autorouter possible on demandanalog parts always routed manuallymanual clean-up |
17 December 2004. Draughtsmen of the electronics
design office DEM-BE have been trained to use the Specctra autorouter to
layout printed circuit boards both for the PCAD and CADENCE systems.
Autorouting is currently only used on demand of the clients for
boards where a layout is needed quickly or where money is the main
criterium. An example of an autorouted board is EDA-00879. For this board first the analog parts were manually routed. Then the autorouter was parametrised and in just 15 minutes it routed the rest of the card. A further two-day manual clean-up resulted in a perfectly acceptable board. It is estimated that for this board a full week of design time has been saved by using the autorouter. To see if the autorouter can be used on your design, discuss it when you come to us with your new job. |
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10 November 2004.
Although not specifically mentioned in the front-page article
Photons on many fronts of the
Weekly bulletin of 8 November 2004,
the TS-DEM group was involved in a large part of the development of the
Hybrid Photon Detector developed by PH-TA1.
The involvement of TS-DEM was up to a level that this new type HPD would not have been possible without them:
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solderability & bondability improvedslower aging of unsoldered boards |
8 November 2004. DEM-PMT will change its fabrication process for standard printed circuit boards to become less sensitive to mask alignment errors. The change that uses liquid solder masks and silkscreen paint instead of solid types will result in a better solderability and a better quality of chip bonding as the NiAu plating will be done as the last step in the process. The new process, that is similar to that used by industry, will replace the one that has been in place in the Gandhi workshop for over 15 years. You can recognise the new boards by the somewhat darker colour. |
 Partbrowser Category view |
5
October 2004. During summer Francesco Marchi has structured
From a web browser (http://dsy-srv1:8080/ipsd), Partbrowser allows you to:
If you have not been able to find the symbol for the component you need, please send a mail to electronics-components-cadence@cern.ch so that we can create the symbol for you and make it public in the CERN central libraries. Use electronics-components-pcad@cern.ch for requesting PCAD symbols. |
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Some of the points discussed were panel sizes, location and size of reference targets, how to verify BGA components, supply of components and ways to improve delivery methods. |
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14 September 2004. Like every year, DEM will train four apprentices on the process of printed circuit board fabrication. All of them will also be trained to layout printed circuit boards in the design office of DEM. The apprentice program for electronics technicians is controlled by the HR-PMD group. |
| 8 September 2004. To attract the best personnel for its cleanroom, DEM will publish an advertisement in the French professional magazine Pistes & Pastilles. |
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30 August 2004. A design made by DEM some six years ago for the
ATLAS TRT detector is now part of the
Parcours
Alph@, a "fitness trail" that is used to invite visitors to discover a
range of scientific topics on a series of notice boards. The "Daisy"
design has been made (and tried out in various versions as it indeed
wasn't easy) by the design office which was at the time led by Alain
Monfort. Also for the fabrication innovative means were invented by
the PMT section led at the time by Angelo Gandhi. It was the young
technician Rui de Oliveira who invented (and patented) the right
chemistries to etch the kapton sheets. The ATLAS TRT detector could not
have worked without this development. Other possible uses of this development could have been:
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27 August 2004. The experiment NA60 is currently setting up one of the last testbeams of this year. As they found out that the Central Control Board (CCB) had a failure on one of the eight channels, it had to be replaced by a second board. Unfortunately, this second board had even more problems. To solve this quickly the brute force method of changing all I/O chips on this board was needed. The NA60 spokesman asked at 2 o'clock the DEM workshop to replace 50 (!) chips and at 4 o'clock the board was already ready to be picked up. With this fast Friday afternoon action Nicole Wauquier has shown again that she is able to do things one imagines that are impossible. |
Central Control Board up and running again |
Job offer: High-density circuit fabrication in cleanroom
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26 August 2004. In the
Photolithography and Microconnectics Technology section where we build
high-density circuits on glass, ceramics and other substrates, we need an
electronics technician who can work very precisely. Most of the work you will do
in a Class 100 cleanroom. After an initial training you will be able to build circuits with line widths downto 5 mm! Your work (which is a CERN core technology) will be absolutely invaluable for the next LHC experiments and beyond. These circuits are for example used very close to the point where the particle collisions happen. In a way the circuits that you build will be the ones closest to the place where our particle accelerators create the same circumstances as existed just after the Big Bang! If you are interested in being part of the search for the smallest particles ever, please read the Vacancy Notice (TS-DEM-2004-154-LD) and apply! Be fast, you can apply until about mid October. Feel free to contact Erik van der Bij if you have any question about this job or deadlines. |
