Design For Manufacturing_ Report

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62561 Design for Manufacturing
Abstract:
The purpose of the Course DFM is to provide an overview of design for
manufacturing techniques which is used to minimize the product cost through design and
process improvements. It also describes and evaluates design of a new product from the
prototype phase and until the mass production phase from applicable standards and
regulations. And to calculate, estimate the lifetime of the electrical product, and to ensure the
quality of an electric product through the production. The course leads us to explain different
processes, optimum production flow based on cost, quality and high volume. This report will
cover some of the major aspects, processes, and considerations for design for manufacturing.
Supervisor(s): Nicolai Vullum
Class: 62561 DFM
Student ID Student name Signature
S104712 Danish Bangash

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Table of Contents
Table of Contents ....................................................................................................................................................... 2
Introduction ................................................................................................................................................................. 4
Stage Gate Process..................................................................................................................................................... 4
HOW DOES A STAGE-GATE PROCESS WORK?....................................................................4
THE STAGES..........................................................................................................................5
Stage 0 – Idea Discovery ................................................................................................................................ 5
Stage 1—Scoping.............................................................................................................................................. 5
Stage 2—Build the Business Case.............................................................................................................. 5
Stage 3—Development................................................................................................................................... 5
Stage 4—Testing and Validation ................................................................................................................ 5
Stage 5 – Launch ............................................................................................................................................... 5
THE GATES ...........................................................................................................................5
Deliverables........................................................................................................................................................ 6
Criteria.................................................................................................................................................................. 6
Outputs ................................................................................................................................................................. 6
IPC Standards .............................................................................................................................................................. 7
IPC AND JEDEC ..................................................................................................................7
SMT AND THT ....................................................................................................................7
SMT (Surface Mount Technology).............................................................................................................. 7
THT (Through-Hole Technology)............................................................................................................... 8
PCB CONSIDERATION .........................................................................................................8
Prepreg (pre-impregnated).......................................................................................................................... 8
Copper layer thickness................................................................................................................................... 8
Solder mask or solder stop ........................................................................................................................... 8
PCB Materials (Glass and Metal)................................................................................................................. 9
Silkscreen............................................................................................................................................................. 9
FOOTPRINTS CONSIDERATION ............................................................................................9
COMPONENT PLACEMENT, SPACING AND ORIENTATION ................................................9
FIDUCIALS AND VIAS.........................................................................................................10

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Considerations regarding Fiducials: .......................................................................................................10
Consider following regarding vias:..........................................................................................................11
PCB BREAKAWAY PANELS................................................................................................12
V-Groove Scoring, Tab Routing and Routed Slots..............................................................................12
Approvals and Standards......................................................................................................................................15
DIRECTIVES AND STANDARDS...........................................................................................15
SOME COMMON SAFETY RELATED IEC STANDARDS........................................................16
CREEPAGE AND CLEARANCE ............................................................................................16
POLLUTION DEGREE...........................................................................................................17
INSULATION .......................................................................................................................17
SCHEMATIC CONSIDERATION...........................................................................................17
Components......................................................................................................................................................19
Mechanical.........................................................................................................................................................19
Layout .................................................................................................................................................................19
Design rules checking ...................................................................................................................................19
MECHANICAL CONSIDERATION .......................................................................................19
ELECTRICAL EMC (ELECTROMAGNETIC COMPATIBILITY) CONSIDERATION.................20
GROUND PLANE..............................................................................................................................................20
DECOUPLING CAPACITOR.........................................................................................20
SHEILDING........................................................................................................................................................21
BOARD LAYERS...............................................................................................................................................21
COMPONENTS SEGREGATION ..................................................................................................................21
Conclusion...................................................................................................................................................................22
References...................................................................................................................................................................22

