SIST EN 140402-801:2015
(Main)Detail specification: Fixed low power wirewound surface mount (SMD) resistors - Rectangular - Stability classes 0,5; 1; 2
Detail specification: Fixed low power wirewound surface mount (SMD) resistors - Rectangular - Stability classes 0,5; 1; 2
Various parameters of this component are precisely defined in this specification. Unspecified parameters
may vary from one component to another.
Bauartspezifikation: Oberflächenmontierbare drahtgewickelte Festwiderstände (SMD) niedriger Belastbarkeit - Rechteckig - Stabilitätsklassen 0,5; 1; 2
Spécification particulière: Résistances fixes bobinées à faible dissipation pour montage en surface (CMS) - Rectangulaire - Catégories de stabilité 0,5; 1; 2
Podrobna specifikacija: upori, nespremenljivi, za male moči, žični, za površinsko montažo (SMD) - Pravokotne oblike - Razredi stabilnosti 0,5; 1; 2
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Bauartspezifikation: Oberflächenmontierbare drahtgewickelte Festwiderstände (SMD) niedriger Belastbarkeit - Rechteckig - Stabilitätsklassen 0,5; 1; 2Spécification particulière: Résistances fixes bobinées à faible dissipation pour montage en surface (CMS) - Rectangulaire - Catégories de stabilité 0,5; 1; 2Detail specification: Fixed low power wirewound surface mount (SMD) resistors - Rectangular - Stability classes 0,5; 1; 231.040.10Fiksni uporFixed resistorsICS:Ta slovenski standard je istoveten z:EN 140402-801:2015SIST EN 140402-801:2015en01-junij-2015SIST EN 140402-801:2015SLOVENSKI
STANDARDSIST EN 140402-801:20061DGRPHãþD
SIST EN 140402-801:2015
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 140402-801
April 2015 ICS 31.040.10
Supersedes
EN 140402-801:2005English Version
Detail specification: Fixed low power wirewound surface mount (SMD) resistors - Rectangular - Stability classes 0,5; 1; 2
Spécification particulière: Résistances fixes bobinées à faible dissipation pour montage en surface (CMS) - Rectangulaire - Catégories de stabilité 0,5; 1; 2
Bauartspezifikation: Oberflächenmontierbare drahtgewickelte Festwiderstände (SMD) niedriger Belastbarkeit - Rechteckig - Stabilitätsklassen 0,5; 1; 2 This European Standard was approved by CENELEC on 2014-12-15. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17,
B-1000 Brussels © 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 140402-801:2015 ESIST EN 140402-801:2015
EN 140402-801:2015 - 2 -
Contents Foreword . 4 1 Characteristics and ratings . 6 1.1 General . 6 1.2 Dimensions and ratings . 6 1.3 Derating curve . 7 1.4 Resistance range and tolerance on rated resistance . 7 1.4.1 Level P . 7 1.4.2 Level R . 8 1.5 Variation of resistance with temperature and temperature rise . 9 1.6 Climatic categories . 10 1.7 Limits for change of resistance at tests . 10 1.8 Non-linearity . 12 1.9 Tests related to soldering . 12 1.9.1 Severities for solderability testing . 12 1.9.2 Severities for testing resistance to soldering heat . 12 1.10 Marking, packaging and ordering designation . 12 1.10.1 Marking of the component . 12 1.10.2 Packaging . 12 1.10.3 Marking of the packaging . 12 1.10.4 Ordering information . 12 1.11 Additional information (not for inspection purpose) . 13 1.11.1 Storage . 13 1.11.2 Mounting . 13 1.11.3 Soldering process . 13 1.11.4 Conductive gluing . 14 1.11.5 Use of cleaning solvents . 14 1.11.6 Pulse load capability . 14 2 Quality assessment procedures . 21 2.1 General . 21 2.1.1 Zero defect approach . 21 2.1.2 100 % Test . 21 2.1.3 Certificate of Conformity (CoC) . 21 2.1.4 Certified test records . 22 2.1.5 Failure rate level . 22 2.2 Qualification approval . 22 2.2.1 General . 22 2.2.2 Level P . 22 2.2.3 Level R . 22 2.3 Quality conformance inspection . 22 2.3.1 General . 22 2.3.2 Qualification approval according to QC 001002-3:2005, Clause 3 . 23 2.3.3 Technology approval according to QC 001002-3:2005, Clause 6 . 23 2.3.4 Non-conforming items . 23 Annex A (normative)
Fixed sample size Qualification Approval and Quality Conformance Inspection test schedule for fixed low power wire wound SMD resistors . 24 Annex B (informative)
