1、ANSIEIA-448-2A-2000 Approved: October 25,2000 EIA STANDARD Test Standard for Electromechanical Components - Environmental Effects of Machine Soldering EIA-448-2A (Revision of EU-448-2) OCTOBER 2000 ELECTRONIC COMPONENTS, ASSEMBLIES e.g., wave soldering. 2.5 Cleaning - The removal of flux and other r
2、esidue from the printed wiring board assembly using chemical and/or aqueous solvent systems. 3. EQUIPMENT 3.1 A conventional wave soldering machine with provisions for fluxing and preheating shall be used. Production equipment outlined in EIA RS-445 may be used. However, in the case of conflict, thi
3、s standard shall take precedence. EIA-448-2A Page 2 3.2 Optional equipment - In lieu of a wave soldering machine, the following may be used, with all steps intended to simulate the operation of a wave soldering machine as much as possible. 3.2.1 Fluxing system - A controlled foam fluxing system capa
4、ble of producing the fluxing action required. 3.2.2 Preheating - A suitable means to elevate the printed wiring board assembly temperature as specified. 3.2.3 Soldering - A solder pot of sufficient size to both allow dipping of the printed wiring board and contain sufficient volume of molten solder
5、to ensure uniform temperature of the solder when the printed wiring board is dipped. 3.3 Cleaning - Suitable containers for the specified cleaning solution and means to implement the vapor and/or spray portions of the test. 4. MARE RIALS 4.1 Solder - to be composition SN6OB or SN63B per ANSIJASTM B3
6、2-76. 4.2 Printed wiring board - The printed wiring board shall conform to the following details unless otherwise specified: 4.2.1 Printed wiring board material - G10 epoxy glass or FR-4 base material with 1 oz. copper. 4.2.2 Physical size and configuration - The physical size and configuration shal
7、l be such that the desired fluxing action can be achieved. 4.2.3 Mounting Hole Diameter - The mounting hole diameter shall be the minimum diameter specified by the manufacturer. In the absence of a specified hole diameter, the following formula may be used: Min. Hole Dia. = Max. Lead Dia. (Max. dime
8、nsion across corners for rectangular terminals) + Min. Drill Tolerance. (Adjust to next larger drill size.) 4.2.4 Pad (Foil) Size - Unless otherwise specified, the pad should completely surround and abut on the mounting hole. The minimum annular ring surrounding the terminal hole shall be 0.015“ for
9、 unsupported holes and 0.005 for plated through holes. 4.2.5 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. EIA-448-2A Page 3 Flux Type Activated Resin (RA) Organic
10、 Acid Applicable Specification (None) MIL-S-14256 5. TEST CONDITIONS The test conditions shall be derived from Table II with the specified options indicated for the type of flux, fluxing, solder time, and cleaning method (see component detail specification) . I II III IV TABLE II Fluxing (See Table
11、I) A Flux touches component body (See 6.2,A) B. Flux does not touch component body (See 6.2,B) Preheat Soldering 1. 2 seconds 2. 4 seconds 3. 6 seconds 4. 8 seconds 5. 10 seconds Cleaning A. Immersion B. Spray C. Vapor and spray EIA-448-2A Page 4 6. 6.1 6.2 6.3 6.4 6.5 TEST PROCEDURE Unless Otherwis
12、e 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, perspirants, etc. Under all soldering test conditions, it is assumed that a clean, fully solderable test board is used. Co
13、mponent Mounting - Components shall be mounted in such a manner as to achieve the fluxing action required under 6.2. Fluxing A. Printed wiring board with the test components mounted shall be fluxed in such a manner that the foam will contact both the bottom surface of the printed wiring board and th
14、e bottom surface of the test component within the immediate area of its terminals. B. Printed wiring board with the test components mounted shall be fluxed in such a manner that the foam will evenly contact the bottom surface of the printed wiring board but does not come in contact with the bottom o
15、f the component being tested. Preheat - The printed wiring board assembly shall be subjected to an evenly distributing preheating. Preheat temperature shall be determined by measuring the top (component side) of the printed wiring board and be maintained at 93 +O/-15 degrees C for a period of 30 - 6
16、0 seconds immediately prior to soldering or entering the solder wave. Soldering - The soldering of the printed wiring board assembly shall be performed immediately after preheating with a soldering temperature of 260 degrees C. Component terminal soldering time shall be chosen from Table II. Time of
17、 soldering is defined as the time required in the molten solder for each terminal on the component. Cleaning Solution - The following cleaning solutions shall be used: A. A terpene defluxer consisting of aminimum EIA-448-2A Page 5 Of 90% d-limonene and 10% surfactant. (Applicable to Activated Resin
18、Fluxes) B. This solution has been deleted. When a suitable replacement solvent has been determined, it will be added as solution B. C. Isopropyl Alcohol (Applicable to Activated Resin Fluxes) D. Deionized WaterjDetergent - (Applicable to Organic Acid Fluxes) 1. 90% deionized water, 10% Alkaline Dete
19、rgent (45% Butyl Cellosolve, 45% Monoethanolamine, 10% Water) by volume. 2. Deionized Water Rinse The method of cleaning shall be chosen from Table II and shall be done in such a manner as to remove all visible flux and other soldering residue from the printed wiring board and test component. One te
20、st board assembly per cleaning solution shall be used. I. EVALUATION The printed wiring board and the components to be tested shall be fluxed, preheated, machine soldered, and cleaned as specified. Defects such as pin holes, dewetted areas, or uncoated base metal on the component terminal shall not
21、constitute more than 10% of the circumference (dia.) of the terminal (s) . Solderability examination shall be limited to the interface of the terminal and the soldered side of the printed wiring board. The component part shall not exhibit and loose or deformed parts. All markings shall be readily vi
22、sible, and the component shall meet all operating characteristics as defined in the detail specification. Additional evaluation shall be performed as outlined in the detail specification. 8. SUMMARY The following details shall be specified in the detail specification: 8.1 Number of Test Samples - as
23、 specified in the detail specification. 8.2 Fluxing - Method A or Method B must be specified. 8.3 Soldering Time - 2,4,6,8,or 10 seconds (Methods 1,2,3,4,or 5) must be specified (See 6.4). EIA-448-2A Page 6 8.4 Cleaning - Method A,B, or C (Immersion,Spray, or Vapor and Spray) must be specified. All
24、four solutions must be used in each method, unless otherwise specified (See 6.5). 8.5 Evaluation Means or Criteria - As specified in the detail specification. 8.6 Aging - Special environmental conditions which may deteriorate the solderability of components should be considered and specified as requ
25、ired. 9. NOTES The use of certain materials listed in this 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
26、 the review or use of this document, a potential change 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:
27、 (703) 907-7501 Document No. Submitters Name: Address: Document 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
