Base Material for Printed Circuit Boards IPC Part: 3 Base Material for Printed Circuit Boards A PWB is born and develops into an unruly teenager.

IPC-2221B IPC-2222A IPC-2581 IPC-7351B IPC-7095C IPC-7525B IPC-7527 Product spec Component data Gerber files Drill files Bare Board Spec Electronic scheme Routing Net list BOM Footprints IPC-2141A Component placement Program for: -Laser Plotter -Drilling -Routing -AOI -Electric test IPC-2251 IPC-2152 IPC-7093 To Bare Board Production IPC-7094 IPC-2221B J-STD-609A IPC-2222A IPC-1752A IPC-2581 IPC-2610 IPC-7351B IPC-7095C IPC-7525B IPC-7527

FR4 Please fill in!! ? IPC-9691A IPC-4562A IPC-4563 IPC-4121 IPC-4101D FR4 IL FR4 BFR Free DATA from CAM FR4 High Tg FR4 Please fill in!!

IPC Standards Base Material Standards. IPC-4101D Rigid Boards. IPC-9691A CAF. IPC-4562A Metal Foil for Board Applications. IPC-4563 RCC Foil for Board Guideline. IPC-4121 Guideline for Selecting Core Construction for Multilayer Applications.

IPC-4101D Material Composition Keywords All Appropriate Specification Sheets BT / Epoxy / Woven Glass 30 Cyanate Ester / Woven Aramid 54 Cyanate Ester / Woven Glass 71 Cyanate Ester / Woven S-2 Glass 70 Cyanate Ester / Woven Quartz 61 Epoxy / Cyanate Ester / Woven Glass 29 Epoxy / Non-Epoxy / Nonwoven Aramid 58 Epoxy / Non-Epoxy / Nonwoven Glass 28 Epoxy / Nonwoven Aramid 55 Epoxy / Paper 04 Epoxy / PPO / Woven Glass 25, 103 Epoxy / Woven Aramid 50 Epoxy / Woven Glass 20, 21, 22, 23, 24, 26, 27, 82, 83, 92, 93, 94, 95, 97, 98, 99, 101, 121, 122, 124, 125, 126, 127, 128, 129, 130, 131

IPC-4101D Material Composition Keywords All Appropriate Specification Sheets Epoxy / Woven Glass / Nonwoven Glass 12, 16, 81 Epoxy / Woven Glass / Paper 10, 15, 80 Phenolic / Paper 00, 01, 02, 03, 05 Polyester / Glass 13 Polyester / Woven Glass / Nonwoven Glass 11 Polyimide / Epoxy / Woven Glass 42 Polyimide / Nonwoven Aramid 53 Polyimide / Woven Glass 40, 41 Polyimide / Woven Quartz 60 PPE / Woven Glass 90, 91, 96, 102

Description or Application Keywords IPC-4101D Description or Application Keywords All Appropriate Specification Sheets Additive / Semi-Additive 80, 81, 82, 83 Composite 10, 11, 12, 14, 15, 16 Consumer Electronics 00, 01, 02, 03, 04, 05, 10, 11, 12, 14, 15, 16, 80, 81, 82, 83 Crossplield Unidirectional 27, 54 Double-Sided 12, 14, 16, 81 Heatsink Application 31, 32, 33 Lead-Free FR-4 99, 101, 121,122, 124, 125, 126, 127, 128, 129, 130, 131 Lead-Free Non-FR-4 16, 102, 103 Microvia 53, 55, 58 RoHS

IPC-4101D ANSI or Military Keywords All Appropriate Specification Sheets CEM-1 10, 15, 80 CEM-3 12, 14, 16, 81 CRM-5 11 FR-1 02 FR-2 03, 05 FR-3 04 FR-4 21, 24, 26, 27, 82, 83, 92, 93, 94, 95, 97, 98 FR-5 23 G-10 20 G-11 22 XPC 00 XXXPC 01 GFN 21 GFT 26, 28 GPY 30, 40, 41, 42

IPC-4101D RoHS RoHS RoHS Material Property Keywords All Appropriate Specification Sheets CAF Resistance 29, 30, 61, 70, 71, 102, 126, 129, 130, 131 High Td (Decomposition Temp) 99, 124, 125, 126, 128, 129, 130, 131 High Reliability 40, 41, 42 Hot Flex Strength 22, 23 Low Dk / Df 13, 25, 50, 53, 54, 55, 58, 61, 70, 71, 90, 91, 96, 102, 103 Low Halogen Content 05, 14, 15, 58, 92, 93, 94, 95, 96, 122, 125, 127, 128, 130, 131 Low X / Y CTE 50, 53, 54, 55, 58, 60, 61, 70 Low Z-axis CTE 99, 101, 102, 121, 122, 124, 125, 126, 127, 128 129, 130, 131 Non-Flame Retardant 20, 22 Thermally Conductive 31, 32, 33 RoHS RoHS RoHS

