ECA 534-1989 Ceramic Capacitor Applications Guide Soldering and Solderability Maintenance of Leaded Electronic Components.pdf

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1、7- EIA 534 89 W 3234600 0073840 2 W AN SI1 EIA - 5 3 4- 19 8 8 APPROVED: November 4, 1988 EIA STANDARD Ceramic Capacitor Appl cat ions Guide Soldering and Solderability Maintenance of Leaded Electronic Components EIA-534 JANUARY 1989 ELECTRONIC INDUSTRIES ASSOCIATION ENGINEERING DEPARTMENT EIA 534 8

2、9 m 3234600 0073843 4 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 ob

3、taining 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-member of EIW from manufacturing or selling products not conforming to sueh Standards and Publications, nor shall the existence of s

4、uch Standards and Publications preclude their voluntary use by those other than EIA members, whether the standard is to be used either domestically or hternationally. Recommended Standards and Publications are adopted by EIA without regard to whether or not their adaptfon may involve patents on arti

5、cles, materials, or processes. By such action, EIA does not assume any liability to any patent oner, nor does it assume any obligation whatever to parties adopting the Recommended Standard or Publication. This Standard does not purport to address all safety problems associated with its use or all ap

6、plicable regulatory requirements. It is the responsibility of the user of this Standard to establish appropriate safety and health practices and to determine the a applicability of regulatory limitations before its use. Copyright 1989 Published by ELECTRONIC INDUSTRIES ASSOCIATION Engineering Depart

7、ment 1722 Eye Street, NOW, Washington, D.C. 20006 All rights reserved PRICE: $10.00 Printed in U.S.A. EIA-534 O APPLICATIONS GUIDE SOLDERING AND SOLDERABILITY MAINTENANCE OF LEADED ELECTRONIC COMPONENTS TABLE OF CONTENTS Page Paragraph 1.0 BACKGROUND AND PURPOSE 2.0 HAND AND WAVE SOLDERING 3.0 CLEAN

8、ING AND RETINNING OF OXIDIZED TERMINATIONS 4.0 PACKAGING AND STORAGE i EIA 534 89 m 3234600 O073843 8 m EIA-534 Page 1 APPLICATIONS GUIDE SOLDERING AND SOLDERABILITY MAINTENANCE OF LEADED ELECTRONIC COMPONENTS (From EIA Standard Proposal No. 1880, formulated under the cognizance of the EIA P-2.1 Wor

9、king Group on Ceramics.) 1.0 BACKGROUND AND PURPOSE Leaded Electronic Component parts are subjected to a wide variety of internal stresses during the soldering of their terminations by solder dips, soldering irons, or automatic wave soldering techniques. The heat can either be conducted through the

10、metal termination into the body of the component part, or absorbed directly or indirectly as radiant heat emanating from solder baths, waves or preheaters, or both. This document is intended as a guide for users of leaded electronic component parts that exist today. Furthermore, recommendations are

11、given on the cleaning, retinning, packaging and storage of these component parts. it is recognized that many components behave differently during installation and lead retinning operations. Hermetically sealed components must be treated differently from non-hermetic sealed types. Other solder compos

12、itions than those recommended in this guide may be used. Solder irons of different mass and tip temperatures may be used providing the end result is not detrimental to the component. This document is intended as a guideline only and in many cases manufacturers suggested procedures should be used. 2.

13、0 HAND AND WAVE SOLDERING Soldering heat can cause electrical and/or mechanical damage to the component part. Many component parts have their terminations attached with solder alloys of varying melting temperatures. Excessive heat during the user soldering processes can reflow this termination solde

14、r joint and cause an electrical open or a joint that ends up intermittent in its electrical contact with the body of the component. Mechanical damage can take the form of lead separation from the body of the component, or cracking of the external body structure or encapsulation, loosening or weakeni

15、ng of windings or mechanically bonded terminations. Proper control is paramount to the reliable processing of electronic components. The following represents guidelines key to the proper wave and hand solder processing of component parts. EIA 534 89 3234b00 0073844 T W EIA-534 Page 2 2.1 Wave Solder

