Introduction of PCB April 4 th 2016 Seo

Introduction of PCB April 4 th , 2016 Seo, Dong-yoon SKKU EMC Laboratory

Agenda ■ Intro ■ PCB Type ■ PCB Material Ø Cu foil, PPG, CCL, PSR ■ PCB Structure Ø PCB Stack-up, PCB Hole ■ PCB Manufacture Process Ø Process, Key parameter ■ PCB Specification ■ Q&A 2

Intro ■ PCB History 3 Source : https: //www. hsdgt. com/pcb/history. asp

Intro ■ PCB ? Ø Printed Circuit Board Ø Purpose ü Complicated Circuit’s Transmission Line Microstrip or Stripline ü Simplify, High Integration, High Efficiency, Small form factor, … Ø Application ü Nearly every electronic device ü Examples PKG Substrate PCB Samsung DDR 3 SODIMM (designed by DY. SEO) i. Phone 6 PCB i. Phone 5 s PCB Intel Server Main Board PCB 4

PCB Type ■ General Criteria of PCB type Ø Number of Layer / Flexibility / Material of PCB. Ø Embedded PCB Technology will be involved additionally. Layer Flexibility Material Single Side PCB Rigid PCB Epoxy PCB Double Side PCB Flexible PCB Teflon* PCB - High frequency - High cost Multi Layer PCB Rigid-Flexible PCB Polyimide PCB - Good Flexibility B. T PCB Metal core PCB Multi Layer PCB Rigid-Flexible PCB - Main - Glass fiber + Resin - Bismaleimide/ Triazine - Good Heat Radiation - Al + Tpreg + Cu * Teflon은 불소와 탄소의 강력한 화학적 결합으로 인해 매우 안정된 화합물을 형성 5

PCB Material (1/4) ■ Copper foil Ø Signal pattern, power plane, SMD pad Ø Unit of Copper foil thickness = Ounce (? ) ü 1 oz : 28. 3495 g / 1 ft x 1 ft = 305 g /1 M× 1 M = 35㎛ ■ PPG (Pre-preg) Ø Thermosetting resin + Glass fiber (and so on) SHEET of B STAGE (B STAGE : semi hardening state of resin ) Ø Type of PPG (1) Glass fiber Type Resin Contents Glass size Number of Fiber / inch 2 Thickness after Press 1080 62 ± 2 % 50. 8 ㎛ 60 X 47 60 ~ 70 ㎛ 2116 52 ± 2 % 101. 6 ㎛ 60 X 58 110 ~ 120 ㎛ 7628 42 ± 2 % 170. 1 ㎛ 42 X 32 180 ~ 190 ㎛ 6

PCB Material (2/4) ■ PPG Ø Type of PPG (2) ü Main Volume : FR-4 Resin Stiffness material Description FR-2 Phenol Paper ≒ FR-1 FR-3 Epoxy Paper FR-4 Epoxy Glass fiber Tg 125~135°C FR-5 Epoxy Glass fiber Hi Tg 150~160°C CEM-1 Epoxy Paper ≒ FR-1 (Less smell) CEM-3 Epoxy Non-woven glass fiber ≒ FR-4 (Low cost) ü Data sheet of FR-4 (DS-7402 Halogen Free) Glass transition temperature Coefficient of Thermal Expansion Global Er = Glass fiber + Resin * Er Example Glass fiber Er : 6. 2 Resin Er : 3. 6 7 Source : http: //www. doosanelectronics. com/common/pdf/catalog/DS-7402. pdf

PCB Material (3/4) ■ CCL Ø Copper Clad Laminate Ø Copper foil + Prepreg + Copper foil 1860 nm Treated side 407 nm Shiny side Laminate with Copper Foil Ø Panel design is important to improve the PCB productivity. 8

PCB Material (4/4) ■ PSR (or Soldermask) Ø Photo imageable Solider Resist Ø Purpose ü Protect the outer layer copper (signal pattern and power plane). ü Form the SMD/NSMD pad • • SMD (Solder Mask Defined Pads) NSMD (Non-Solder Mask Defined Pads) Ø PSR ink type ü Screen type • Coating goes well and because developing solution uses alkali aqueous solution, problem of environmental pollution is less and is excellent. It is suitable for various kinds Finish Treatment (HASL, ENIG, Tin Plate, OSP, etc). ü Spray type • Good Productivity, Uniform coating thickness. Pad definition Source : http: //taiyoink. co. kr/catalogue. pdf Various color of PSR 9

