1. Park/Nelco N4000-11 Next Generation High Tg FR-4

2. Changing Industry Needs
Improved CAF resistance
Less than 20% resin recession after solder cycles
Improved IST cycling performance and consistency
-45°C to +125°C liquid to liquid cycling
Low wicking / crazing (<2 mil wicking)
6X or higher solder floats 
Lead-free assembly tolerance
Lower Z-CTE
Ability to fill buried vias
Processing attributes similar to current high-Tg FR-4
Lower cost (to the fabricator and OEM)
Minimum 160°C Tg TMA

3. Next Generation High-Tg FR-4 Product Development Targets
Robust in lead free assembly environments
CAF resistant
Superior to conventional high-Tg FR-4 in all thermal resistance tests (T260, T288, solder float, PCSD)
Lower Z–CTE than existing high-Tg FR-4
Better moisture resistance than existing FR-4 systems
Little or no degradation in processing attributes (compared to conventional high-Tg FR-4)
No added cost of utilization for fabricators
Cure cycle comparable to existing high-Tg FR-4

4. Phenolic Cure Resin System Advantages
Reduced moisture sensitivity
A factor in thermal performance
Improves CAF resistance
Improved thermal reliability
Better IST, T260, T288 even though Tg is not significantly different.
Lower Z-Axis CTE
DICY curing agent suspected as a contributor to electromigration (CAF)
Faster curing

5. DICY vs. Phenolic Curing Agents
Investigated in response to customer / industry needs
Higher cross link density
Improved chemical and thermal resistance
Decreased latency of cure
Faster cure
Narrow resin flow window
Short prepreg shelf life
Dicyandiamide (DICY)
Conventional curing agent for FR-4 resin systems
Inherent latency of cure
Wide resin flow window
Excellent shelf life
Efficient removal of air from package
Excellent thickness control
DND

6. N4000-11 Product Summary Fully commercialized product
FR-4 epoxy laminate and prepreg system
Filled dielectric
Superior thermal performance
Low Z-Axis expansion rate
Superior moisture resistance
PCSD
Wet relamination tolerance
Outstanding performance in lead free assembly
CAF resistant (> 750 hours)
UL recognition under Nelco FR-4 family
Available through NY, CA, and Singapore business units
No plans to obsolete N and N FC

7. N4000-11 Property Comparison

8. N4000-11 Property Comparison

9. N Prepreg Rheology

10. Tg as a Function of Cure Time
Tg by DSC, N
170
175
180
185
190
195
200 50
100
150
250
Time at Cure Temperature (182 °C) Tg

11. N4000-11 Prepreg Aging Study Prepreg Tests 0 mo 1 mo 2 mo 3.5 mo 5 mo
Gel / M.V.
87 / 0.9
83 / 0.6
85 / 0.5
83 / 0.8
83 / 0.5
87 / 0.6
TgI
(30 min)
175ºC
176ºC
188ºC
182ºC
N/A
T260
35 min
42 min
36 min
29 min
Pressure Cooker SD
0.3%
800 sec.
0.25%
650 sec.
570 sec.
0.27%
560 sec
0.30 %
570 sec
Panel Appearance
Normal
Prepreg storage conditions: 66ºF (24ºC) and 44% RH
Test laminate produced with 8 ply 7628 construction and N FC press cycle

12. N Dk vs. Resin Content

13. Resin Recession After Thermal Shock
Sample
N FC N
Comments
Production material
Treater run material
1080 with ~50% RC
Roll #
C A
B A
Resin Recession after 3x20 sec Solder Shock
>15%
0 %
Resin Recession after 5x20 sec Solder Shock
Resin Recession after 10x20 sec Solder Shock
>50%, de-lamination
<15%

14. Residual Moisture Tolerance

15. Residual Moisture Tolerance
Processing Conditions
N FC Laminate Cycle  Copper Etch  Photo-resist Strip  Alternative Oxide  Conditioning  Re-lamination Conditions = 60 min at 360°F (182 °C) with 10 °F (5.5 °C)/min Heat Rise
Product N
Conditioning
Ambient 24 h
75 °F / 75 RH, 24 h
IPC TgI / TgU (w/o cu-pad), °C
172.1 / 172.9
170.0 / 172.1
IPC TgI / TgU (w/ cu-pad), °C
173.2 / 177.6
177.6 / 182.2
T-260 (w/o cu-pad), °C
26.4
25.5
T-260 (w/ cu-pad), °C
13.1
13.3

16. N4000-11 Heavy Innerlayer Cu Fill Capability
12 Layer Board with 4 oz. Cu innerlayers
6x Solder Float at 288oC
Dark field photos at 100X
No cracks or delamination

17. N CAF Resistance
85 C / 85 % RH / 100 volt bias using Sun TV 1 vehicle at 10.4 mil min. via to via spacing

18. Samples Tested at 2.25 Gbs / sec.
N Eye Pattern Testing
N4000-6 N
Samples Tested at 2.25 Gbs / sec.

19. Samples Tested at 5.0 Gbs / sec.
N Eye Pattern Testing
N4000-6 N
Samples Tested at 5.0 Gbs / sec.

20. Samples Tested at 12.5 Gbs / sec.
N Eye Pattern Testing
N4000-6 N
Samples Tested at 12.5 Gbs / sec.

21. PWB Processing Oxide Processing Lamination Drilling Desmearing
No known issues with any commercial oxides or oxide alternatives
Lamination
Standard high-Tg FR-4 lamination process
60-70 minutes at 182 oC(360°F)cure
Drilling
Standard chiploads for high-Tg epoxy
Maximum 1.5 mil chipload recommended
Desmearing
Standard permanganate or plasma desmear chemistries
Resin attack rates approx. 20% lower than conventional FR-4