Letter symbols and abbreviations . 34 SIST EN 140402-801:2015
- 3 - EN 140402-801:2015 B.1 Letter symbols . 34 B.2 Abbreviations . 35 Annex C (normative)
Normative references . 36 Annex D (normative)
Mounting of components. 37 D.1 Layout for mechanical tests . 37 D.2 Layout for electrical test. 38 Bibliography . 39
SIST EN 140402-801:2015
EN 140402-801:2015 - 4 -
Foreword This document (EN 140402-801:2015) has been prepared by CLC/TC 40XB "Resistors". The following dates are fixed:
• latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2015-12-15 • latest date by which the national standards conflicting with this document have to be withdrawn (dow) 2017-12-15
This European Standard supersedes EN 140402-801:2005. Preceding document on the subject covered by this specification has been: – CECC 40 402-801:2000-02. EN 140402-801:2015 includes the following significant technical changes with respect to EN 140402-801:2005: – adoption of P70 as the rated dissipation, leaving the prior used P25 as an additional information; – for style RW1607M, increase of P70 to 2,4 W, with P25 = 3,0 W; – introduction of a test on the resistance to electrostatic discharge (ESD) in 1.7 and Annex A; – introduction of code letters for the temperature coefficient (TCR) as in EN 60062:2005; – revision of ordering information in 1.10.4; – adoption of the IECQ rules of procedure according to QC 001002-3:2005; – revision of the sample quantities and the sequence of tests in Annex A; – editorial revision. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights. This specification is part of a series of documents describing fixed low power wire wound surface mount (SMD) resistors as follows: – EN 60115-1, Fixed resistors for use in electronic equipment — Part 1: Generic specification (IEC 60115-1, modified) – EN 60115-8, Fixed resistors for use in electronic equipment — Part 8: Sectional specification — Fixed surface mount resistors (IEC 60116-8, modified) – This detail specification. Any detail specification within this series is written on the basis of
– EN 140402, Blank Detail Specification: Fixed low power wirewound surface mount (SMD) resistors. __________ SIST EN 140402-801:2015
- 5 - EN 140402-801:2015
Specification available from CENELEC Central Secretariat,
Avenue Marnix 17, B – 1000 Brussels,
or from the National Committees members of CENELEC EN 140402-801
Electronic components of assessed quality in accordance with: EN 60115-1:2011 EN 60115-8:2012 EN 140402:2015 Issue 2 April 2015
Other shapes are permitted within the given dimensions. Figure 1 — Outline and dimensions (see Table 1) Fixed low power wire wound resistors with rectangular base for surface mounting. Style: RW Wire wound, insulated resistor with end terminations for application on printed board and flexible foils. Assessment level EZ a Level P: with 100 %-test Level R: with failure rate level
and 100 %-test Stability classes 0,5; 1 and 2 a See 2.1.1 for an explanation on the assessment level EZ. SIST EN 140402-801:2015
EN 140402-801:2015 - 6 -
1 Characteristics and ratings 1.1 General Various parameters of this component are precisely defined in this specification. Unspecified parameters may vary from one component to another. 1.2 Dimensions and ratings The shape and dimensions of the resistors covered by this specification are shown in Figure 1, with the specific styles and their respective dimensions given in Table 1. Other shapes are permissible within the given dimensions. Table 1 — Style and dimensions Style a Length L
mm Width W
mm Height H
mm Termination width D mm Termination seating length J mm Mass b
mg metric inch b min. max. min. max. min. max. min. max. min. max. max. RW0503M RW2012 4,6 5,6 2,0 3,6 2,0 3,6 1,0 2,0 0,7 1,4
120 RW0704M RW2515 5,7 8,0 3,0 4,5 2,4 4,5 1,0 3,0 0,8 1,6
250 RW1107M RW4527 9,8 12,5 5,5 7,5 3,9 6,0 1,8 5,6 1,4 2,8
1 000 RW1607M RW6927 14,5 19,0 5,5 7,5 5,5 7,5 3,0 5,8 1,4 2,8
2 000 a The given styles correspond to the historical styles of the prior CECC 40 402-801 as follows: Style Historic style RW0704M RW1 RW1107M RW2 RW1607M RW3 b
For information only.
