1SMT PROCESS SPECIFICATION 2CONTENTS1 SHIPPING, STORAGE and PRODUCTION ENVIRONMENT ...................................................... 41.1 General.................................................................................................................................. 41.2 General shipping and storage conditions ............................................................................... 51.3 Storage and handling conditions for solder paste .................................................................. 61.4 Storage and handling conditions for printed wiring boards [PWBs] ........................................ 61.5 Storage conditions for underfill epoxy materials ..................................................................... 71.6 Shelf life time for different component categories .................................................................. 81.6.1 Expired material handling................................................................................................ 81.7 Moisture sensitivity levels....................................................................................................... 81.8 Drying (baking) moisture sensitive devices ............................................................................ 91.8.1 Drying (baking) restrictions ............................................................................................. 91.9 DRY STORAGE CONDITIONS............................................................................................ 102 STENCIL PRINTING PROCESS SPECIFICATIONS ................................................................. 112.1 Paste specification ............................................................................................................... 112.2 Squeegee ............................................................................................................................ 122.3 Stencil.................................................................................................................................. 122.4 Support tables...................................................................................................................... 132.5 Printing process parameters (stencil printing) ...................................................................... 132.6 Print result validation............................................................................................................ 143 Process control and monitoring .................................................................................................. 153.1 Automated Optical Inspection, AOI ...................................................................................... 153.2 Location of the machine in the production line ..................................................................... 153.3 Utilization of inspection results ............................................................................................. 153.4 Component and paste alarm limits....................................................................................... 163.5 Specification limits for capability analyses............................................................................ 174 PLACEMENT PROCESS SPECIFICATIONS............................................................................. 184.1 Nozzles................................................................................................................................ 184.2 Feeders................................................................................................................................ 184.3 NC-Programs....................................................................................................................... 184.4 Part Data / Vision processing............................................................................................... 194.5 Placement process management data compatibility table.................................................... 195 Dipping process ......................................................................................................................... 205.1 Dipping flux specification and handling instructions ............................................................. 205.1.1 Storage and handling instructions................................................................................. 205.1.2 Flux specifications......................................................................................................... 205.2 Dipping process specifications ............................................................................................. 215.2.1 Dipping device .............................................................................................................. 215.2.2 Dipping process parameters ......................................................................................... 216 Reflow soldering profile measurement ....................................................................................... 226.1 Profile measurement equipment .......................................................................................... 226.2 Reflow profile measurement method with standard calibration board .................................. 227 Standard, lead containing soldering process .............................................................................. 237.1.1 Recommended reflow oven settings ............................................................................. 248 Lead free soldering process ....................................................................................................... 258.1 Reflow profile definition for Pb-free process......................................................................... 258.2 General Pb-free reflow soldering profile specification .......................................................... 268.3 Basic profile specification for standard calibration board in Pb-free process ........................ 278.4 Start-up settings for Pb-free process ................................................................................... 298.5 Reflow profile measurement on product PWBs.................................................................... 3039 UnderfiLl process ....................................................................................................................... 319.1 General................................................................................................................................ 3110 NK ACA SMT Process Specification .................................................................................... 