driving cost out of your designs - eagle … cost out of your design through your pcb...

DRIVING COST OUT OF YOUR DESIGNS THROUGH YOUR PCB FABRICATOR’S EYES!

Brett McCoy Eagle Electronics

Schaumburg IL. New England Design and Manufacturing Tech Conference

4/3/2013

DRIVING COST OUT OF YOUR DESIGN THROUGH YOUR PCB FABRICATOR'S EYES!

Brett McCoy:

Vice President / Director of Sales

Circuit board fabrication for over 15 years.

Operations and company financial responsibility

Sales and marketing

Oversight of Quality and Engineering Departments

Key technical contact for all customer inquiries

Over 5 years experience in CAM Engineering

4/3/2013


History Operations begin in 1979 with a focus on medium to high

volume rigid PCB fabrication. Evolved into a quick turn to medium volume domestic facility focused on the North American market. ISO 9001:2008 certified since 1996 and ITAR registered. 50K sqft facility based in Schaumburg, IL with 80 employees. Currently produces product in as little as 24 hours ranging from simple single sided to large format 32 layer with blind/buried vias.

4/3/2013


We Are your partner!

We have to “be the customer”

The difference between a great product and a

merely good product is that the great product

embodies an idea people can understand and

learn about –an idea that grows in their minds,

one they emotionally engage with

Creating the customer experience

4/3/2013


Partner with your suppliers

They are your resource

They are product experts

They are there to help you succeed

4/3/2013


Key Topics

Material utilization and specification

Surface finishes

Understanding and specifying via protection

Who is building your PCB design?

Panelization

What level of test do you need?

What is tooling and who owns it?

Ensuring Transferability

Simple ways to control costs

4/3/2013



PCB basic building blocks?

Laminate

Most laminates are produced with dielectrics ranging from

0.002” to 0.200” thick. Copper thickness ranges from 1/4oz to

12oz, however the most readily used is 1/2oz to 4oz.

Pre-preg

Typical glass styles and their associated thickness

106 = 0.0018” thick

1080 = 0.0025” thick

2113 = 0.0035” thick

2116 = 0.0045” thick

7628 = 0.007” thick

4/3/2013



Why choose one laminate system over another?

Electrical performance

Dk – Dielectric Constant

Ratio of capacitance of an electrically insulating material

Df – Dissipation Factor (loss tangent)

Ratio of the power loss of a dielectric material

Thermal performance

Td – Decomposition Temperature

Temperature at which the dielectric material will breakdown

Tg – Glass transition Temperature

Temperature at which the resin system will begin to flow

CTE – Thermal expansion (X-Y-Z)

4/3/2013



Why choose one laminate system over another?

Impedance or RF

Low loss material for high speed signals

Leaded or Lead-Free Assembly

Lead Free assembly requires a Td of 340C or higher

Typical lead free material has a Tg value of 150C or above

Material Availability (When specifying a manufacturer)

Always keep in mind to utilize STANDARD materials readily

available to your PCB fabricator.

4/3/2013



How to specify material?

IPC-4101C

Slash sheet

/126 = Most compliant for lead free FR-4 material

/21 = standard FR-4 (non lead free compatible)

By Electrical/Thermal Performance

Dk/Df if impedance/rf is required

Tg/Td of material based on assembly and end application

4/3/2013



How to specify material?

IPC-4101C (example)

Laminate and pre-preg to be in accordance with IPC-4101C/126

By Electrical/Thermal Performance (example)

Laminate and pre-preg to have a minimum Td value of 340C

Controlled Impedance required with a Dk value of 3.8

4/3/2013



When to specify a specific laminate/pre-preg?

Impedance/RF Required

Tight Impedance (+/- 5% or below) and especially RF designs

can be very sensitive to changes in the laminate system. Even if

the material change is an equivalent in terms of electrical

attributes small differences in fillers used, resin content, and

glass style will impact signal output. Prototype and production

parts of this nature should specify the exact type (manufacturer)

and grade of the laminate/pre-preg as well as a specific layer

stack-up defined.

4/3/2013



Reduce Cost and Lead Time?

Allow the PCB manufacturer to choose the material

whenever possible. By specifying by IPC-4101C or the

electrical/thermal requirements will allow the fabricator

to utilize their standard materials.

Each fabricator has their own preferred materials based

on region, price, support, and service. By leveraging

these stocked items you will be assured of the lowest

laminate cost, highest yield, and virtually no delays in raw

material procurement.