NOTE
Information about manufacturers who have components qualified to this detail specification is available in the approvals section of the website http://www.iecq.org. Table 2 — Ratings Style Rated dissipation Maximum dissipation a Limiting element voltage d.c. or a.c. (r.m.s.) b Insulation voltage d.c. or a.c. (peak)
P70 W P25 W Umax V Uins V
1 min continuous RW0503M 0,6 0,75 28 500 75 RW0704M 0,8 1,0 50 500 75 RW1107M 1,6 2,0 112 500 75 RW1607M 2,4 3,0 200 500 75 a
For information only. b
For all resistance ranges given in Tables 3 and 4, the applicable voltage is determined by the rated or maximum dissipation and not limited by the limiting element voltage. SIST EN 140402-801:2015
- 7 - EN 140402-801:2015 1.3 Derating curve The permissible dissipation of resistors covered by this detail specification is the rated dissipation as given in Table 2, which is derated for an ambient temperature above the rated temperature 70 °C according to the diagram in Figure 2. The manufacturer of the resistors covered by this detail specification may uprate the products by specification of an increased dissipation up to the maximum dissipation given in Table 2, which is derated for an ambient temperature above the reference temperature of 25 °C according to the diagram in Figure 2. The manufacturer shall support such uprating with respective test results.
Key X ambient temperature ϑamb Y fraction of the rated dissipation P70 Figure 2 — Derating curve
NOTE
Climatic tests and the assessment of the temperature coefficient of resistance apply the upper category temperature, UCT, as the highest temperature, whereas the loads applied under endurance testing aim to subject the resistive element to the maximum element temperature, MET. The use of the full specified dissipation and temperature range results in a high temperature on the substrate (PCB) and in the solder joints. It may hence be required to select suitable substrate material and suitable solder material in order to maintain the reliability of the assembly. 1.4 Resistance range and tolerance on rated resistance 1.4.1 Level P NOTE
Product classification to Level P adopts and succeeds the former Version A as used in prior revisions of this detail specification. Table 3 gives the combinations of temperature coefficient, tolerance on resistance and resistance range which may be approved to Level P according to this detail specification. The respective E Series are specified as a recommendation only for Level P. SIST EN 140402-801:2015
EN 140402-801:2015 - 8 -
Products from the extent given in Table 3 shall be used for the initial product qualification approval to Level P according to 2.2.2, and for the quality conformance inspection according to 2.3. The qualification of resistances below or above the specified resistance ranges is permissible if they fulfil the requirements of the stability class prescribed for the closest resistance within a specified range; e.g. resistors of Style RW0704M, 1 %, > 2,43 kΩ shall fulfil the requirements of stability class 1. Table 3 — Resistance range and tolerance on rated resistance for Level P Style Tolerance on rated resistance Temperature coefficient a Resistance
range Stability class E
Series c % Code b
10-6/K Code b RW0503M ± 5 J See Table 5. 0,047 Ω to 1 kΩ 2 E24 ± 1 F 0,1 Ω to 1 kΩ 1 E96 ± 0,5 D 0,1 Ω to 1 kΩ 0,5 E192 RW0704M ± 5 J 0,047 Ω to 2,4 kΩ 2 E24 ± 1 F 0,1 Ω to 2,43 kΩ 1 E96 ± 0,5 D 0,1 Ω to 2,43 kΩ 0,5 E192 RW1107M ± 5 J 0,047 Ω to 5,6 kΩ 2 E24 ± 1 F 0,1 Ω to 5,62 kΩ 1 E96 ± 0,5 D 0,1 Ω to 5,62 kΩ 0,5 E192 RW1607M ± 5 J 0,047 Ω to 13 kΩ 2 E24 ± 1 F 0,1 Ω to 13 kΩ 1 E96 ± 0,5 D 0,1 Ω to 13 kΩ 0,5 E192 a The waivers given in EN 60115-1:2011, 4.8.5 concerning the measurement of the temperature coefficient at resistors below 10 Ω and below 5 Ω shall not apply for this specification. A suitable test method shall be applied in order to ensure the required measurement accuracy. b Code letters according to EN 60062. c E Series according to IEC 60063. The range of resistors approved in each style, together with the associated temperature coefficient and tolerance, shall be given in the register of approvals, as available for example on the website http://www.iecq.org. 1.4.2 Level R NOTE
Product classification to Level R adopts and succeeds the former Version E as used in prior revisions of this detail specification. Table 4 gives the combinations of temperature coefficient, tolerance on resistance, resistance range and mandatory E Series which may be approved to Level R according to this detail specification.
