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DFM知识点培训教材


DFM 101
Part 1
DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM 101 Outline
Objective: ? Provide basic training on performing manual DFM Included: ? Relevant gu

idelines from the DFx guidelines document ? Identify which checklist items can be evaluated using Valor ? Examples of DFM violations ? Some hands-on DFM exercises Not included: ? DFT and DFA ? DFM using Valor ? Impact assessment of violations

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM 101 Outline
After the session, attendees should be able to:

?

Manually identify DFM violations in a customer’s design, using the DFM checklist and the PCA DFx Guide

?

Create a DFM report for the customer using the standard template

DFM 101 Part1 | Dec 2008 Confidential

DFM Review Process

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM 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 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 changes

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM Review Process
Background Define context for the review ? Service level & product “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 customer’s “hot buttons”? e.g. cost, quality, schedule, product functionality/performance, reliability, 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 reports

DFM 101 Part1 | Dec 2008 Confidential

DFM Review Process
High Level Design
Define basic manufacturing process ? Typically use BOM, assembly drawing &/or outer layers (lands) ? 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, selective solder (softbeam, Ersa), etc. ? Test / inspect strategy ? Define a preliminary panelization concept, to optimize Master Panel utilization & meet assembly panel requirements

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM Review Process
Detailed Design Identify specific violations & general priority ? Use previous DFM reports, BOM, design file &/or gerber files, assembly 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 designer’s limited time on the most critical items ? prioritize any additional detailed work required, e.g. impact assessment & alternatives ? keep customer’s priorities in mind: cost, quality, schedule, etc. ? Request clarification or additional information from designer &/or suppliers if required

DFM 101 Part1 | Dec 2008 Confidential

DFM Review Process
Impact Assessment

Quantify impact, in order of priority
? Time consuming, not many tools available yet to assist 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 on items that may not be fixed

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM Review Process
Investigate Alternatives

Specific 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 suggest

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM Checklist

DFM 101 Part1 | Dec 2008 Celestica Confidential

DFM Checklist Topics
? ? ? ? ? ? ? ? ? ? ? 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 101 Part1 | Dec 2008 Celestica Confidential

DFM Checklist
? The DFM Checklist is used to ensure that a comprehensive review is done, 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 customer
DFM 101 Part1 | Dec 2008 Confidential

Higher 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.
Checklist Item 21 PTH Assembly

DFM Checklist
Checked DFM Notes

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.
Manual / Valor M

Refer to the CLS DFx Guide for detailed guidelines.

Comments Consider pressfit, paste-in-hole, wave solder, change to SMT parts. Avoid double-sided PTH soldering.

DFx Guide References (Internal) 1.13 Process Flow Hierarchy 8.1.1 PTH Component Placement

Around PTH component pins. Avoid fixture 'islands', e.g. under PGAs. 24 Automated PTH Insertion Enough parts to automate? Machines available at production site? Check clearances for automated insertion equipment. 25 Component Orientation PTH part orientation should be optimized for wave solder. 26 For manually installed parts, check for mistake-proofing (keying) e.g. asymmetric pins, orientation pin. 22 Selective Wave 23 Component Keepouts 27 For non-keyed parts, prefer similar parts to have same orientation to aid manual placement, inspection & rework.

X X

c2toep c_otherside_area M

8.5.4 Selective Wave Solder

8.5.2 Component Keepouts for Automated PTH Insertion

M M

8.5.3 Wave Solder 2.1.5 Manually and Automatically Installed Components

uncommon_orient X

8.2 General Component Spacing/Orientation Guidelines

Note: the priority of a line item on the checklist does not necessarily correspond to a “hot / warm / cool” severity level of a particular issue (severity level depends on the specific issue found).
DFM 101 Part1 | Dec 2008 Confidential

The Checklist can be filled in softcopy or hardcopy (printed), whichever is more convenient.
Check off each item as it is reviewed, to ensure all items are covered during the review. Notes can be made during the review, to gather information for writing the DFM Report for the customer.

DFM Checklist

Checklist Item 21 PTH Assembly

Comments Consider pressfit, paste-in-hole, wave solder, change to SMT parts. Avoid double-sided PTH soldering.

