Manufacturing Considerations for Optimum Throughput and Quality

Transcription

1 Manufacturing Considerations for Optimum Throughput and Quality

2 Factory Automation Critical to US Manufacturers To compete domestically with offshore CM s, to reduce man labor design s need to consider reducing use of manually installed (Thru-hole) components to full extent possible. Isolate Thru-Hole from solder side SMT to allow access for selective soldering and minimize masking requirements. (i.e. Connectors, Transformers, Relays.) (consider pre-design meeting with manufacturing dept. / company) Maximize Computer Integrated Manufacturing - using CAM enables us to optimize line efficiency, substantially improve our responsiveness and accuracy CIM can also be a baseline for a PLM Tools and establish a forward compatible package and part number library. Establish Consistency Now with component libraries, document formats and define your Revision Control with PLM and factory automation in mind.

3 TJM Core Objectives To deliver electronic hardware that is: 1) Built to print. 2) In conformance with specified standards. 3) Delivered on time.

4 TJM s Value Added Communication Response to RFQ s Daily status updates Project interface (access to Insightly) We verify everything. DFM Report Documents any design, documentation or data concerns throughout the manufacturing cycle. Quality System AS9100 Exceeds commercial standards Delivery One week is currently standard

5 What has the most impact to meeting these 3 main objectives? 1) Kit Condition (when customer supplies parts) 2) Lack of ASCII / CAD / (intelligent machine data) 3) Poor or incomplete documentation -no drawing is provided, silkscreen does not have ref des, polarity and orientation markings missing or ambiguous) 4) Layout / Design issues Most are silkscreen, panelization or fiducial related.

6 RFQ or Build Data / Document Checklist Musts Nice to Have ASCII CAD Data File Revision Controlled BOM Revision Controlled DWG XY file (if ASCII not avail.) Gerber Set Bare Board for Oven Profiling (Baseline) Step File Schematic Board Fabrication Drawing Extra parts set for profiling Sample

7 Procurement / Kit Staging CAM Set Up AOI Inspection SMT ASSEMBLY FIRST ARTICLE Touch up / TH Final Inspection Ship

8 ASCII CAD File CircuitCAM Pick and Place Program AOI Inspection Program Color Coded Visual Aids Build Planning

9 ASCII CAD Design File CAD Data Includes: PWB dimensions, Pad geometries, part package geometries and part number information not provided in standard XY file. Improves our manufacturing efficiency, expediency, quality, and responsiveness. Minimizes the potential for human error (no manual entry) CAD Imports build your component library over time, reducing package and part number entry and programming from job to job.

10 BOM Import Sources and Formats Supported in Format Text (ASCII) CheckPoint Yes CircuitCAM Yes Fixed Column or Character Excel Yes No N/A ODBC (Access) Delimiters Yes No N/A Required Fields Part Number, Reference Designators Preferred Fields Description, Quantity (CheckPoint) Optional Text Fields Part Marking, Package, Population Type, Customer P/N, Mfr, Mfr P/N, Vendor, Vendor P/N, Bin Location, Stock Code, Software Ver, Part Rev, URL Optional Number Fields Cost, Height (mils) Optional Boolean Fields Polarity, Socketed (Y/N,Yes/No, T/F, True/False) Custom BOM Fields Unlimited Additional Functions in CheckPoint Template Definition, Join Multiple Files to Form 1 BOM, Analysis Reports, Use Customer or Internal Number as Primary, AML/AVL Mgmt, Revision Control

11 Fiducials Most common problem we see is there are none. Use of Fids are key to controlling #1 Defect (Tombstones) Have Global Fids in the design data (preferrably as the origin 0,0. Use Panel Fids Once Global fids are used to set up program the panel fids (most often) can be used for production and reduce camera location time.

12 Fiducial Types

13 Yield Results using optimized fiducials Production Defect rate reduced to.012% (down from 3%) on modules with 0402, 0201 and ubga packages. Touch up time reduced by 1/3 of the original board build that had no fiducial locations.

14 Most Common Component Kit Challenges Exact Quantities ordered No Attrition. Part ID - Customer provides alternates in the kit but does not identify alternates on pick list and BOM. (we require to get approval for substitutes to proceed) Chopped Tape Dilemma Need to specify continuous tape from Digikey/Mouser. Component Leads on fine pitch items damaged not protected properly on multipin devices. Customer often holds kit until last item is received. Send kits ahead for review and staging, drop ship final items.

15 WATCH OUT Some things we have come across recently..

16 Inconsistent Pad Geometry on BGA

17 Case sample: Samtec SeaRay Connectors Has an interesting interconnect technology (solder charge) Recommends.006 thick stencil and (min of.005 ) Recommends over sized apertures Notes:If the solder charge does not collapse, due to incorrect stencil parameters, part is difficult to remove, and is not re-useable. Note: we use.004 thick stencils on 80% of our builds due to 0402 and 0201 passives. So here is a situation where you have one part challenging the other for correct tooling.

18 Please Don t use unless you have to White Solder Mask Dark Ledger White mask reflects light and reduces AOI image quality. Machine operators can not see polarity markings or ledger through machine camera during set up

19 Panelization Stencil data in gerber set is for (1) unit. Array data requirement must be communicated to, and provided by, the board house. Why is that difficult to get that from Chinese board vendors? Mousebites Be careful where these are located, keep away from traces, via, components in general. Prefer Scored Tabs Careful about location. Be careful of long, thin scored boarders on boards.063 or thicker. This inflicts mechanical stress on board while trying to break border away

20 Keep Out Areas for Panel Tabs? Mousebites Scored Tab

21 Fab Issues / Most common No Fab drawing and notes or Read-Me files for specs Clear stack up instructions Clarify material types, Copper Weights Trace and spacing should be no less than.005 Finished hole sizes.008 or above

22 Summary Providing ASCII CAD File is key to throughput and accuracy Use Fids Both Global and Panel Oven Profile is Critical Spare Board and Parts provded? Consider letting CM (TJM) buy parts. It s cleaner Mask vs PAD defined(see image) Watch for new component packages with special requirements (Samtec SEARAY)