1、整 体 概 述THE FIRST PART OF THE OVERALL OVERVIEW,P L E A S E S U M M A R I Z E T H E C O N T E N T第一部分DFM 101Part 1Objective:Provide basic training on performing manual DFMIncluded:Relevant guidelines from the DFx guidelines document Identify which checklist items can be evaluated using Valor Examples
2、of DFM violations Some hands-on DFM exercisesNot included:DFT and DFA DFM using Valor Impact assessment of violationsDFM 101 OutlineAfter the session,attendees should be able to:DFM 101 OutlinelManually identify DFM violations in a customers design,using the DFM checklist and the PCA DFx GuidelCreat
3、e a DFM report for the customer using the standard templateDFM Review Process No single“best”way to approach a DFM review,find your own preferred method through experience.One possible approach:start at a high level,and progressively“zoom in”Background information define context for the review High
4、level design define basic manufacturing process Detailed design identify specific violations&general priority Impact assessment quantify impact,in order of priority Investigate alternatives specific suggestions for changesDFM Review ProcessBackgroundDefine context for the review Service level&produc
5、t“context”:What is expected by the customer?e.g.turnaround time for the review,level of detail,etc.What type of product is it?e.g.low volume/high mix,high volume/low margin,high reliability,consumer,etc.What are the customers“hot buttons”?e.g.cost,quality,schedule,product functionality/performance,r
6、eliability,etc.Data review:what design information is available to include in the reviews?History:what past information is available?e.g.production data,previous DFM reportsDFM Review ProcessHigh Level Design Define basic manufacturing process Typically use BOM,assembly drawing&/or outer layers(land
7、s)Look for parts/issues that may influence the basic process flow:PTH parts Complex connectors Topside vs.backside Define a preliminary assembly process flow,to ensure that correct guidelines are applied during later detailed review PTH parts:selective wave,full wave,paste in hole,press fit,selectiv
8、e solder(softbeam,Ersa),etc.Test/inspect strategy Define a preliminary panelization concept,to optimize Master Panel utilization&meet assembly panel requirementsDFM Review ProcessDetailed Design Identify specific violations&general priority Use previous DFM reports,BOM,design file&/or gerber files,a
9、ssembly drawing,PCB fabrication drawing,mechanical assembly drawing Work through Checklist,referring to DFM Guidelines as required Transfer items found to DFM Report,identify as hot/warm/cool focus designers limited time on the most critical items prioritize any additional detailed work required,e.g
10、.impact assessment&alternatives keep customers priorities in mind:cost,quality,schedule,etc.Request clarification or additional information from designer&/or suppliers if requiredDFM Review ProcessImpact AssessmentQuantify impact,in order of priority Time consuming,not many tools available yet to as
11、sist with this Business office needs to support providing this feedback to the customer&incorporating it into product quoting/pricing Need an overall DFx business model in place:who pays for the service?who benefits from improvements implemented in the design?etc.Could provide for all items,or only
12、on items that may not be fixedDFM Review ProcessInvestigate AlternativesSpecific suggestions for changes Very time consuming,should only be performed if appropriate&as time permits Start with highest impact issues,or ones most likely to have an alternative that we can suggestDFM Review ProcessDFM Ch
13、ecklist Data&History Components Process Flow PTH Assembly SMT Assembly Layout&Spacing Land Patterns Silkscreen Board Outline PCB Fabrication Drawing Mechanical Assembly(not covered in this session)DFM Checklist TopicsDFM Checklist The DFM Checklist is used to ensure that a comprehensive review is do
14、ne,covering all important areas Each item on the DFM Checklist should be verified on the design being reviewed,either using Valor automated analysis or by manual checking The DFM Checklist is a tool to use during the review,it should NOT be included in the DFM Report given to the customerChecklist I
15、temCommentsCheckedDFM NotesManual/ValorDFx Guide References(Internal)21 PTH AssemblyConsider pressfit,paste-in-hole,wave solder,change to SMT parts.Avoid double-sided PTH soldering.M1.13 Process Flow Hierarchy8.1.1 PTH Component Placement22Around PTH component pins.Xc2toep23Avoid fixture islands,e.g
16、.under PGAs.Xc_otherside_area24 Automated PTH Insertion Enough parts to automate?Machines available at production site?Check clearances for automated insertion equipment.M8.5.2 Component Keepouts for Automated PTH Insertion25PTH part orientation should be optimized for wave solder.M8.5.3 Wave Solder
17、26For manually installed parts,check for mistake-proofing(keying)e.g.asymmetric pins,orientation pin.M2.1.5 Manually and Automatically Installed Components27For non-keyed parts,prefer similar parts to have same orientation to aid manual placement,inspection&rework.Xuncommon_orient 8.2 General Compon