Products from the extent given in Table 4 shall be used for the initial product qualification approval to Level P according to 2.2.3, and for the quality conformance inspection according to 2.3. SIST EN 140402-801:2015
- 9 - EN 140402-801:2015 Table 4 — Resistance range and tolerance on rated resistance for Level R Style Tolerance on rated resistance Temperature coefficient a Resistance
range Stability class E
Series c % Code b 10-6/K Code b RW0503M ± 5 J See Table 5 0,47 Ω to 510 Ω 2 E24 ± 0,5 D 0,464 Ω to 511 Ω 0,5 E96 RW0704M ± 5 J 0,47 Ω to 1,2 kΩ 2 E24 ± 0,5 D 0,475 Ω to 1,21 kΩ 0,5 E96 RW1107M ± 5 J 0,47 Ω to 3,0
kΩ 2 E24 ± 0,5 D 0,475 Ω to 3,01 kΩ 0,5 E96 RW1607M ± 5 J 0,47 Ω to 6,8 kΩ 2 E24 ± 0,5 D 0,475 Ω to 6,81 kΩ 0,5 E96 a The waivers given in EN 60115-1:2011, 4.8.5 concerning the measurement of the temperature coefficient at resistors below 10 Ω and below 5 Ω shall not apply for this specification. A suitable test method shall be applied in order to ensure the required measurement accuracy. b Code letters according to EN 60062. c E Series according to IEC 60063. The range of resistors approved in each style, together with the associated temperature coefficient and tolerance, shall be given in the register of approvals, as available for example on the website http://www.iecq.org. 1.5 Variation of resistance with temperature and temperature rise The permissible limits for the reversible change of resistance at variation of resistance with temperature tests are given in Table 5 for the category temperatures applied in this detail specification. Table 5 — Temperature coefficients and permissible change of resistance Temperature coefficient Resistance range Limit of resistance change ∆R/R d %
Lower TCR Upper TCR
Code b Code c
LCT /
Reference temperature Reference temperature / UCT 10-6/K a
Ω -55 °C / 20 °C 20 °C / 200 °C ± 250 U A R < 0,47 ± 1,875 ± 4,5 ± 100 S B 0,47 ≤ R < 1 ± 0,75 ± 1,8 ± 50 R C 1 ≤ R ≤ 10 ± 0,375 ± 0,9 ± 25 Q D R > 10 ± 0,188 ± 0,45 a The unit 10-6/K is traditionally referred to as ppm/K. b Code letters according to EN 60062. c Historical code letters according to EN 140400, for information only. d The waivers given in EN 60115-1:2011, 4.8.5 concerning the measurement of the temperature coefficient at resistors below 10 Ω and below 5 Ω shall not apply for this specification. A suitable test method shall be applied in order to ensure the required measurement accuracy. The permissible temperature rise (∆ϑ)max for the temperature rise test according to EN 60115-1:2011, 4.14 is given in Table 6. SIST EN 140402-801:2015
EN 140402-801:2015 - 10 -
Table 6 — Limit of temperature rise Stability class Limit of temperature rise
