1、ANSIEIA-448-2 1A-2000 Approved: April 25,2000 EIA STANDARD Test Standard for Electromechanical Components - Environmental Effects of Machine Soldering Using An Infrared System EIA-448-21A (Revision of EU-448-21) OCTOBER 2000 ELECTRONIC COMPONENTS, ASSEMBLIES & MATERIALS ASSOCIATION THE ELECTRONIC CO
2、MPONENT SECTOR OF THE ELECTRONIC INDUSTRIES ALLIANCE NOTICE EL4 Engineering Standards and Publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the
3、purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such Standards and Publications shall not in any respect preclude any member or nonmember of EL4 fiom manufacturing or selling products not conforming to such Standards and Publications,
4、nor shall the existence of such Standards and Publications preclude their voluntary use by those other than EIA members, whether the standard is to be used either domestically or internationally. Standards and Publications are adopted by EIA in accordance with the American National Standards Institu
5、te (ANSI) patent policy. By such action, EL4 does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Standard or Publication. This EIA Standard is considered to have International Standardization implication, but the International Electro
6、technical Commission activity has not progressed to the point where a valid comparison between the EIA Standard and the IEC document can be made. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility
7、of the user of this Standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. (From Standards Proposal No. 4674, formulated under the cognizance of the P- 13 Committee on Switches & Interrupting Devices.) Published by E
8、LECTRONIC INDUSTRIES ALLIANCE 2000 Technology Strategy & Standards Department 2500 Wilson Boulevard Arlington, VA 2220 1 PRICE: Please refer to the current Catalog of EIA Electronic Industries Alliance Standards and Engineering Publications or call Global Engineering Documents, USA and Canada (1-800
9、-854-7179) International (303-397-7956) All rights reserved Printed in U.S.A. EIA-448-21A Page 1 METHOD 21 TEST STANDARD FOR ELECTROMECHANICAL COMPONENTS ENVIRONMENTAL EFFECTS OF MACHINE SOLDERING USING AN INFRARED SYSTEM (From EIA Standards Proposal No. 4674, formulated under the cognizance of the
10、P-13 Committee on Switches & Interrupting Devices 1. PURPOSE The purpose of this standard is to evaluate electromechanical surface mountable components that have been subjected to the environmental effects of machine soldering using an infrared system. This standard shall not be construed as a produ
11、ction procedure in machine soldering operations. The solderability determination is made on the basis of an effective bond between the component terminals and the printed wiring board. The acceptable performance of a component subjected to this test is determined by visual examination and those test
12、s specified to be performed upon completion of the test. This test deals with vapor soldering and cleaning operations only, and does not consider additional factors in the assembly of surface mounted devices such as oven drying of soldering pastes. 2. DEFINITIONS 2.1 SOLDERABILITY - The property of
13、a metal surface to be readily wetted by molten solder. 2.2FLUXING - The preconditioning of a metal surface prior to the soldering operation utilizing activated flux. 2.3PREHEATING - The elevating of the printed wiring board temperature prior to soldering. 2.4 CLEANING - The removal of flux and other
14、 residue from the printed wiring board assembly using chemical and/or aqueous solvent systems. 3. EQUIPMENT 3.1An infrared soldering system of the batch type with provisions for adjustment so that the time/temperature profile is within the shaded area of Figure 1. Use of an in-line system is accepta
15、ble provided the time/temperature profile agrees with Figure 1. EIA-448-21A Page 2 3.2 Optional Equipment - None, because it is unlikely that the environment of an infrared system can be simulated without, in effect, duplicating the system. “I FTGURE I Time-Temperature Profile EIA-448-21A Page 3 4.
