Eurocircuits Printed circuits blog

What keeps us busy at Eurocircuits, projects we are working at, new idea's, background information and a platform where you can participate, give your opinion and guide us to what is important for you as an electronics developer

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Posted by   Dirk stans  on 24 Jun 2014  | Posted under   PCB Visualizer Hits: 2101

How to achieve an ideal PCB Design flow by using the Eurocircuits smart menus ?

Helping our electronics design customers to define the best PCB layout flow possible and thus save time, avoid communication problems and achieve the best price and reliability for their PCB, is our goal. To achieve this goal, we have created smart menus and PCB visualization tools.

Our BLOG contains an online presentation and a movie.

Smart menus.

The Eurocircuits price calculator is based upon the technology of our PCB Configurator software - part of the PCB Visualization tools on our website. You can use the calculator with or without data. Even without attaching data, you will have the complete Eurocircuits service at your finger tips including all technical validation rules that apply when choosing different technical options for your board.

We therefore call them "smart menus". They contain:

  • Build-up wizard: including more than 700 pre-defined build-ups including blind and buried via combinations.
  • Panel editor: contains full CAM editing functionality to define a professional customer delivery panel
  • Technical validation: around 300 rules are built into the smart menus to help you to choose only those combinations of options that are viable. All violations are explained and possible corrections proposed. If these are not clear or or do not meet your requirements, you can always get help from our engineers by using the  "launch inquiry" option.
  • Classification wizard: our classification guide shows you the pattern and drill classes available for your chosen base copper foils.
  • Price guidance: on every option you choose, the smart menu informs you if there will be a slight cost increase or if the board is no longer poolable.  If the board is not poolable then the price will be calculated on the basis of production panels containing only this board. Prices calculations always include a matrix showing alternatives based upon other more favourable quantities and delivery terms. You can also define your own price matrix to show your own preferred alternative quantities and deliveries.

Visualization tools

After you have finished your PCB Layout based upon the PCB design parameters you defined using our smart menus , you can load your PCB data into the shopping basket section of your account. Our PCB Visualizer software will then start analysing your data. A few minutes later you will be able to view your board on screen and see the results of the analysis. What can you discover?

  • PCB Configurator: you can view the board and the analysis based upon the order details entered into the price calculator.  If you use the alternative pricing option "Analyse my data", PCB Visualizer will fill out the board parameters in the calculator menu and present its analysis based on our default values.  In either case, go through the order details, viewing all the comments and any possible design rule check (DRC) violations. You can then correct the data to fit the order details, or change the order details to fit the data. Other CAM data preparation functions available include:
    • Panel editor: design standard or complex customer panels interactively on screen.
    • Marking editor: add QR-code, UL-logo, text, date codes, etc... if and where you want them
  • PCB Checker: shows the results of the DRC analysis of your data against the order details. You can view all potential errors one by one and decide what to do in each case. PCB Checker also contains DFM functions including plating index, solder paste surface area, possible fiducials in a design, ....

Presentation "Your optimum PCB design flow"

Our presentation takes a tour through all Eurocircuits' smart menus and PCB Visualization tools and shows how they can help you gain time, avoid misunderstandings and save costs by defining an ideal PCB design flow.

View the Presentation - click here

The presentation is best viewed when you open the speaker notes and view them on a second screen. This can be controlled from the option button in the bottom left corner.

 

MOVIE: How to use our smart menus and PCB Visualizer

This film gives an overview of how to use our smart menus efficiently to determine your PCB layout parameters and how to then use PCB Visualizer to check your layout against your pre-set design values.

You can always view this video in full screen mode by clicking the right symbol  on the navigation bar and upgrade the resolution by clicking the setting symbol .

 
 
 
 

 
Posted by   Lengyel Norbert  on 21 Oct 2014  | Posted under   Technology Hits: 196

Quality assurance -  Microsection analysis

Introduction

Microsectioning or cross-section analysis is a destructive sample testing procedure, used throughout the PCB fabrication industry. We make regular microsections each day, as they allow us to see inside the PCB and make precise measurements to check our production processes and to confirm the quality of the finished PCBs.

We use microsectioning to check the quality of:

  • PCB base material
  • inner structure of multilayer boards
  • plating in plated-through holes
  • thickness and registration of external and internal conductors
  • connection between the layers
  • soldermask cover
  • surface finish thickness

Microsectioning procedure

  1. Select the appropriate PCB or quality-control test coupon
  2. Cut out a piece for sample
  3. Embed the sample in resin
  4. Grind down to a flat surface
  5. Polish and etch back if needed

Multilayer build checking

We check the build-up of the multilayer PCB, the thickness of the cores, copper foils and prepregs, and the effectiveness of the bonding process. We also look for any defects in the laminate after thermal stress (delamination, blistering, voids or cracks etc.)

We inspect the registration of inner copper lands to the holes. The next picture shows the same PCB as the last one, but when we measure the registration of the hole to the inner layer copper we see that there is some misalignment (in this case within tolerance).  We also use a special test coupon on all multilayer production panels to confirm the position of the drilled holes relative to the (already printed) inner layers.

 

 

There should be a robust connection between the wall of the plated through hole and the inner layer copper as shown in the next picture.  A poor or broken connection points to process issues in drilling or hole-wall cleaning.  A broken internal connection on a finished board would be caught by electrical test.

 

Through hole plating

We make 5 non-destructive measurements of the thickness of the plated copper in the holes on every production panel.  We back this up with regular microsectioning to get more information about process quality. For this we use the test coupon which we put on every production panel.

The plating thickness is the average of six measurements taken three on each side of the hole roughly a quarter, a half and three-quarters down.

 

Our standard tolerance for component holes is +/- 0,1 mm. We measure the finished hole diameters at final inspection using a tapered gauge.  Microsectioning backs this up and provides more detailed information on the quality of our processes.  The next picture shows the actual width of a plated hole with nominal diameter of 250 microns.

 

Copper thickness

Inner layers

Inner layers are not plated so the copper thickness is that of the copper foil used.  However, some copper is lost during the cleaning processes.  The IPC A 600 Class 2 standard gives the following values for the minimum acceptable copper foil thickness after processing:

Start copper

Minimum thickness after processing

12 µm

9,3 µm

18 µm

11,4 µm

35 µm

24,9 µm

70 µm

55,7 µm

 

This image show the copper thickness after processing for an inner layer with 35 µm start copper:

 

Outer layers.

Outer layers are plated up when we plate through the holes, so that the final copper thickness is the start copper foil less any copper lost during cleaning plus the plated copper.  IPC A 600 Class 2 gives the minimum acceptable finished copper thickness after processing as:

Start copper

Minimum thickness after processing

12 µm

29,3 µm

18 µm

33,4 µm

35 µm

47,9 µm

70 µm

78,7 µm

 

Microsectioning shows the thickness of an outer layer track with 18 µm start copper:

 

We can also measure separately the thickness of the base copper and of the plated copper.  The base copper foil in this case was 12 microns.

 

Solder mask

The minimum solder mask thickness over the copper conductors should be 8 µm.

 

Surface finish

We can use microsectioning to measure the thickness of Leadfree Hot Air Levelling (HAL). For electroless gold over nickel (ENIG or Che Ni/Au) we can only use microsectioning to measure the nickel thickness (as shown in the picture) as the gold thickness is under 0.1 µm. For measuring the thickness of the gold and for Immersion silver we use non-destructive X-ray measurement.

 

Posted by   Dirk stans  on 17 Jun 2014  | Posted under   PCB Design Hits: 1342

Can standard Gerber still be used to order PCBs?

As you can read from Ucamco's announcement, Standard Gerber (RS-274D) is declared obsolete as input format for their Computer Aided Manufacturing tools for PCB production.

Eurocircuits has for a long time promoted the use of Extended Gerber (RS-274X) for communicating PCB designs as described in our BLOGs:

It's safer, faster and fully compatible with our PCB Visualizer tools.  PCB Visualizer cannot process Standard Gerber files as they are incomplete, lacking the built-in shape definition tables etc...

We therefore support Ucamco's decision to declare the Standard Gerber (RS-274D) format obsolete.

=> Yes, you still can use Standard Gerber (RS-274D) but we STRONGLY recommend you to use Extended Gerber (RS-274X) instead.

If you have any questions on outputting Extended Gerber, please contact us via our Chat service or email us at euro@eurocircuits.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it .  If you need boards made from old files which are only available in Standard Gerber, please contact us on a case by case basis.

We recommend you to also read Ucamco's announcement in this BLOG.

Open Letter to the Gerber User Community

Please use Extended Gerber for all your operations.
Standard Gerber is technically obsolete.  If you are still using it, you are putting your business and that of your clients and business partners at a useless risk, without benefit.

As the developer and custodian of the Gerber format, Ucamco hereby wishes to communicate the following important information about Standard Gerber.

Standard Gerber is now technologically obsolete.

  • Despite its name, Standard Gerber is not a defined standard for PCB data transfer:  Units and aperture definitions, rather than being governed by a recognisable standard, are in an informal document, the interpretation of which is unavoidably subjective. As a result, Standard Gerber files cannot be machine-read in a standardized, reliable way.
  • Standard Gerber requires aperture painting and copper pours, both of which create manual work in CAM, adding cost, delay and risk to the PCB manufacturing process.
  • Standard Gerber does not support attributes.

Extended Gerber files ARE machine readable, they do not require painting, and they do support attributes. Virtually all software read Extended Gerber and many new implementations no longer support Standard Gerber. There is not a single good reason left to use Standard Gerber. Using of Standard rather than Extended Gerber is a self-inflicted competitive disadvantage.

Extended Gerber fully supersedes Standard Gerber. Extended Gerber is the current Gerber format. Standard Gerber files therefore do not comply with the Gerber specification.

Ucamco's position regarding the Gerber format is therefore as follows:  Any party that chooses Standard rather than fully standardized Extended Gerber is responsible for any issues that might arise as a result of its use.

Thank you.

Karel Tavernier
Managing Director
Ucamco

Read the full article - with detailed motivation - in pdf format

 
Posted by   Luc Samyn  on 14 Aug 2014  | Posted under   Technology Hits: 2114
This blog is also available in following languages

What is UL?

The Underwriters Laboratory (UL) was set up around 120 years ago in the USA as an independent facility to test the safety of new products and new technologies.  Today it has a network of sites around the world focussed on product safety.  It test products, certifies manufacturers, and produces and updates safety standards across a broad range of industrial and commercial sectors. More.

For PCBs the main standards are UL 796, the specific PCB standard, and UL 94 for flammability testing of all plastics.  These specify a number of performance tests to measure the long-term reliability and fire safety of the PCB.  If a board is released to these standards, it is marked with the UL logo, the fabricator’s logo and the board type.  So here for Eurocircuits, we see on the left the UL logo, then Eurocircuits’ UL trademark, and last ML for “multilayer”.

 
UL on the PCB

When is UL marking used?

UL marking is required whenever safety, especially flammability, is a critical issue.  For European OEMs it is often required on any boards that go into equipment that will be imported into the USA.  The requirement may be set by the OEM or by the end customer.

What does UL marking mean?

  1. The base material meets the specified flammability level laid down in UL94.  For FR4 the level required is UL94 V0.  This means that when a vertical sample of the material is introduced into the test flame and then removed, it will self-extinguish within 10 seconds.  It will not drip flaming particles.
    All Eurocircuits FR4 materials meet the requirements of UL 94 V0.  For boards requiring UL marking we use Isola and Nan Ya materials
    • For STANDARD pool multilayer boards we use IS400 Mid Tg 150°C (this Tg is higher than standard FR4 to ensure full compatibility with lead-free soldering).
    • For all high Tg (170° - 180° C) requirements we use Isola PCL-FR4-370-HR.
    • For one and two layer boards we use IS400 Tg 150°C or Nan Ya NP-155F Tg 150°C
      => For more information on their properties see UL Certificate E41625 for Isola materials and E98983.
  2. The base material meets the specified level for ability to resist ignition from electrical sources.  For the values see E41625 and E98983.
  3. The base material meets the specified electrical breakdown (tracking) or Comparative Tracking Index (CTI) value.  This is the voltage difference at which the insulation properties of the base material may break down, causing safety and performance issues.  The Isola and Nan Ya FR4 materials meet the requirements of Class 3 (175 – 249 V).
  4. The base material meets the performance profile levels specified for direct support of current carrying PCBs (DSR).  These are specified in UL Standard ANSI/U/796A.
  5. The boards meet the other specifications set out in the table under UL marking in STANDARD pool below.

Eurocircuits UL specs

Our UL certificate E142920 can be found on the UL website

Abbreviations used.

  • Cond = conductor
  • Edge: this is explained below
  • Thk = thickness
  • SS = One copper-clad side
  • DS = Two copper clad sides including single-sided and multilayer
  • DSO = Double-sided only
  • Max Area Diameter: this is explained below
  • Meets UL796 DSR requirement.  See item 4 above.
  • CTI = Comparative Tracing Index.  See item 3 above.

TIPS.

  1. UL marking is free of charge.
  2. To add UL marking to your order, click on “Advanced options” at the bottom of the Price calculator menu, and then tick the “UL marking” box.  The smart Price calculator menu will flag any options that are not UL-compatible.
  3. When data has been uploaded, the Marking editor can be used to define the UL logo position.

General.

  1. All boards requiring UL marking are made in our factory in Eger, Hungary.
  2. We offer UL marking in STANDARD pool only.
  3. We have 3 active board classes, each with its own UL marking:
    1. i. Multilayer boards: designator ML; marking:

       
      UL ML
    2. ii. 1- and 2-layer boards with minimum thickness 0.63 mm: designator DV; marking:

       
      UL DV
    3. iii. 1- and 2-layer boards with thickness 0.38 mm – 0.62 mm: designator DS; marking:

       
      UL DS

The other classes listed in the certificate are no longer used.

UL marking in STANDARD pool

UL marking is only available for PCBs which are conform to the parameters listed here (the numbers in brackets indicate more information below). This includes poolable and non-poolable options.

UL type Designator

ML

DV

DS

Usable for

Multilayer

Single and Double sided

Single and Double sided

Base Materials

IS400

PCL-FR-370HR

IS400

NP-155F

PCL-FR-370HR

IS400

NP-155F

PCL-FR-370HR

UL 94 Flame Class

V-0

V-0

V-0

Min. build-up thickness (mm) (1)

0,63

0,63

0,38

Min. bonding sheet (prepreg) thickness (microns) (2)

126

Minimum outer layer conductor thickness (microns) (3)

18

18

18

Maximum inner layer conductor thickness (micron) (4)

70

Minimum track width (mm) (5)

0,10

0,10

0,10

Minimum edge track width (mm) (6)

0,15

0,15

0,15

Maximum conductor area diameter (mm) (7)

76,20

76,20

76,20

Surface finishes:

Leadfree HAL

Immersion NiAu (ENIG) (8)

Immersion Ag

 

Yes

Yes

Yes

 

Yes

Yes

Yes

 

Yes

NO

Yes

Hard gold edge connector

Yes

Yes

Yes

PTH on the board edge

Yes

Yes

Yes

Round-edge plating

Yes

Yes

Yes

Copper up to board edge (9)

NO

NO

NO

Carbon paste

Yes

Yes

Yes

ViaFill (10)

Yes

Yes

NO

Heatsinkpaste (11)

NO

NO

NO

Soldermask types (12)

ELPEMER 2467

XV501T Screen XV501T-4 Screen

ELPEMER 2467

XV501T Screen XV501T-4 Screen

ELPEMER 2467

XV501T Screen XV501T-4 Screen

Hole plugging material (ViaFill)

XV501T-4 Screen

XV501T-4 Screen

Peelable soldermask

Yes

Yes

Yes

Carbon ink

SD 2841 HAL *IR

SD 2841 HAL *IR

SD 2841 HAL *IR

Solder limit

Maximum temperature (°C) (13)

265

265

265

Solder limit

Maximum time (sec) (13)

20

20

20

Maximum operating temp (°C)

130

130

130

1. Minimum build-up thickness (mm)

This is the thickness of the PCB measured over the laminate where there is no internal or external copper.

The minimum  STANDARD pool thicknesses which can be UL marked are:

 

UL-ML

UL-DV

UL-DS

UL min. build-up thickness (mm)

0,63

0,63

0,38

Min. STANDARD pool thickness (mm)

0.80

0.80

0.50

TIP

For UL marking of UL-DS PCBs the surface finish must be Che Ag or No surface finish (leadfree/leaded HAL is not possible due to the min board thickness requirement of 0.80mm for HAL and Che Ni/Au is not available for UL-DS-marked PCBs due to the fact that we always use  a via-fill in combination with Che Ni/Au).

2. Minimum bonding sheet (prepreg) thickness (microns)

Minimum prepreg thickness in a multilayer. This may be one prepreg or a combination of different prepreg.

 

UL-ML

UL-DV

UL-DS

UL min. bonding sheet (prepreg) thickness (microns)

126

In STANDARD pool most of the 700+ pre-defined builds meet this requirement. The smart Price calculator menu will flag any pre-defined build that is not UL-compatible.

3. Minimum outer layer conductor thickness (microns)

Specifies the minimum END copper thickness for the outer layers.

 

UL-ML

UL-DV

UL-DS

UL min. outer layer conductor thickness (microns)

18

18

18

For 2-layer and multilayer boards all start copper foil thicknesses may be used: 12µm (end +/-30µm), 18µm (end +/-35µm), 35µm (end +/-60µm), 70µm (end +/-95µm) and 105µm (end +/-130µm).

For 1-layer boards the start copper foil is the same as the end copper thickness, so following start copper foils are available: 35µ (end +/-35µm), 70µm (end +/-70µm) and 105µm (end +/-105µm).

