首页资源分类PCB layout > 电路板阻抗介绍

电路板阻抗介绍

已有 445110个资源

下载专区

文档信息举报收藏

标    签:PCB阻抗阻抗计算叠层

分    享:

文档简介

si9000 阻抗叠层 线宽线距 软件的使用介绍!!!!!!!!!

文档预览

How is a PCB made ? What determines impedance ? www.polarinstruments.com Version IIa Manufacturing Processes Manufacturing Processes for a Multi-layer PCB The following presentation covers the main processes during the production of a multi-layer PCB. The diagrams which follow represent a section through a 6 layer PCB, as indicated in red. Tracks under solder mask Via hole SMD Pad Section through PCB 2 www.polarinstruments.com Typical Layer Construction - 6 Layer PCB Manufacturing Processes Copper Laminate Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 3 FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • Layer build / stackup is one of the most important aspects of controlled impedance • Many combinations of material thickness and copper weights can be used. • PCB Fabricators manufacturing techniques vary www.polarinstruments.com Inner Layer Processing – Material Selection Copper Laminate (Dielectric) Manufacturing Processes Layer 2 (Inner) Layer 3 (Inner) 4 Impedance Considerations • Selecting inner layer Core Core materials is very important when using embedded microstrip and offset stripline structures • Inner layer Core materials are usually processed as “Layer pairs” www.polarinstruments.com Laminating and Imaging of Internal Layers UV sensitive film is laminated over top and bottom surfaces of the Core Areas of the Core where no copper is required are left exposed Layer 2 (Inner) Layer 3 (Inner) Core Manufacturing Processes Impedance Considerations • Does not effect impedance 5 www.polarinstruments.com Etch Process - Remove Exposed Copper Copper Removed Manufacturing Processes Layer 2 (Inner) Layer 3 (Inner) 6 Impedance Considerations • The etch process produces Core an ‘etch back’ or undercut of the tracks. This can be specified by the W1 / W2 parameters • This means that tracks will end up approximately 0.025 mm (0.001”) thinner than the original design. www.polarinstruments.com Remove Laminating Film Manufacturing Processes Layer 2 (Inner) Layer 3 (Inner) 7 Impedance Considerations • Does not effect impedance Core www.polarinstruments.com Completed Inner Layer Core All inner layer Core materials are processed as “Layer Pairs” prior to Bonding At this stage the Cores are inspected visually (AOI) and defective Cores rejected Sometimes a surface treatment is applied to the Cores to aid with the Bonding process Layer 2 (Inner) Layer 3 (Inner) Core Manufacturing Processes Impedance Considerations • Does not effect impedance 8 www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 9 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 10 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 11 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 12 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 13 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 14 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 15 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 16 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 17 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 18 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Layer stackup Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 19 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Bonding – Heat Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 20 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Bonding – Multilayer Press Layer 1 (Outer) Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 21 Manufacturing Processes FOIL PRE-PREG INNER LAYER PRE-PREG INNER LAYER PRE-PREG FOIL Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Bonding – Multilayer Press Layer 2 (Inner) Layer 3 (Inner) Layer 4 (Inner) Layer 5 (Inner) Layer 6 (Outer) 22 Manufacturing Processes Impedance Considerations • During the Bonding process, press temperature and pressure have a great influence on substrate heights, which greatly affects impedance. • It is important to use the Finished Post-Processed height when calculating Impedance www.polarinstruments.com Bonding – Multilayer Press Manufacturing Processes Photo © Robert Bürkle GmbH www.buerkle-gmbh.de 23 www.polarinstruments.com Drilling of Bonded Panel Copper Laminate Drilled Hole Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 24 Manufacturing Processes Impedance Considerations • Drilling itself does not effect impedance www.polarinstruments.com Electroless Copper Process Addition of Copper to all Exposed Surfaces Copper Drilled Hole Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 25 Manufacturing Processes Impedance Considerations • Electroless copper effects copper thickness on outer layers (T1) • Sometimes other solutions are used containing carbon, etc. www.polarinstruments.com Laminating and Imaging of External Layers UV sensitive film is laminated over top and bottom surfaces of PCB It is then exposed and developed, leaving an exposed image of the PCB pattern Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 26 Copper Manufacturing Processes Impedance Considerations • Does not effect impedance www.polarinstruments.com Electro-plating Process 