Noname 2010-05-11 DFM Report
DFM analysisCustomerXXProduct NameXXEAQXXBOM numberXXReport Date11/5-2010Report byClaus E. Nielsen & PeterRiis1. IntroductionThe aim of this document is to identify potential problems foreseen to occur during production,enabling proper remedies to be taken prior to a production run.1.1 StandardsThe following assessments, suggestions and recommendations regarding component and PCBdesign are based on the following standards in the newest revision.1.1.1 AcceptanceIPC-A-610, Acceptability for Electronic Assemblies1.1.2 AdvancedJ-STD 013, Implementation of Ball Grid Array and Other High Density TechnologyIPC-SM-784, Guidelines for Chip-on-Board Technology Implementation1.1.3 AssemblyJ-STD 001, Requirements for Soldered Electrical and Electronic AssembliesIPC-HBD-001, Handbook and Guide to Supplement J-STD-001IPC-D-279, Design Guidelines for Reliable Surface Mount Technology Printed BoardAssembliesIPC-7351, Surface Mount Design and Land Pattern Standard 1.1.4 Assembly SupportIPC-CM-770, Guidelines for Printed Board Component MountingIPC-SM-780, Component Packaging With Emphasis on Surface MountingIPC-7095, Design and Assembly Process Implementation for BGA’sIPC-7525, Stencil Design GuidelinesIPC-7530, Guidelines for Temperature Profiling for Mass Soldering Processes (Reflow &Wave)1.1.5 ComponentsJ-STD-020, Moisture/Reflow Sensitivity Classification for Nonhermetic Solid StateSurface Mount DevicesJ-STD-033, Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive SurfaceMount Devices 21-06-20101Design Link
DFM analysis1.1.6 Laminate1.1.6.1 Rigid IPC-4101, Specification for Base Materials for Rigid and Multilayer Printed Boards1.1.7 OtherIPC-7251, Generic Requirements for Through-Hole Design and Land Pattern Standard1.1.8 Printed BoardIPC-2221, Generic Standard for Printed Board DesignIPC-2222, Sectional Design Standard for Rigid Organic Printed Boards1.1.9 Printed Board AcceptanceIPC-A-600, Acceptability of Printed BoardsIPC-6011, Generic Performance Specification for Printed BoardsIPC-6012, Qualification and Performance Specification for Rigid Printed BoardsIPC-6013, Qualification and Performance Specification for Flexible Printed BoardsIPC-6015, Qualification and Performance Specification for Organic Multichip Module(MCM-L) Mounting and Interconnecting StructuresIPC-6016, Qualification and Performance Specification for High Density Interconnect(HDI) Layers or BoardsIPC-6018, Microwave End Product Board Inspection and Test 1.2 Definitions of categories.Design improvements and suggestions are categorized in the following manner:ABCXOKNAMajor error / problem which must be altered before next revision.Process improvement / cost saving suggestion.Minor issue.BB Electronics internal issueIssue checked and found okay.Not Applicable: Issue is not possible / relevant to check.1.3 Sources used in the analysis. Cad data: GenCad data-file provided by customer created 19th of February 2010.Gerber data in 274x format provided by customer created 19th of February 2010.BOM provided by customer: XX.pdf.Component placement drawing provided by customer: XX.pdf, created 21st of February2010.Additional information provided by Mats Persson, BB Electronics.21-06-20102Design Link
DFM analysis2. Drawing of product2.1 Topside2.2 Bottom side21-06-20103Design Link
DFM analysis3. Contents1.Introduction . 11.1 Standards . 11.1.1 Acceptance . 11.1.2 Advanced . 11.1.3 Assembly. 11.1.4 Assembly Support . 11.1.5 Components . 11.1.6 Laminate . 21.1.7 Other . 21.1.8 Printed Board . 21.1.9 Printed Board Acceptance. 21.2 Definitions of categories. . 21.3 Sources used in the analysis. . 22. Drawing of product . 32.1 Topside . 32.2 Bottom side . 33. Contents . 44. Proposed manufacturing processes. . 54.1 Suggested test setup . 55. PCB Layout . 66. SMT process . 227. Through hole components. 298. Reflow soldering . 309. Reflow/adhesive . 3110.Wave soldering . 3111. Selective soldering . 3112. Summary . 3221-06-20104Design Link
DFM analysis4. Proposed manufacturing processes.The following processes are recommended in connection with production of the PCB.Single sided PCBDouble sided PCBSMTSMTProcessReflowPin in pasteSuggestedProcessReflow/reflowPin in pasteReflow/adhesiveSuggestedProcessWave solderingSelective solderingHand solderingTHTProcessWave solderingSelective solderingHand solderingSuggestedXTHTSuggestedXInstead of lead free hand soldering or lead free wave pallet soldering of the components JTP1,JTP2, J3 (center ground pins) and J4, it is recommended to use lead free selective soldering.The main argument being that you insure a consistent high level of quality and repeatability.Further you avoid the costs of design and fabrication of expensive special solder pallets for wavesoldering.4.1 Suggested test setupNot considered.21-06-20105Design Link
