed Pixel Map

• Cluster Judge Method


Cluster Judge Method :

CMOS Imager

ΣXi

N Frames 1/N

Mean X

Bad Pixel Map

ConvolutionFilter

Count Judge


Build Bed Pixel Map :

R

Mean

G

Mean

R

Mean

G

Mean

G

Mean

B

Mean

G

Mean

B

Mean

R

Mean

G

Mean

R

Mean

G

Mean

0 0 0 0

0 1 1 1

0 1 0 1

R

Value

G

Value

R

Value

G

Value

G

Value

B

Value

G

Value

B

Value

R

Value

G

Value

R

Value

G

Value

_


0 0 0 0 0

0 1 1 1 0

0 1 0 1 0

0 0 0 0 0

0 0 0 0 0

1 16 2

64 256 128

8 32 4

416 460 352

274 211 273

16 3 16

Judge Method 1:

For 3 * 3:

You can judge the relation of bed pixels by value Ex: 274

*

1 1

1


0 0 0 0 0

0 1 1 1 0

0 1 0 1 0

0 0 0 0 0

0 0 0 0 0

1 1 1

1 9 1

1 1 1

11 13 11

11 5 11

1 2 1

Judge Method 2:

For 3 * 3:

If the value >10 , There are 3 bad pixels in the 3*3 area(don’t care relation of bad pixels)

*


Standard Light Test• Mean Level ( Light, R, G, B )• Std. ( Overall, R, G, B )• S/N ( Overall, R, G, B ) -FPN(Fixed Pattern Noise) -Random Noise• Row/Column Variation (R, G, B )• Uniformity (R, G, B ) PRNU(Photon Response non-uniformity) • Defect Pixel (Overall):Defect judge by R, G, B independently• Cluster

Ps1: G1, G2 maybe need to be separated


Saturation Test

• Saturation Mean Level (Overall, R, G, B )

• Dynamic range (R, G, B)

20 * log( V_sat / V_noise)


Color Frame Test

• R (G, B)Mean Value in R(G, B) Light

• R (G, B)Std. in R(G, B) Light

• Prime Response in R(G, B) Light

• Cross Response in R(G, B) Light


Prime Response in R Light

(Light R Mean – Dark R Mean) / (Light Overall Mean – Dark Overall Mean)

Cross Response in R Light

((Light G(B) Mean – Dark G(B) Mean) / (Light R Mean – Dark R Mean)


Micro Lens


Color Filter

On-chip Micro Lens

PhotoShielding Film

Sensor Die

Micro-Lens


Normalize Micro Lens Shift

By low pass filter:


Solution1 for Micro Lens ShiftBy HW(Pupil Lens)


1 1 1 1 1 1 1

1 1 1 1 1 1 1

1 1 1 1 1 1 1

1 1 1 10 1 1 1

1 1 1 1 1 1 1

1 1 1 1 1 1 1

1 1 1 1 1 1 1

1/9 1/9 1/9

1/9 1/9 1/9

1/9 1/9 1/9

1 1 1 1 1

1 2 2 2 1

1 2 2 2 1

1 2 2 2 1

1 1 1 1 1

×

Image Uniformize

1 1 1 1 1

1 2 2 2 1

1 2 2 2 1

1 2 2 2 1

1 1 1 1 1

1 1 1 1 1

1 1 1 1 1

1 1 10 1 1

1 1 1 1 1

1 1 1 1 1

1 1 1 1 1

1 0.5 0.5 0.5 1

1 0.5 5 0.5 1

1 0.5 0.5 0.5 1

1 1 1 1 1

÷

÷

Solution2 for Micro Lens ShiftBy SW


CIS Test System

• System Structure• IP Module• Illuminator(Light Source)• Main System• Analog Module(option)• Debug Tool


DUT

Main System

Control Signal Sync

LightSource

IP Module(Frame Grabber

included)

Analog Module

Data Bus

Sync

Sync

AnalogWaveform

Data

Control & Result

Prober / Handler

System Structure


Docking method:

Light source connect with testhead directly


AC Power

illuminator

Testhead

Cable system

Top View

Prober

PIB (Prober Interface Board)

Docking with Prober (Cable system)


Docking with Handler (Cable system)

Cable system

Handler

Testhead

illuminator

Side View

DIB (Device Interface Board


IP Module

DUT

32 pinsmax.