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Introduction
Design for manufacturing is the integration of product design and process planning into one
common activity. The goal is to understand the design methodology and processes to design a
product in future which can be easily and economically manufactured. The importance of
design for manufacturing is underlined by the fact that about 70% of the manufacturing cost
of product (cost of materials, process, and assembly) are determined by design decisions.
Further in the report we will be explaining the process of innovation and design process and
will also cover some of the very important considerations such as: PCB, PCB material,
Footprint, fiducials, via etc. step by step. We will introduce here how to implement a design
following the Design for manufacturing criteria and considerations.
Stage Gate Process
 Stage gate is a value-creating business process and risk model designed to quickly and
profitably transform an organization’s best new ideas into winning new products.
 When embraced by organizations, it creates a culture of product innovation excellence,
product leadership, accountability, high performance teams, customer and market
focus, robust solutions, alignment, discipline, speed and quality.
Figure: Stage gate Product innovation Process
How Does a Stage-Gate Process Work?
 The stage gate model is based on the belief that product innovation begins with ideas
and ends once a product is successfully launched into the market.
 This has a lot to do with the benchmarking research that the Stage-Gate model design
is premised on, and is much broader and more cross-functional view of a product
development process.
 The Stage-Gate model is often complex and chaotic process of taking idea from
inception to launch and breaks it down to smaller stages ( where project activities are
conducted) and gates (where evaluations and Go/Kill decisions are made).

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The Stages
 Each stage is designed to collect specific information to help move the project to the
next stage or decision point.
 Each stage is defined by the activities within it. Activities are completed in parallel and
cross functional.
 These activities are designed to gather information and progressively reduce
uncertainty and risk.
 Each stage is increasingly more costly and emphasizes collection of additional
information to reduce uncertainty.
Note: in the typical Stage-Gate model, there are 5 stages in addition to idea discovery Stage
Stage 0 – Idea Discovery
 Pre-work designed to discover and uncover opportunities and generate new
ideas.
Stage 1—Scoping
 Quick, inexpensive preliminary investigation and scoping of the project—
largely desk research.
Stage 2—Build the Business Case
 Detailed research involving primary research-both market and technical—
leading to Business Case, including the product and project definition, project
justification, and the proposed plan for development.
Stage 3—Development
 The actual detailed design and development of the new product and the design
of the operations and production process required for eventual scale
production.
Stage 4—Testing and Validation
 Test or trails in the market place, lab and plant to verify and validate the
proposed new product, brand/ marketing plan and production/ operations.
Stage 5 – Launch
 Commercialization—beginning of full-scale operations or production,
marketing and selling.
The Gates
 Preceding each stage, a project process through a gate where a decision is made
whether or not to continue investing in the project.
 These serve as quality control –control checkpoints with three goals:
 Ensure quality of execution.

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 Evaluate business rationale
 Approve the project plan and resources.
Each gate is structured in a similar way:
Deliverables
 The project leader and team provide Gatekeepers with the high-level results of
the activities completed during the previous stage.
Criteria
 The project is measured against a defined set of success criteria that every new
product or project is measured against.
 Criteria should be robust to help screen out winning products, sooner.
 The authentic Stage-Gate process incorporates 6 proven criteria: Strategic fit,
Product and Competitive Advantage, Market Attractiveness, Technical
Feasibility, Synergies/Core Competencies, Financial Reward/Risk.
Outputs
 A decision is made (Go/Hold/Kill/Recycle). New product resources are
committed to continuing the project.
 The action plan for the next stage is approved. A list for deliverables and date
for the next gate is set.
Figure: The Gates
 The Stage-Gate model is designed to improve the speed and quality of execution of new
product development activities.
 The Process helps the project team to prepare the right information, with right level of
detail, at the right gate to support the best decision possible, and allocate capital and
operating resources.
 The process empowers the project team by providing them with a road map, with clear
decisions, priorities, and deliverables at each gate.
 Higher quality deliverables submitted to Gatekeepers enables timely decisions.