Checked

DFM Notes

Manual / Valor M

DFx Guide References (Internal) 1.13 Process Flow Hierarchy 8.1.1 PTH Component Placement

Around PTH component pins. Avoid fixture 'islands', e.g. under PGAs. 24 Automated PTH Insertion Enough parts to automate? Machines available at production site? Check clearances for automated insertion equipment. 25 Component Orientation PTH part orientation should be optimized for wave solder. 26 For manually installed parts, check for mistake-proofing (keying) e.g. asymmetric pins, orientation pin. 22 Selective Wave 23 Component Keepouts 27 For non-keyed parts, prefer similar parts to have same orientation to aid manual placement, inspection & rework.

X X

c2toep c_otherside_area M

8.5.4 Selective Wave Solder

8.5.2 Component Keepouts for Automated PTH Insertion

M M

8.5.3 Wave Solder 2.1.5 Manually and Automatically Installed Components

uncommon_orient X

8.2 General Component Spacing/Orientation Guidelines

Issues found that are not covered in the DFM Checklist should also be noted and included in the DFM Report for the customer.
DFM 101 Part1 | Dec 2008 Confidential

Putting an ‘X’ in these boxes will automatically ‘X’ the items covered by Valor analysis.

DFM Checklist
x Valor automated analysis done? ('X' if done) Valor Pin2pad analysis done? ('X' if done) DFM Engineer: Board Size (L x W, thickness): Target Production Site(s):

Celestica Confidential Date: Product Name & P/N: Assembly Process:

DFM CHECKLIST
Revision 2.1 Customer:

Checklist Item 36 Component Orientation 37

38 Component Weight Limits 39 Back-to-back BGAs 40 Ceramic BGAs 41 SMT Components in Full Wave Solder 42

Comments SMT part orientation optimized for full wave solder. Prefer similar parts to have same orientation to aid inspection & rework. Check for heavy parts on backside during 2nd reflow. Reliability concerns. Stencil step near fine pitch may impact screening. Check for components incompatible with full wave solder. If Pin2pad checks not run, check for chips smaller than 0603.

Checked X

DFM Notes

Manual / Valor fs_orientation M

DFx Guide References (Internal) 8.5.3 Wave Solder 8.2 General Component Spacing/Orientation Guidelines 8.1.6 SMT Weight Limits for Side 2 8.5.7 Back-to-back BGAs NA 8.1.5 Wave Soldered SMT Components

M M M X c_pitch, pinw2padp M

DFM 101 Part1 | Dec 2008 Confidential

Data & History

DFM 101 Part1 | Dec 2008 Confidential

Data & History
Checklist Item Comments Data & History 1 Data Adequate for DFM Request ECAD, softcopy AVL BOM, assembly drawings, PCB Review fabrication drawing, custom components drawings. 2 Previous DFM? Similar to another board? 2nd or 3rd pass of this board? Member of product family? For redesign or EC of existing 3 Design-related production board. Production Issues Has customer verified appropriate 4 RoHS / Pb-free BoM & PCB compliance? Compliance Manual / Valor M DFx Guide References (Internal) 10.1 Data Package for DFM M NA

M M

NA NA

DFM 101 Part1 | Dec 2008 Confidential

Data Adequate for DFM Review
? CAD data (intelligent and appropriate for input to Valor) ? AVL BOM with RefDes ? Assembly drawings ? PCB fabrication drawing, including outline dimensions, hole sizes/tolerances, surface finish ? Component drawings of complex or unique components ? Custom component information

DFx Guide:10.1 Data Package for DFM Manual check
DFM 101 Part1 | Dec 2008 Confidential

Data Adequate for DFM Review

This will be covered in more details in the CLS Valor DFM training session.
DFM 101 Part1 | Dec 2008 Confidential

If any DFM reviews have previously been performed on the board, they should be reviewed again for the new design.

Previous DFM

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.
DFM 101 Part1 | Dec 2008 Confidential

Design-Related Production Issues

Review any existing 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, e.g. component quality, single / sole source parts, delivery problems ? Etc.

DFM 101 Part1 | Dec 2008 Confidential

RoHS / Pb-free Compliance
What is RoHS?

? RoHS = Restriction 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 legislation covering other regions being implemented or under development

DFM 101 Part1 | Dec 2008 Confidential

RoHS / Pb-free Compliance

Components: ? 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 minimal warping, adequate MSL ratings at Pbfree 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 not 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 assembly

DFM 101 Part1 | Dec 2008 Confidential

RoHS / Pb-free Compliance

? The customer must clearly define the product requirements:
? 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 components 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 227°C, but this may cause other components on the board to be overheated.