1 Additional Copper to all Exposed Surfaces Laminated Film Plate Additional Copper Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 27 Manufacturing Processes Impedance Considerations • Electro-plating increases the copper thickness on outer layers (T1) • There will always be variations in the amount of copper added. • This finished copper thickness should be used in structure calculations www.polarinstruments.com Electro-plating Process 2 Add Tin over Exposed Copper Areas Laminated Film Additional Copper Tin Plating Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 28 Manufacturing Processes Impedance Considerations • Does not effect impedance www.polarinstruments.com Electro-plating Process 3 Remove Laminated Film Laminated Film Removed Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 29 Tin Plating Manufacturing Processes Impedance Considerations • Does not effect impedance www.polarinstruments.com Etch Process - Remove Exposed Copper Copper Removed Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 30 Tin Plating Manufacturing Processes Impedance Considerations • The etch process produces an ‘etch back’ or undercut of the tracks. This can be specified by the W1 / W2 parameters • This means that tracks will end up approximately 0.025 mm (0.001”) thinner than the original design. www.polarinstruments.com Tin Strip - Remove Tin Plating Manufacturing Processes Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 31 Tin Plating Removed Impedance Considerations • The removal of tin will slightly reduce the copper thickness (T1) on the outer layers www.polarinstruments.com PCB is now complete except for surface finishes and panel routing Layer 1 Tracks Via Hole Layer 6 Manufacturing Processes SMD Pad Tracks 32 www.polarinstruments.com Solder Mask Application - Curtain Coated Method Layer 1 Apply Liquid Photo-Imageable Resist, then dry Layer 6 33 Manufacturing Processes Impedance Considerations • Some PCB fabricators chose to check the impedance before the solder mask is added • Structures can be checked in Normal and Coated mode • Thickness of solder mask should be specified using C1 and C2 www.polarinstruments.com Solder Mask Application Image, Develop and Cure Layer 1 UV Image, Develop and Cure Layer 6 34 Manufacturing Processes Impedance Considerations • Does not effect impedance www.polarinstruments.com Surface Finish Process Layer 1 Apply Solder to Exposed Copper Areas Layer 6 35 Manufacturing Processes Impedance Considerations • Surface Finish (Tin / Lead / Gold / Silver) is usually only added to pads • If board has no solder mask the thickness of finish should be added to T1. www.polarinstruments.com Component Notation SCL2 9624 R34 IC3 36 Manufacturing Processes Impedance Considerations • Does not effect impedance www.polarinstruments.com Routing (includes second stage drilling) Manufacturing Processes Impedance Considerations • Controlled Impedance coupons are routed from the panel • Good controls are necessary to ensure that coupons can be matched to manufacturing panels 37 www.polarinstruments.com Process finished PCB and coupons for testing Manufacturing Processes Coupons Impedance Considerations • It is good practice to place TDR coupons in the “X” and “Y” axis of the manufacturing panel to ascertain any process variations due to spray patterns when using horizontal conveyorised equipment. 38 www.polarinstruments.com Process finished PCB and coupon for testing Manufacturing Processes Impedance Considerations • Controlled Impedance coupons are routed from the panel • Controls are necessary to ensure that coupons can be matched to manufacturing panels — this should be performed on trial panels prior to production ramp up. 39 www.polarinstruments.com Why as a designer do you need to discuss your design with your PCB fabricator? Manufacturing Processes PCB manufacture is a process, it uses materials which are not “ideal” FR4 for example is a glass resin mix made of two substances with differing electrical properties. PCB Manufacturers need to make small adjustments to designs to maximise yields 40 Impedance Considerations • Glass Er 6 • Resin Er 3 (FR4) • Resin Er < 3 (High performance laminates) www.polarinstruments.com Why as a designer do you need to discuss your design with your PCB fabricator? Manufacturing Processes Process varies from one fabricator to another. Press pressures temperatures may vary Prepreg and core may vary from one supplier to another. Impedance Considerations • Supplier variations 41 www.polarinstruments.com Polar tools to assist in layer stackup: SB200a PCB Stackup design system Manufacturing Processes 42 www.polarinstruments.com Polar tools to assist in impedance prediction: Si8000m Controlled impedance design system Manufacturing Processes 43 www.polarinstruments.com For more information please visit: www.polarinstruments.com Your contacts at Polar: USA Software sales: Ken Taylor (503) 356 5270 USA Equipment sales: Richard Smith (650) 344 1416 UK / Europe: Neil Chamberlain +44 23 9226 9113 Asia / Pacific: Amit Bhardwaj +65 6873 7470 ©2006 Polar Instruments

Top_arrow
回到顶部
EEWORLD下载中心所有资源均来自网友分享,如有侵权,请发送举报邮件到客服邮箱bbs_service@eeworld.com.cn 或通过站内短信息或QQ:273568022联系管理员 高进,我们会尽快处理。