Best BTC prototype production

Ersa Hybrid Rework Systems HR 500 and HR 550

Ersa is well-known as one of the leading manufacturers of soldering systems in the world. In addition to template printers, soldering systems for SMT and THT manufacturing and a wide range of manual soldering tools, the system supplier has been working successfully for many years in the field of assembly repairs. Numerous companies use Ersa rework systems in development and prototype production too. With the presentation of the latest additions to the rework family at the productronica 2019 and APEX 2020 trade fairs, Ersa underlined its strong position, which includes close customer relations and consistent further development of technologies to benefit users. Whether used in electronics manufacturing, product development, testing or analysis, Ersa rework systems maintain value creation on the customer side and speed up the market launch of planned products.

During the development of electronic assembles, a series of soldering-related tasks have to be performed which demand a high level of both flexibility and precision: prototype boards must be equipped and soldered, components often need exchanging, changes must be made to the circuitry following comprehensive service life or function tests. In face of the numerous types of components and solder connections available today, it is thus necessary to always have suitable tools on hand. Because in line with the “time is money” maxim, development phases must be observed and products launched on the market quickly. The development departments of many renowned manufacturers are already using Ersa rework systems for prototype manufacturing. New housing designs or components are equipped and soldered for the first time here. Even more often, first assemblies are equipped with newly programmed or modified components. Other, somewhat more exotic areas of analysis or technical forensics also often make use of rework technology: cross-replacement during troubleshooting are just as much the order of the day as the desoldering of memory modules from mobile phones or notebooks in order to analyse the data saved.

Sensitive sample board

So-called “Golden Samples” are the most closely guarded treasures in development. Accordingly, these sensitive assemblies should be handled with the utmost care. In prototyping, many working steps that run automatically in a production line have to be done by hand or with the aid of tools and semi-automatic devices. As a rule, the printed circuit board is the starting point. There are suppliers who supply low-price Golden Samples for standard electronics within a few days. For special requirements, manufacturers including LPKF Laser & Electronics AG offer equipment for structuring printed circuit boards in company laboratories. In any case, the Golden Sample can have different properties in terms of structure than the later final product. Sample substrates may not have the same temperature stability, for example, or have a sensitive coating. Accordingly, the subsequent equipping processes and the soldering must be carried out with great care.

The Golden Sample usually runs through a number of processes (through to cleaning) which deviate from those used in series manufacturing later. There can be a mixture of manual and machine equipping, while soldering can be a mixture of reflow and manual soldering as well as soldering with rework systems. A high level of expertise and precision is required of those involved. Prudent developers may include sockets for processors in the prototype design. These involve individual equipping and soldering processes which will not be done in the same way in later series production. Very often, adaptations have to be made to the first assemblies which frequently involve further soldering processes. This is another reason why all soldering work should be done as gently as possible, in order to avoid damage to assemblies or substrates.

BTC and Prototyping

Ersa supports its customers more than ever today in processes involving the production of prototypes or functional samples. Ersa rework systems have made a name for themselves as ideal assistants for development departments, in particular in the field of “Bottom Terminated Components” (BTC). The soldering of seemingly simple designs such as MLF (Micro Lead Frame) or QFN (Quad Flat No Lead) can quickly become a large obstacle during the completion of sample assemblies. With these components, the right quantity of solder paste must be applied – this is just as critical for a good soldering result as the even heating of the soldering spots. One method that has proved its worth in practice both for sample equipping and for repairs is the printing of solder paste on the component using a precisely dimensioned template, followed by placement and soldering. The Ersa Dip&Print Station serves well during component printing. The component is fixed precisely in a recess in the template, printed on the underside with solder paste and then lifted out of the template. Then the printed component is further processed.

In the case of the Ersa rework systems HR 550 and HR 500, the component is aligned to the lands on the board with the aid of a beam splitter lens and then set in place by a motor-driven unit. Component sizes from 50 x 50 mm (HR 500) or 70 x 70 mm (HR 550) are possible. Thanks to an additional zoom lens, the HR 550 can even place tiniest chips up to the 01005 design. Here, “01” stands for the length and “005” for the width of the component in the unit inch/100. The strengths of the two systems really come into play when components with a large number of connections and tight contact spacing have to be placed precisely. They are indispensable for BGA (Ball Grid Arrays) and QFP (Quad Flat Packs) in particular. For near-series soldering processes the assembly is pre-heated from below in accordance with the preselected soldering profile, and the component soldered in place during a sensor-guided soldering process. All the soldering points receive the same quantity of heat and the assembly only experiences the temperature necessary for safe soldering. Customers who would like to make use of automated equipping and soldering processes during the prototyping phase can process SMD components down to size 01005 reliably using the Ersa HR 600/3P.

Soldering complete assemblies

Thanks to their hybrid heating technology, Ersa rework systems are even suitable for soldering several components in one process. With small assemblies, such as those used in the field of sensor systems, all soldering points can even be generated in one process – sometimes over several boards in the panel, providing the maximum process area of 70 x 70 mm is not exceeded. The Ersa systems use extremely homogeneous infrared systems from below to ensure the boards are preheated evenly. The hybrid heater heads also stand out due to their very balanced heat transfer. They do not need any component-specific nozzles in the soldering process. Suitable profile settings enable many components to be soldered, right through to a completely equipped board. The controlling of temperature by means of a thermal element on the top of the board makes a controlled and safe process possible even at the first attempt. It has been shown in practice that the quality of the soldering spots is comparable with the series standard.
The open system design of the hybrid rework systems permits additional process checks with the aid of a reflow process camera. This provides high-resolution images during solder melting, thus reducing the thermal load to the minimum necessary.

More Ersa systems for sample assemblies

The product portfolio of Ersa GmbH contains further equipment for the ideal processing of sample assemblies: For gentle manual soldering work the i-CON VARIO 4 provides four soldering tools that can be used at the same time plus an optional pre-heating plate – contact soldering with the i-TOOL or the 250 W power pack POWER-TOOL, hot air soldering with the i-TOOL AIR S, THT desoldering with the X-TOOL VARIO and the SMD desoldering tweezers CHIP TOOL. The rework station HR 100 is a good choice for pure soldering work at components up to 20 x 20 mm edge length. The HR 200 rework system is suitable for components up to 30 x 30 mm.

Prototyping with Ersa systems

  • Successful processing from the very first assembly
  • Simple and reliable component placement with BTC
  • Components up to 01005 can be processed
  • Safe, controlled soldering processes
  • Assembly repairs possible at all times
  • ESimple operation thanks to operator guidance and standardised software HRSoft 2

Article Author

Jörg Nolte Product Manager Soldering Tools, Ersa GmbH

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