CLS Green Services can assist the customer by providing BOM analysis to verify compliance & compatibility
DFM 101 Part1 | Dec 2008 Confidential

Components

DFM 101 Part1 | Dec 2008 Confidential

Components
Checklist Item Components 5 New Packages 6 Comments Manual / Valor M M NA 2.1.6 Process Compatibility Requirements DFx Guide References (Internal) 7 May need development &/or qualification. Prefer washable parts for process Washable and flexibility. SMT & paste in hole parts Reflowable must be reflowable. Packaging Prefer shipment packaging not specified on BoM, or follow preferred formats in DFx Guide. Part Removal from Remove any non-production parts Production BOM prior to final BOM release e.g. test header. Fine Pitch Components Impact to SMT & PTH assembly yields. Check for vacuum pickup for SMT placement, e.g. connectors. M 2.1.13 Component Supply/Packaging Formats NA

8

M

9

c_pitch

10 Autoplacement

M

2.1.9 Non-Preferred Components 2.2.1 Package Selection 2.5.1 Wave Solder PTH Components 2.5.2 Paste-in-Hole Components 2.6.4 SMT Connectors

DFM 101 Part1 | Dec 2008 Confidential

New Packages

Examples of new component packages:
? ? ? ? New advanced packages (BGAs, CSPs) New connectors New oddform parts, e.g. RF components Leadless components

DFx Guide: N/A Manual check
DFM 101 Part1 | Dec 2008 Confidential

New Packages
(1) Consult documents CELQ-001-PROC-1293 Global Product Transfer Process for guidance (2) Consult document CELQ-001- 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 execution, 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.

In production at target site?

Y

OK

N
In production at another site? (3)

Y

Perform Process / Technology Transfer (1) (2)

N
Development / Qualification required? (3)

Y

Create & Execute Development / Qualification Plan (2) (3) (4)

N OK

DFM 101 Part1 | Dec 2008 Confidential

New Packages

Process Development & Assembly Qualification considerations:

? Process set-up & optimization ? Tooling (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 reliability ? Mechanical integrity of the interconnection between the component and the
PCB (e.g. solder joints, press fit connection) is usually the focus

DFM 101 Part1 | Dec 2008 Confidential

New Packages

Sources 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 supplier’s recommended 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:

DFM 101 Part1 | Dec 2008 Confidential

Washable and Reflowable

? Components that are washable are preferred over those that are not. This provides maximum process flexibility. ? Components must be able to withstand the manufacturing process and temperature profiles. The required processing temperatures are typically higher for Pb-free assembly.

DFx Guide Section: 2.1.6 Process Compatibility Requirements Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Washable and Reflowable
Component Temperature Requirements Note: 1. Components should be specified to J-STD-020, which states a maximum temperature of 220?C for SnPb and 260?C for Pb-free (unless otherwise specified by manufacturer). 2. SnPb moisture sensitive parts are acceptable at 220?C 3. Pb-free moisture sensitive parts are acceptable at 260?C

DFM 101 Part1 | Dec 2008 Confidential

Shipment Packaging

Type Discretes

Preferred Supply Formats Tape and Reel

Type Axials Non-Polarized Radials Polarized Radials Conformal Coated SIPs PTH Inductors DIPs Plastic / Ceramic SIPs

Preferred Supply Formats Tape and Reel Tape and Reel Tape in an Ammo Box Tape and Reel or Bulk Tube Tube (consistent Pin 1 orientation) Tube (consistent Pin 1 orientation)

SOPs, J-Leads, Tape and Reel TSOPs Small BGAs Tape and Reel up to 32mm tape width Fine Pitch Parts Tray BGAs Connectors (SMT or PTH) SMT Inductors Tray or Tape and Reel Tube or Tape and Reel (including vacuum pickup) Tape and Reel (Large inductors may be preferred in tubes)

DFx Guide Section: 2.1.13 Component Supply/Packaging Formats Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Part Removal from BOM

? Remove any non-production parts prior to final BOM release ? Parts which may be candidates for removal:

? Header pins used only for debug of the design, e.g. grounding of oscilloscope probes
? Sockets, e.g. to enable frequent upgrade of microcode during design debug ? Diagnostic connectors, e.g. to logic analyzers

? Small headers/connectors spread across the board, e.g. for measurement of signal integrity or power distribution and noise
? Ask the designer if any parts are not required for production

DFx Guide Section: 2.4.5 Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Fine Pitch Components
Fine Pitch PTH Components