22. N4000-11 Test Site Evaluation Results
22-layer production part #
Processing parameters (lamination, drilling, plating, etc.) identical to conventional high-Tg FR-4
Technical results
Tg (DSC) > 180°C (356 °F)
T260 = 46 min., T288 = 7.3 min.
Passed 6 x 10 sec. solder float with 0 % resin recession and 10 x 10 sec. solder float with 6.6 % resin recession
No voids, no dryness, hole wall roughness <0.2 mil
Peel strength lower than N FC materials

23. N4000-11 Thermal Shock Testing
As Received
After 6 x 10 sec. Solder
After 10 x 10 sec. Solder

24. N4000-11 Test Site Evaluation Results
22-layer prototype part #
Final board thickness of 0.180” (4.5 mm)
Test evaluation of pad lifting, resin recession, and z-axis expansion
N used as outer prepreg layer for pad lifting comparison
Processing parameters (lamination, drilling, plating, etc.) as per N processing guidelines
Direct comparison with competitive non-dicy cured material

25. Thermal Property Comparison
Parameter / Sample N
N / -7
N FC
Competitor # I
Tg by DSC,
TgI/IPC-TgU, °C
172.3 / 177.7
154, 172 / 144,176.7
176.5 /
181 / 183
TMA, Tg, °C
169.9
168.1
162.7
167.2
Z-CTE (50-260)
3.5%
3.7%
4.1%
4.2%
T260, min
19.9
18.2
0.6
>30
DND

26. Pad Lifting Comparison

27. Resin Recession Testing

28. Lead Free Assembly Resin system TMA N4000-6 Finished PWB N4000-11
After Cu Plating **
T245
minutes
minutes
minutes
T260
6.63 minutes
minutes
minutes
T288
Delam before 288°C
2.97 minutes
3.40 minutes
**Note – Results are for inner layers with full bare oxide Cu surface.
DND

29. ITRI IST Testing Lead and Lead Free Assembly
24 Layer board, OSP finish
3 Laminate suppliers, x 2 materials each
2 Mini Panels (12 IST coupons) of each material processed through SMT reflow
Tin/Lead reflow at 220 °C (428 °F) peak
Lead-Free reflow at 255 °C (490 °F) peak
Resistance read before and after each reflow process
IST test vehicles cycled to failure

30. CDF vs. Cycles to Failure for 6x220C

31. CDF vs. Cycles to Failure 6x255C

32. Nelco IST Testing Lead Free Assembly Compatibility
22 layer PTH/Post generic test vehicle
HASL final finish
0.120” (3.0 mm) thick
min ” (0.38 mm) vias
single ply 2116 construction (53% resin content)
Three resin systems compared for;
Tin/Lead reflow at 220 °C (428 °F) peak
Lead-Free reflow at 255 °C (490 °F) peak
Low mean Cu plating thickness in barrel
0.0006” ” (0.015 – mm)
IST test vehicles cycled to failure

33. IST Test Summary Coupon Design Test Condition N4000-11 N4000-6 FC
.015” vias / .040” grid
As Received
390
615
374
220 C
500
485
408
255 C
440
574
3X NEMI SMT
580
647
401

34. Siemens Level C Automotive Qualification
1000 hours of preconditioning at 140 oC (284 °F)
1038 thermal cycles from -45 oC to oC (-49 °F to 284 °F)
Pass criteria: less than one decade resistance change
All N coupons passed

35. N4000-11 Attributes Highly thermally resistant high-Tg FR-4
Phenolic cure resin chemistry
Slightly lower gel time and MV than traditional Dicy cured systems
Higher Crosslink Density than N (FC)
Higher ∆Tg due to advancing cure
Difficult to use Nelco ∆Tg test as a measure of degree of cure
Product Tg can be ‘tuned’ by varying relamination conditions
Target °C Tg (DSC) to meet 165°C TMA

36. N Attributes
Dramatically lower susceptibility to the effects of moisture inclusion
No Tg suppression
Stable T260 and PCSD
Ability to hit minimum Tg values greatly enhanced compared to N FC
Material attributes are consistent after 170°C Tg by DSC
Advanced cure may degrade drill results (>190°C DSC, internal test results indicate no change)
More susceptible to hole roughness at high chip loads
Chip loads >1.5 not recommended

37. N Attributes
Material has a slightly greater tendency to craze than N (FC)
Wicking is much better than N FC
<1 mil vs. >2 mils for N FC
Resin attack during desmear slightly lower than N FC
E/Cu deposition rate slightly lower than N FC
Z-CTE is very low (3.2% vs % for N4000-6)
Resin recession very low (<7% after 10x solder shock)
Peel Strength is lower than traditional Dicy cured FR-4 systems
N outer layers to minimize pad lifting
Investigating alternate Cu foils to improve adhesion

38. N4000-11 NFC Technology Attributes
Product Enhancement for HDI Applications
Greatly improved X / Y dimensional stability
Improved curling characteristics, particularly in asymmetric constructions
Improved dielectric breakdown performance
Tighter thickness tolerance for ultra thin core
Smoother surface finish
Possible improvement in CAF resistance

39. N4000-11 NFC Dimensional Stability
DND

40. N4000-11 Technical Data Most data available on line www.parknelco.com
Users can register as a “web customer”
Web customers have a unique password
Web customers can access all data such as MSDS, processing guidelines and technical data as it becomes available
Designers corner