18、ent Spacing/Orientation GuidelinesSelective Wave Component KeepoutsComponent Orientation8.5.4 Selective Wave SolderHigher priority items are shown in bold text.If time is limited and a full review cannot be performed,the higher priority items should be covered first.Refer to the CLS DFx Guide for de
19、tailed guidelines.Items covered by Valor automated analysis will list the name of the check,e.g.c2toep.Items not covered by Valor are marked M and must be checked manually.Note:the priority of a line item on the checklist does not necessarily correspond to a“hot/warm/cool”severity level of a particu
20、lar issue(severity level depends on the specific issue found).DFM ChecklistChecklist ItemCommentsCheckedDFM NotesManual/ValorDFx Guide References(Internal)21 PTH AssemblyConsider pressfit,paste-in-hole,wave solder,change to SMT parts.Avoid double-sided PTH soldering.M1.13 Process Flow Hierarchy8.1.1
21、 PTH Component Placement22Around PTH component pins.Xc2toep23Avoid fixture islands,e.g.under PGAs.Xc_otherside_area24 Automated PTH Insertion Enough parts to automate?Machines available at production site?Check clearances for automated insertion equipment.M8.5.2 Component Keepouts for Automated PTH
22、Insertion25PTH part orientation should be optimized for wave solder.M8.5.3 Wave Solder26For manually installed parts,check for mistake-proofing(keying)e.g.asymmetric pins,orientation pin.M2.1.5 Manually and Automatically Installed Components27For non-keyed parts,prefer similar parts to have same ori
23、entation to aid manual placement,inspection&rework.Xuncommon_orient 8.2 General Component Spacing/Orientation GuidelinesSelective Wave Component KeepoutsComponent Orientation8.5.4 Selective Wave SolderCheck off each item as it is reviewed,to ensure all items are covered during the review.Notes can b
24、e made during the review,to gather information for writing the DFM Report for the customer.The Checklist can be filled in softcopy or hardcopy(printed),whichever is more convenient.Issues found that are not covered in the DFM Checklist should also be noted and included in the DFM Report for the cust
25、omer.DFM Checklist DFM CHECKLISTx Valor automated analysis done?(X if done)Revision 2.1 Valor Pin2pad analysis done?(X if done)Date:Customer:DFM Engineer:Product Name&P/N:Board Size(L x W,thickness):Assembly Process:Target Production Site(s):Celestica ConfidentialPutting an X in these boxes will aut
26、omatically X the items covered by Valor analysis.DFM ChecklistChecklist ItemCommentsCheckedDFM NotesManual/ValorDFx Guide References(Internal)36SMT part orientation optimized for full wave solder.Xfs_orientation 8.5.3 Wave Solder37Prefer similar parts to have same orientation to aid inspection&rewor
27、k.M8.2 General Component Spacing/Orientation Guidelines38 Component Weight LimitsCheck for heavy parts on backside during 2nd reflow.M8.1.6 SMT Weight Limits for Side 239 Back-to-back BGAsReliability concerns.M8.5.7 Back-to-back BGAs40 Ceramic BGAsStencil step near fine pitch may impact screening.MN
28、A41Check for components incompatible with full wave solder.Xc_pitch,pinw2padp 42If Pin2pad checks not run,check for chips smaller than 0603.MSMT Components in Full Wave Solder8.1.5 Wave Soldered SMT ComponentsComponent OrientationData&HistoryData&HistoryChecklist ItemCommentsManual/ValorDFx Guide Re
29、ferences(Internal)Data&History1 Data Adequate for DFM ReviewRequest ECAD,softcopy AVL BOM,assembly drawings,PCB fabrication drawing,custom components drawings.M10.1 Data Package for DFM2 Previous DFM?Similar to another board?2nd or 3rd pass of this board?Member of product family?MNA3 Design-related
30、Production IssuesFor redesign or EC of existing production board.MNA4 RoHS/Pb-free ComplianceHas customer verified appropriate BoM&PCB compliance?MNACAD data(intelligent and appropriate for input to Valor)AVL BOM with RefDesAssembly drawings PCB fabrication drawing,including outline dimensions,hole
31、sizes/tolerances,surface finishComponent drawings of complex or unique componentsCustom component informationDFx Guide:10.1 Data Package for DFMManual checkData Adequate for DFM ReviewThis will be covered in more details in the CLS Valor DFM training session.Data Adequate for DFM ReviewIf any DFM re
32、views have previously been performed on the board,they should be reviewed again for the new design.If these still exist in the new design,they should be included in the new DFM report.Items that were not implemented previously may be candidates to address in the new design.Previous DFMReview any exi
33、sting production problems to determine if any are design-related:Quality problems,major yield detractors Operation time adders,e.g.manual operations,inefficient process flow Supply chain problems,ponent quality,single/sole source parts,delivery problems Etc.Design-Related Production Issues RoHS=Rest