? Correct pin protrusion and use of solder thieves are critical for fine pitch wave solder ? Solder thieves are currently required for all PTH components for Pb-free soldering (needs more study) ? Defect rate for fine pitch typically 10X the rate for standard pitch (SnPb data)

DFx Guide: 2.5.1 Wave Solder PTH Components Valor check: c_pitch (Component Analysis)
DFM 101 Part1 | Dec 2008 Confidential

Fine Pitch Components
Fine Pitch SMT Components
SMT peripheral leaded components (gullwings, leadless): ? Minimum recommended pitch is 0.5mm ? Pitches down to 0.4mm can be assembled, but with lower yields

Area array components: ? Pitches of 1.0mm and above are recommended, as they can be assembled with very low defect rates ? Pitches below 1.0mm can be used with caution: – May have lower assembly yields – Difficult to mix with high paste volume parts, e.g. CBGA (step stencil) – Land pattern design is more challenging – May require advanced PCB technology, e.g. micro-via, high capability solder mask (web width & registration) ? Pitches of 0.5mm and below are not recommended, as they are challenging to assemble with high yields

DFx Guide: 2.1.9 Non-Preferred Components, 2.2.1 Package Selection Valor check: c_pitch (Component Analysis)
DFM 101 Part1 | Dec 2008 Confidential

Fine Pitch Components
QFP Assembly Defects by Pitch

60000 50000 40000 30000 20000 10000 0 0 100 Number of I/O 200

PPM per Part

25 mil Gullw ing 20 mil Gullw ing 16 mil Gullw ing

DFM 101 Part1 | Dec 2008 Confidential

Auto placement
Pick-up method for placement in the SMT line, in order of preference:

? Auto-placeable parts with a flat surface on the top of the part for vacuum pick-up (minimum diameter 7.5mm (0.3”)). Some parts have a removable pick-up cap to provide a pickup area. ? Flat surface on the side for side vacuum ? Special gripper designed for the part, or manual placement ? Note that a metal pick-up cap will interfere with TestJet or Opens Express (capacitive) testing at ICT.

SMT connector with removable pick-up cap

DFx Guide Section: 2.5.2 Paste-in-Hole Components, 2.6.4 SMT Connectors Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Components
Checklist Item Components 11 Complex Connectors Comments May need development &/or qualification. Consider additional processes & equipment required. Check retention method is suitable vs. requirements. Consider impact on assembly & rework. Avoid using ceramics larger than 1210 size & film capacitors. Use 0603 or larger if possible, especially for capacitors. Combine 0402s or 0603s to Rpacks to reduce placement time. Avoid prep / pre-form requirements on parts. Check topside & bottomside height vs. equipment limitations. Manual / Valor M NA DFx Guide References (Internal) 12 Connector Mechanical Retention M 2.6.2 Alignment and Retention 2.6.3 Retention for SMT Connectors 2.5.2 Paste-in-Hole Components 2.4.6 Capacitors 2.1.9 Non-Preferred Components 2.1.8 Component Count Reduction NA 8.1.3 Height Limitations

13 Capacitors 14 Small Chip Discretes 15 Discretes to Rpack 16 Lead Prepping / Preforming 17 Component Height

M M M M c_height_p, c_height_s

DFM 101 Part1 | Dec 2008 Confidential

Complex Connectors

? Complex connectors may significantly impact: ? NRE (assembly &/or repair), e.g. custom tooling, process development or optimization, operator training for customized operation ? Operation time (assembly and/or repair) ? Yield ? Often very little opportunity to change connectors, as they can be an integral part of the system mechanical design. However, feedback should still be provided on their impact to manufacturing.

DFx Guide Section: 2.6.4 SMT Connectors, 2.6.5 PTH Connectors Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Complex Connectors
Example: SMT MicropaxTM
? Fine pitch SMT connector with rivet mechanical retention ? Connector must be riveted in place prior to reflow due to the lead configuration - if not riveted, it would not sit flat on the PCB surface. Riveting must therefore be done with all components placed in wet paste.
Rivet location

Leads are not flat on the component

Leads must be pressed into a flat position when mounted on the PCA

? Leads extend underneath the connector body, making visual inspection and touch-up of solder bridges very difficult.
DFM 101 Part1 | Dec 2008 Confidential