at rated dissipation 0,5; 1; 2 ∆ϑ ≤ 180 K The thermal resistance is calculated to Rth = (∆ϑ)max / P70. 1.6 Climatic categories The climatic categories applied in this detail specification are given in Table 7. Table 7 — Climatic categories Stability class Climatic category LCT / UCT / Duration 0,5; 1; 2 55 / 200 / 56 The upper category temperature (UCT), which is used for a number of test procedures, is lower than the maximum element temperature (MET), which may be observed in application conditions. 1.7 Limits for change of resistance at tests The permissible limits for the change of resistance at tests are given in Table 8 for the stability classes applied in this detail specification. SIST EN 140402-801:2015
- 11 - EN 140402-801:2015
Table 8 — Limits for change of resistance at tests
Stability class Limit of resistance change ∆R Ω=Long term tests Short term tests Advanced stress tests EN 60115-1:2011, 4.23
Climatic
sequence 4.24
Damp heat,
steady state 4.25.3 Endurance at
a maximum
temperature EN 60115-1:2011, 4.25.1 Endurance at the rated
temperature 70 °C a or 4.25.2 Endurance at room
temperature EN 60115-1:2011, 4.13 Short time overload 4.18 Resistance to soldering heat 4.19 Rapid change of temperature, 5 cycles 4.21 Shock 4.22 Vibration 4.33 Substrate
bending test EN 60115-1:2011, 4.19 Rapid change of temperature, 100 cycles 4.27 Single-pulse high-voltage overload test b 4.38 Electrostatic discharge c
EN 60115-1:2011, 4.39 Periodic-pulse overload test 1 000 h Extended, 8 000 h
2 ± (2 % R + 5 mΩ) d ± (2 % R + 5 mΩ) d ± (5 % R + 5 mΩ) d ± (0,5 % R+ 2 mΩ) d ± (1 % R + 2 mΩ) d ± (2 % R + 5 mΩ) d 1 ± (1 % R + 2 mΩ) d ± (1 % R + 2 mΩ) d ± (2 % R + 2 mΩ) d ± (0,25 % R+ 2 mΩ) d ± (0,5 % R+ 2 mΩ) d ± (1 % R + 2 mΩ) d 0,5 ± (0,5 % R + 2 mΩ) d ± (0,5 % R + 2 mΩ) d ± (1 % R + 2 mΩ) d ± (0,1 % R + 1m Ω) d a Testing endurance at the rated temperature 70 °C is mandatory for Level R.
b This test shall be applied to resistors of 10 Ω or above. c Human body model (HBM) according to EN 61340-3-1, 3 positive + 3 negative discharges.
d Tightening of the general definition of stability classes against the requirements of EN 60115-8:2012, 2.1.4. SIST EN 140402-801:2015
EN 140402-801:2015 – 12 –
1.8 Non-linearity
No Provisions NOTE
Measurement of non-linearity is generally not considered as a meaningful or significant test for wirewound resistors.
1.9 Tests related to soldering 1.9.1 Severities for solderability testing See EN 60115-8:2012, 2.3.2. 1.9.2 Severities for testing resistance to soldering heat See EN 60115-8:2012, 2.3.3. The solder bath method represents the soldering stress of all wave soldering and reflow soldering methods.
