1、I. I Method 21 ANSljEIA-448-21-1989 APPROVED: August 11,1989 Test Standard for Electromechanical Switches: Machine Soldering Using an Infrared System 1 Environmental Effects of I a ij IA STANDARD EM-448-21 SEPTEMBER 1989 ELECTRONIC INDUSTRIES ASSOCIATION ENGINEERING DEPARTMENT EIA 448-23 89 m 323460
2、0 0067069 7 m , NOTICE EIA 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 purchaser in selecting and obtaining
3、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 non-memberof EIA from manufacturing or selling products not conforming to such Standards and Publications, nor shall the existence of such Stand
4、ards and Publications preclude their voluntary use by those other than EIA members, whether the standard is to be used either domestically or internationally. Recommended Standards and Publications are adopted by EIA without regard to whether or not their adoption may involve patents on articles, ma
5、terials, or processes. By such action, EIA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Recommended Standard or Publication. This EIA Standard is considered to have international standardization implication, but the Internation
6、al Electrotechnical Commission activity has not progressed to the point where a valid comparison between the EIA standard and the IEC document can be made. 9 This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the res
7、ponsibilityof the user of this Standard to establish appropriate safety and health practices and ta determine the applicability of regulatory limitations before its use. Copyright 1989 Published by -_IC- .- - ,- - -. ELECTRONIC INDUSTRIES ASSOCIATION Engineering Department 2001 Eye Street, N.W. Wash
8、ington, D.C. 20006 PRICE: $10.00 All rights reserved Printed in U.S.A. - EIA q48-21 89 3234b00 00b070 3 M EIA-448-21 Page 1 Method Test Standard For Electromechanical Components Switch Environmental Effects Of Machine Soldering Using An Infrared System (From EIA Standards Proposal No. 2202, formulat
9、ed under the cognizance of the P-13 Switch Engineering Working Group.) I. PURPOSE The purpose of this standard is to evaluate electromechanical surface- mountable components which have been subjected to the environmental effects of machine soldering using an infrared system. This standard shall not
10、be construed as a production procedure in machine soldering operations. The solderability dete-ination 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 exam
11、ination and those tests specified to be performed upon completion of the test. This test deals with infrared 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 SOLDERA
12、BILITY - The property of a metal surface to be readily wetted by molten solder. 2.2 FLUXING - The conditioning of a metal surface prior to the soldering operation utilizing activated flux. 2.3 * PREHEATING - The elevating of the printed wiring board temperature prior to soldering. 2.4 CLEANING - The
13、 removal of flux and other residue from the printed wiring board assembly, generally by using chemical and/or aqueous solvent systems. 3. EQUIPMENT 3.1 An infrared soldering system with provisions for adjustment so that the time/temperature profile falls within the shaded area of Figure 1. EIA 448-2
14、3 89 W 3234b00 OOb9073 5 W EIA-448-21 Page 2 3.2 Optional Equipment - None, because it is unlikely that the environment of an infreed system. can be simulated with0u.t , in effect, duplicating the system. . . 4. o a C i .- ._ . i;. . FIGURE 1 Time-Temperature Profile EIA 448-23 89 = 3234b00 OOb9072
15、7 W EIA-448-21 Page 3 4. 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 co
16、nfiguration shall be of good 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
17、 . that of the component terminals and a minimum length which is .O15 inch 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 su
18、fficient to provide good bond 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 i
19、s performed. Solder pastes or 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. Immersio
20、n B. Spray C. Vapor and Spray 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
21、is assumed that a clean, fully solderable test board is used. o - - EIA 448-21 9 3234b00 00b073 9 EIA-448-21 Page 4 6.1 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. 6
22、.2 FLUXING - Fluxing, if used, shall be in place as a result of component mounting. Flux shall be R or RMA in accordance with MIL-F-14256. 6.3 6.4 SOLDERING - The test samples, suitably mounted to a printed wiring board, shall be run through a cycle of an infrared soldering machine having a time/tem
23、perature profile within the envelope of Figure 1 . PREHEATING - Preheating shall be within the profile of Figure 1. 6.5 CLEANING - The specified method(s) of cleaning shall be applied to the component/printed wiring board assembly using all of the following cleaning eqlutions (one at a .time). A. 1,
24、1,1 Trichloroethane B. “Freon“* TF or TE, or equivalent C. Deionized water/detergent 1. 90% deionized water, 10% alkaline detergent (45% butyl cellosolve, 45% monoethanolamine, 10% water) by volume. 2. Deionized water rinse. * DuPont registered trademark D. Isopropyl alcohol Cleaning shall be done i
25、n a manner 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 after soldering. 7. EVALUATION After the test, solder
26、joints shall be visually examined under 1OX magnification for wetting and adherence, good solder bonds and metallic continuity. Defective areas shall not constitute more than 10% of the area of any individual connection, Solderability examination shall be limited to those areas affecting the compone
27、nt under test. The component shall not exhibit loose or deformed parts, and St shall meet all operating characteristics as defined in the detail specification. Additional evaluations shall be performed as prescribed in the detail specification. - - - -_ r- - EIA 448-23 7 = 3234600 0067074 O EIA-448-
28、21 Page 5 Ib 8. SUMMARY 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 meth
29、od, 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 this standard, such as lead contained in solder, 1,1,1 trichloroethane and the“Freon“ family 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.