Complex Connectors
Complex Connector Examples ? Panda connector ? Four rows of interlaced “butt joint” connections (pinned SMT joints). Visual inspection and touch-up of inner 2 rows is almost impossible due to pitch and interlacing on pins ? Metal clamp must be placed around the connector to keep it from bowing from the card and producing opens during reflow. Clamp acts as a heat sink making it more difficult to get the connector leads to reflow

DFM 101 Part1 | Dec 2008 Confidential

Connector Mechanical Retention

DFM 101 Part1 | Dec 2008 Confidential

Connector Mechanical Retention

Other considerations: ? For paste in hole attach: avoid using snap-in legs unless required, as they may push solder out of the hole ? Kinked PTH leads may be cheaper than adding a separate hold-down feature ? Screws, rivscrews, & rivets may require additional assembly time, e.g. to invert the assembly, install the hardware, apply masking for wave ? Screws may need to be re-torque after wave solder ? Avoid rivets due to rework difficulty; try rivscrews instead ? If using screws, use captive nuts or pem nuts to reduce assembly time

DFM 101 Part1 | Dec 2008 Confidential

Connector Mechanical Retention
Other considerations: ? Snap-in mechanisms should accommodate the PCB thickness and tolerance (typically +/-10%) ? If the PCB is too thick, the part may not engage properly ? If the PCB is too thin, the part may float during soldering ? Install retention hardware before the part is soldered, to avoid inducing stress in the solder joints that could lead to early failure ? Pegs that must be deformed after insertion should be avoided as they require additional assembly time and may require special equipment, e.g. ultrasonic bonder ? Alignment pins should have a taper and should be longer than the functional pins, so that they engage first

Alignment Pin
DFM 101 Part1 | Dec 2008 Confidential

Connector Mechanical Retention
Other considerations: ? Retention mechanisms should be low force, so that any functional PTH pins bent during insertion can be detected ? To reduce incidence of bent PTH pins, the maximum installation force should be applied only after the tips of the functional pins are inside the barrels of the PCB ? Mechanical retention for SMT connectors is challenging: ? Absence of mechanical retention, or installation of mechanical retention after soldering can both lead to early solder joint failure ? Installation of mechanical retention prior to reflow risks smearing of solder paste and incurring defects in other placed components on the PCB ? Some preferred methods are soldered PTH pins (without latches or barbs) or SMT tabs. To facilitate rework, PTH pins should not be connected to planes, or at a minimum must have thermal reliefs.

DFM 101 Part1 | Dec 2008 Confidential

Capacitors
Ceramic: ? Parts larger than 1210 size may need additional analysis of CTE mismatch and stress cracking susceptibility to understand potential reliability effects. ? Avoid using high voltage surface mount ceramic capacitors. They require special processes (encapsulation) to prevent voltage flashover. ? Not all ceramic capacitors are wave solderable. Refer to the manufacturer’s specifications. Film: ? Not recommended due to poor solderability and rework issues. Close attention should be given to specified soldering conditions. ? Moisture sensitive - the manufacturer’s storage requirements should be followed. ? Often not suitable for wave soldering.

DFx Guide Section: 2.4.6 Capacitor Selection Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Capacitors

Tantalum: ? Molded parts are recommended over conformally coated parts. ? For lower voltage values (<10V), Niobium Oxide capacitors may be considered. They offer comparable electrical characteristics, are safer, more reliable, and require a smaller derating than tantalums.

Aluminum Electrolytic: ? Integral standoff >0.38mm (0.015") required on PTH parts to raise the part off the PCB during wash.

DFx Guide Section: 2.4.6 Capacitor Selection Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Small Chip Discrete

Avoid the unnecessary use of discrete component sizes below 0603.

0603 vs. 0402 Assembly Defect Rates
1200 1000 800 600 400 200 0 Resistors Capacitors 0603 0402

DFx Guide Section: 2.1.9 Non-Preferred Components Manual check
DFM 101 Part1 | Dec 2008 Confidential

DPMO

Small Chip Discrete
Added Placement Time for Discretes vs. Rpacks

Placement time per board (min)

2 1.5 1 0.5 0 0 200 400 600 800 1000 Resistors per board

Use resistor packs rather than individual resistors where a number of the same value of resistor exist.

DFx Guide Section: 2.1.8 Component Count Reduction Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Lead Prepping / Preforming

Lead prepping or pre-forming requires extra operation time and should be avoided where possible

Even the shortest available lead length will require trimming.