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IPC Standards
IPC and JEDEC
 IPC — Association Connecting Electronics Industries® since 1957 IPC has been
guiding the electronic interconnection industry through its dramatic changes. A global
trade association dedicated to the competitive excellence and financial success of its
more than 3,400 member companies, IPC represents all facets of the industry including
design, printed circuit board manufacturing and electronics assembly.
 JEDEC is the global leader in developing open standards for the microelectronics
industry, with more than 3,000 volunteers representing nearly 300 member
companies.
 JEDEC’s collaborative efforts ensure product interoperability, benefiting the industry
and ultimately consumers by decreasing time-to-market and reducing product
development costs.
SMT and THT
SMT (Surface Mount Technology)
 It is a method for producing electronics circuits in which the components are mounted
or placed directly onto the surface of printed circuit board (PCBs).
 An electronic device so made is called a surface-mounted device (SMD)
 In the in industry it has largely replaced the through-hole technology construction
method of fitting components with wire leads into holes in the circuit board.
 Both technologies can be used on the same board for components not suited to surface
mounting such as large transformers and heat –sinked power semi conductors.
 SMT can be soldiered by reflow on PCB top and bottom side and must be glued for
wave soldiering
 Glue process requires a minimum component size equal to the glue dot size.
Advantages
 Much higher component density and many more connections per component
 Lower initial cost and time of setting up for production
 Fewer holes need to be drilled
 Simple and faster automated assembly, some placement machines are capable of
placing more than 136,000 components per hour
 Better mechanical performance under shake and vibration conditions.
Disadvantages
 SMDs’ cannot be used directly with plug in breadboards.

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 SMDs’ soldier connections may be damaged by potting compounds going through
thermal cycling.
 SMT is unsuitable for large, high-power, or high voltage parts, for example in power
circuitry.
THT (Through-Hole Technology)
 It refers to the mounting scheme used for electronics components.
 It involves the use of leads on the component that are inserted into the holes drilled in
the printed circuit board (PCB).
 They are soldiered to the pads on the opposite side either by manual assembly or by
the use of automated insertion mount machines.
 THT almost completely replaced earlier electronics assembly techniques such as point-
to-point construction.
 Through hole mounting provides strong mechanical bonds when compared to SMT
techniques.
 The additional drilling required makes the board more expensive to produce.
PCB Consideration
Prepreg (pre-impregnated)
 Those layers are present to reinforce the boards.
 It is also used to stick the core layers together.
 A Prepreg (pre-impregnated) is fiber glass impregnated with resin.
 The resin is pre-dried, but not hardened, so that when it is heated, it flows, sticks,
and is completely immersed.
 Prepreg are thus fiberglass strengthened by an adhesive layer (similar to FR4
material).
Copper layer thickness
 On the printed circuit board (PCB) affects the behavior of the circuit.
 PCB copper thickness is usually measured in ounces per square foot, or frequently,
just ounces.
 It can also be given in micrometers, inches or mils.
 Standard copper thickness is 35um, other sizes: 70um and 105um.
 We have to be aware that during the soldering process the metal have to be heated
up to a certain temperature so that the soldering will be performed correctly.
 Thicker layers require higher temperatures. This high temperature may be
destructive to the components.
 The appropriate balance in this matter is important.
Solder mask or solder stop

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 It is used as protectection against oxidation and prevents solder bridges between
components that are close to each other.
 Thickness 0.02 mm up to 0.1 mm. Solder mask can be chosen in different colors.
PCB Materials (Glass and Metal)
 The different materials have advantages and disadvantages.
 Some have good thermal specifications, others is good for high speed designs.
Silkscreen
 It is normally used on the component side to identify components, test points, PCB
and PCBA part numbers, warning symbols, company logos and manufacturer
marks.
Footprints Consideration
 Considering the use of IPC footprint requirements is important.
 Some SMD components cannot be glued and wave soldered.
 Considerations regarding fine pitch components.
 Density regarding IPC: M = Most density, N = Nominal density, L = Least density
Figure: Footprints Consideration
Component Placement, Spacing and orientation
 Keeping a certain distance between components is important.
 Keeping a certain distance to PCB edges is an important factor.
 We need to keep certain distance to the mounting holes for screws and other
mechanical parts.
 It is very important to keep distance between footprints and via holes.
 To improve trace routing we need to consider the use of grid based placing.
 To ease components pick’n’place process aligning components is a good consideration
if possible.
 Considering test pads alignment and spacing for test probes is important.