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24 August 2004. The Technology Transfer group at CERN has received a request from an American company for licences for the fabrication of GEMs and for the chemical microvia process. Both of these processes are patented by CERN. |
| 24 August 2004. Claude Millerin, section leader of the assembly
workshop, organises at CERN a meeting of the GESO (Groupement Electronique et
microélectronique de Suisse Occidentale), a working group of companies working
on electronics in the french speaking region of Switzerland. This first meeting
after some period of inactivity of the group, will be dedicated to the state of
using lead-free solder in the different companies. The change to lead-free will
be obligatory from mid 2006 and will not be easy as the melting point of this
type of solder is over 40 degrees higher than currently used solders. Also the
appearance of solder joints is radically different. For many companies it will
mean a change of equipment and processes. Within GESO information about this
technology will be shared and CERN is playing a major role in it, both as
organiser and as provider of knowledge. In the past, collaborations with local industry has benefitted both industry and CERN. We have several examples of companies trying out our equipment (e.g. vapour phase oven and solder paste dispenser) where they later bought exactly the same equipment. |
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Now, in 2004, GEMs have become such a commodity item that you can even get them from the CERN Stores, just like your inkjet cartridges and screws! |
| 17 August 2004. The Assembly Workshop led by Claude Millerin is doing much more than mounting components on printed circuit boards. Indeed, they are really good at that and notably they are specialised in surface mount components: they are even capable of replacing BGA's with special tools and the condensation oven! But the workshop is also capable of building racks and crates, making the front-panels for it and wiring it up. Below you find some of the examples of work done. If you have some prototype to be made quickly, or even if you want us to organise a production of several 10's or even 100's of racks or boards, don't hesitate to contact C. Millerin. |
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| 5 August 2004. In January Rui de Oliveira was invited at the Intellect Technical workshop to present the ChemicalVia process. Intellect is the trade body for the UK based information technology, telecommunications and electronics industry. Over 1000 Intellect members employ more than 1.1 million people and make a huge contribution to the UK economy accounting for around 10% of GDP. Concise minutes of this meeting were published in the Journal Circuit World. |
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 4 August 2004. The Journal
Circuit World,
Vol.30 No.4. has published the article
An innovative ChemicalVia process for the production of high density
interconnect printed circuit boards (pdf)
written by Vitor da Silva, technical student in the DEM-PMT section
and his collegues.The article describes the ChemicalVia process which is a fabrication process patented by CERN that provides a new method of making microvias in high-density multilayer printed circuit boards of different types, such as sequential build-up (SBU), high density interconnected (HDI), or laminated multi-chip modules (MCM-L). The process uses chemical etching instead of laser, plasma or other etching techniques and can be implemented in a chain production line. This results in an overall reduced operation and maintenance cost and a much shorter hole production time as compared with other microvia processes. The Journal of the Institute of Circuit Technology called Circuit World provides a central, authoritative, international and independent forum for the exchange of information pertaining to the standard, design, analysis, materials, process, reliability and manufacturing of substrates for the first level packages such as ball grid array (BGA), chip scale package (CSP), flip chip, and multichip module (MCM) and printed circuit board (PCB) for the second-level assembly of the BGA modules, MCM and direct chip attach (DCA). |
| 9 June 2004. The ELectronics Engineering Committee (ELEC) at CERN discusses and agrees on common policies to be followed, along with work plans and budget requests. ELEC is helped by the subcommittees Analog Users Group (AUG) and the Digital Users Group (DUG). The Analog Users Group is looking for a new chairman . With this job that will take you about two hours per week, you can make a serious influence on how the Analog engineers at CERN can do their job, and what support and tools will be provided by CERNs infrastructure. If you're interested, please contact Fabio Formenti, chairman of ELEC or Erik van der Bij, ex-chairman of the Digital Users Group. |
DEM-PMT provides experiments help for fabrication problems in industry |
25 May 2004. In May a company who manufactures ceramic hybrids for the
CMS experiment had problems with variations in quality. The problems were in
fact so serious that the production of the 18000 pieces had to be stopped which
of course posed a problem for the planning of the experiment. As CMS has no
experts in manufacturing technology they called in the help of Rui de Oliveira
of DEM-PMT to find out the reasons of the variations.
