Comparison of Singulation Techniques

Transcription

1 Comparison of Singulation Techniques Electronic Packaging Society, Silicon Valley Chapter Sept. 28, 2017 ANNETTE TENG Sept 28, Definition of Singulation 9/28/2017 Annetteteng@promex-ind.com 2 1

2 Assembly Flow for Singulation Wafer (>0.70mm) Apply front side tape Rough grind Fine grind Wash wafer Backend assembly Singulate/dicing Remove front side tape Mount dicing tape on backside of wafer 9/28/ Wafer Singulation Techniques Plasma dicing Thermal Laser Separation Stealth Laser Dicing Laser Dicing Scribe & Break Saw with Blade

3 SAW LASER Ablation Stealth TLS Plasma Sept 28, Saw Machines Cut Precision: 0.1um Blade height control:0.1um Auto blade wear adjust Broken blade detect 10/24/

4 Saw Blades-18um and up Resin bond blade Saw Tape UV-TAPE High Saw Non UV-TAPE UV irradiation Die pick Adhesive Strength Low 10/24/

5 Dice Before Grind allows for ultrathin dies groove Groove groove Wafer Frontside groove Dicing tape BackGrind + stress relief Backgrind tape Wash Backgrind tape Wafer Frontside Tape Flip 10um Si dies Tape and frame 10/24/2017 Annetteteng@promex-ind.com um dies well established in DRAM and Flash drives (Micron, Sandisk, Samsung) 25um copper pillars 25-40um die thickness 6-7um TSV diameter Sept 28, 2017 Annetteteng@promex-ind.com

6 VERSATILITY of SAW Profile cuts DAF Multilayer material Metallized wafer Making needles Metallized street Multilayer materials 10/24/ WAFER THICKNESS CUTOFF FOR LASER AND PLASMA SAW 5000um Sept 28,

7 Problems with Saw -Water issues; chipouts; Saw dust Sedimentation on bond pads GaAs chipout Sapphire chipout InP chipout Galvanic corrosion of Aluminum pads Galvanic corrosion of Aluminum pads 1. SAW 2. LASER 2a. Ablation 2b. Stealth 2c. Thermal Laser Separation 3. Plasma Sept 28,

8 Laser Singulation Thermal shock Coating Saw Laser ablation / stealth Cleave Tape stretch Removal of Coating Roller break 10/24/2017 Annetteteng@promex-ind.com 15 Ablation vs Stealth Technology Method Ablation (requires coating & washing) Sublimation by irradiating short pulse laser Short pulse laser Collecting lens Workpiece Stealth (coating not required) Creating SD (modified) layer by focusing laser inside material Short pulse laser Collecting lens Workpiece Process Grooving Scribing Full cut DAF cut Chip separation by SD layer creation + Breaking/Expand 10/24/2017 Annetteteng@promex-ind.com

9 STEALTH DICING on GaAs Example on GaAs mirror wafer Wafer Thickness: 100um(DP finish), Chip size 5x5mm, Feed speed 240mm/sec Top side Back side CH1 CH2 Chip Separation Method 1 pass SD Irradiation Side SD Irradiation Side Tape expand + 3 point breaking SD Irradiation Side SD Irradiation Side 2 pass Tape expand only SD Irradiation Side SD Irradiation Side 3 pass Tape expand only 2014 Disco Corporation. 17 InP Laser scribe & Break vs Through Cut Laser Grooving InP Apply Protective film Dicing tape 110 m InP LASER Protective film Metal film Wash off protective film Dicing tape Dicing tape Expand on stretchable dicing tape Slit Breaking process Dicing tape Metal film Protective film 110 m LASER InP InP Laser Full Cut Dicing tape Expand on stretchable dicing tape Shipping format Clean 2015 Disco Corporation

10 Disco DDS2010 Expanding -stretchable tape Tape Expanding + Breaking Die separation will be performed by following the curve on breaking bar Breaking -stretchable tape Direction of separation Vacuum 2013 Disco Corporation. 19 Machine InP Ablation Fullcut vs. Scribing + Breaking Thickness 100um, Index 0.25 x 0.25mm, street width 20um Pa ss Power [W] Freque ncy [khz] Feed speed [mm/s] Kerf width [µm] DFL7160 Type-D F-1, BSS3 Laser full cut Photographs* Front side *Photographs were taken with the parameter setting sample. Machine Pas s Frequen Feed Kerf Power cy speed width [W] [khz] [mm/s] [µm] Laser scribing Photographs* Front side Cross section Cross section DAL7020 Type-S1 No Processed depth: 49.8 µm 2015 Disco Corporation

