Upload
craig-myers
View
3.295
Download
3
Embed Size (px)
DESCRIPTION
Choosing the right PCB laminate is key to a quality product, You must consider application, assembly techniques, etc. But don't get caught by the "latest & greatest" fad. Make sensible decisions and save yourself money without compromising quality.
Citation preview
PCB LaminatesWhat you need to know!
What Is It?
Components•Core•Pre-Preg•Foil
Vendor Datasheet• Thickness• Glass Weave
What Is It?
• Fiberglass Reinforced Epoxy
High Speed vs. Glass Weave
The “Players”
• USA
• Asia
The “Choices”
*Isola’s Product Ladder
The “Choices”
• FR-4 - Flame Retardant Class 4
• DICY Epoxy
• Modified DICY Epoxy
• Fillers
• Low Loss
• Halogen-Free
• Others
• PTFE, LCP, Polyamide, CEM
Properties
• Tg - Glass Transition Temperature
• Td - Decomposition Temperature
• CTE - Coefficient of Thermal Expansion
• Dk - Dielectric Constant
• Df - Dissipation Factor
• Moisture Absorption
• Flammability
• Anti-CAF - Conductive Anodic Filament
Physical Properties
• Glass Transition Temperature (Tg)
Physical Properties
• Decomposition Temperature (Td)
Physical Properties
• Effects of Multiple Lead-Free Cycles
Anti-CAF?
Lead-Free Failures
Electrical Properties
• Dielectric Constant (Dk)
Electrical Properties
• Dissipation Factor (Df)
Why Do We Care?
• Lead-Free Assembly
• Higher Layer Counts
• Smaller Feature Sizes
• Faster Edge Rates
How Do They Stack-Up?
PCB Categories
• Lead Assembly
• 2L Lead-Free Assembly
• ≥4L Lead-Free Assembly
• ≥4L Lead-Free Assembly (High Speed)
• RF (>2GHz)
Lead Assembly
• Traditional Epoxy System (/21)
• I.e. Nan Ya NP-140
• I.e. TLM TLM-140
• Meets Customer Tg≥135˚C Requirement
• Low Cost Materials (~0.8x)
• Easy to Manufacture
2L Lead-Free Assembly
• Modified Epoxy System (/101 /121)
• I.e. Nan Ya NP-140M - NOT NP-140!
• I.e. TLM TLM-140(mt)
• Pb-Free Compatible Materials
• Low Risk for Z-Axis CTE Failures
• Low-Medium Cost Materials (~0.9x)
• Easy to Manufacture
≥4L Lead-Free Assembly
• Modified & Filled Epoxy System (/99 /126)
• I.e. Nan Ya NP-175F - NOT NP-170!
• I.e. TLM TLM-170(t)
• Pb-Free Compatible Materials
• Anti-CAF
• Low CTE Z-Axis Expansion
• Medium Cost Materials (~1.0x)
• Difficult to Manufacture
• Routed NOT Punched!
High Speed & RF
• Modified & Filled Epoxy Systems (/29 /129)
• I.e. Isola FR408HR
• I.e. Nelco N4000-SI
• I.e. Panasonic Megtron4
• Same as ≥4L Lead-Free Assembly, But Lower Dk/Df c/o Specialty Fillers
• Higher Cost Materials (~1.8x)
• Difficult to Manufacture
• Other Important Considerations
Discussion
• HATS Testing
• Define Qualified Materials in PCB Specification
• Specify as IPC-4101 Slash Sheet
• More Engineering Consideration
• USA vs. Asia Materials
• Vendor Portability
• Customer Communication
• Cost vs. Quality