4/3/2013


Surface Finishes

What surface finish to use and costs associated?

ENIG – Electroless Nickel Immersion Gold

IPC-6012 table 3-2 defines the nickel thickness to be 118u”

(min). Typical process range is 150 – 200 u”

IPC-6012 table 3-2 defines the gold thickness to be 1.97u”

(min). Typical process range is 2-4 u”

Flat solderable surface ideal for SMT components especially

tight pitch devices such as BGA’s.

Easier to control plated hole diameters; good for press fit holes

Long shelf life (1 year or longer when properly stored)

Can survive multiple reflow cycles.

Expensive – Can be nearly 30% more than HASL

4/3/2013


Surface Finishes


Immersion Silver

IPC-6012 table 3-2 defines the silver thickness to be solderable.

Typical process range is 8–16 u”.

Flat solderable surface ideal for SMT components especially

tight pitch devices such as BGA’s.

Easier to control plated hole diameters; good for press fit holes

Special care must be taken in packaging and storage.

Short shelf life ranging from 2-6 months.


Less expensive than ENIG by as much as 20%.

4/3/2013


Surface Finishes


Lead Free HASL

IPC-6012 table 3-2 defines the LFHASL thickness to be

coverage/solderable. Typical process range is 50–400 u”.

Similar solderability as HASL

ROHS

Uneven surface finish not ideal for tight pitch devices.



Low Cost ROHS alternative (5% more than HASL)

4/3/2013


Surface Finishes


HASL

IPC-6012 table 3-2 defines the HASL thickness to be

coverage/solderable. Typical process range is 50–400 u”.

Extremely good solderability.

Contains lead (non-ROHS)

Uneven surface finish not ideal for tight pitch devices.



Lowest cost surface finish

4/3/2013


Surface Finishes


Specialty or Selective surface finishes

Hard gold fingers (bussed)

Card edge connectors

Selective hard gold internal to the part

Typical use for keypads or switches

Selective soft gold

Gold wire bonding

ENEPIG – Electroless Nickel Electroless Palladium Immersion Gold

Can be used for both SMT and gold wire bonding with one finish

OSP – Organic solder protection

Immersion Tin

4/3/2013


Understanding and Specifying Via Protection

What is via protection?

Simply put, it is a means to protect the via for several

reasons.

To keep solder from flowing from one side to the other.

To keep chemistry from being trapped in the via.

For thermal heat transfer.

To allow for assembly directly over a hole (via-in-pad).

To improve surface planarity.

To provide a surface ideal for ICT testing (vacuum).

To provide additional reliability to a via.

4/3/2013



Types of via protection?

IPC-4761 identifies seven via protection types

Type I = Tented (dry film mask only)

Type II = Tented and Covered (Type I with additional mask material

applied over the dry film)

Type III = Plugged (Partial fill in the barrel with mask material)

Type IV = Plugged and Covered ( Type III with additional mask material

applied over the plug)

Type V = Filled (100% fill of the via barrel)

Type VI = Filled and Covered (Type V with additional mask material

applied over the plug)

Type VII = Filled and Capped Plated (Type V with a metalization formed

over the top and bottom of the via)

4/3/2013




Type I Tented

4/3/2013

Dry Film Mask



Type II Tented and Covered


4/3/2013

Dry Film Mask

LPI Mask



Type III Plugged


4/3/2013

LPI Mask



Type IV Plugged and Covered


4/3/2013

LPI Mask

Secondary LPI Mask



Type V Filled


4/3/2013

100% fill with non-conductive

or conductive ink



Type VI Filled and Covered


4/3/2013

100% fill with Non-conductive

or conductive ink

Secondary LPI Mask



Type VII Filled and Capped Plated


4/3/2013

100% fill with non-conductive

or conductive ink

Copper Metallization Via-in-pad formation



Type VII Filled and Capped Plated


4/3/2013



Tented?

The term tenting has been used with many different end

results.

Tenting = Vias are to be covered with LPI solder mask on both sides.

Tenting = Dry film mask covering vias.

Tenting = Vias are to be plugged and covered with LPI solder mask.

A very dangerous and outdated term which is still used in

many specifications today.

Per IPC-4761 Type I dry film mask is a capability few board

fabricators posses today. Nearly 100% of all manufactures

utilize LPI solder mask.

4/3/2013



When to use a plugged or filled via? A plugged via is typically used to prevent solder transfer from one

side of the hole to the other. It can also be used to improve the

vacuum effect during ICT testing.