PCB Structure (1/2) ■ PCB Stack up Ø (IPC 6012) 1. 3. 2 Board Type Printed boards without plated-through holes Type 1 and with plated-through holes Types 2 -6 are classified as follows: ü ü ü Type Type 1—Single-Sided Board 2—Double-Sided Board 3—Multilayer board without blind or buried vias 4—Multilayer board with blind and/or buried vias 5—Multilayer metal core board without blind or buried vias 6—Multilayer metal core board with blind and/or buried vias Ø Configuration of multi layer PCB Preferred Method ü Example for 6 -Layer 3 CCL + 2 PPG + 0 Cu foil 2 CCL + 3 PPG + 2 Cu foil 10 Source : http: //www. eupcb. com/2011/upfile/IPC%206012%20 Standard. pdf

PCB Structure (2/2) ■ PCB Holes Ø Purpose ü Interconnect layers Via ü Mechanical support for PCB manufacturing or SMT Assembly Tooling hole Ø Cu Plating difference Ø Drilling method Ø Interconnection method Term ACRONYM None Plated Through Hole NPTH Plated Through Hole PTH Interstitial Via Hole IVH Blind Via Hole BVH Buried Via Hole (BVH) LASER Via Hole LVH Stacked Via - Staggered Via - Skipped Via - : Plated vs None plated : Mechanical hole vs LASER hole : Full layer vs Partial layer Skipped Via Staggered Stacked Via IVH 11

PCB Manufacture Process (1/3) ■ Process for Multi layer Ø General process ü Step 10 (DF striper) and 11 (Etching) are swapped at below table. ü Step 12 (PSR) has DRY FILM process for PSR patterning like copper etching process. ü Step 14 is surface finish process. • ENIG / OSP / HSAL / EPENIG … 12 Source : https: //www. hsdgt. com/3 D/index. html

PCB Manufacture Process (2/3) ■ Key Parameter Ø Aspect ratio ü Aspect ratio is the ratio between the thickness of the board and the size of the drilled hole before plating. ü According to the aspect ratio, the plating method will be changed. Term DC Plating Reverse Pulse Plating Hole height (PCB Thickness) ~ 2. 0 mm ~ 8. 4 mm Drilled hole size 0. 2 ~ 0. 35 mm 0. 2 ~ 0. 3 mm Aspect ratio ~8 6 ~ 20 Plating method 13

PCB Manufacture Process (3/3) ■ Key Parameter Ø Etching factor @ Copper ü Etching factor is the ratio between the Cu thickness (V) and side attack of Cu (X). ü Higher is better. Ø Throwing power @ Electroplating ü Throwing power is a measure of an electroplating solution's ability to plate to a uniform thickness over an irregularly shaped cathode. 14 Source : https: //www. corrosionpedia. com/definition/1090/throwing-power

PCB Specification (1/2) ■ IPC (The Institute for Interconnecting and Packaging Electronics Circuits) Ø The industry association for printed circuit board and electronics manufacturing service companies, their customers and suppliers ■ ROHS(Restriction of Hazardous Substances) * 전기전자제품 유해물질 사용제한 지침 Ø Do not use ‘Lead, cadmium, mercury, chromium’. 15 Source : https: //vanderby. web. cern. ch/vanderby/dem/images/technology/IPC/Spec. Tree. jpg

PCB Specification (2/2) ■ UL (Underwriters Laboratories Inc) * 소비용품의 안정성을 확보 및 소비자를 보호하기 위해 운영하는 인증제도 Ø Leading product safety testing and verification organization in US. Ø UL certifies, validates, tests, verifies, inspects, audits, advises and educates. Ø FLAMMABILITY STANDARD (EX. SAMSUNG MEMORY MODULE 94 V-0) You can see this logo at PCB UL Logo 16 Source : http: //korea. ul. com/wp-content/uploads/sites/29/2014/08/UL_plastic. pdf

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