34、riction of Hazardous Substances A European Union Directive,effective from July 2006 Bans 6 materials,including lead and certain brominated flame retardants Applies to a broad range of electrical products-some exemptions apply Covers products both manufactured in or imported into Europe Similar legis
35、lation covering other regions being implemented or under developmentWhat is RoHS?RoHS/Pb-free ComplianceComponents:Must not contain any of the 6 materials prohibited by RoHS Must meet requirements for high-yield Pb-free assembly,including:compatible surface finish,higher temperature resistance with
36、minimal warping,adequate MSL ratings at Pb-free reflow temperatures,adequate reliability after Pb-free assembly All components must be clearly identified as Pb-free,RoHS compliant,or RoHS exempt.If a component cannot be clearly identified,then it cannot be used in RoHS compliant products.PCBs:Must n
37、ot contain any of the 6 materials prohibited by RoHS Must be compatible with Pb-free assembly,including:compatible surface finish,higher temperature resistance with minimal warping,adequate reliability after Pb-free assemblyRoHS/Pb-free Compliance The customer must clearly define the product require
38、ments:RoHS compliant or not?Assemble with SnPb or Pb-free solder?The customer must verify that the BOM&PCB are compliant and compatible with the chosen assembly Many components intended for Sn/Pb assembly are not Forward Compatible,i.e.able to be attached to a PCB using Pb-free assembly.Not all comp
39、onents intended for Pb-free assembly are Backward Compatible,i.e.able to be attached to a PCB using SnPb assembly.For example:Pb-Free(SAC)BGAs are not drop-in compatible with standard SnPb assembly.They can produce satisfactory solder joints if the reflow Tmax is greater than 227C,but this may cause
40、 other components on the board to be overheated.CLS Green Services can assist the customer by providing BOM analysis to verify compliance&compatibility RoHS/Pb-free ComplianceComponentsComponentsChecklist ItemCommentsManual/ValorDFx Guide References(Internal)Components5 New PackagesMay need developm
41、ent&/or qualification.MNA6 Washable and ReflowablePrefer washable parts for process flexibility.SMT&paste in hole parts must be reflowable.M2.1.6 Process Compatibility Requirements7 PackagingPrefer shipment packaging not specified on BoM,or follow preferred formats in DFx Guide.M2.1.13 Component Sup
42、ply/Packaging Formats8 Part Removal from Production BOMRemove any non-production parts prior to final BOM release e.g.test header.MNA9 Fine Pitch Components Impact to SMT&PTH assembly yields.c_pitch 2.1.9 Non-Preferred Components2.2.1 Package Selection2.5.1 Wave Solder PTH Components10 Autoplacement
43、Check for vacuum pickup for SMT placement,e.g.connectors.M2.5.2 Paste-in-Hole Components2.6.4 SMT ConnectorsExamples of new component packages:New advanced packages(BGAs,CSPs)New connectors New oddform parts,e.g.RF components Leadless componentsNew PackagesDFx Guide:N/AManual check In production at
44、target site?In production at another site?(3)Perform Process/Technology Transfer(1)(2)Create&Execute Development/Qualification Plan(2)(3)(4)Development/Qualification required?(3)YNYNOKYOKN(1)Consult documents CELQ-001-PROC-1293 Global Product Transfer Process for guidance(2)Consult document CELQ-001
45、-SPEC-16 New Technology Development and Qualification for guidance(3)Contact Corporate Process Development for assistance(Thilo Sack&Alex Chen(Americas),None(Europe),Teng Hoon Ng&Daniel Tan(Asia)(4)Should be performed by the Manufacturing Engineer responsible for the product.Prior to starting execut
46、ion,proposed Plan should be approved by the appropriate Engineering Manager and by the Customer.Program Manager or Operations Manager should address how the work will be funded,and obtain Customer approval for any charges.New PackagesProcess Development&Assembly Qualification considerations:Process
47、set-up&optimizationTooling(e.g.stencil design,placement nozzle/gripper,reflow nozzle)Process parameters(e.g.screening parameters,wave solder parameters,press fit force parameters,profiles for assembly and rework)Assembly reliabilityMechanical integrity of the interconnection between the component an
48、d the PCB(e.g.solder joints,press fit connection)is usually the focusNew PackagesSources for land pattern design information:PCA DFx Guidelines document,Chapter 6 Component Library Creation(standard component package types)Other sites already using the same or similar part Component suppliers recomm
49、ended land pattern,from spec sheet IPC land pattern calculator website http:/www.ipc.org IPC-7351(replacement for IPC-SM-782)DFx Technical Forum database on Lotus Notes:New Packages Components that are washable are preferred over those that are not.This provides maximum process flexibility.Component
50、s must be able to withstand the manufacturing process and temperature profiles.The required processing temperatures are typically higher for Pb-free assembly.Washable and ReflowableDFx Guide Section:2.1.6 Process Compatibility RequirementsManual CheckNote:1.Components should be specified to J-STD-02