11 Stealth Dicing on InP Thickness: 200um, Index: 2mm x 2mm Top side Back side X side Cross-section Y side CH1 CH2 Process Flow Mapping pass 1st 2nd 3rd 4 5th Feed speed [mm/s] 280 Power [W] DF [ m] SD Condition DC tape mount Front side Laser backside UV frontside UV Flip & Expand Grip ring Detape topside Tape mount on back side 2015 Disco Corporation. 21 Laser Dicing Technologies vs. materials/applications Process Material Device Laser grooving + blade full cut Low-k CPU & Logic Laser full cut Laser scribe + Break Stealth dicing Si, Ge, SiC, GaAs Metal Substrate, DAF Sapphire Alumina Ceramics Silicon, Sapphire, SiC Glass, FuSi, InP, GaAs Solar Cells/Power Device LED, Power Device RF Device, NAND Flash LED, Sensors MEMS/RFID/Linear Sensor LED, Power Device Medical, etc Via Hole LitaO3, LiNb, SOI Wafer SAW Device, MEMS 2015 Disco Corporation

12 Disco Laser Systems (Head + Optics) Wafer Type Ablation Laser Stealth Dicing Low-K Grooving Si Full cut Type-F + Standard Optics Type-FX + BSS6 Optics Type-D + BSS3 Type-M BSS5 (Ultra thin) SDE01 / SDE03 SDE03R / SDE05/ SDE06 GaAs / InP Full cut Type-G + BSS3G Type-D + BSS3 SDE21 Ge Type-K + BSS4 SDE03 Sapphire Full cut Type-F + Sapphire Optics SDE31 SiC Full cut Type-D + BSS3 SDE41 DAF Cut Type-A + DAF Optics ( Use DDS2300 ) Glass / LT LN / GaN Others Under R&D (see below) Feasibility for most of Laser process available in Japan. Such as VIA, glass dicing, curved shape dicing, LLO etc. SDE33/ SDE12 Some SD engine are under R&D phase. To be released 2013 Disco Corporation. 23 Sept 28, 2017 Annetteteng@promex-ind.com

13 Sept 28, Sept 28,

14 Sept 28, REDUCING KERF ON REDUCING COST & INCREASING PRODUCTIVITY Diode L x W x mm KERF/street width ies per wafer Total d of cuts Total number Street width reduction vs yield NUMBER OF DIES/8" WAFER NUMBER OF DIES/12" WAFER Street width (mm) added to a 0.250mmx0.200mm die Singulation /wafer cost high for smaller dies Street widtrh (mm) added to diode Sept 28, 2017 Annetteteng@promex-ind.com

15 SMALL DIES MAKERS OF RFID & DIODES ARE TO PLASMA Sept 28, SAW $0.2m 2. LASER Ablation >$1m 3. Stealth Dicing >$1m 4.Plasma >$5m Sept 28,

16 2014, ON Semiconductor, All Rights Reserved 31/11 Issues Removal of Flourinated residues Plasma resistant carrier tape 32/

17 PLASMA DICING PROCESS FLOW Photo lithography Laser grooving Plasma singulation Removal of F residues Removal of PR Saw grooving 10/24/ ESTABLISHED PLASMA SINGULATION FROM ONSEMI (courtesy of Harry Gee) Si wafer FEOL Redistribution Solder bump PR Silicon wafer carrier IR and Stepper pattern PR PR Silicon wafer IR Image of underlying metal from top for alignment of the street PR pattern of the street after exposure Bond to carrier wafer Encapsulatie around dies Wafer Backgrind Carrier removal Plasma singulation Wafer probe carrier After Plasma etch PR die die carrier Remove PR CSP singulation Laser mark die carrier die Sept 28, 2017 Annetteteng@promex-ind.com

18 1. SAW $0.2m 2. LASER Ablation >$1m 3. Stealth Dicing >$1m 4. Plasma >$5m Comparison Sept 28, Sidewall Comparison of Saw Techniques Plasma dicing TLS Stealth Laser Plasma Ablation Laser Laser ablate and stretch Saw with Blade Scribe and Break Saw Sept 28,

19 Sept 28, /11 Advantages of Plasma Batch process High UPH for tiny dies Narrow Kerf yields more die per wafer Accuracy of die defined on passivation Improvement in Die Strength Rounded corner at each die Shape other than rectangular Multi Project Wafer(MPW) Pizza cut Sept 28, /

20 Foundry equipment suppliers to assembly. Foundry Plasma Dicing Suppliers includes PlasmaTherm has partnered with Disco Panasonic SPTS Sept 28, Acknowledgement: Disco Hi-Tec America, Inc. & Sept 28,