Opportunities and Challenges for Fan-out Panel Level Packaging (FOPLP)

Transcription

1 Opportunities and Challenges for Fan-out Panel Level Packaging (FOPLP) T. Braun ( 1 ), M. Töpper ( 1 ), S. Raatz ( 1 ), S. Voges ( 2 ), R. Kahle ( 2 ), V. Bader ( 1 ), J. Bauer ( 1 ), K.-F. Becker ( 1 ), T. Thomas ( 2 ), R. Aschenbrenner ( 1 ), K.-D. Lang ( 2 ) ( 1 ) Fraunhofer Institute for Reliability and Microintegration Gustav-Meyer-Allee 25, Berlin, Germany tanja.braun@izm.fraunhofer.de phone: / fax.: / ( 2 ) Technical University Berlin, Microperipheric Center

2 Outline Motiv ation for Panel Lev el Packaging PLP Res ults Assembly on 24 x18 Panel Level Compression Molding Die Shift Redis tribution Outlook Summary: Advantages & Challenges for FOPLP Outlook

3 PLP MOTIVATION

4 FOWLP/FOPLP Process Flow Options Mold first RDL first Apply thermal release tape on carrier Apply release layer on carrier Die assembly on carrier RDL (e.g. thin film, PCB based, ) Wafer/panel overmolding Die assembly on carrier Carrier release Wafer/panel overmolding RDL (e.g. thin film, PCB based, ), balling, singulation Carrier release, balling, singulation

5 Roadmap Fan-Out Panel Level Packaging Source: Yole

6 Material Equipm ent Challenges for Panel Packaging Tape laminator Available automatic equipment? Pick and Place Accuracy on panel size? Material application Dispensing, sprinkle, Molding Uniformity, thickness control, Debonder Available automatic equipment? Lithography Stepper, laser ablation, LDI Sputtering, plating Thickness variation, lines & spaces Thinning & Dicing Available automatic equipment? carrier preparation assembly compression molding debonding redis tribution handling, thinning & s ingulation Carrier steel, glass,..? Thermo release tape Alternatives? EMC liquid, granular, sheet? Dielectric polymers liquid or film? photosensitive or not? Sputter targets Plating Handling carrier Tape or other material Temporary adhesives

7 From Wafer to Panel Size for Fan-out Packaging Wafer Technologies PCB Technologies 24 x x 457 mm² mm Panel Technologies

8 IZM Wafer Level Packaging Line (RDL) for Wafer Sizes 100 mm / 150 mm / 200mm / 300 mm Sputter Spin Coater Mask Aligner Wafer Plating Wet Etching Spin Coater Mask Aligner Spin Coater N 2 Oven RIE

9 IZM Panel Level Embedding Line from Wafer Scale to Panel Scale 610 x 456 mm²/24 x18 Datacon evo/ ASM Siplace CA3 Mahr OMS 600/ IMPEX prox3 WL: Towa up to 8 PL: APIC up to 18 x24 incl. 12 WL Lauffer/ Bürkle Siemens Microbeam/ Schmoll Picodrill with HYPER RAPID 50 Schmoll MX1 CREAMET 600 CI 2 S3 Ramgraber automatic plating line Orbotech Paragon Ultra 200 Schmid

10 PLP RESULTS

11 FOWLP/FOPLP Process Flow Steps Mold first RDL first Apply thermal release tape on carrier Apply release layer on carrier 24 x x 18 Die assembly on carrier Wafer/panel overmolding RDL (e.g. thin film, PCB based, ) Die assembly on carrier Carrier release Wafer/panel overmolding RDL (e.g. thin film, PCB based, ), balling, singulation Carrier release, balling, singulation

12 High Speed Assembly on 24 x18 Assembly of dies and fiducials chips (2 x 3 x 0.25 mm³) have been placed on the panel Assembly speed of ~ chips/h using one collect and place 20-nozzle revolver head using four assembly heads maximum assembly speed could be accelerated up to chips/h Assembled reconfigured 18 x24 panel