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 To avoid solder shadowing and solder bridging wave solder component orientation
need to be considered.
Fiducials and Vias
Considerations regarding Fiducials:
 A minimum of two global fiducials marks are recommended by most of the
manufacturer when it is necessary translational (X-Position, Y-Position) and rotational
offsets (Theta Position).
 The Global fiducial marks should be located diagonally opposite one another and as far
apart as possible on the printed circuit board or fabrication panel.
 For non linear distortions such as scaling, stretch and twist, a minimum of three global
fiducial marks are recommended by most of the manufacturer. The global fiducials
should be located in triangular pattern and should be located as far apart as possible
on PCB.
 A minimum of two local fiducial is recommended when it is necessary to correct for
translational and rotational offsets. The placement of the local fiducial could be either
diagonally to one another or accordance to the requirements.
 The shape of the fiducials should be solid filled circle see figure below.
Figure: Fiducial Marks and its Clearance area
 The Minimum diameter of the fiducial mark is recommended to be 1.0 mm and the
maximum diameter of the fiducial mark is recommended to be 3.0 mm by most of the
manufacturers.
 The fiducials should be bare or covered copper, it is recommended to have high degree
contrast between the surface of fiducial mark and the adjacent PCB base material
 The surface of the fiducial mark is recommended to be flat with in 0.015 mm.
 Fiducials serve as target used by the placement system to offset the coordinates In the
computer for any variation in true board location.
 It is recommended by most of the manufacturers that “local” (panel) and ”Universal ”
(Global) Fiducials be added to the PCB’s

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 There is an option to ignore this step during component mounting, but that will cause
the placement system to assume that the PCB, while clamped or held firm for
placement, is in the accurate position.
 Ignoring the fiducials check is not ideal for PCB’s with fine pitch components BGA’s etc.
or heavily populated boards.
 Scattered fiducials could be local to individual parts as well as group of parts in a
region. Figure below illustrates the fiducials requirements of most of the
manufacturers.
Figure: The fiducial requirements
Consider following regarding vias:
 Increasing the pad size of the vias is an inexpensive way to improve the thermal
spreading capacity,
 Placing multiple vias evenly at high power dissipation area can improve the overall
thermal transfer ability comparing with one big via,
 Vias may be filled with solder in reflow process this will result in less effectively of heat
spreading ,
 Place power/ ground near power supply pin IC, so get the power supply path short.
 Via in pad design is better thermally then normal pads but it could be the reason of
pseudo soldering in the reflow soldering process,
 For BGA and µBGA solder joints it is suggested to use filled vias if VIA-in Pad Design
has to be established.

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 High density vias can negatively affect the PCB mechanical performance. PCB
twist/Wrap check is recommended.
PCB Breakaway Panels
 As PCB part placement gets denser, it is necessary to add breakaway panels that add
additional material (edge rails) to accommodate the assembly process.
 Two parallel edges are required for a PCB to be processed in the SMT line. This is to
prevent skewing through the conveyer system.
 Also, all odd shaped PCB’s must have edge rails incorporated to meet this requirement.
 V Groove score and Tab routing are two common methods used for creating
breakaway tabs
V-Groove Scoring, Tab Routing and Routed Slots
 Tab routing uses perforated breakaway tabs sometimes it is referred to as “Mouse
Bites”.
 The breakaway tab closet to the PCB corner should be located between 10mm and
12mm from the edge to remove sagging during reflow and wave soldering.
 It is also recommended to have at least one tab per side, if the PCB placement is too
dense for a Tooling Hole then it should be placed on the breakaway tab. Figure below
shows the optimized breakaway tab.

