WIMA SMD capacitors in size codes 1812, 2220, 2824, 4030, 5040 and 6054, capacitance values from 0.01 µF through 6.8 µF and voltage ranges from 63 VDC through 1000 VDC cover nearly the entire application range of conventional through hole plastic film capacitors. All WIMA SMD series are produced with the proven box technology, showing the following advantages in comparison with non-encapsulated or moulded SMD capacitor versions:
■Safe protection of the capacitor element against mechanical and thermal stresses during processing and operation.
■No danger of internal cracks or tearing away of the contacts due to construction elasticity.
■No danger of delamination due to solder plates over the capacitor's entire end surfaces.
■Flame-retardant plastic case in accordance with UL 94 V-0.
These features and the wide capacitance range enable WIMA SMDs to substitute other capacitor technologies and become standard components in electronic developments.
WIMA plastic film capacitors in PCM 2.5 mm are available in metallized, self-healing version WIMA MKS 02 or in pulse duty film and foil version WIMA FKP 02. As a dielectric, Polyester or Polypropylene is used. The capacitance range includes values of 100 pF through 1.0 µF and voltage ratings of 50 VDC, 63 VDC, 100 VDC, 250 VDC and 400 VDC.
The realization of the smallest plastic film capacitors in the world has been made possible by the use of ultra-thin plastic film in thicknesses of 0.8 µm and below. The film processing with highly sensitive machines requires a high degree of experience and technical know-how.
The WIMA series with 2.5 mm PCM are contacted at the end surfaces and have very low self-inductance due to the small pin spacing of the capacitor and its fully contacted electrodes. Furthermore, the pulse and current loading capacities basically increase, the smaller the PCM can be designed, because - provided that the thickness of the film is the same - a longer band length is needed to achieve a particular capacitance value.
WIMA capacitors in PCM 2.5 mm are outstandingly suitable for HF decoupling in the field of high frequencies and open up new possibilities for use in applications with limited space requirements and high packing density.
In the case of film and foil types, the electrode is not applied as for the metallized capacitors, but is wound with the dielectric as a metal foil. Due to their lower series resistance, the components produced this way have excellent pulse and current carrying capability, as well as a very high insulation resistance.
The film/foil construction is mainly used for capacitors with smaller capacitance value. The advantage of this construction principle is the easy contactability of the metal foil electrodes and the good pulse strength. To avoid breakdowns caused by weak spots in the dielectric, the insulating film chosen is always thicker than theoretically required by the values which are determined from the specific breakdown strength of the material.
WIMA film/foil capacitors in PCM 5 mm to 15 mm are available in two dielectric versions. WIMA capacitors with a Polyester dielectric (PET) are suitable for general applications such as coupling, decoupling and by-passing. Polypropylene capacitors (PP) are used in the high frequency field. This includes resonant circuits, power supplies, deflection circuits, oscillator circuits and audio equipment.
WIMA film/foil capacitors in PCM 5 mm to 15 mm are available with capacitance values from 33 pF to 0.22 µF and rated voltages from 63 VDC to 1000 VDC.
In the case of metallized capacitors, thin layers of aluminium (approx. 0.03 µm) are vacuum-deposited on the insulating film as conducting electrodes. In the case of a breakdown, the short circuit current causes the thin metal coating to evaporate around the point of failure and an insulating area is formed. The capacitor remains intact (self-healing). Due to their construction principle metallized capacitors stand out for their very favourable capacitance/volume ratio.
Metallized WIMA capacitors in PCM 5 mm - 52.5 mm are available in two dielectric versions. Capacitors with a Polyester dielectric (PET) are suitable for general applications such as coupling, decoupling and by-passing. By making use of ultra thin film and appropriate manufacturing experience, it has been possible to achieve high capacitance values in very small box sizes. Polypropylene capacitors (PP) are used in the high frequency field. This includes resonant circuits, power supplies, deflection circuits, oscillator circuits and audio equipment.
Upon customer request, larger box sizes can be supplied in 4-pin versions. Types with terminating plates can also be manufactured on request. The advantage of this method of construction, besides the improved mechanical stability of the component on the board, is the excellent electrical contact reliability.
WIMA capacitors are produced with the proven box technology using solvent-resistant, flame-retardant plastic cases according to UL 94 V-0. They are environmentally compatible with the RoHS 2011/65/EU regulations of the European Union.
An important construction criterion in the manufacture of reliable, self-healing capacitors for pulse applications is the current-carrying capacity of the contacts, i.e. the connection between the terminating wires and the electrodes.
The construction principle of the series WIMA MKP 10 consists of a non-metallized dielectric film and an carrier film metallized on both sides acting as electrode. Thanks to the metallization on both sides, the electrical conductivity is considerably improved and the contact surface between the electrodes and the schoopage layer is doubled. This results in better contact and allows for high current and pulse loading capability. The properties of metallized capacitors such as excellent self-healing and high volume capacitance remain unchanged.
The WIMA FKP 1 series was developed for extremly high pulse loads. It has an internal series connection, the metal foil electrodes being combined with a floating electrode metallized on both sides. The metal foil electrodes are safely contacted on both sides of the end surfaces. At the same time the capacitor is fully self-healing due to the floating electrode metallized on both sides. As regards pulse loading capability, WIMA FKP 1 represents the high-end of capacitor technology.
