IEC 61191-4:1998 pdf download – Printed board assemblies -Part 4: Sectional specification – Requirements for terminal soldered assemblies

IEC 61191-4:1998 pdf download – Printed board assemblies -Part 4: Sectional specification – Requirements for terminal soldered assemblies.
IEC 61191-4 prescribes requirements for terminal soldered assemblies, The requirements pertain to those assemblies that are totally terminal/wire interconnecting structures or to the terminalwire portions of those assemblies that include other related technologies (i.e. surface mounting, through-hole mounting, chip mountingl.
1.2 ClassIfication
This specification recognizes that electrical and electronic assemblies are subject to classifications by intended end-item use. Three general end-product levels have been established to reflect differences In producibility. complexity. functional perlormance requirements, and verification (inspection/test) frequency. These are the following:
Level A: General electronic products
Level B: Dedicated service electronic products
Level C: High-performance electronic products
The user of the assemblies is responsible for determining the level to which his product belongs. The contract shall specify the level required and indicate any exceptions or additional requirements to the parameters, where appropriate. II should be recognized that there may be overlaps of equipment between level where appropriate (see clause 4 in IEC 61191-1).
2 Normative references
The following normative document contains provisions which, through reference In this text. constitute provisions of this part of IEC 61191. At the time of publication, the edition indicated was valid. All normative documents are sublect to revision, and parties to agreements based on this part of IEC 61191 are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. Members of IEC and ISO maintain registers of currently valid International Standards
IEC 61191-f: 1998, Printed board assemblies — Part 1: Generic specification — Requirements for soldered electrical and electronic assemblies using surface mount and related assembly technologies
3 General requirements
Requirements of IEC 61191-1 are a mandatory part of this specification.
4.2.6 Shank discontinuitles
After installation, the shank of the terminal shall meet the requirements of 4.2.2.
4.2.7 Flared flange discontinuitles
The flared flange of a terminal shall not be perforated, split, cracked, or otherwise discontinuous to the extent that flux, oils. Inks or other substances utilized for processing the printed board can be entrapped. After flaring, the flange shall conform to 4,2.3.
4.3 Mounting to terminals
The detailed requirements for mounting of components and wires to terminals installed in printed boards, terminal boards or chassis members are defined in the following subclauses.
4.3.1 Wire and lead wrap-around
Leads and wires should be mechanically secured to their terminals before soldering. Such mechanical securing should prevent motion between the parts of the connection during the soldering operation. Leads and wires shall be wrapped around turret and straight pin terminals for a minimum of 180 and may overlap provided there is sufficient room on the turret (see figure 5).
The last wire on a straight pin terminal shall be at least one wire diameter from the top to allow for an adequate solder fillet. Adequate service loops should be provided to allow for field maintenance.
For wires with a diameter less than 0.25 mm, a minimum of one turn and a maximum of three turns shall be used. Exception is made in the case of those small parts used for terminating wires where such mechanical securing would be impracticable. such as connector solder cups. slotted terminal posts and heat shrinkable solder devices. Wires and leads shall contact the post for at least 180 and shall not be wrapped on each other.