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Figure: Breakaway Tab
 One of the important aspects is to have a clean edge after the breakaway tab is
removed.
 Slight inset of perforation is important because it provides an edge little to no
additional labor to clean up as illustrated in figure below :
Figure: Breakaway Tab Acceptable Placement
 The spacing between the breakaway tabs can range from 60mm to 90mm.
 The plane pull-back should be at least 1mm from all slots and perforation holes. We
should keep the components 2mm-3mm away from the routed slots.
 These rules help prevent components and trace damage during the de-paneling
process. Figure below illustrates the scenario
Figure: Plane and Components Spacing
 Tab routing is more precise than V-Groove scoring and surfaces are smooth
 The breakaway tabs require consideration for additional smoothing if necessary to
comply with the fabrication drawing note regarding smooth edges.

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 The dilled perforation provides low stress break point on the tab and if the hole
pattern is recessed within the oriented broad edge, secondary sanding and grinding
can be avoided.
 It is not recommended to substitute perforation holes with a V- Groove score as it does
not provide durable tab that will withstand handling.
 V-Groove scoring can however be used instead of routing, but requires board edge
grinding to smooth the surface.
 The V-Groove feature is generally provided on both sides of PCB and only I straight
line.
 A V-Groove depth that will provide a sturdy work piece and still separate with light to
moderate pressure after assembly is an important element in manufacturing. Many
fabrication shops recommend a V-groove depth that is 1/3 of the PCB thickness from
both sides using Computer Numerical Control (CNC) equipment.
 The alignment or positional accuracy is critical for clean separation and minimizes
post separation board edge smoothing.
 According to IPC -2222 Sections 5.3.1, the alignment tolerance for the V-Groove is ±80
µm. Figure below illustrates 90 degree scoring option. It is important that all the
conductors be routed with in a distance of 1mm from the top scoring edge to prevent
damage during the de-paneling.
 The inner layer planes should be pulled back 1mm from the V-Groove
Figure: 90 Degree V-Groove scoring option
 Figure below illustrates the 30 degree scoring and uses the same rules

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Figure: 30 Degree V-Groove scoring option
 It is important to know that the 1/3 depth rule only applies to “Breakaway Panels”.
 V-Groove scoring inner web material can range from 0.15 mm to 0.4 mm for panel
separation depending on the length of the score. If the score length is less then 25mm,
it can have web thinness of 0.15mm to 0.4mm of panel separation depending on the
length of the score.
 If the score length is less than 25mm, it can have a web thickness of 0.4mm.
Approvals and Standards
Directives and standards
 We introduced here CE markings. CE marking on a product is a manufacturer’s
declaration that the product complies with the essential requirements of the
relevant European health, safety and environmental protection legislation.
 CE marking on a product indicates to government officials that the product may
be legally placed on the market in their country.
 It also ensures the free movement of the product within the EFTA and EU single
market and it permits the withdrawal of the non-confirming products by
customs and enforcement authorities.
 In general, the CE marking indicates that the manufacturer has met the
minimum legal requirements for their products in regard to health and safety
under European Directives.
Figure: CE marking

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Some common safety related IEC standards
 There numerous numbers of IEC Standards, one example could be EMC.
 The aim of EMC considerations is to avoid the influence of electromagnetic
phenomena on a device.
 It specifies requirements for products and system operating in residential or
industrial environments and specifies a limited number of essential emission
and immunity test.
Creepage and clearance
 Clearance refers to as the shortest distance through air between two conductive
parts and creepage is the shortest distance between two conductive parts along
the surface of any insulating material common to both parts.
 We could consider a spacing of 4mm air clearance and a 5 mm creepage
distance or the distance between primary and secondary components.
 There are different requirements need to be considered when discussing about
clearance and creepage.
 We have to consider a protection with insulation, pollution degree level, and
class categories.
 Electrical clearances are important requirements for all boards.
 Too tight a clearance between tracks and pads may lead to a problem during the
manufacturing process.
 There is a clearance limit for basic through holes designs, if go below the
recommended clearance limit then we have to consult the PCB manufacturer
first.
 For 240V mains on PCB’s there are various legal requirements, and we would
need to consult the relevant standards if we are doing this kind of works.
 As a rule of thumb, an absolute minimum of 8mm spacing should be allowed
between 240V tracks and isolated signal tracks.
 For non-mains voltages, the IPC standard has a set of tables that define the
clearance required for various voltages.
 The clearance will vary depending on whether the tracks are on an internal
layers or the external surface.

