Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Earl Moon

#10264

PCB fab supplier supplier/evaluation | 5 August, 1999

Mike,

Got your message and those of others concerning PCB fab supplier evaluation and qualification check lists, etc. I have a severe problem here in WI as I can hardly access the internet, and when I do it is cut off abruptly for no good reason.

I appreciate your positions. I am seeking local service as I cannot use my connection at work to get the messages out.

I'll find a way to get you all the information in a simple, easy to use format?

Earl

reply »

#10265

Re: PCB fab supplier supplier/evaluation | 5 August, 1999

| Mike, | | Got your message and those of others concerning PCB fab supplier evaluation and qualification check lists, etc. I have a severe problem here in WI as I can hardly access the internet, and when I do it is cut off abruptly for no good reason. | | I appreciate your positions. I am seeking local service as I cannot use my connection at work to get the messages out. | | I'll find a way to get you all the information in a simple, easy to use format? | | Earl | Thanks Earl I knew you would come through....

MD Cox

reply »

JohnW

#10266

Re: PCB fab supplier supplier/evaluation - connection problems | 7 August, 1999

| | Mike, | | | | Got your message and those of others concerning PCB fab supplier evaluation and qualification check lists, etc. I have a severe problem here in WI as I can hardly access the internet, and when I do it is cut off abruptly for no good reason. | | | | I appreciate your positions. I am seeking local service as I cannot use my connection at work to get the messages out. | | | | I'll find a way to get you all the information in a simple, easy to use format? | | | | Earl | | | Thanks Earl | I knew you would come through.... | | MD Cox | | Earl,

a buddy of mine had really bad problem's connecting when he was over there ( in the US) he ended up using his digital Mobile and a fancy addapter for his modem, don't know how quick it was but he definatley got a better service.

just a thought

JohnW

reply »

Earl Moon

#10267

Re: PCB fab supplier supplier/evaluation - connection problems | 7 August, 1999

| | | Mike, | | | | | | Got your message and those of others concerning PCB fab supplier evaluation and qualification check lists, etc. I have a severe problem here in WI as I can hardly access the internet, and when I do it is cut off abruptly for no good reason. | | | | | | I appreciate your positions. I am seeking local service as I cannot use my connection at work to get the messages out. | | | | | | I'll find a way to get you all the information in a simple, easy to use format? | | | | | | Earl | | | | | Thanks Earl | | I knew you would come through.... | | | | MD Cox | | | | Earl, | | a buddy of mine had really bad problem's connecting when he was over there ( in the US) he ended up using his digital Mobile and a fancy addapter for his modem, don't know how quick it was but he definatley got a better service. | | just a thought | | JohnW | | John,

Appreciate the thought. I'm examining the options first by starting with a very local IP. It will be installed Monday so we'll see. I also thought of using the cell capabilities offered as "Ricochet" or some other similar, portable brand. Anything to get back in business except at midnight only and having to pay for long distance 800 number charges at over $100 extra/month.

Thanks,

Earl

reply »

Earl Moon

#10268

Re: PCB fab supplier supplier/evaluation | 8 August, 1999

| | Mike, | | | | Got your message and those of others concerning PCB fab supplier evaluation and qualification check lists, etc. I have a severe problem here in WI as I can hardly access the internet, and when I do it is cut off abruptly for no good reason. | | | | I appreciate your positions. I am seeking local service as I cannot use my connection at work to get the messages out. | | | | I'll find a way to get you all the information in a simple, easy to use format? | | | | Earl | | | Thanks Earl | I knew you would come through.... | | MD Cox | | Mike and others,

I've never had a more frustrating time with our wonderful internet. Even on a Sunday it sucks from WI. Maybe tomorrow it will change with a local provider or?

I cannot do anything email but this may get the job done. The following is a dated master drawing requirement profile you all will have to work on to make it better. However, it ain't bad now but for updating with appropriate specifications, etc. Also, is a check list derived from my PCB Fab Basics article. Hope all this helps. It helps me all the time though not on the internet.

PRINTED CIRCUIT BOARD BASIC MASTER DRAWING NOTES AND SUPPLIER AUDIT CHECK LIST

MASTER DRAWING REQUIREMENTS Master Drawing requirements shall take precedence over all other specified requirements supporting the contract. POD PCB Acceptance Specifications (ES -0200) support this drawing as inspection and test methods indicated therein. Neither this drawing nor attendant specifications provide fabrication process methods. They provide only acceptance criteria and reference inspection and test methods to determine quality, respectively. The following requirements shall be agreed upon by POD suppliers so POD printed circuit quality is assured before contract issue, acceptance, and performance:

1.0 GENERAL ACCEPTANCE REQUIREMENTS

1.1 MASTER DRAWING All printed circuit fabrication requirements shall conform to the following notes and graphic information as part of the master drawing:

1.2 ACCEPTANCE CRITERIA Printed circuitry, fabricated to meet POD contract requirements, shall be inspected, tested, analyzed, and accepted in accordance with this drawing, other POD acceptance criteria (when required), and referenced (herein) inspection and test Methods.