Test Head

IP D

ata

I/F

DigitalImage

TimingControl& Setup

Digital Pins

DC Pins

LF/HF/VHF Pins

5pins:

FrameGrabberBoard

IP Controller

IP Cabinet

DC Test Functions

Digital Test Functions

Analog Test Functions

Time Measurement

MasterClocks

UIPTC

Tester Cabinet

Light SourceController

CRT &Keyboard

CRT &Keyboard

IP Module


Illuminator

Light Source Structure

AGC


Lamp AGC


•Multi Sites (CP: Depend on Illuminator Area Size

FT: Depend on Illuminator multi sites Design)

•Area: Area Sensor >25*25 mm Line Sensor > 100*100 mm

•LUX: W > 1000 LUX

•Uniformity: < 3%

Illuminator Specification

For Blue Light


•R/G/B/W Light (option)

•Pattern Turret (option)

•Shutter Turret

•F-number

•Calibration Table

•External / Internal Type


Light Source Uniformity Measure Method :

(Lx max - Lx min) ((Lx max + Lx min)/2) *100 Uniformity (+/- %) = / 2


F-Number=Focal Length / Iris Diameter

Light Source F-number :


Select Illuminator:

Uniformity Halogen > LED

Spectrum Halogen > LED

Intensity Halogen > LED

Lamp Life Time Halogen < LED

Cost Halogen > LED

Color Temperature Halogen = LED


Compare External type Illuminator and Internal type Illuminator

•External type Illuminator(Cable Mount) Advantage: Mount handler/prober Easily Disadvantage: -Long cable effect test speed limitation -Need special handler/prober design

•Internal type Illuminator(Direct Mount) Advantage: -Signal performance is better -Use Standard handler/prober


Main System / Analog Module

Waveform

Source

Waveform

Digitizer

Digital

DC

AWGSequencer

Waveform

DigitizerSequencer

DC DCData Memory

Test Vector

GeneratorPin

Electronics

Sequencer

Capture Memory

Digital

Capture Memory

Waveform

Source Memory

AWG

Digitizer

Syn

chro

-Pip

e

Time Measurement

Unit

TIAData

MemoryTime Interval

Analyzer

DigitalMaster

Sequencer

DualMasterClocks

Time Measure


•DPS

•Digital I/O (Image data out not included) pin count : > 64 pins data rate : > 30MHz pattern depth : >2M

•Image Data Differential Transfer

•System Noise Floor : < -90dB

•Prober/Handler Control

•Illuminator (Light source) Control

Main System Specification


Analog Module

• Digitizersample rate: > 40MHzresolution: >12Bits

• AWGsample rate: >40MHzresolution >12Bits


Debug Tool

IP Image Viewer• Display Image• View Pixel Value and Color• Change Display Scale of image • Displaying Line Profile• Histogram


• Socket

• Light Source

• Multi Sites

Production Issue


Socket

Tester Load Board

Socket PCB

DUT

Socket

Pogo PinSocket Cover

Sensor Glass


Light Source

• Adjust the light source focus

• Calibration Light Source

Light Source Correction(Use same type light Source)


• Support a small hole light source

• Let’s the hole imagine put on the center of frame

• Adjust the light source focus

• Convert iris

Adjust Light Source Focus


If the Slope is Sharp,The focus adjustment is good.


Use different Light Source

Spectrum is the most important concern - light Source: Halogen or LED

- Color Temperature (Color Temperature ,Blue Response )

- Filter


F-number is the other concern


Multi SitesFor wafer: Assign needle location

cis testing technology

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