IPC-4101D RoHS Material Modifier Keywords All Appropriate Specification Sheets Fillers 10, 11, 12, 13, 14, 15, 16, 31, 32, 33, 40, 41, 42, 80, 81, 82, 83, 97, 98, 99, 101, 102, 103, 126, 127, 128, 130 Multifunctional Epoxy 24, 55, 83, 94, 95, 98 RoHS

Early & New Curing Agents Dicy Dicyandiamide. Cure system for epoxy launched in 1970s. Replaced ”Novolac” Phenolic cure system . The reason was that ”Novolac” miss colored the laminate. Used in standard FR-4 base material. 13

Early & New Curing Agents Non-Dicy The “old” Phenolic (Novolac) cure system. Reintroduced due to RoHS! Improves the Thermomechanical parameters for the laminate: Higher Tg and Td. Lower Overall CTE. Used in FR-4 base material suitable for Lead Free processes. RoHS 14

Early & New Curing Agents Filler Talc [Mg3Si2O10(OH)2] But can be something else; often proprietary Fillers more heavily used due to RoHS! Improves the Thermomechanical parameters for the laminate: Lower overall CTE Higher Td Used in FR-4 base material suitable for Lead Free processes. RoHS 15

IPC-4101D Specification for Base Material Cupper foil thickness. Thickness tolerances. Overview Tables. Specification Sheets for Base Laminates (66 separate base Materials) 17

IPC-4101D

Important Parameters for Base Materials Tg = Glass transition temperature Td = Degradation temperature T260 = Time to delaminating at 260˚ C T288 = Time to delaminating at 288˚ C CTE = Coefficient of Thermal Expansion 20

Tg = Glass Transition Temperature

Glass Transition Temperature Tg ( PCB Laminates) Z-axis Expansion 280 ppm Effects of Entrapped Moisture in PCB !!! Expans Ion P/ P M Z Tg Tg a1 Tg Reduction from 10 to 30°C depending on PCB material, fabric,Cu % a1 Glass Epoxy Laminate FR4 Tg ~125˚C Warping of PCB and Substrate of P-BGA < 60 ppm 0˚C 50˚C 100˚C 150˚C 200˚C 250˚C 300˚C

PCB Moisture Absorption – Additional issue Since moisture acts as a plasticizer, it reduces the Glass Transition Temperature Tg (- 10 to 30°C), effects on CTEz, which in turn increases stresses on PCB features such as Plated Tthrough-Holes (PTH), and the same for P-BGA substrate (ie. FR4, BT), etc.. Room Temperature Expansion After Tg

CTE = Coefficient of Thermal Expansion

RoHS

Temp over Tg gives high CTE CTE Cu = 15 ppm/ºC Nu har ett pläterat hål färdigt för montering och lödning skapats. CTE FR-4 in z-axis  250-300 ppm/ºC over Tg CTE FR-4 in z-axis  50-60 ppm/ºC under Tg 28

Influence of CTE SAMPLE A

How many PTH do you have in your PCB?

What is the Result? What is the consequence of the Base material in the Reflow process? What is the Result?

FR4 ? IPC-9691A IPC-4562A IPC-4563 IPC-4121 IPC-4101D DATA from CAM FR4 IL FR4 BFR Free DATA from CAM FR4 High Tg FR4

CAF Conductive Anodic Filament

How does it look like in the real world? Regarding CAF

CAF – Example RoHS? Conductive Anodic Filament = Electrochemical reaction between copper anode and cathode Formation of copper filaments (Electro migration) RoHS?

Resin Bonding zone Cu Cu Glass fabrics

Resin Glass fabrics Humidity is absorbed in the PCB Bonding zone Cu Cu Glass fabrics After some time a humidity layer is formed by time

Conductive Anodic Filament CAF Bad Drilling, Bad Hole Metallization, PTH Voids, Laminate Blistering, ecc, together with Moisture and DC Power, easy to have CAF Formation  Power DC  Cathode (-) Anode (+) CAF Cu salts OH- ions H+ions H2O PTH - PTV Walls Cu Cu Fabric Fiber Glass plus Resin Moisture (H2O) and Ionic Impurities - pH

CAF Formation and Growing Mechanism Anode (+) DC Power Catode (-) Cu Cu H2O Moisture H+ions OH- ions Cu salts CAF Fiber Glass Epoxy resin

A SEM micrograph illustrating the type of catastrophic failure that can be caused by CAF + 20 Volt Power Plane Component Through Hole CAF

PCB Moisture Absorption Moisture can cause : Interfacial degradation resin-fiber glass (and moisture).can result in a reduced Time To Failure (TTF) due to ..Conductive Anodic Filament Formation (CFF) (CAF). Demand for laminate and PCB material CAF Resistant is Growing as the Lead Free and HDI Technology has an increased market .

IPC User Guide for the IPC-TM-650 IPC-9691A 2.6.25 Conductive Anodic Filament (CAF) Resistance Test (Electrochemical Migration Testing)

FR4 ? IPC-9691A IPC-4562A IPC-4563 IPC-4121 IPC-4101D DATA from CAM FR4 IL FR4 BFR Free DATA from CAM FR4 High Tg FR4

Practical Advice You need an IPC Checklist!!