16、MATERIALS 4.1 Printed Wiring Board 4.1.1 Printed Wiring Board Material - G10 epoxy glass or FR-4 base material with 1 oz Copper, or any other appropriate material that is thermally compliant with the component. 4.1.2 Physical Size and Configuration - The physical size and configuration shall be of g
17、ood design and layout such that a reasonable number of samples can be soldered in a pass through the machine. Land and trace design shall facilitate the making of any specified post-test measurements. 4.1.3 Land Size - The attachment lands shall have a minimum Width equal to that of the component te
18、rminals and a minimum length which is 0.015“ greater than that of the component terminals. 4.1.4 Land Finish - The land finish shall be of fused tin-lead, or an oxide-resistant coating of adequate thickness such that it is readily solderable. Solder quantity shall be sufficient to provide good bond
19、characteristics after reflow, but not excessive so as to be detrimental to effective bonding. 4.1.5 Printed Wiring Board Preparations - The printed wiring Board shall be prepared in such a manner as to ensure A clean and readily solderable surface at the time the Test is performed. Solder pastes or
20、other fluxing means Shall be dried adequately after mounting of components. 5. TEST CONDITIONS The test conditions for soldering shall be within the profile of Figure 1. Test conditions for cleaning shall be specified as one or more of the following options: A. Immersion B. Spray C. Vapor and Spray
21、6. TEST PROCEDURE Unless otherwise specified, parts shall be checked in an “as received“ condition from the supplier, and care shall be exercised to prevent contamination of the surfaces to be tested by grease, perspiration, etc. Under all soldering test conditions, it is assumed that a clean, fully
22、 solderable test board is used. EIA-448-21A Page 4 6.1 6.2 6.3 6.4 6.5 COMPONENT MOUNTING - Components shall be mounted in their Normal manner. More than one and/or different styles of test components may be mounted to a single printed wiring board. FLUXING - Fluxing, if used, shall be in place as a
23、 result Of component mounting. Flux shall be R, or RMA in accordance with MIL-F-14256. PREHEATING - Preheating shall be within the profile of Figure 1. SOLDERING - The test samples, suitably mounted to a Printed wiring board, shall be run through a cycle of an infrared soldering machine having a tim
24、e/temperature profile within the envelope of Figure 1. CLEANING - The specified method(s) of cleaning shall be Applied to the component/printed wiring board assembly using all of the following cleaning solutions (one at a time) : A. A terpene defluxer consisting of a minimum of 90% d-limonene and 10
25、% surfactant. B. This solution has been deleted. When a suitable Replacement solvent has been determined, it will be added as solution B. C. Isopropyl Alcohol D. Deionized water/detergent 1. 90% deionized water, 10% alkaline detergent (45% butyl cellosolve, 45% monoethanolamine, 10% water) by volume
26、. 2. Deionized water rinse. Cleaning shall be done in a manner so as to remove all visible flux and other soldering residue from the component and the printed wiring board. One test board assembly per cleaning solution and cleaning method shall be used. Cleaning shall be accomplished within one hour
27、 after soldering. 7. EVALUATION After the test solder joints shall be visually examined under 1OX magnification for wetting and adherence, good solder blends and metallic continuity. Defective areas shall not constitute more than 10% of the area of any individual connection. Solderability examinatio
28、n shall be limited to those areas affecting the component under test. EIA-448-21A Page 5 The component shall not exhibit loose or deformed parts, and it shall meet all operating characteristics as defined in the detail specification. Additional evaluations shall be performed as prescribed in the det
29、ail specification. 8. The following details shall be specified in the detail Specification: 8.1 NUMBER OF TEST SAMPLES - as specified in the detail specification. 8.2 CLEANING - Method A, B, and/or C (immersion, spray, vapor and spray) must be specified. All four solutions must be used in each metho
30、d, unless otherwise specified. 8.3 EVALUATION MEANS OR CRITERIA - as specified in the detail specification. 8.4 AGING - Special environmental conditions which may deteriorate the solderability of components shall be considered and specified as required. NOTES The use of certain materials listed in t
31、his standard, such as lead contained in solder are, or may be, controlled or regulated through actions of OSHA or EPA. This standard does not contain details or requirements of such regulation or control. EIA Document Improvement Proposal If in the review or use of this document, a potential change
32、is made evident for safety, health or technical reasons, please fill in the appropriate information below and mail or FAX to: Electronic Industries Alliance Engineering Department - Publications Office 2500 Wilson Blvd. Arlington, VA 22201 FAX: (703) 907-7501 Document No. Submitters Name: Address: D
33、ocument Title: Telephone No.: FAX No.: e-mail: Urgency of Change: Immediate: 0 At next revision: 0 Problem Area: a. Clause Number and/or Drawing: c. Reasoflationale for Recommendation: Additional Remarks: Signature: Date: FOR EIA USE ONLY Responsible Committee: Chairman: Date comments forwarded to Committee Chairman: Electronic Industries Alliance