DFx Guide Section: N/A Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Component Height

DFx Guide Section: 8.1.3 Height Limitations Valor coverage: c_height_p, c_height_s (Component Analysis)
DFM 101 Part1 | Dec 2008 Confidential

Component Height Selective Wave Solder

Component to be soldered

Maximum component height = 0.375” (9.53mm)
Solder wave profile Selective wave solder fixture

DFM 101 Part1 | Dec 2008 Confidential

04/12/1998

Component Height

Problem: ? Component height is 0.482” (12.24mm) ? Maximum allowable height is 0.375” (9.53mm) for selective wavesolder
0.482”

? Component must be attached
post-SMT with a rework tool. Impact: ? $30-40 cost adder per part Ceramic Column Grid Array on Secondary Side of PCB

DFM 101 Part1 | Dec 2008 Confidential

Components
Component Selection Exercise
Assess the following parts for manufacturability. Datasheets are provided. ? Molex 52837-0609 ? FCI Berg 54102-G08-02 ? Panasonic ERJ2RKF102V
Checklist Item Components 5 New Packages 6 Comments Manual / Valor M M NA 2.1.6 Process Compatibility Requirements DFx Guide References (Internal) May need development &/or qualification. Prefer washable parts for process Washable and flexibility. SMT & paste in hole parts Reflowable must be reflowable. Packaging Prefer shipment packaging not specified on BoM, or follow preferred formats in DFx Guide. Part Removal from Remove any non-production parts Production BOM prior to final BOM release e.g. test header. Fine Pitch Components Impact to SMT & PTH assembly yields. Check for vacuum pickup for SMT placement, e.g. connectors. May need development &/or qualification. Consider additional processes & equipment required. Check retention method is suitable vs. requirements. Consider impact on assembly & rework. Avoid using ceramics larger than 1210 size & film capacitors. Use 0603 or larger if possible, especially for capacitors. Combine 0402s or 0603s to Rpacks to reduce placement time. Avoid prep / pre-form requirements on parts. Check topside & bottomside height vs. equipment limitations.

7

M

2.1.13 Component Supply/Packaging Formats NA

8

M

? AVX 18255C223MAT2A

9

c_pitch

10 Autoplacement 11 Complex Connectors

M M

2.1.9 Non-Preferred Components 2.2.1 Package Selection 2.5.1 Wave Solder PTH Components 2.5.2 Paste-in-Hole Components 2.6.4 SMT Connectors NA

12 Connector Mechanical Retention

M

2.6.2 Alignment and Retention 2.6.3 Retention for SMT Connectors 2.5.2 Paste-in-Hole Components 2.4.6 Capacitors 2.1.9 Non-Preferred Components 2.1.8 Component Count Reduction NA 8.1.3 Height Limitations

13 Capacitors 14 Small Chip Discretes 15 Discretes to Rpack 16 Lead Prepping / Preforming 17 Component Height

M M M M c_height_p, c_height_s

DFM 101 Part1 | Dec 2008 Confidential

Components
Component Selection Exercise
Assess the following parts for manufacturability. Datasheets are provided. Molex 52837-0609 ? unclear whether the cover can be used as a vacuum pick-up cap, contact supplier to verify ? if not & it will be manually placed, prefer tube packaging over tape & reel

? does this component have the thermal resistance for reflow?

Operating temperature, not processing temperature

FCI Berg 54102-G08-02 ? may not be required in production, verify with designer - ensure removal from production BOM if not required ? if using wave, will likely float: recommend change to retentive leg option (see Note 5 on drawing)

DFM 101 Part1 | Dec 2008 Confidential

Components

Components
Component Selection Exercise

Assess the following parts for manufacturability. Datasheets are provided.

Panasonic ERJ2RKF102V
? no concerns - 0402 resistor yield approximately equal to 0603, providing land patterns are acceptable ? depending on quantity of the same resistance value, consider changing to Rpack

AVX 18255C223MAT2A ? ceramic cap > 1210 may need additional analysis to understand potential reliability effects, if possible replace with smaller package(s) ? suggest P/N 12105C223MAT2A ? we do not recommend having packaging information in the P/N, but if it is required, then recommend changing the 2nd-last number to a 4 - for a 13” reel

DFM 101 Part1 | Dec 2008 Confidential

Process Flow

DFM 101 Part1 | Dec 2008 Celestica Confidential

Process Flow
Checklist Item Process Flow 18 Handsolder, Solder Fountain 19 Non-standard Processes Comments Adds operation time & typically increases defects. May need qualification. Consider added equipment & operation time required. May limit site to site transfer &/or volume upside. Adds operation time & typically increases defects. Manual / Valor M M DFx Guide References (Internal) 1.13 Process Flow Hierarchy 1.13 Process Flow Hierarchy

