When manufacturing higher technology circuit boards, there are many variables that could increase the costs of your parts or increase the lead time. The goal of this webinar is to demonstrate how design choices add cost and time to the manufacturing process of printed circuit boards.
While we all understand that hi-speed/high technology PCBs need to have these complex features in order to deliver their intended result,in many cases these features can be left out during the development and prototype stages in order to help the designer prove out ideas quicker.
In this webinar, our goal is to help everyone understand what to expect in terms of delivery time for features,such as the material selection, vias, castellated edges, and embedded resistors that they incorporate into their circuit boards.
For more information on our printed circuit board solutions,visit http://www.epectec.com/pcb/.
Double Revolving field theory-how the rotor develops torque
How PCB Design Choices Affect Overall Cost from Your PCB Fabricator
1. Manufacturing That Eliminates Risk & Improves Reliability
04.24.2020
How PCB Design Choices Affect Overall
Cost From Your PCB Fabricator
2. Manufacturing That Eliminates Risk & Improves Reliability
2
Agenda
Intro – HDI PCBs
Via Types – How they are made
Filled Vias – It’s more complicated than it looks
Castellated Edges/Half Plated Holes
Cavities, Air Pockets, and Heat Sinks
Hybrids – PCBs with mixed dielectrics
Materials – Type and other factors
Inspection AS9100 – What it takes
Summary
4. Manufacturing That Eliminates Risk & Improves Reliability
4
HDI – High Density Interconnect PCB
HDI is a PCB with a higher wiring density
per area, finer lines and spacing, smaller
vias, higher aspect ratios, and pads than
conventional PCBs.
HDI boards contain blind and/or buried
vias and often contain microvias of
0.006” or less in diameter.
To produce HDI boards, investment in
laser direct imaging, laser drilling,
vacuum controlled pressure plugging,
alkaline permanganate desmear, and
advanced planarization equipment is a
must.
6. Manufacturing That Eliminates Risk & Improves Reliability
6
Via Types
Need Laser Drilling Equipment to accurately control the depth of the
hole with such a small diameter.
7. Manufacturing That Eliminates Risk & Improves Reliability
7
Via – Definitions
IPC definition of a microvia = a hole with an aspect ratio of 1:1
– They usually are:
1. Filled with epoxy resin (b-stage) during a sequential lamination process step.
2. Filled with non-conductive or conductive material other than copper as a
separate processing step.
3. Plated closed with electroplated copper.
4. Screen printed closed with a copper paste.
A stacked microvia is usually filled with electroplated copper to make
electrical interconnections between multiple HDI layers and provide
structural support for the outer level(s) of the microvia or for a
component mounted on the outermost copper pad.
8. Manufacturing That Eliminates Risk & Improves Reliability
8
Lamination Cycles
Every buried or
stacked via requires
a lamination cycle.
Think Delivery…
75% Processes Every Time
2
Hours
1
Hour
9. Manufacturing That Eliminates Risk & Improves Reliability
9
Blind and Buried Vias
It’s all about lamination and plating cycles.
6 Layer Example:
– Each Cycle Requires
• Drill & Hole Prep
• Plate
• Deburr
• Via Fill
• Image/Etch/AOI
• Repeat
– Standard 6 Layer
• Image/Etch/AOI (A)
• Laminate
• Drill
1
2
2
3
A
A
10. Manufacturing That Eliminates Risk & Improves Reliability
10
Blind versus Buried
3 sets of blind vias
Only one lamination cycle
Control depth laser drill
One exception
– Dissimilar laminates
Buried, staggered, or stacked vias
all require more lamination cycles.
12. Manufacturing That Eliminates Risk & Improves Reliability
12
Old School
Many companies still use these
methods today.