Together with the CMS responsibles, the DEM specialist paid several visits to the company and made several phone calls which was sufficient to find out the reasons for the manufacturing problems. The analysis resulted in a DEM document describing a quality procedure that should allow the production to restart. This quality procedure describes the organisation of the production documentation and the documents and test reports that the company should hand over to CERN with each fabrication lot. The above is an example of a reason of existence of the DEM group: whenever there is any problem, the necessary knowledge is immediately available at CERN. The only way to have this type of knowledge is to run a lab on the CERN site where we fabricate high-density components. In fact our facilities also make things that cannot be made by outside companies so we make all our mistakes before the companies make them, thus generating an invaluable amount of experience that is available on demand to anyone involved in the high-energy physics community. Makes me think about the time when my car didn't start and I had to call in a technicien. He came, tried once, looked under the hood, took out a hammer, knocked once with it somewhere under the hood and the motor started! Then he said: "That'll be 100 Euro, please". When I said that I thought it was a bit expense just for a single knock with a hammer, he replied: "The knock with the hammer is only 1 Euro, it's knowing where to knock that is worth the other 99!". |
| 27 April 2004. After some absence, Claude Millerin, section leader in DEM is back on the track. In the Tour Auto 2004, a famous Rally for classic cars, Claude arrived 8th out of 180 cars. In fact he and pilot Merian arrived as first of the non-professional teams in the 1969 Ligier JS1. |
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Your creations will be as close to the Big Bang as possible! |
18 February 2004. In the
Photolithography and Microconnectics Technology section where we build
high-density circuits on glass, ceramics and other substrates, we need an
electronics technician who can work very precisely. Most of the work you will do
in a Class 100 cleanroom. After an initial training you will be able to build circuits with line widths downto 5 mm! Your work (which is a CERN core technology) will be absolutely invaluable for the next LHC experiments and beyond. These circuits are for example used very close to the point where the particle collisions happen. In a way the circuits that you build will be the ones closest to the place where our particle accelerators create the same circumstances as existed just after the Big Bang! If you are interested in being part of the search for the smallest particles ever, please read the Vacancy Notice (TS-DEM-2004-21-LD) and apply! Be fast, you can apply until the end of May 2004.
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| 27 January 2004. ALICE is making a very compact Pixel detector consisting of several highly complicated modules. Modules are the Pixel Bus, a Multi-chip Module, kapton cables. On those modules chips have to be directly bonded. To complicate matters more, the fibre-optic components that should be mounted do not withstand 60 degrees Celcius which makes it impossible to use certain types of glues. | |
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| As in total 70 modules are needed, external
companies are used for the production and assembly. As little is standard, three
specialists of DEM (design, fabrication and assembly) have visited two companies
who are likely going to manufacture the modules. The visit highlighted several
problem areas and came up with innovative solutions that ease the assembly and
test of the modules.
Also other issues such as packaging (the circuit is only 35 um thick so can break easily), cleaning of solderflux, shielding covers, glob-top protection and testing steps were discussed. The solutions and options were presented to the ALICE engineers and decisions have been taken so that DEM can now finalise the design. After that we will present the complete files to the companies, ask offers and organise the production. |
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The result of an hour discussion |
More information about this project can be found at Michel Morel's web pages, notably the presentation Pixel bus and Pilot MCM connections. |
The
innovative part of that detector is that the electronics is fully
integrated inside. For this a round ceramic circuit had to be developed
and new soldering techniques with Gold-Germanium solder had to be tested
that withstand a temperature of 300 degrees Celcius! The components
mounted also should withstand this temperature as during the assembly of
the detector the whole detector should be heated up to 250 degrees to
de-gaz the detector and the electronics inside to improve the final
vacuum. 
the
Cadence component library so that it can be used with the
25 September 2004.
As part of the program to train the design office team, Betty
Magnin has organised company visits to a company specialised in the assembly
of components on printed circuit boards. After the visit all players better understood the
difficulties that can arrive in the assembly chain. Many of those can be
removed rather easily by paying attention to certain details in the design
of boards.
23 September 2004.