DFM analysis5. PCB LayoutNo.IssueResultOptimal Board size, and shape [ 100 x110 mm, 300 x 200mm, square or5.01rectangle.] Largest size allowed 460 x460mm.[Position:] CommentsOK200mm x 82mmNANo panelization data available.Due to the current PCB outline, itis recommended to apply a breakoff frame of 10mm on the longsides of the PCB for optimaltransport efficiency.NANo panelization data available.NANo panelization data available.5.05 Board thickness [0.8 – 4 mm] rigidityOK1.6mm specified.5.06 Board warpageOKSee comment below.Proper Panelization [optimal 300 mm x200 mm],(Largest size allowed 460 x5.02460mm) .minimum material waste,optimal transport efficiency.Breakout tab. Type:shear/score/router/mouse-bite, V-groove,5.03 and the location. Keep away from ceramiccaps min. 5mm. Smooth edges vs. roughedges.Break-offs have cut outs and no break5.04 points under protruding Connectors to bewave soldered or selectively soldered5.075.085.095.105.11Specified silkscreen width not less than0.2mmSpecified silkscreen height not less than0.1mmVia hole. 0.250mm min diameter.Min location from pads 0.254mm incl.trace. Min edge-to-edge 0.381mm if notmasked. No underneath part (wave oradhesive). No mask if used for test.Tented/Capped when wave-soldered.Via hole minimum 0.5mm from PCBedge.Ground planes where possible.Crosshatched copper to fill in gaps. Evenlydistributed copper throughout entire boardto avoid bow & twist.Solder Mask Webbing min. 0.1mmSolder mask between fine pitch 0.5mm or5.12smaller is not necessary. SoldermaskClearance min. 0.1mm, BGA 0.15mmAAAError in silkscreen layer for bottomside of PCB. See comment below.Error in silkscreen layer for bottomside of PCB. See comment below.Numerous occasions, where viasare placed under pads. Seecomments below.OKOKA21-06-2010See comment for 5.06Numerous occasions of too smallsolder mask webbing.IC222, IC223 & IC802 soldermask present between fine pitch.See comment below.6Design Link
DFM analysis5.13No solder mask between 0402 or 0201solder padsOptimal PCB surface finish. HASL not tobe used with fine pitch, CSP or smaller,5.140402, or 0201 technology, or PCB thinnerthan 0.8mm.IPC-7351 land patterns used for general5.15SMT designFine pitch land patterns set to 60% of lead5.16 pitch. E.g. 0.5mm pitch 0.3mm landwidth.No natural bridges on fine pitch, networks5.17or other areas.Non-solder mask defined (NSMD) pads on5.18 CSP’s, QFN’s, LLC’s, BGAs and flipchips.BGA land pattern, pad geometry &location.Keep away from press-fit areas and otherattachments.5.19BGA vias must include a sufficient solderdam or completely covered. Solder maskrelief around Land 0.10mm. Oval shapelands preferred.Documentation, drawings, data with5.20acceptable quality5.21 Min etch distance from PCB edge 0.5mmMin Etch width (0.1mm) and Etch to Etchspacing (0.1mm)Critical apertures optimized for solder5.23paste screening.Rework process feasible with regards to5.24space and thermal load.5.225.25General orientation of polarizedcomponents.5.26Fine pitch devices are limited in numbers.BGA type used where possible.5.27 Any heat sensitive components identifiedANANumerous occasions of soldermask present between pads for0402 components. See commentbelow.Due to no PCB specificationpresented.ANumerous occasions where therecommendations listed in IPC7351 has not been adhered to. Seecomments below.AIC222, IC223, IC802; seecomment below.OKAIC202, IC222, IC223, IC802; seecomment below.CRound shape apertures used inBGA design is acceptable.Numerous occasions where soldermask relief around land is below0.1mm. See comment belowANo PCB specification available,see comment below.AIC104; see comment below.OKOKCJTP1; see comment below.CTantalum and IC’s OK, CANCAPcomponents have randomorientation.OKC21-06-2010C730: Max peak. 240 C, IC201:Max peak: 245 C.7Design Link
DFM analysis5.28 Other issues related to PCBBSe comments below.5.06:We do not suspect any problems related to warpage. All though the copper is unevenlydistributed in layer 4 (see picture below), the even distribution of copper in the other layers willoverrule any tendency of warpage related to this layer. As no PCB specification has beenpresented, please observe that the laminate used in the PCB construction has not been taken intoaccount when making this judgment.21-06-20108Design Link
DFM analysis5.07 & 5.08:Error in silkscreen specification in gerber data for bottom layer (sno.gdo), see picture below.As can be seen from above, a large amount of the silkscreen text is present outside the PCB. Asno print specification has been presented to us, we are not aware, whether silkscreen is desiredon the final product. From a production point of view, we would not recommend the use ofsilkscreen.21-06-20109Design Link