Plugging is a partial penetration of the mask material into the hole.

There are different processes for performing this task. Consult your

board fabricator for which method is used.

Plug before final mask application, Plug performed after final finish is

applied.

A filled via is typically used for either thermal transfer (utilizing a

conductive ink) or a via-in-pad requirement. Other uses may be for

improved reliability of the hole as it is 100% encapsulated.

4/3/2013



Specification and why it’s so important The best way to specify via protection is to utilize the IPC-4761

specification.

Over half of all new prototype orders we take do not specify via

protection correctly.

This creates costly delays as well as the potential for the finished

PCB to be manufactured based on an incorrect interpretation.

Potential for adding additional costs where they are not needed or

not providing the needed protection required by the design.

4/3/2013


Who is building your PCB Design? OEM designs often are turned over to a contract

manufacturer to be procured.

From there the design may be sourced domestically or offshore. It may utilize both.

Depending on the relationships the CM has these boards may go through multiple middle men before the actual PCB manufacturer gets the design to build.

There could be as many as 3 or more hands which touch the design in this process.

4/2/2013


Who is building your PCB Design? Each one adds additional costs and could add critical

delays if questions arise.

Having a relationship directly with the board house is vital to quickly and cost effectively bring the product to market.

Although CM’s, board distributors, and other’s can add value in the supply chain effort, losing connection with the backbone of your electronic platform can make or break a successful product launch.

4/2/2013


Panelization: who decides and why does it matter?

Panelization is the process of taking a single-up design and step and repeating that design.

Array – Step and repeated one-up design

Panel – PCB fabricator takes the array and step and repeats it into the manufacturing panel.

Consulting both the assembly house and PCB house is critical to getting the most cost effective usage of the manufacturing panel.

Poor panelization can often double the cost of a PCB.

4/2/2013



4/2/2013

Single Up Design

Step and Repeated

Design - Array

Step and Repeated

Array - Panel



Utilizing software tools like Kwickfit (www.micromeg.com) array and panel utilization can be easily developed before the fabricator receives the design.

Understanding the CM’s most efficient assembly set-up, component placement, and fabricator’s panel is critical to avoiding long delays at the fabricators front end CAM department.

These delays increase labor content and extend lead times sometimes significantly.

It is not uncommon to have to set-up an array 2 or more times at the PCB fabricator due to the array not being defined during the design cycle.

4/2/2013

http://www.micromeg.com/


What level of test do you want and need? 100% electrical test for opens and shorts should always

be done on any PCB.

AOI (automatic optical inspection) is typically performed on all inner layers and will identify open, shorts, nicks, neck downs, and other etching and material defects. The earlier these defects can be detected the quicker the board fabricator can react especially in a quick turn order.

If impedance is part of your design then TDR testing is a most.

Ionic contamination

Solder floated cross section

4/3/2013


What level of test do you want and need? Electrical test of the final PCB

4/3/2013


What level of test do you want and need? AOI for inspection of inner and outer layers

4/3/2013


What is tooling and who owns it ? Tooling is the artwork and associated programs which

must be generated to produce the PCB.

All Copper layers

All Solder mask layers

All legend layers

All drill data

All routing data

AOI data

Electrical test data

TDR test (if required)

Specialty data

Carbon pads

Beveling

Counter bore/sinks

4/3/2013


What is tooling and who owns it ? The company who places the purchase order to the PCB

fabricator is the one who owns the tooling.

The PCB shop can not provide or release any information to anyone with out the permission of the company who placed the PO to them.

4/3/2013


Ensuring Transferability? Engage with your board fabricator directly and early in

the design phase.

Specify so that any fabricator will understand your requirements. Use IPC spec call outs whenever possible.

Get feedback from the prototype build.

Stack-up used (construction)

Material certs

Cross section results

Test data

Own your tooling when ever possible.

4/2/2013


Simple ways to control your costs?

In Summary Panelize your design into an economical array which works for both

the CM and PCB fabricator. Consider this just as important as the design itself.

Specify material’s based on the IPC-4101C whenever possible.

Chose a final finish which meets the needs of your CM taking into account the lesson's learned today.

Specify via protection utilizing IPC-4761 whenever possible.

Understand who owns the tooling and how that may affect the product through the prototype to production cycle.

4/2/2013

driving cost out of your designs - eagle … cost out of your design through your pcb...

Documents