20 Wire Adds / Deletes

M

2.4.3 Hand Wires or Wire-Adds

DFM 101 Part1 | Dec 2008 Confidential

Hand solder, Solder Fountain

Minimize hand solder and solder fountain attach by selecting components and designing board layout for higher yielding, more automated batch processes, e.g. auto SMT, paste in hole, full or selective wave solder, press fit

Examples where manual soldering is required: ? Temperature sensitive components ? Double-sided soldered PTH components ? Secondary side component too heavy ? Secondary side component too tall, on a selective wave solder board ? Few SMT components placed on secondary side (too few for automated line) ? Etc.

DFx Guide Section: 1.13 Process Flow Hierarchy Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Non-standard Processes
New Assembly Processes
Examples of new processes: ? Heatsink attach using new adhesive material ? Low temperature attach and rework using different solder alloy ? Manual attach method, requiring new equipment / tooling ? Etc.

Procedure for determining whether a package is “new”, and requires any development / qualification work is the same as for new processes.

DFx Guide Section: 1.13 Process Flow Hierarchy Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Non-standard Processes
New Assembly Processes
(1) Consult documents CELQ-001-PROC-1293 Global Product Transfer Process for guidance (2) Consult document CELQ-001- 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 execution, proposed Plan should be approved by 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.

In production at target site?

Y

OK

N
In production at another site? (3)

Y

Perform Process / Technology Transfer (1) (2)

N
Development / Qualification required? (3)

Y

Create & Execute Development / Qualification Plan (2) (3) (4)

N OK

DFM 101 Part1 | Dec 2008 Confidential

Non-standard Processes

Non-standard Processes
New Assembly Processes

Process Development & Assembly Qualification considerations: ? Process set-up & optimization ? New equipment installation & qualification ? New materials or combination of materials (e.g. solder paste, flux, adhesive) ? Tooling (e.g. stencil design, placement head, reflow nozzle) ? Process parameters (e.g. screening parameters, wave solder parameters, press fit force parameters, rework profiles) ? Assembly reliability ? Mechanical integrity of an interconnection, or corrosion/migration risk of new soldering materials are usually the focus ? Manufacturing flexibility / transferability ? Can this product be built at any site, or only a select few?

DFM 101 Part1 | Dec 2008

Sample Assembly Qualification Plan
17 panels 3 panels 4 panels 2 panels 5 panels 3 panels

Set Up
(1) SMT Profiles (1) Rework profiles

Torque
* ±0.7? * 1cycle/min * RT * 4/4/4 heat sinks

Thermal 1 panel
Bake

Vibration
* 6 Grms * 20-2000Hz * 8 hrs. each axis * 6/6/6 heat sinks

4 panels
Moisture Load Sonoscan

(1) Single card profiles

Rework 1 panel
Torque * 1X only * 3 cards P1 * 3 cards P2

2 panels
Thermal

1 panel
Vibration * 1X only * 3 cards P1 Ship Shock * -40 to 65 ? C * 10 cycles * 2/2/2 heat sinks

* 12 / 24 cards.
Ship Shock * -40 to 65 ? C * 10 cycles * Keep 3 /24 cards to failure * 8/8/8 heat sinks ATC * 0 to 100 ? C * 2 cycles / hr. ATC * 0 to 100 ? C * 2 cycles / hr.

1 panel
Pattern 1 * 3 cards 1X * 3 cards 2X

1 panel
Pattern 2 * 3 cards 1X * 3 cards 2X

* 3 cards P2

Pattern 1 (P1)
776 525 1004 776

Pattern 2 (P2)
525 1004

776

655

776

655

DFM 101 Part1 | Dec 2008 Confidential

Wire Adds / Deletes

Eliminate if possible by incorporating into PCB. ? Additional manufacturing time to perform deletes / adds. ? Manual operation and subject to errors, causing additional repair time (up to 20k ppm per wire) ? Wires on probe side of PCB can interfere with ICT test fixture, and should be avoided. If required, routing paths to avoid test points should be documented.

DFx Guide Section: 2.4.3 Hand Wires or Wire-Adds Manual Check
DFM 101 Part1 | Dec 2008 Confidential

Continue in part 2….


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