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Figure: Creepage and clearance
Pollution degree
 Pollution degree is a classification according to the amount of dry pollution and
condensation present in the environment.
 This classification is important as it affects parameters required to ensure safe
operation of the product.
 The best choice could be Pollution degree of category 1 because it has
extremely good insulation.
 It has no pollution, nonconductive pollution, which has no influence on safety.
 It can be achieve by encapsulation or the use of hermetically sealed components
or through conformal coating of PCB’s. We have to design for safety
Insulation
 There are different types of insulation. We have functional insulation, basic
insulation, supplementary insulation, double insulation and reinforced
insulation.
 A good choice could be Class 11 or double insulated because it has been
designed in such a way that it does not require a safety connection to ground.
 Reinforced insulation is of Class II category.
Schematic Consideration
 Before we even begin to lay out a PCB, we must have a complete and accurate
schematic diagram.
 Many people jump straight into PCB design with nothing more than the circuit
in their head, or the schematic drawn on loose post-it notes with no pin number
and no order. Without accurate schematic, then the PCB will most likely end up
a mess and takes twice as long as it should.

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 A PCB is a manufactured version of schematic, so it is natural for the PCB design
to be influence by the original schematic.
 Schematic should be neat, logical, and clearly laid out then the PCB design
would be easier.
 Like for example, placing bypasses capacitors, it should be put next to the
component it is meant for.
 Putting some notes would also be a big help, even if it is you or someone else
who designed the circuit and drew the schematic, notes not only remind
yourself when it comes to laying out the board, but they are useful for people
reviewing the design.
Figure: Schematic
PCB Layout Consideration
 When designing PCB’s, one has to go through several steps and consideration to
come up with a perfect and working design. It starts of course by making the
schematic.
 When it’s done then you can start making the PCB following all the
requirements and standards.
 You have to consider many decisions in the design process where a knowledge
of safety requirements and application of their principles can go a long way
toward easing the time and cost of the safety certification process. Things to
consider are:

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Components
 It is advised to use components and materials that have prior safety
certification. And place components according to IPC standards.
Mechanical
 One should make sure that all the components is securely attached. All areas
containing hazardous voltages should be protected from access by the user.
Layout
 Creepage and clearance spacing must separate all hazardous voltage from
users. Place test pads for testing and power planes to distribute power
across the board.
Design rules checking
 Design rule checking allows one to check the PCB automatically for
connectivity, clearance, and other manufacturing errors. It checks that every
track of the board matches the connectivity of the schematic. It checks the
clearance between tracks, pads, and components and lastly checks
tolerances like min/max- hole sizes, tracks width, and short circuits.
Figure: Layout Consideration
Mechanical Consideration
 Designing PCBs can be a very daunting task. It takes a great deal of knowledge
and talent to position hundreds of components and thousands of tracks into an
intricate design that meets physical and electrical requirements.
 We need to fulfill some mechanical considerations in order to do the right thing.
 One could be the type of boards. Either single sided or double side board.
 It’s very important for the designer to know the overall physical size of the
board:
 One must consider optimal size of board that is compatible with the PCB
manufacturing process