1.3 CONFLICT In case of conflict between POD contract, master drawing, artwork, or other specified requirements, the master drawing shall take precedence.

2.0 SPECIFIED ACCEPTANCE REQUIREMENTS The following material, plating, and other requirements shall be met to assure contract conformance and quality acceptance:

2.1 MATERIAL

2.1.1 Metal Clad Laminate And Thin Laminate Tg Requirements All metal clad laminate, and thin laminate Tg requirements shall be met in accordance with MIL-P-13949H, or IPC-4101, and shall have a minimum Tg of 150 degrees C. determined using thermomechanical analysis (TMA), differential scanning calorimetery (DSC), or other appropriate test methods per IPC-TM-650, Test Method #?

2.1.2 Metal Clad Laminate And Thin Laminate UL Recognition All metal clad laminate and thin laminate shall be recognized to UL-94 V2, or better. Prepreg and thin laminate flammability shall be tested in accordance with IPC-TM-650, Test Method # 2.3.9. Laminate flammability shall be tested in accordance with IPC-TM-650, Test Method # 2.3.10. Solder Mask flammability shall be tested in accordance with IPC-TM-650, Test Method # 2.3.10.1.

2.1.3 Metal (Copper) Foil Metal foil shall be electrodeposited (ED) copper and shall be the thickness indicated in the POD MLB construction graphic herein. Metal (Copper) foil purity shall be determined in accordance with IPC-TM-650, Test Method # 2.3.15.

2.2 METALIC PLATING COATING AND SOLDER MASK

2.2.1 Copper Plating Thickness Copper plating thickness shall be .001" minimum in all holes and shall be determined using X-Sectional and other appropriate test methods.

2.2.2 Copper Plating Ductility Copper plating ductility shall be 20% minimum determined using appropriate ASTM test methods to measure specified tensile strength and elongation characteristics.

2.2.3 Immersion Gold Over Immersion Nickel Conductors shall be immersion "plated/coated" with a minimum of three (3) to a maximum of ten (10) micro-inches, as measured using "microderm" or beta back scatter test methods, applied over immersion "plated/coated" nickel with a maximum thickness of 120 micro-inches over contamination free copper surfaces to promote solderability.

2.2.4 Solder Mask Location There shall be no solder mask on any solder surface except that applied in lieu of "silkscreened" marking inks as indicated on the legend drawing/artwork.

2.2.5 Part Identifying Legends Part identifying legends shall be clearly legible, black, nonconductive, liquid photoimageable (LPI) "soldermask" - not applied on any solderable area or where not visible.

2.3 PHYSICAL FEATURES AND UNACCEPTABLE CONDITIONS VISUAL

2.3.1 Dimensions And Tolerances Dimensions and tolerances shall be as indicated or + or - .005".

2.3.2 Warp (Bow) And Twist PCB warp or bow and twist shall not exceed more than .007" per inch (L&W) and shall be determined using appropriate IPC test methods.

2.3.3 Conductor Pattern Tolerances Conductor pattern tolerances shall be + or - 20%, and nicks, cuts, or other anomalies shall not reduce overall conductor width and thickness by more than 10%.

2.3.4 Surface Or Subsurface Imperfections There shall be no visual evidence of surface or subsurface imperfections as meazling, crazing, delamination, haloing, laminate voiding, residue contamination, foreign object inclusions, solder mask (when required) failures, surface plating anomalies, or other unacceptable conditions or anomalies exceeding IPC or MIL-P-55110 requirements. X-SECTIONAL

2.3.5 Hole To Pad Registration And Annular Ring Requirements Hole to pad registration shall be such that .002" minimum internal and external (.005" where a trace intersects a pad) annular rings are assured in each hole in the MLB.

2.3.6 Hole Wall Preparation - Resin Smear Hole wall preparation shall be effected to ensure no resin, or other smear, is apparent in plated hole to conductor interfaces.

2.3.7 Hole Wall Preparation - Glass Fiber Protrusion Hole wall preparation shall ensure no glass fiber intrusion is apparent in hole wall plating.

2.3.8 Hole Wall Preparation - Plating Support All hole wall preparation requirements shall be met to ensure specified electroless and subsequent electroplating requirements are met.

2.3.9 Electroless Copper Deposition Electroless copper deposition in hole walls shall be sufficient to support electro copper plating with voiding not exceeding IPC and MIL-P-55110 requirements.

2.3.10 Electro Plated Copper Electro plated copper shall be .001" minimum in all holes.

2.3.11 Electro Plated Copper Ductility Copper plating ductility shall be 20% minimum as measured using appropriate ASTM methods.

2.3.12 Multilayer Laminate And Hole Integrity Multilayer laminate and hole integrity shall meet IPC and MIL-P-55110 requirements ensuring no delamination or hole wall failures (cracking, separation, etc.) are apparent as received and after thermal stress and shock testing.