4. Maximum inner layer conductor thickness (micron)

Specifies the maximum END copper thickness for the inner layers.

 

UL-ML

UL-DV

UL-DS

UL max. inner layer conductor thickness (micron)

70

On inner layers start copper foil is the same as end copper thickness.  UL marking is available only for 12µm, 18µm, 35µm and 70µm (not 105 µm)

5. Minimum standard track width (mm)

The minimum width of any track on any layer placed more than 0.40mm from the edge of the board.

 

UL-ML

UL-DV

UL-DS

UL min. standard track width (mm)

0,10

0,10

0,10

eC PCB Classification pattern class

Class 8

Class 8

Class 8

6. Minimum edge track width (mm)

The minimum width of any track on any layer placed less than 0.40mm from the edge of the PCB-board.

 

UL-ML

UL-DV

UL-DS

UL min. edge track width (mm)

0,15

0,15

0,15

eC PCB Classification pattern class

Class 6

Class 6

Class 6

This is a UL requirement to prevent damage to fine tracks near the edge of the PCB.

TIPS.

  1. Eurocircuits’ standard specifications still apply.  If a PCB is break-routed, there can be no copper on the outer layer within 0.25 mm of the edge of the board or 0.40 mm on the inner layer.  For V-cut scoring the clearance must be 0.45 mm on all layers.
  2. Copper up to the board edge is not allowed under UL rules – see (9) below.

7. Maximum conductor area diameter (mm)

This specifies the maximum solid, unpierced conductor area on any layer of a PCB-board, measured by the diameter of the largest circle that can be inscribed within the conductor pattern.

 

UL-ML

UL-DV

UL-DS

UL max. conductor area diameter (mm)

76,20

76,20

76,20

A “solid, unpierced copper area” is defined as any “full” or “solid” copper plane that does not have any PTH or NPTH holes in it.  This rule has been introduced by UL to reduce the thermal mismatch between a large solid copper plane and the laminate.

The diameter is measured thus:

 
UL maximum copper area

TIP

In most cases copper planes will include clearances for drill holes and so are not solid.  Otherwise if UL marking is required for designs with very large unbroken copper areas, consider using cross-hatching.

8. Surface finish - Immersion NiAu (ENIG)

To ensure optimum quality on immersion nickel-gold PCBs with closed vias we use ViaFill. As we do not offer UL marking on ViaFill for boards less than 0.63 mm thick, we cannot offer UL marking on type UL-DS PCBs (less than 0.63 mm).

9. Copper up to board-edge

This is not permitted under UL rules (risk of exposed or torn copper).

10. ViaFill

We do not offer UL marking for ViaFill for boards less than 0.63mm thick.

11. Heatsinkpaste

We do not offer UL marking for heatsinkpaste.

12. Soldermask types

All colours that we offer are covered.

13. Solder limit – temperature and time

These are the values that we use in our quality checks.

 

If you have any questions, please contact us by email at euro@eurocircuits.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it or use our online Chat.

 

Posted by   Dirk stans  on 10 Mar 2014  | Posted under   Meet Eurocircuits Hits: 323

World of Electronics 2014 - Een leuk beursgadget - registreer nu reeds !

 

"De virtuele memo", het beursgadget voor de branche Industriële Elektronica, is een praktisch dagelijks gebruiksvoorwerp met een plezante functie:"geheugensteun".

De virtuele memo stuurt draadloos, via de lage energievariant van Bluetooth, een unieke code uit gelinkt aan een geheugensteuntje wat u er voordien heeft in geplaatst. Deze code ontvangt u via uw smart phone waar de "memo APP" u het geheugensteuntje weer laat zien. Vermits meerdere personen deze info kunnen ontvangen kan men zo boodschapjes aan mekaar doorgeven: "Schat, vanavond komt mijn moeder op bezoek." Het aantal mogelijkheden is daardoor zeer uitgebreid.

Voor de elektronicaliefhebber zullen we uiteraard weer alle ins en outs beschrijven en kenbaar maken.

 

Het gadget kan u alleen bekomen, als u zich als bezoeker voor de beurs aanmeldt en tijdens de registratie aangeeft dat u het gadget wil ophalen.

Registreer nu als Eurocircuits klant als eerste via deze link en verzeker u van uw gadget en een gratis toegangsbewijs. Vanaf eind maart zal iedereen kunnen registreren en is het aantal gadgets mogelijk snel uitgeput.

Meer info over de World of Electronics vindt u hier.