DFM analysis5.09:Numerous occasions with via in pad;IC206, IC221, IC222, IC223 & IC802 all have vias in ground pad. Where this is considerednecessary due to thermal relief, we recommend, that the vias should be plugged according toIPC-4761.IC223: Via in ground pad.For the other occurrences of vias in pad, it is recommended to move the via outside the pad.21-06-201010Design Link
DFM analysisC445: Via in SMD-pad.A via in pad is considered a problem since it makes it very hard to control the solder amount onthe pad. Further air is very easily trapped underneath the solder paste on the pad, which in turncan lead to voids during the soldering process.5.12:The solder mask webbing has been observed as small as 51µm. Such small webbings areimpossible to manufacture; attempting to do so, could very well lead to small pieces of soldermask polluting the PCB.IC222, IC223, IC802:IC222, IC223, IC802 are fine pitch components (pitch equal or less than 0.5mm). Neverthelesssolder mask has been specified, probably due to the fact, that some of the pads are solder maskdefined. Using solder mask for fine pitch components can result in irregular screening of solderpaste on the pads, due to the fact, that the height of the solder mask can obstruct the screeningprocess.5.13:Specifying solder mask between pads for such small components can lead to the components"riding" on top of the solder mask webbing. We recommend that the solder mask is removedbetween the pads for the 0402-components. Please bear in mind also to remove any ghost traces(i.e. traces between 0402-pads), that otherwise will be exposed, when the solder mask isremoved.21-06-201011Design Link
DFM analysis5.15:0402 chip resistor layout, general:The current 0402 chip resistor layout does not comply with the IPC-7351 recommended padlayout for this component type regarding the pad to pad distance.The IPC-7351 suggests the following nominal pad layout dimensions for a standard 0402 chipresistor:The current PCB layout for the 0402 chip resistor has been measured to the followingdimensions:With 0402 chip resistor:Pads shown only:Outline pad to pad distance ismeasured to 2.12mm where IPC7351 LP Calculator denotes anoptimal distance of 1.32 to1.72mm. (Least to most value).Pad width is measured to 0.67mmwhere IPC-7351 LP Calculatordenotes an optimal distance of 0.52to 0.72mm. (Least to most value).21-06-201012Design Link
DFM analysis0402 chip capacitor layout, general:The current 0402 chip capacitor layout does not comply with the IPC-7351 recommended padlayout for this component type regarding the outline pad to pad distance.The IPC-7351 suggests the following nominal pad layout dimensions for at standard 0402 chipcapacitor:The current PCB layout for the 0402 chip capacitor has been measured to the followingdimensions:With 0402 chip capacitor:Pads shown only:Outline pad to pad distance ismeasured to 2.12mm where IPC7351 LP Calculator denotes anoptimal distance of 1.35 to1.75mm. (Least to most value).Pad width is measured to 0.67mmwhere IPC-7351 LP Calculatordenotes an optimal distance of 0.52to 0.72mm. (Least to most value).21-06-201013Design Link
DFM analysis0603 chip resistor layout, general:The current 0603 chip resistor layout does comply with the IPC-7351 recommended pad layoutfor this component type, but it could be optimized to fit the nominal IPC layout since the currentlayout is quite close to the “least” IPC layout recommendation regarding the pad width.The IPC-7351 suggests the following pad layout dimensions for at standard 0603 chip resistor:The current PCB layout for the 0603 chip resistor has been measured to the followingdimensions:With 0603 chip resistor:Pads shown only:Outline pad to pad distance ismeasured to 2.30mm where IPC7351 LP Calculator denotes anoptimal distance of 2.10 to2.90mm. (Least to most value).Pad width is measured to 0.85mmwhere IPC-7351 LP Calculatordenotes an optimal distance of 0.85to 1.05mm. (Least to most value).21-06-201014Design Link
DFM analysis0603 chip capacitor layout, general:The current 0603 chip capacitor layout barely complies with the IPC-7351 recommended padlayout for this component type, but it could be optimized to fit the nominal IPC layout since thecurrent layout is less than the “least” IPC layout recommendation regarding both the outline padto pad distance and the pad width.The IPC-7351 suggests the following nominal pad layout dimensions for at standard 0603 chipcapacitor:The current PCB layout for the 0603 chip resistor has been measured to the followingdimensions:With 0603 chip capacitor:Pads shown only:Outline pad to pad distance ismeasured to 2.14mm where IPC7351 LP Calculator denotes anoptimal distance of 2.15 to2.95mm. (Least to most value).Pad width is measured to 0.84mmwhere IPC-7351 LP Calculatordenotes an optimal distance of 0.90to 1.10mm. (Least to most value).21-06-201015Design Link