13 Assembly Strategies on 18 x 24 Assembly Option A: three fiducial dies have been placed first and in a second step all other dies have been place in reference to the initial fiducial dies A 0,10 0,08 0,06 0,10 0,08 0,06 initial fiducial dies x [mm] 0,04 0,02 0,00-0,02-0,04-0,06-0,08 y [mm] 0,04 0,02 0,00-0,02-0,04-0,06-0,08 B G1 G2-0, x-position [mm] -0, y-position [mm] Assembly Option B: Global fiducials (G1, G2 and G3) have been assembled first. Local fiducial dies for the four segments (A, B, C) have been placed in a second step in reference to the global fiducials. Finally all other dies are assembled in reference to the local fiducials. 0,10 0,08 0,06 0,10 0,08 0,06 B C A B C A x [mm] 0,04 0,02 0,00-0,02 y [mm] 0,04 0,02 0,00-0,02 B C A B C A -0,04-0,06-0,04-0,06-0,08-0,08 G3-0, x-position [mm] -0, y-position [mm]

14 Compression Molding - Principle process principle process profile Mold Tool Release Film Cavity EMC Vacuum Mold Tool Wafer panel mold machine 2 15 min Short cycle time Constant temperature -> no heating or cooling ramps No full compression pressure over longer time PMC and mold release extra process steps

15 Molding Compounds for Large Area Encapsulation Liquid Compression Molding Compounds Granular Compression Molding Compounds Sheet Lamination Molding Compounds Standard material for wafer level embedding Paste-like material is dispensed in the cavity and flows during tool closing and compression of the tooling Limited potential for large area due to complex dispense patterns needed and longer flow length? Standard material for MAP compression molding Granular material is distributed nearly homogeneously all over the cavity and melts and the droplets have to fuse during closing and compression of the tooling No limitations for large area application Standard material for wafer level embedding Material sheets are melting and only flow around dies for encapsulation Sheets in defined thicknesses/volume No limitations for large area application

16 Material Evaluation for Compression Molding properties A B liquid granular filler content 89 wt.-% 90 wt.-% filler cut size 75 µm 55 µm CTE 1 7,5 ppm/k 7,2 ppm/k CTE 1 33 ppm/k 30 ppm/k T g 165 C 175 C flexural RT 22 GPa 27 GPa mold temperature 125 C 125 C inmold cure time 600 s 420 s PMC temperature 125 C 125 h PMC time 1 h 2 h heat flow [W/g] DS C material B material A temperature [ C] viscosity [Pas] Rheology 10 7 material B material A temperature [ C] Comparable cured material properties Comparable low mold and cure temperature but different cure times Significant different flow properties with much lower viscosity of the liquid compound

17 Mold Compound Application Liquid EMC Granular EMCs Dispensing of dot patterns Volume control by insitu weighing Homogeneous spreading Volume control by weighing Manually by sieve technology, automatically by vibrating unit

18 Compression Molding on 12 /300 mm Wafer Size Liquid EMC Granular EMCs Dispensing of one dot in the center Homogeneous filling without flow marks or knit lines Homogeneous spreading Homogeneous filling without flow marks or knit lines

19 Compression Molding on 24 x18 Panel Size Liquid EMC Evaluation of dot size pattern Evaluation of different dot patterns target panel thickness of 450 µm (~ 250 g) Dispense time with state of the art material and equipment min

20 Compression Molding on 24 x18 Panel Size Liquid EMC Evaluation of dot size pattern 1 Strong flow 2 marks and knit lines Strong flow marks and knit lines 3 Strong flow 4 marks and knit lines Panel broken along knit line Strong flow marks and knit lines Complete filling of the 24 x18 panel feasible Strong flow marks and knit lines for all patterns, dispense time too long Process and material optimization needed

21 Compression Molding on 24 x18 Panel Size Granular EMC Evaluation of spreading 1 2 Evaluation of two different spreading patterns target panel thickness of 450 µm (~ 250 g) o Dot pattern o Homogeneous spreading Application time with state of the art material and manual equipment 5 10 min

22 Compression Molding on 24 x18 Panel Size Granular EMC Evaluation of spreading 1 2 Flow marks in the shape of the granular dot pattern No flow marks Complete filling of the 24 x18 panel feasible Granular compound distribution has also an influence on flow marks Homogeneous distribution of the compound required

23 Compression Molding on 24 x18 Panel Size Molding of panels with assembled dies (die thickness: 250 µm, mold thickness: 450 m) Liquid EMC Granular EMCs Molded panels with liquid EMC show less flow marks as blank panels Significant marks only visible at the panel edges where no dies are assembled Molded panels with granular EMC show nearly no flow marks Encapsulation of assembled panels with liquid and granular compound feasible Granular EMC show slightly better mold results and shorter process time