13. Manufacturing That Eliminates Risk & Improves Reliability
13
Processes Needed – 3 ways
Drilling of only the vias that
need filling
Cleaning: plasma and brushing
Electroless copper
Apply dry resist
Imaging of ONLY the via holes
Electrolytic plating
Strip dry resist
Baking: 150°C for 2 hours
Via plugging with resin
Baking: 150°C for 1.5 hours
Planarize the panel
Drilling the remainder of the
holes
Cleaning: plasma and brushing
Electroless copper
Apply dry resist
Imaging of ONLY the via holes
Electrolytic plating
Drilling of all vias
Cleaning: plasma and brushing
Electroless copper
Electrolytic plating
Baking: 150°C for 2 hours
Build a fixture so to only fill the
holes that need filling
Via plugging with resin
Baking: 150°C for 1.5 hours
Planarize the panel
Electroless copper
Apply dry resist
Imaging of the circuitry
Electrolytic plating
Drilling of all vias
Cleaning: plasma and brushing
Electroless copper
Electrolytic plating
Baking: 150°C for 2 hours
Fluid nozzle fill of only the
holes – Requires CNC
programming
Via plugging with resin
Baking: 150°C for 1.5 hours
Planarize the panel
Electroless copper
Apply dry resist
Imaging of the circuitry
Electrolytic plating
All 3 add at least 6-8 hours
14. Manufacturing That Eliminates Risk & Improves Reliability
14
Proper Filled Vias
>10 mil vias – Easy to Fill
<10 mil vias – Easier to Plate Shut
16. Manufacturing That Eliminates Risk & Improves Reliability
16
Castellated Edges/Half Plated Holes
The process is very specialized, and
everyone thinks that they have a secret
sauce.
Pre-Plate Route
Feeds and Speeds
Tool Sharpness
Customers need to specify what is
acceptable.
17. Manufacturing That Eliminates Risk & Improves Reliability
17
What happens if you try and go cheap?
You can’t just plate a standard PTH and then try and mechanically
rout through the plating or this happens.
19. Manufacturing That Eliminates Risk & Improves Reliability
19
Required tight tolerance machining
Traditional PCB CNC equipment is
not suitable for controlled depth
tight tolerance machining.
OR – no flow pre-preg, which
requires intricate machining
How to help?
– Specify a radius
– Minimize 90% edges on internal
features
Cavities and Air Pockets
20. Manufacturing That Eliminates Risk & Improves Reliability
20
Heat Sinks
Heat sink made separate
Attach using no flow precut prepreg
Need a lamination press
How to help?
– Work with your fabricator when
choosing the type of prepreg to be
used
– Make sure that your heat sink and
your PCB laminate can withstand
the temperature of lamination
27. Manufacturing That Eliminates Risk & Improves Reliability
27
AS9100 Inspection - Bubble Drawing
Is it really needed?
28. Manufacturing That Eliminates Risk & Improves Reliability
28
AS9100 Inspection
InspectionXpert Software
Balloon your part drawings and extract the characteristics in one step.
Your tolerances are automatically applied, and the spec limits are
calculated.
Reduces time and cost to complete AS9100 reports and improves
accuracy.
Import the CMM data into a project and have the measurement results
auto-assign to the corresponding feature. Then publish the data
directly to your inspection report.
29. Manufacturing That Eliminates Risk & Improves Reliability
29
A few more things to know….
Teflon – Drill hit counts reduce 50% (additional cost)
PTFE – Needs to be in press soon after etch (can’t sit overnight)
ENEPIG – Most fabricators outsource this (adds time)
– Very expensive and plates out without enough use
Embedded Resistors – Bigger is better for tolerance
– 25 Ohm material – with a +/-1 mil etch tolerance
• 10 mil x 10 mil: 9/11 x 25 = 20.45 Ohms
• 100 mil x 100 mil: 99/101 x 25 = 24.8 Ohms
31. Manufacturing That Eliminates Risk & Improves Reliability
31
Summary
Design choices factor into the cost and
delivery of PCBs.
Not all vias are the same.
Material choices – anything just not
everything
When delivery is paramount – can you
make it easier.
Working with your fabricator EARLY is
critical in meeting all your cost and
delivery targets.
32. Manufacturing That Eliminates Risk & Improves Reliability
32
Upcoming Webinars
Go to…
https://www.epectec.com/webinar/
– May 29th
• Do You Really Need Lithium or Will
Nickel Metal Hydride Suffice?
– August – TBD
– November 20th
• Reducing Risk in Your Custom
Cable Assembly
34. Manufacturing That Eliminates Risk & Improves Reliability
34
Q&A
Questions?
– Enter any questions you may have
in the Control Panel
– If we don’t have time to get to it, we
will reply via email
35. Manufacturing That Eliminates Risk & Improves Reliability
35
Thank You
Check out our website at www.epectec.com.
For more information email sales@epectec.com.
Stay Connected with Epec Engineered Technologies
Follow us on our social media sites for continuous technical updates and information: