Transitioning from Rigid to Flex / Rigid-Flex PCB Manufacturing
History of SEC
Peak of North American PCB Industry
Trough of North American PCB Industry m
illio
ns
year
Keys to Recovery
• Hold Production Quality Standards
• Pursue additional certifications
• Wide range of volume and technology
• (layers, materials, blind/buried, etc.)
• (proto through volume)
• Continued investment reduces cost by:
• Increasing operating efficiencies while reducing yield loss
Acquisition Details
• Formerly known as Proto Circuits, established 1978
• No investment since 1997 (or before)
• No sales force
• Few new customers within the last 10 years
• All certs dropped over time
Acquisition Challenges
• Customers designing around Proto’s weaknesses
• Loose systems
• Neglectful vendor base
• High cost structure
• Lack of management structure
Current Operating Results
• Attained profitability within 14 months
• Producing >10 layers rigid flex
• 2 mil line / spacing outer layers
• Complex blind / buried / sequential lamination builds
• In process of reinstating ISO9000 and Mil-Prf-31032
Ease of Transition
Dependent on Starting Point
• Standard 2-6 layer rigid shop?
• Blind / Buried; HDI; Advanced Technologies shop?
Identifying transferrable skills
• Drill development
• Tooling for multi-Lam registration
• Imaging Techniques
Myths
• Black Magic
• Materials difficult to handle
• Materials difficult to register
Truths
• Black Magic
• Materials difficult to handle
• Materials difficult to register
Truths
Black Magic = Experience and Learning
• Stackups
• Various flexible materials (adhesive vs. adhesiveless)
• Hybrid constructions
• Coverlay vs. Soldermask
• Sequential laminations
• Laminating with Cavity cutouts
Truths (cont.)
Materials difficult to handle
• 1 to 3 mil cores of flex material are commonplace
• Leaders are commonplace (increase labor content)
• Automation is very different than in rigid shops
Truths (cont.)
Materials difficult to register
• Standard rigid tooling systems no longer apply
• Multiple pins for each sequential lamination and drill cycle
Flex material has no grain
• Material behavior very different from FR-4
• Often expands rather than contracts
Change Management
Extract better parts of Rigid MFG system and apply to Flex
• Automation
• Quality Control verifications
• Sales / Service
• QTA offerings
Equipment
Standard Rigid Equipment can easily be used
• Slight re-tooling may be required
• Leaders for conveyorized processes
AOI and Testers
• Specialized for thin materials
All in all, not so much work needed here…
SO LONG AS YOU INVEST TIME TO ENGINEERING THE PROCESS
General Workforce
• Rigid shop machine operators simply operators
• Especially lower technology shops
• Subsequent inspection steps for filtering out bad parts
• With rigid-flex, however…
• No such thing as “just an operator”
General Workforce
Continuous Training should be required
• Engineering reviews for new part #’s
• Discussion of yield loss
• Root cause
• Potential actions that could have corrected for this
• Operators should be aware of selling prices and raw materials costs
• Dramatically higher than rigid prices and costs
Management
Rigid Shops (especially lower tech) tend to minimize costs via:
• Minimal Engineering
• Reduced training initiatives
• How to do the job vs. what the job means
• Throughput is paramount
Management, cont.
Demands of a Rigid-flex environment
MGT must provide financial/organizational support to the following:
• Continuous Process Engineering
• Promote Workmanship
• Sacrifice Throughput for better yield
Management, cont.
Continuous Process Engineering
• Tremendous amount of upfront engineering (establish that baseline)
• Drill Quality
• Lamination control
• Registration
• Adjust to changing designs / stackups
• Engineering on-the-fly is commonplace
Management, (cont.)
Promote Workmanship
Significantly increased training at the operator level
• Extra handling care
• Extra process setup verification
• More in-process testing
• Every operator needs to become an inspector
Management, cont.
Sacrifice Throughput for better yield
Rigid Production
• Based on number of panels per hour
Rigid-Flex
• Focused on number of perfect panels per hour
Management, cont.
Flex Customers are typically more scrutinizing
• Medical
• Military
• High-End Commercial
Flex’s scrupulous nature results in higher-reliability
Management, conclusion
Transitioning effectively from Rigid to
Rigid-Flex requires a commitment from
Management to absorb the educational
requirements necessary to not only
comprehending the Product but are also
vital to understanding Process Flows.