16、 Processing Guidelines 2.1.1 Machine Conveyor Should have an incline of at least 5O with respect to the ground plane. Horizontal conveyors are not recommended. 2.1.2 2.1.3 Flux Should be clean and fresh. Density should be closely monitored. Preheat Top of board temperature controlled to 150-2000F (6

17、5O-95OC) range depending upon thickness of PC board and component being attached. Verify by : a) Thermocouple imbedded in or attached to printed circuit board top. b) Temperature sensitive labels/dots. c) Temperature sensitive wax sticks. d) Pyrometers - although not as accurate. Temperature measure

18、ments should be made on a non-metallic portion of the PC Board. Adjustments should be made to the preheaters and the conveyor speed to achieve proper top-of-board temperature. 2.1.4 Conveyor Speed Depends primarily upon machine design; however, speeds range should be between 3.5 and 10 FPM. Speed ul

19、timately should be dictated by the preheat top-of-board temperature, max-dwell time in wave, flux activity level, and below-board soldering results. EIA 534 89 m 3234600 0073845 L b e 2.2 EIA-534 Page 3 2.1.5 Components Lead Solder Dwell Time 3 & 2 seconds. 2.1.6 Solder Wave Temperature 490F & 10F (

20、255OC 5OC) standard SN60 solder. Temperature should be verified at the wave itself using a good quality glass thermometer since differences in solder pot controller setpoints and actual pot temperature of - + 50F (k 28OC) are not uncommon. Care should be taken in the use of glass thermometers. Hand

21、Solder Processing Guidelines 2.2.1* 2.2.2* 2.2.3 2.2.4 2.2.5 Temperature Controlled Soldering Iron 15-30 watts Tip Temperature 650F (343OC) maximum, temperature controlled. Dwell Time Governed by the absolute minimum time necessary to reflow the solder alloy being used. Normally 3 seconds, no more t

22、han 5. Heat Sink If physically possible, the use of a tweezers or alligator type metallic heat sink dip is highly recommended to prevent thermal shock. Soldering iron should always be applied to the bottom side of the board, not from component side. Soldering iron should be removed within three seco

23、nds of solder reflow. *Temperature wattage and tip mass can vary to allow adequate soldering to take place. 0 EIA 534 89 = 3234b00 0073846 3 , EIA-534 Page 4 3.0 CLEANING AND RETINNING OF OXIDIZED IEFtMINATIONS 3.1 3.2 The cleaning of heavily oxidized or contaminated leads is not recommended. If the

24、 retinning steps of paragraph 3.2 do not yield leads which meet solderability test requirements, the only potential recovery of the leads involves abrasive cleaning or dry scrubbing. Cleaned leads then may be retinned and found acceptable. Retinning Sequence: 3.2.1 Fluxing Dip one or both terminatio

25、ns in a suitable flux (usually type RA or RMA). 3.2.2 3.2.3 Finish Dip one or both terminations in a suitable finishing alloy (maximum temperature 26OoC), making sure that the alloy comes no closer than 0.05 inch to the component body. Maximum dwell time in the alloy pot is 5 seconds. Do not dip lea

26、ds a second time. Reliabilty evaluation of retinned pats must be made as some components may exhibit internal degradation due to this rework process. Post Dip Cleaning Should be carried out with a pressurized spray of a suitable chlorinated or fluorinated solvent and/or detergent, making sure that a

27、ll residual flux is removed from the terminals. Caution should be exercised in the use of these solvents as they are detrimental to some components if ingress occurs, such as with Aluminum Electrolytic capacitors. 4.0 PACKAGING AND STORAGE In an effort to minimize degradations to component terminati

28、on solderability, the following guidelines should be adhered to: EIA 534 89 3234600 0073847 5 EIA-534 Page 5 4.1 Packaging Guidelines Low or non-sulphur containers and packing materials should be utilized, especially when the material comes in direct contact with the component. Sealed plastic contai

29、ners with desiccant are recommended for high humidity areas. 4.2 Storage Guidelines 4.2.1 Relative Humidity Should be less than or equal to 50%. If this cannot be accomplished, see paragraph 4.1. 4.2.2 Time Stock should be carefully rotated to permit a maximum storage time of six months. Evaluation should be made at shorter intervals if storage conditions are less than optimum as noted above.