3310.1 ACA Technology Introduction ........................................................................................... 3310.2 ACA Process.................................................................................................................... 3310.3 Anisotropic Conductive Film ............................................................................................. 3510.3.1 ACF Material Specification ........................................................................................ 3510.3.2 ACA Process Parameters.......................................................................................... 3610.3.3 Cooplanarity measurement ....................................................................................... 3710.3.4 Measurement of bond line temperature ..................................................................... 3710.3.5 Interposer .................................................................................................................. 3810.4 ACA Storage Conditions................................................................................................... 3810.5 Interconnection Area Designing for Hitachi Chemical AC-2056T-45 ACF......................... 3910.6 Bonding Force Calculation................................................................................................ 4011 MANUAL SOLDERING PROCESS AND WORKMANSHIP CRITERIA ................................ 4112 Specifications for visual inspection; error criteria, faults classification and training material .4113 Related Documents ............................................................................................................. 4141 SHIPPING, STORAGE AND PRODUCTION ENVIRONMENT1.1 GeneralGlobal NK Workplace Resources (NWR) organization specifies and takes care of general environmental conditions in material storage and factory hall, containing:-heating-ventilation-air conditioning-water/sewage-fire extinguishing systems-cooling-special HVAC (vacuum, soldering exhaust etc.)-electrical & ESD protectionSpecial process related matters like local machine/process step related filtering, lightning; AC and ESD protection should be take care by Time Zones and factories. Environmental conditions should be continuously monitored. Longer than four hour weighted average out-of-specification situations should trigger corrective actions.If tighter conditions are required or if these specifications/limits can’t be remain local air conditioning (AC) systems like cooler/heater and laminar flow cabins must be used.More detailed and up-to-date environmental specifications can be found from Global NK Workplace Resources Intranet pages.51.2 General shipping and storage conditions Expected shipping conditions (components and materials) 1Relative humidity RH 15 % - 70%Temperature -5°C...+40°CGeneral NK Storage conditions 2Relative humidity RH 10%-70%Temperature Temperature 15°C - 30°C 3Component packing level Components must be at least in the first level, so called intimate delivery packing:- MBB (Moisture Barrier Bag) for humidity sensitive components- ESD (Electro Static Discharge) protective packing- Air flow preventive plastic packing (vacuum or not, but tightly closed)- Cardboard box if nothing of above mentioned packing are usedGeneral storage requirementsMaterials are not allowed to be stored:- in direct sun shine, not even through windows- close to heater/cooler/humidifier/light source- close to outdoors so that temperature/humidity limits are repeatedly exceeded NK production conditionsRelative humidity 35%-55%Temperature 20.5°C – 26.5°C1 External environment. Materials should be packed so that special requirements like maximum temperatures for underfill epoxy is not exceeded. Solder paste has it’s own specified shipping condition.2 . Look special storage conditions for solder paste and underfill epoxy below3 Components, esp. those having high mass (e.g. PWBs), should reach factory room temperature before entering process.61.3 Storage and handling conditions for solder pasteSolder paste storage and handlingStorage temperature Refrigerator, 0… 8 ?C or paste specific requirementsShelf storage time 6 months max.Storage time in room temperature General: 4 weeks (T= 20,5 - 25°C),Alpha Metals OM 338T: 2 weeksStabilization time before usage 4 hoursEnvironment in shipping Temperature +5…+25 ?CHandling instructions Do not store cartridges nozzle-end upPaste should warm up in room temperature without extra heating at least 4 hoursDo not put paste into refrigerator if it has reach room temperature1.4 Storage and handling conditions for printed wiring boards [PWBs]PWB delivery, handling and storage conditionsDelivery package and storageAir evacuated (vacuum) Moisture Barrier Bag (MBB) according EIA-583 class 2, 50 panels/bag, all from same manufacturing lot.X-out marked panels should be packed separately and marked according separate documentHumidity Indicator Card (HIC), 5 levels, on the top of PWB stackDesiccant optional, must be placed so that panels don’t bendIncoming inspectionCheck that MBB is not broken or HIC reading is ?40% RHActions if NOK:-return to vendor or-bake in 60 ?C, 5 hours, RH ?5%, soldering within 24 hoursShelf time Look table below . Panels must be stored on flat shelf to prevent warpage(see section 1.5)Open time for bare PWBsNiAu plating: Soldering within 48 hoursOSP plating: floor life limit 48 hours, time between solderings 24hCleaning/ washing Not allowed71.5 Storage conditions for underfill epoxy materialsMaterial name and typeLoctite 3593 Emerson&Cuming E 1216Material Codes 7520029 (30 cc, 30 ml)7520025 (55 cc, 50 ml)7520031 (6 oz, 150 ml)7520027 (20 oz, 500 ml)7520033 (30 cc, 30 ml)7520035 (55 cc, 50 ml)7520037 (6 oz,150 ml)7520039 (20 oz, 500 ml)Max transportation timeGoods must be received within 4 days after shipmentGoods must be received within 4 days after shipmentPackage type Syringe, EFD compatible 6 oz or 20 oz only available at the momentSyringe, EFD compatible 50 cc, 6 oz or 20 ozStorage condition Syringes must be transferred immediately from transportation package to intermediate storage cartridges tip down (freezer/refrigerator -20 ?C - +8?C)Following items must be recorded:- product type, package size- color (black) without deformation- lot number- date of shipment- amount of coolantSyringes must be transferred immediately from transportation package to intermediate storage cartridges tip down (freezer, -20 ?C)Following items must be recorded:- product type, package size- color (black) without deformation- lot number- date of