Microdul AG has been cooperating with Juki Automation Systems for six years. A real win-win situation. Microdul achieves its innovative goals in new technologies thanks to JUKI's highly-developed KE2060RL placement systems. Juki Automation Systems benefits as regards flipchip and 01005 placement from the special needs of Microdul for its continuing development.
Microdul AG is an expert in high quality microelectronics. It includes three business areas: modules, thick-layer technology and semiconductors. In these disciplines the firm, based in Zurich, has access to a wide and comprehensive body of specialist knowledge. Microdul AG is particularly strong in the miniaturisation of electronic circuits. Its core competence lies in the development and production of highly-specific, individual solutions, created in close collaboration with its customers.
A wide diversity of industries take advantage of the specialised know-how and consistent high-quality products of Microdul AG. Satisfied customers include companies from the following areas:
- Medical technology
- Sensors
- Control and instrumentation systems
- The watch industry
- Safety engineering
- Power electronics
- Telecommunications
- Mechanical engineering
- The automotive industry, etc.
Quality - also due to reliable partners like JUKI
It becomes immediately clear from this demanding range of customers that Microdul AG must deliver the highest quality. Medical technology will tolerate no compromises; likewise sensors, watches, measuring instruments and safety elements must function with the greatest possible reliability. To meet this requirement in the industrial conversion of the products,  the technical knowledge of highly-qualified employees and a consistent quality management system are necessary. Microdul AG is ISO 9001 and ISO 13485 certified. Quality is a priority in the company values set out in writing, and the bosses lead by example of what they expect from each employee.
Top quality cannot be achieved single-handedly given such complex tasks. Reliable partners are required. One of these is JUKI.
In 2002 Microdul AG first decided to purchase a placement system from Juki Automation Systems, the JUKI KE2020 model. An important criteria for this choice was the excellent placement accuracy of the JUKI KE2020, an important prerequisite for miniaturisation, which Microdul offers to its clients. At that time, placement of components of size 0201 was still a major challenge, and was perfectly mastered by the JUKI KE2020.
A further important criterion that speaks for the JUKI KE2020 is the unit's high degree of reliability in operation. This allows Microdul AG to achieve its highest goals concerning throughput time and adherence to delivery schedules.
Individual matching of systems in cooperation with JUKI
Among the components handled by Microdul AG are flexprints. During placement, these must be fixed. To this end, an innovative vaccuum table was designed. The design came from Microdul AG while the manufacture of the special components was taken on by JUKI. This collaboration worked perfectly. The vaccuum table perfectly compliments the placement systems and has continued to provide exemplary service at Microdul AG. The overall system, developed in partnership, thus meets the highest expectations for placement quality and availability that one could have of a JUKI placement system.
The introduction of flipchip placement - again with JUKI
At that time the market was continuing to evolve. Micromodul AG was facing new challenges. The push for miniaturisation drove the microelectronics specialist - realising that it could double its turnover - to embrace and implement new technologies such as the processing of CSPs (chip-scale packages) and flipchips and the placement of 01005 components.
 Micromodul AG's good experiences with the KE2020 supported its decision to continue to work with Juki Automation Systems and to acquire the successor KE2060RL system with dip station. The dip station for flux consists of a metal plate with a milled cavity of selectable depth and a blade with integrated flux container that coats the cavity, thus creating a flux film of predefined thickness.
In December 2006 Micromodul commenced industrial placement of flipchip products on the KE2060. This was done in close co-operation with Juki Automation Systems and its local representation, Neutec.
At first the placement accuracy was satisfactory but not yet perfect. By recalibrating the high-resolution camera it was possible to eliminate a systematic offset of about 20um.
The viscosity of the necessary gel flux posed a major difficulty. Movement of the blade of the dip-station grew slower as operating time increased, due to the sticking and gradual drying out of the flux. As a result, after about an hour the process came to a halt because of timing-out of the blade movement. The process could only be resumed after thoroughly cleaning the dip station and filling it with new flux.
It became clear that the advancing force of the blade was not sufficient to overcome the resistance created by the flux. Consequently, technicians at JUKI developed a new blade with a higher advancing force that allows the system to sustain more than three hours of flipchip placement without interruption.
At present Microdul AG assembles a range of different products on the KE2060 that contain CSPs or flipchips. The smallest of these involve a ball pitch of 170um and a ball diameter of 90um. On such products the fine-pitch placement accuracy of the KE2060 can be fully exploited.
Side view of a soldered flipchip with 250um pad pitch
Solder balls from (sheared-off) flipchip on flexprint demonstrate placement accuracy
The dip-station has potential for further functions, as yet unrealised, such as the stamping of flux or conductive glue. This would allow repairs or retro-placements to be largely automated.
A new push for placement of 01005 components
 In order to check the process capability for placement of 01005 components, in 2005 Microdul AG developed a test print containing various components of sizes from 0805 to 01005 on a 4" FR4 print. The more than 2,000 0105 components are divided into groups with various spacings, pad sizes and conductor path connections. Since however the KE2020 was not capable of the necessary placement accuracy, the project was suspended.
Once Microdul AG had acquired its Juki KE2060 and, in a second step, armed itself with the new software, it resumed the project and completed it in 2007. A deciding factor in successful placement is the quality of the print. Microdul AG had deliberately selected a combination of the smallest and largest components. This meant that it was necessary to make compromises in the stencil and to select a greater stencil thickness. The consequences included a slightly excessive paste pressure, so that extremely light components were in danger of slipping from the paste. By adjusting the print height it was possible to ensure that the components were pressed deeper into the solder paste, which much improved soldering performance. With these minor adjustments the placement accuracy of the Juki KE2060 proved itself more than sufficient for successfully placing 01005 components.
The six-year partnership between Microdul and Juki Automation Systems has thus developed into a valuable and mutually beneficial co-operation whose story is still far from ending under the current conditions.
Contact Details:
Urs Merki
Head of Production
Tel. +41 44 455 35 06
urs.merki@microdul.com
Peter Baumgartner
Process Development
Tel. + 41 44 455 35 62
peter.baumgartner@microdul.com
Microdul AG
Grubenstrasse 9
8045 Zürich
www.microdul.com
|
){kind=link}
){kind=link}
){kind=link}