2.3.13 Pad Lifting (Rotation) Pad lifting ("rotation") requirements shall be met in accordance with IPC and MIL-P-55110.

2.4 OTHER REQUIREMENTS Other requirements, including visual, electrical, X-Sectional, and solderability, shall be met in accordance with POD Acceptance Specifications And Test Methods (ES -0200) - when required.

2.4.1 Marking, Identification, And Traceability Marking and identification requirements shall be met to ensure traceability and identification of specific boards, lots, and test circuitry to each other. Test circuitry shall be traceable to the board and panel from which it was detached. Boards processed in the same manner, within the same process, at the same time, under the same process conditions shall be identified, and marked as an individual lot. Individual test coupons shall be traceable to the quality conformance test circuitry from which they were detached.

2.4.2 Surface Solderability Conditions Surface solderability conditions shall be met to ensure proper wetting of all surface areas to be soldered. No more than 2% dewetting, or nonwetting, shall be allowed. Excessive, copper/tin, gold, or other intermetallic formations, deleterious to soldering and solderability, shall be cause for rejection.

2.4.3 Hole Solderability Hole solderability shall indicate the same wetting characteristics as surface condition requirements. Solderability testing for holes and surfaces shall be performed in accordance with MIL-P-55110, paragraphs 3.5.6, 3.5.6.2, 4.8.2.6.2, and with IPC-S-804, paragraphs 3.6.4, 3.7.1.1, 3.7.8.1.3, 3.7.2.7, and 4.4.

2.4.4 Surface Mount Pad Bond Strength Surface mount pad bond strength shall be a minimum of 5 lbs. when measured after rework simulation in accordance with IPC and MIL-P-55110 requirements, and pads on PCB's shall exhibit no sign of pad lifting after testing or normal aPODmbly operations.

2.4.5 Electrical Properties, Performance, And Parameters Electrical properties, performance, and parameters shall be tested both on bare boards and test circuitry. Continuity shall be tested on the bare board and on the test circuitry. Dielectric withstanding voltage and insulation resistance shall be measured on the test circuitry. Dielectric withstanding voltage, when required, shall be determined in accordance with MIL-P-55110, paragraphs 3.10.2, 4.8.7.2, and with MIL-STD-202, Method 301. Moisture, and insulation resistance testing, when required, shall be determined in accordance with MIL-P-55110D, paragraphs 3.6.3, 3.10.1, and 4.8.7.1, with IPC-TM-650, Method 2.6.3, and with IPC-A-600. Time Domain Reflectometry, used in direct conjunction with X-Sectional Analysis, shall be used to determine characteristic impedance values.

2.4.6 Cleanliness Requirements Cleanliness testing shall be conducted in accordance with MIL-P-55110 (paragraph 4.8.7.4.1) and MIL-C-28809 (paragraph 4.8.2) requiring that resistivity of solvent extract solution testing be performed indicating ionic contamination levels of 2 megohm/cm or greater. All chemical residues shall have been removed, and no evidence of foreign matter, or other contamination shall be apparent (EXPAND THIS TO INCLUDE SIR OR IONIC AS REQUIRED).

2.4.7 Quality Conformance Test Circuitry Suppliers shall use attached quality conformance test circuitry to verify quality of all requirements stated herein.

2.5 MULTILAYER CONSTRUCTIONS Multilayer construction requirements shall be met in accordance with the following graphic ensuring highest laminate integrity, bond strength, dimensional stability, and electrical performance while ensuring dielectric and overall MLB thickness does not exceed + or - 10%:

Note: Clearly indicate MLB constructions here for your specific need. I recommend you also learn about glass styles and resin contents for better dimensional stability, electrical performance, and inner laminar bond strength, as well as surface foil bond strength.

Note: Customize these master drawing notes for you use. I it obvious some of these requirements are dated. You will need to review IPC requirements for design and fabrication to convert such things as MIL-P-55110 requirements to 6012. It will be a good exercise though I still use the MIL specification often as it is very specific and clear.

Note: Convert whatever requirements you come up with, based on the above, to clearly defined acceptance specifications. Master drawing notes and graphics must provide suppliers information concerning basic requirements. Acceptance specifications are much more detailed. Neither is intended to tell suppliers how to process boards, but are intended to specify required quality.

PCB FABRICATION SUPPLIER AUDIT CHECK LIST For this check list, I used my article about PCB Basics and Supplier Evaluation and Qualification - Laboratory Information. You may do the same.

1) UP FRONT LABORATORY 2) CAM 3) MATERIAL PREPARATION 4) IMAGE 5) ETCH 6) LAMINATION 7) DRILLING 8) PLATING (AND ATTENDANT WET CHEMICAL PROCESSES) 9) SOLDER MASK 10) FABRICATION 11) QUALITY ASSURANCE LABORATORY ANALYSIS 12) FINAL INSPECTION AND TEST

reply »

reflow oven profiler

SMT Equipment