shipment- amount of dry iceMax storage time 6 months @ -20?C - +8?C 6 months @ -20 ?C Stabilization time before usageMaterial should reach room temperature before usage3 h for 6 oz cartridgePot life 5 weeks @ +25?C 5 days @ +25?C1.6 Shelf life time for different component categoriesTable below specifies shelf time at NK or NK’s suppliers storages starting from the date when material is received. Elapsed time between component manufacturing and receiving at NK is not 8calculated. General maximum shelf time is 12 month. Semiconductor packing materials should fulfill NS025 and EAI-583 & JESD625 standards and FIFO- principle should be applied.Component type Component intimate package Shelf timeGeneral for all components if not otherwise stated on delivery packageOpen shelf, components in their intimate delivery package12 monthPrinted Wiring Boards (PWBs) Vacuum package with dryer 6 monthsComponents having silver plated terminations packed into MBBComponents should be packed into vacuum package with dryer6 monthsComponents having silver plated terminations in cardboard box or open plastic bagLonger storage time, if components are not packed into vacuum package will destroy solderability and affect to reliability3 months1.6.1 Expired material handlingIf above-mentioned shelf times are exceeded material is not allowed to be used in normal production1.6.1.1 Handling of waist solder pasteExpired, defective or waist solder paste material is environmentally harmful and it should be handled according ISO14001 and local/global EMS (Environmental Management System) instructions and directives.1.7 Moisture sensitivity levelsNK applies following JEDEC moisture sensitivity level classification:FLOOR LIFELEVELTime Conditions1 Unlimited ?30?C/85% RH2 1 year ?30?C/60% RH2a 4 weeks ?30?C/60% RH3 168 hours ?30?C/60% RH4 72 hours ?30?C/60% RH5 48 hours ?30?C/60% RH5a 24 hours ?30?C/60% RH6 Time on Label (TOL) ?30?C/60% RH1.8 Drying (baking) moisture sensitive devices9The components that typically are moisture sensitive are PWBs, semiconductors, especially CSP packages, most optical devices (IR modules, all LEDs), special plastic capsulated integrates structures (power devices, RF power amplifier, packages including polyimide tape or equivalent (FR-4) substrates).JEDEC MSL level is marked on components intimate packing. If component has been in open environment longer that MSL level specifies it should be baked before useage.The purpose of baking is to decrease the amount of humidity from plastic packages prior soldering. As absorbed water inside package vaporizes during reflow soldering, internal vapor pressure can cause cracks and other, visible or hidden, damages like delamination. This is commonly known as Popcorn phenomenon. Note standards and instructions for moisture sensitive components regarding protective packing in shipping and storage together with this specification.NK applies IPC/JEDEC J-STD-033A Bake Conditions for drying SMD's packed into T&R:Bake @ 40 ?C, RH15 min), if more than 50% of paste volume is refilled or after paste collection together outside squeegee area paste should be kneeded122.2 SqueegeeProperty SpecificationSqueegee blade materialNi or Titanium plated stainless steel with adequate stiffness for high speed printing.Thickness 275? 10 ?mSqueegee holder angle* (critical parameter)60° ? 2.5°Squeegee width for DEK&MPM and equivalent printersPanel length rounded up to closest std widthPaste retainersRequired, adjust close to stencil surface, but retainers must not touch stencil during printing operations if not spring loadedNote: Squeegee flexural strength is a critical parameter.*) Method of measurement: Bevel protractor2.3 StencilProperty SpecificationScreen materialNormal grade polyester screen 55T-66T (140-167 mesh/inch), equivalent stainless steel acceptedAlso interchangeable stencils corresponding frames can be usedScreen tension (measurements on stencil foil will give erroneous, but indicative results) after stencil attachment at any point*min 25N/cmStencil aperture opening dimensional variation max ? 10 ?m or ? 5% deviation maximumStencil thickness 0.10mm ? 0.01mmStencil material/manufacturing process Electroformed nickel or laser cut stainless steel or nickelStencil rejection criteria by tension in production measured at screen at any point*1.33) based on AOI alarm limits or fixed (?150um) process tolerances.Repair loop is required to enable repairs for defects found in AOI inspection. Optimum location of repair phase depends on line layout. Reporting of made corrective actions and defect modes is mandatory part of repair loops. Analyses of verified defect modes should 16be utilized in optimization of AOI inspection process in order to achieve lower than 50ppm false call level with all products.3.4 Component and paste alarm limitsNext table describes recommended alarm limits and acceptable range of alarm limits for different component types and for paste deposits. Alarm limits are used in AOI systems as pass/fail limits. The objective is to detect defects that can't be fixed by self-alignment during reflow process and to avoid unnecessary alarms. Therefore alarm limits are recommended values that can be changed based on self-alignment properties or false call/accept levels.Component type Recommended alarm limits Acceptable range0402chip componentsX & Y Offset: ? 180 ?m? Offset: ? 15 ?X & Y Offset [?m]: ? 150 ? 200? Offset: ? 10? ? 30 ?>0603 chip componentX & Y Offset: ? 220 ?m? Offset: ? 15 ?X & Y offset [?m]: ? 180 ? 250? Offset: ? 10? ? 30 ?Component X & Y Offset: ? 130 ?m? Offset: ? 10?ComponentX & Y Offset: ? 120 ?m ? 150?m? Offset [?] ? 8 ? 150.5 mm pitch CSP Paste X & Y Offset: ? 120 ?mArea: 35% - 150%Bridging: 20%PasteX & Y Offset: ? 100 ?m ? 150?mArea: 35% - 180%Bridging: 15% - 30%ComponentX & Y Offset: ? 120 ?m? Offset: ? 10?ComponentX & Y Offset: ? 120 ?m ? 160?m? Offset [?] ? 8 ? 150.4 mm pitch CSPPasteX & Y Offset: ? 100?mArea: 45% - 150%Bridging: 20%PasteX & Y Offset: ? 100?m ? 150?mArea: 35% - 170%Bridging: 15% - 30%Other paste depositsPaste X&Y Offset: ? 150 ?mArea: 50%-150%Bridging: 0.4x aperture dim.Paste X&Y Offset: ? 100?m ? 200?mArea: 35%-200%Bridging: 0.3 – 0.5 x aperture dim.Generic tolerances for other components X & Y Offsets: ? 200 ?m? Offset: ? 15 ?X & Y Offset [?m]: ? 180 ? 250? Offset: ? 10? ? 30 ?17Specification limits for capability analysesTable below describes specification limit values for capability studies. The objective is to define process window for most critical processes and use these values in machine capability monitoring and control to optimize paste printers and p