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 Position of board mounting holes, brackets, mounting of components,
electrolytic capacitors alignment.
 Proper holes measurements for component mounting.
 Proper fixation arrangement for heavy components.
 Specific location requirements of components.
 Using screws. It should have a distance to the components because it will
stress or affect the components.
 Using glues for PCB mounted components helps to avoid vibrations.
Recommended type of screw could be a metal as they are just ground.
We can use a major diameter of the screw for the PCB hole depending on
feasibility.
Electrical EMC (electromagnetic compatibility) Consideration
 When designing new product, we need to consider different aspects to reduce
the problems caused by EMC.
 One must be certain that the design complies with the EMC standards.
 There are many design considerations that need to be taken into account.
 EMC means Electro-Magnetic Compatibility addresses a product's ability to
resist electric noise and its ability to emit electrical noise.
 It is very important to start thinking EMC from the beginning.
 One of the most expensive mistakes a designer can make is to assume that EMC
is something that could be dealt with after everything else is finished.
 Take into consideration ground plane, board layers, decoupling capacitors,
components segregation, crosstalk, and shielding, digital and analog circuits.
GROUND PLANE
 When talking about ground plane, it is one of the least understood EMC
subjects.
 Improper grounding is the source of many EMI problems.
 Grounding is necessary to prevent shock hazard, which occurs when wiring or
component insulation in equipment housing breaks down.
 It also Important to reduce EMI due to electric filed flux coupling.
 The whole current loop should also be analyzed: Vcc terminal to Vcc
distribution, through the decoupling capacitors and back to VCC.
 The return current tries to follow the signal trace; it follows the path of least
inductance.
DECOUPLING CAPACITOR
 When designing PCB, an important thing to consider is placement of decoupling
capacitors on the PCB for EMI.

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 Capacitors do many things. They filter voltage drops, represent a brick wall for
transients and the most common function, are filtering of EMI noise going into
and coming out of the chip on the PCB.
 Decoupling capacitors are the only instant source of current, and provides a
return path for external current.
 It must have low inductance and low series resistance.
 The capacitance value is irrelevant, as long as it is sufficient.
 It is possible to use 10nF or 1nF for higher frequencies, and 1uF or 10uf for low
frequencies.
SHEILDING
 When measuring small circuits or individual components, the whole PCB can be
fitted into a metal enclosure for testing or a plastic with conductive coating.
 This enclosure or chassis can be used as first line of defense for Radiated
emission or susceptibility and reduces the EMI by attenuating both the E-field
and H-field component of the radiating wave.
 The PCB should be shielded to prevent possible pick-up on cables and external
EMC sources.
BOARD LAYERS
 We are considering to use a two sided layers which consists of signals, ground,
and supplies on the top, dielectric in the middle and ground plane at the bottom.
Two sided layers is inexpensive, EMI
 Mitigation/minimized with ground plane and impedance control simplified
with ground plane.
 It can also give a chance to make use of good ground plane techniques, required
for high frequency designs.
COMPONENTS SEGREGATION
 Components segregation refers to grouping the components according to their
functionality.
 We would need to partition off electrically sensitive parts of the design into
bigger blocks. One major example is with mixed analog and digital circuit which
is a big NO.
 They should be physically and electrically separated, components should be
neatly lined up.
 Having ICs in the same direction, resistors in neat columns, polarized capacitors
all around the same way and connectors on the edge of the board.

62561 DFM
12-05-2015
DTU Diplom
Ballerup
Conclusion
The course can be concluded as that the Design for manufacturing process is very reliable and
speed up process; it leads to go through the sub processes from Idea (Prototyping) and final
stage where the product is ready and finalized. The main phenomena of the course is the
Stage gate process, schematic consideration, IPC standards, and many more as described in
the report. After studying and understanding the design for manufacturing process it is way
easy now to start from scratch and end up with innovative electronics project from Design to
final real world model. Point to be noticed, that most of the manufacturer have the same rules
for design for manufacturing and are using the IPC standard as common standard regulations.
There are a lot of safety aspects which play a very important role in design for manufacturing.
I would conclude that though the process of design for manufacturing from scratch to the
finished product is a long process but its clean and more efficient, systematical process with
understandable aspects and the outcome will be as expected.
References
http://www.ipc.org/
http://www.jedec.org/
http://landpatterns.ipc.org/default.asp
http://www.pcblibraries.com
http://www.jedec.org/category/technology-focus-area/esd-electrostatic-discharge-0
http://www.quick-teck.co.uk/TechArticleDoc/19895134801360697091.pdf
http://www.logasmfg.com/Fiducials.aspx
http://en.wikipedia.org/wiki/Phase%E2%80%93gate_model
http://www.stage-gate.com/
Teacher Class Material Slides etc.

Design For Manufacturing_ Report

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