DFM analysis0805 chip capacitor layout, general:The current 0805 chip capacitor layout barely complies with the IPC-7351 recommended padlayout for this component type, but it could be optimized to fit the nominal IPC layout since thecurrent layout is less than the “least” IPC layout recommendation regarding the pad width.The IPC-7351 suggests the following nominal pad layout dimensions for at standard 0805 chipcapacitor:The current PCB layout for the 0805 chip capacitor has been measured to the followingdimensions:With 0805 chip capacitor:Pads shown only:Outline pad to pad distance ismeasured to 2.79mm where IPC7351 LP Calculator denotes anoptimal distance of 2.55 to3.35mm. (Least to most value).Pad width is measured to 1.28mmwhere IPC-7351 LP Calculatordenotes an optimal distance of 1.35to 1.55mm. (Least to most value).21-06-201016Design Link
DFM analysis1206 chip resistor layout, general:The current 1206 chip resistor layout barely complies with the IPC-7351 recommended padlayout for this component type, but it could be optimized to fit the nominal IPC layout since thecurrent layout is quite close to the “least” IPC layout recommendation regarding the pad width.The IPC-7351 suggests the following nominal pad layout dimensions for at standard 1206 chipresistor:The current PCB layout for the 1206 chip resistor has been measured to the followingdimensions:With 1206 chip resistor:Pads shown only:Outline pad to pad distance ismeasured to 4.00mm where IPC7351 LP Calculator denotes anoptimal distance of 3.75 to4.55mm. (Least to most value).Pad width is measured to 1.55mmwhere IPC-7351 LP Calculatordenotes an optimal distance of 1.70to 1.90mm. (Least to most value).21-06-201017Design Link
DFM analysis1206 chip capacitor layout, general:The current 1206 chip capacitor layout barely complies with the IPC-7351 recommended padlayout for this component type, but it could be optimized to fit the nominal IPC layout since thecurrent layout exceeds the “most” IPC layout recommendation regarding the pad width.The IPC-7351 suggests the following nominal pad layout dimensions for at standard 1206 chipcapacitor:The current PCB layout for the 1206 chip capacitor has been measured to the followingdimensions:With 1206 chip capacitor:Pads shown only:Outline pad to pad distance ismeasured to 3.90mm where IPC7351 LP Calculator denotes anoptimal distance of 3.75 to4.55mm. (Least to most value).Pad width is measured to 2.55mmwhere IPC-7351 LP Ca
1.1.8 Printed Board IPC-2221, Generic Standard for Printed Board Design IPC-2222, Sectional Design Standard for Rigid Organic Printed Boards 1.1.9 Printed Board Acceptance IPC-A-600, Acceptability of Printed Boards IPC-6011, Generic Performance Specification for Printed Boards
Subject to change 2014/05 Guided drives DFM/DFM-B Key features Drive and guide unit in a single housing Sturdy and accurate High resistance to torques and lateral forces Wide choice of variants Minimal space requirement Minimal assembly time Choice of supply ports Versatile mounting optio
manufacturers and buyers exploring their direct-sell and direct-purchase options. In fact, one of the most surprising findings was the extent to which buyers said their companies already buy directly from manufacturers (DFM), or have considered doing so. 88% Very likely Somewhat likely Increase DFM purchase 37% 51% 66% Start DFM purchase 8% 58%
DFM-1 Rev -C May 16, 2001 Design For Manufacturing Specification For Thru-Hole/Surface Mount Technology 1.0 Introduction 1.1 Scope - This DFM Guideline establishes minimum criteria for the design and layout of single, double-sided, and multi-layer designs using through-hole, surface mount, or mixed technologies. For PWB's or also known as PCB's
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same image; the process is shortly discussed here to show that a function can be resampled a number of times with MWSR without significant loss of power up to a predetermined frequency. Concerning tomography, we will illustrate and discuss the use of MWSR in "Direct Fourier Methods" (DFM) of reconstruction. A DFM consists of
Design for Manufacturability (DFM) Guidelines These international guidelines developed by the Association Connecting Electronics Industry or IPC have helped standardize the assembly and production of electronic equipment and assemblies. Following these guidelines will allow for a smooth and accurate quoting and manufacturing process.
10 Annual Book of ASTM Standards, Vol 02.02, in the Related Material section (gray pages). 11 Available from Standardization Documents, Order Desk, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. TABLE 1 Chemical Composition Limits NOTE 1—When single units are shown, these indicate the maximum amounts permitted. NOTE 2—Analysis shall be made for the elements .