1.10 Marking, packaging and ordering designation 1.10.1 Marking of the component SMD wirewound resistors are generally marked on the body. If some marking is applied to the body of resistors classified to Level P, the component shall be marked with the rated resistance using a letter and digit code according to EN 60062:2005, Clause 4, preferably the RKMG code system according to EN 60062:2005, 4.2.1. If possible, the tolerance shall be marked using the letter code of EN 60062:2005, 5.1. Resistor classified to Level R shall be marked with the rated resistance using the RKMG code system according to EN 60062:2005, 4.2.1, and with the tolerance using the letter code of EN 60062:2005, 5.1. Marking of the temperature coefficient and of any other item from the list given in EN 60115-1:2011, 2.4.1 shall be the choice of the manufacturer. 1.10.2 Packaging Components shall be taped according to EN 60286-3, type 2a. 1.10.3 Marking of the packaging The packaging of the component shall be marked with ordering information in accordance to 1.10.4 and additionally with – CECC or IECQ sign of conformity, – CECC or IECQ manufacturer code, – NATO manufacturer code (only Level R), – date code of manufacture according to EN 60062. Additional information is permissible. 1.10.4 Ordering information Orders for resistors covered by this specification shall contain the following information: – detail specification number; – assessment level; – style; – temperature coefficient; SIST EN 140402-801:2015
– 13 – EN 140402-801:2015
– rated resistance; – tolerance on rated resistance; – failure rate level (only for Level R; “E0” for Level P); – form of delivery (in addition to the ordering information given in the schematic below). Schematic of the ordering information for resistors covered by this specification: Level P: EN140402–801EZRW1607MQ4K75FE0 Level R (with failure rate level): EN140402–801EZRW1607MQ4K75FE5 NOTE 1
Level P succeeds the former Version A, and Level R succeeds the former Version E. The elements used in this ordering information have the following meaning: EN140402–801 Detail specification number EZ Assessment level RW1607M Style (see Table 1) Q Temperature coefficient according to EN 60062 (see Table 5) 4K75 Resistance value, RKMG code system according to EN 60062, 4 characters F Tolerance on rated resistance (see Table 3 or Table 4) E0; E5 Failure rate level according to EN 60115-1:2011, Table ZR.1 NOTE 2
The specific values for style, temperature coefficient, resistance, tolerance and failure rate level applied above have been used to exemplify the schematic and hence need to be replaced by the user’s relevant choices. The ordering information used for electronic order processing shall not contain any spaces. 1.11 Additional information (not for inspection purpose) 1.11.1 Storage The permitted storage time is 20 years under the conditions of EN 60115-1:2011, 2.7. Solderability and resistance may be affected by storage. Therefore test of solderability and measurement of resistance are recommended before delivery if the storage time exceeds two years. 1.11.2 Mounting The resistors are suitable for mounting on alumina substrates, common printed boards and flexible foils. Temperatures next to the resistor resulting from use of the full specified dissipation and temperature range may exceed the specification limits of the substrate material and thus are likely to affect the reliability of the assembly. It may hence be required to select a suitable substrate material in order to maintain the reliability of the assembly. 1.11.3 Soldering process The resistors are suitable for all soldering methods according to EN 61760-1. This includes full compatibility with – lead free solder, e.g. SnCu, SnCuNi, SnAg or SnAgCu, – conventional SnPb solder. The immersion time shall not exceed 10 s when the components are immersed in a solder of 260 °C. Temperatures in the solder joints resulting from use of the full specified dissipation and temperature range may exceed the specification limits of the above solder materials and thus are likely to affect the reliability of the assembly. It may hence be required to select a suitable solder material, e.g. a PbSn alloy SIST EN 140402-801:2015
EN 140402-801:2015 – 14 –
with a higher melting point, in order to maintain the reliability of the assembly. However, solderability to PbSn alloys and resistance to the increased level of soldering heat required for such solder is not subject to any test prescribed within this specification. It is recommended to only use fluxes which do not require a cleaning process after soldering. Flux residues may be hard to remove, particularly from the space between the resistor and the circuit board or substrate. Flux residues may establish some conductivity in parallel to the assembled resistor and thereby adversely affect the performance of the electronic circuit. 1.11.4 Conductive gluing No provisions. 1.11.5 Use of cleaning solvents For the removal of flux residues the following agents may be used: – alcohol, such as ethanol, propanol, isopropanol (IPA) or butanol; – aqueous solutions; – deionized water. Reaction time of the solvent shall not exceed 5 min. Consultation with the resistor manufacturer is recommended if the use of other cleansing agents is intended. 1.11.6 Pulse load capability
1.11.6.1 General The pulse load capability defines the ability of a resistor to withstand short overloads within the provided working period. The pulse load capability is limited by the maximum pulse dissipation maxˆP and the maximum pulse voltage maxˆU both depending on a given pulse duration tp and possibly also on the actual resistance R for which the pulse load capability is examined. The following conditions shall be considered. 1.11.6.2 Average pulse dissipation The average pulse dissipation P of any group or sequence of pulses shall not exceed the rated dis
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.