24 Die Shift on 18 x 24 Assembly Option A: three fiducial dies have been placed first and in a second step all other dies have been place in reference to the initial fiducial dies A initial fiducial dies x [mm] 0,6 0,5 0,4 0,3 0,2 0,1 0,0-0,1-0,2-0,3-0,4-0,5-0, x-position [mm] y [mm] 0,6 0,5 0,4 0,3 0,2 0,1 0,0-0,1-0,2-0,3-0,4-0,5-0, y-position [mm] Linear die shift in x- and y-direction => compensation possible Same slope in in x- and y-direction

25 Die Shift on 18 x 24 Assembly Option B: Global fiducials (G1, G2 and G3) have been assembled first. Local fiducial dies for the four segments (A, B, C) have been placed in a second step in reference to the global fiducials. Finally all other dies are assembled in reference to the local fiducials. Reference to global fiducials B G1 G2 0,6 0,5 0,6 0,5 B C A B C A 0,4 0,3 0,2 0,4 0,3 0,2 x [mm] 0,1 0,0-0,1 y [mm] 0,1 0,0-0,1 B C A B C A -0,2-0,3-0,2-0,3-0,4-0,4 G3-0,5-0, x-position [mm] -0,5-0, y-position [mm] Comparable results to assembly option A Linear die shift in x- and y-direction => compensation possible Same slope in in x- and y-direction

26 Die Shift on 18 x 24 Assembly Option B: Global fiducials (G1, G2 and G3) have been assembled first. Local fiducial dies for the four segments (A, B, C) have been placed in a second step in reference to the global fiducials. Finally all other dies are assembled in reference to the local fiducials. Reference to local fiducials B G1 G2 B C A B C A B C A B C A G3 Linear die shift in x- and y-direction in each quarter => compensation possible Same slopes in all quarters Lower die shift

27 RDL on Panel Size Quo Vadis? x x 457 mm² mm PCB based technologies Already available on panel level proof of concept has been demonstrated Currently limited to 10 µm lines and spaces Maskless adaptable processes possible No die surface opening possible for e.g. sensors or LEDs Low cost potential Thin film technologies Proven and established process for FOWLP Fine line structuring down to 2 µm lines and spaces Die surface opening possible for e.g. sensors or LEDs Quite expensive equipment No simple upscaling of technologies from WL to PL Not one solution for everything Application defined best of both worlds New materials in combination with new processes must be developed

28 PLP SUMMARY & OUTLOOK

29 Advantages for FOWLP and PLP Electrical Performance: Proof of concept for very RF-Modules beyond 30 GHz. Improved wiring and I/O: There is several decades of experience in fine line wiring and interconnection technology in the IC industry that can be leveraged for packaging technology. S tandardization: Standardization is key for embedding die package to multi-sourcing Thermo-mechanical reliability : Improved reliability compared to FIWLP due to additional plastic packaging Cos t: Cost advantages are perceived with the ultra-miniaturized approach proposed when coupled with large area, high throughput and high volume production.

30 Challenges for FOPLP Warpage ( Assembly, Manufacturability) Heterogeneous materials and non-symmetric structure cause bow Polymer materials with adapted CTE& modulus and low shrinkage are required Optimized layer sequence and design required Accuracy/Resolution ( Miniaturization) Improved optical recognition systems for placement equipment Die shift compensation Imaging with high depth of focus and high resolution Local alignment LDI or scanner or stepper Yield ( Cost) Suited materials and components Optimized processes Production experience learning curve Low k Polymers for RDL ( Performance) Standard epoxy polymers are not sufficient for high performance RDL Low k with low loss are essential for RF performance Dry-film polymers offer the possibility for thick polymer layer beneficial for RF

31 FOPLP Current Status performance f(l/s, pitch, no. dies,.) WL PL cost

32 Fraunhofer IZM FOPLP Industrial Consortium Phase I performance f(l/s, pitch, no. dies,.) WL PL cost Validation of current FOPLP concerning equipment, material, performance and cost Differentiation against FOWLP

33 Fraunhofer IZM FOPLP Industrial Consortium Phase II performance f(l/s, pitch, no. dies,.) WL PL cost FOPLP enhancement with adapted/optimized equipment and materials Developments in direction of higher performance and lower cost

34 Thanks for your attention!