WIMA pulse capacitors are suitable for high pulse and high frequency applications in e.g. switch mode power supplies, TV and monitor sets, lighting industry, audio/video equipment, converters in drives and power electronics or in electronic ballasts. They are available with capacitances from 100 pF through 47 µF and with voltage ratings from 100 VDC through 6000 VDC.
Radio interference suppression capacitors must not only satisfy EMC requirements in suppressing outgoing interference from an application but they must also protect the application from incoming power surges. Hence careful selection of these components is essential.
The special feature of WIMA Polypropylene RFI capacitors are the high capacitance values at smaller case sizes compared to metallized paper capacitors, being available up to 10 µF with AC voltages of 300 VAC, 305 VAC and 440 VAC for class X1, X2 and Y2 . Based on the dielectric used they are highly cost-effective.
WIMA metallized paper are neither actively nor passively flammable. The components are resin impregnated under vacuum and encapsulated with self-extinguishing cast resin. Thanks to the good oxidation behaviour of the paper dielectric, they have outstanding self-healing properties even with high energy pulses. The capacitors are specified for temperatures up to 110° C and are available for class X1, X2 and Y2 applications.
Class X capacitors are connected between phase and neutral or phase and phase conductors. Class Y capacitors have an increased degree of electrical and mechanical safety and are connected, for example, between phase conductors and earthed casing, and thus by-pass operating insulation.
The specified rated AC voltage takes into account a rise of the mains voltage of up to 10% above the nominal value, in accordance with IEC 60384-14.
Development of the WIMA Snubber MKP and WIMA Snubber FKP capacitor series for high power conversion is based on decades of experience with Polypropylene pulse capacitors.
WIMA Snubber capacitors are available both as double-sided metallized pulse version - WIMA Snubber MKP - and for extremly high pulse ratings in self-healing film/foil technology - WIMA Snubber FKP. Their electrical performance as well as the manifold number of available connecting options makes the WIMA Snubber technology unique:
■Plates soldered directly to the schoopage for safe contacts at high rms currents
■Low inductance construction achieved by end-surface contacts
■High pulse reliability due to double-sided metallization and/or film/foil construction
■High voltage/overvoltage strength by internal series connection with self-healing metallized floating electrode
■Available in various contact configurations
■Flame retardant plastic case in accordance with UL 94 V-0
■Production sites ISO 9001:2008 certified
WIMA Snubber capacitors are manufactured under conditions of large volume production, but are also available in small quantities as individually configurable high-rel. components.
WIMA GTO MKP capacitors are especially designed to attenuate voltage spikes on GTO (Gate-Turn-Off) Thyristors and IGBT (Insulated Gate Bipolar Transistor). They are manufactured in dry-type technology with a dielectric of metallized polypropylene film and encapsulated in a cylindrical plastic case sealed with self-extinguishing polyurethane resin. Their construction creates outstanding features, e.g.:
■Very low self-inductance
■High pulse reliability
■High rms current carrying capability
■Excellent self-healing properties
■High shock and vibration resistance
■Outstanding mechanical stability
■Almost unlimited life expectancy
Fields of applications are designs where high current and voltage carrying capabilities are required, e.g. converter equipment in power generation or in traction technology for train drives, hoists, crane drives etc.
WIMA GTO MKP capacitors are available with capacitances from 1.0 µF through 100 µF and with nominal voltages from 400 VDC through 2000 VDC. For mounting purposes M6 and M8 threaded terminations are possible. Customer-specific requirements can be realized on demand.
WIMA DC-Link capacitors are especially designed for applications in high power converter technology where due to increasing electrical requirements they are more and more substituting electrolytic capacitors. Manufactured with a low loss polypropylene dielectric they show a higher current carrying capability as well as lower dissipation/self-heating at high frequencies compared to electrolytic capacitors. Further outstanding features are, e.g.:
■Very high capacitance/volume ratio
■High voltage rating per component
■Very low dissipation factor (ESR)
■Very high insulation resistance
■Excellent self-healing properties
■Long life expectancy
■Particularly reliable contact configuration
■High shock and vibration resistance
■Outstanding mechanical stability
WIMA DC-LINK MKP 3 capacitors in cylindrical case with screw fixing are available with capacitances from 35 µF through 200 µF and with voltage ranges from 700 VDC through 1500 VDC. They can be provided with male or female terminations.
WIMA DC-LINK MKP 4 capacitors with rectangular case are available with capacitance values from 1 µF through 400 µF and with rated voltages from 400 VDC through 1300 VDC. For mounting purposes 2-pin and 4-pin versions are possible. The WIMA DC-LINK MKP 4S series has been designed for stringent requirements
WIMA DC-LINK MKP 5 capacitors in cylindrical plastic case are available with capacitances from 16 µF through 260 µF and with rated voltages from 500 VDC through 1300 VDC. They are provided with tinned wire terminations for PCB mounting.
WIMA DC-LINK MKP 6 capacitors have a cylindrical aluminium case. They are available with capacitances from 75 µF through 4920 µF and with rated voltages from 600 VDC through 1500 VDC. For bus bar mounting they are designed with M6 screw terminations and M12 screw bolt.
Customized solutions e.g. can be realized with WIMA DC-LINK HC and WIMA DC-LINK HY with variable connecting configurations.