Among the foremost of reasons an electronic project frequently fails to work properly is due to "poor" soldering practices. This is usually caused by "dry joints" when soldering. Here I discuss the correct procedures for soldering electronic projects.

www.electronics-tutorials.com



IC Op-Amp Cookbook

Google
Search WWW Search www.electronics-tutorials.com

This site is hosted at WebWizards.Net for better value.

Don't leave this valuable site without visiting my book shop to see my recommendations. This helps keep this site FREE for everyone.

recommend this page to a friend
 

you can have this page translated /vous pouvez faire traduire ces pages /Sie können lassen diese Seiten übersetzen /potete fare queste tradurre pagine /você pode ter estas páginas traduzido /usted puede hacer estas paginaciones traducir

LAST MODIFIED:
Friday, 28-Sep-2001 00:12:06 EDT

SOLDERING PRACTICES


How important is soldering?

Among the foremost of reasons an electronic project frequently fails to work properly is due to "poor" soldering practices. This is usually caused by "dry joints" when soldering. Here I discuss the correct procedures for soldering electronic projects.

Dry joints when soldering

At first glance many solder joints appear to be quite "O.K." but on closer examination many are in fact defective. The insidious problem with dry joints in soldering is that the circuit frequently performs alright for a period of time, even years before failure.

This problem even occurs with manufactured equipment. Ask any TV / Video repair technician who has torn a lot of hair out over an elusive fault ultimately traced back to a dry joint.

Good soldering practices for your electronic project

The cause of dry joints in soldering is mostly the improper application of heat. Both the component leg and the PCB need to be both heated simultaneously to the correct temperature to allow the solder to flow freely between BOTH surfaces. Obviously this requires practice and most newcomers inevitably get it wrong.

Improper heating while soldering and its consequences can be seen below.

correct soldering procedures to avoid dry joints

Figure 1 - correct soldering procedures to avoid dry joints

Here in figure 1 entitled "correct soldering procedures to avoid dry joints" we have three examples of soldering depicted. The first example indicates the component lead was heated while the PCB wasn't heated. As a consequence the solder only flowed onto the component lead.

In the second example of soldering in figure 1 we find the PCB was correctly heated while little or inadequate heat was applied to the component lead. This is the most treachorous example because although I have made it very obvious in the diagram, in practice it is not always particularly obvious. Often this type of dry joint "just" allows the solder to "touch" the component lead while not actually being "soldered" to the lead. Of course it might work for a period of time depending upon environmental conditions of heat and cold.

In the final example of "correct soldering procedures to avoid dry joints" I have depicted the solder bridging both the PCB and the component lead. In this case the PCB and the component lead were both heated "simultaneously" AND the solder was applied to either the component lead or the PCB to "flow" freely from one to the other to provide a good "electrical" joint. Such a joint is always "bright and shiny", dull looking joints are often suspect.

You never apply the solder to the soldering iron "tip". Solder is always applied to the "job", never the soldering iron. Allow the solder to "set" and cool before proceeding to the next joint.

Other cases of soldering

We have discussed soldering components to a PCB yet this is not the only case of soldering. Often we need to connect wires to switches and other components. A common misconception is that soldering is designed to provide a good mechanical joint. - It isn't!

Any connection should have it's own mechanical strength perhaps by twisting wires together or twisting the wire around a binding post or through a hole provided for the purpose. The solder is only intended for a good "electrical" connection. Never provide a connection which can't stand mechanically on it's own merits.

What's soldering flux?

Modern quality electronics solders contain a "flux" resin within the solder. This flux is designed to flow over the job and prevent contact with the atmosphere. Metals, particularly copper when heated tend to "oxidise" and prevent the alloying or good electrical bond between the copper and the solder.

Good solder containing the resin will have resin flowing over the leads and prevent this oxidisation process and as the solder flows the resin is displaced allowing the solder to form an "atomic" bonding with the items being soldered together. A good resin helps to keep the surfaces clean.

Rules for good soldering

Of course some of these rules might seem very obvious but are worth repeating.

 Use a reasonable quality iron of the correct wattage for the job.
 Only use "electronic" resin cored solder of fine gauge.
 Make sure all surfaces to be soldered are "bright, shiny" and thoroughly clean.
 If a mechanical joint, make sure it can "stand alone" before soldering.
 Make sure the solder tip is clean, shiny and properly "wetted".
 Remember the soldering iron tip is only to heat up the surfaces to be soldered.
 Apply the resin cored solder to the heated "job", not to the soldering iron tip.
 Remember to visually inspect ALL of your soldered joints, preferably with magnifying glasses.
 Consider using your multimeter to provide an "electrical continuity" check between various parts of the circuit.

Also see my page on tools for constructing electronic projects.
 


VHS Video - Electronic Soldering Techniques

The Consumer Electronics Association (CEA)

Edition Details: • NTSC format (US and Canada only)

Description:

An important addition to any electronics curriculum or service facility, this step-by-step video assists student and electronics technicians to develop soldering skills essential in today's miniaturized and complex electronics products. Teaches proper soldering methods and necessary equipment used on traditional electronics components and surface-mount devices. Covers procedures and handling of electrostatic sensitive devices.

 Electronic Soldering Techniques   ORDER - U.S.A. - Electronic Soldering Techniques - Usually ships within 24 hours.
 

These VHS video's are brought to you by The Consumer Electronics Association (CEA)NTSC format (US and Canada only)

Electronic Soldering Techniques

An important addition to any electronics curriculum or service facility, this step-by-step video assists student and electronics technicians to develop soldering skills essential in today's miniaturized and complex electronics products. Teaches proper soldering methods and necessary equipment used on traditional electronics components and surface-mount devices. Covers procedures and handling of electrostatic sensitive devices.

 Electronic Soldering Techniques   ORDER - U.S.A. - Electronic Soldering Techniques - Usually ships within 24 hours.

 

Soldering Iron - 25 watt

Cooper Group SP23 25 Watt Solding Iron - available for delivery within U.S.A. only.

Cooper Group SP23 25 Watt Solding Iron

Features:
    Fine quality consumer mini iron, 8 1/4" long
    Featherweight iron with pencil handle, ideal for hobbies, kits, radios, and
    electronics work
    Includes 1/8" diameter replaceable nickel-plated copper tip
    Stainless steel barrel and heat/impact resistant handle
    Develops 750 degrees F

 Cooper Group SP23 25 Watt Solding Iron   ORDER - DELIVERY WITHIN U.S.A. ONLY - Cooper Group SP23 25 Watt Solding Iron - ORDER NOW $US 12.65 usually ships within 1-2 weeks.

The Art of Soldering - R. Brewster - Babani 84 pages

This book by R. Brewster proves a very inexpensive source of a wide range of tips on the "art of soldering"

 The Art of Soldering - R. Brewster   ORDER - U.K. - The Art of Soldering - R. Brewster - ORDER NOW £3.99 This title is usually dispatched within 2-3 days.

 The Art of Soldering - R. Brewster   ORDER - DEUTSCHLAND - The Art of Soldering - R. Brewster - ORDNUNG JETZT Preis: DM 13,51 EUR 6,90 Versandfertig innerhalb von 1 bis 2 Wochen.

Link to this page

NEW! - How to link directly to this page

Want to create a page link to me from your site? It couldn't be easier. No HTML knowledge required; even the technophobes can do it. All you need to do is copy and paste, the following code. All links are greatly appreciated; I sincerely thank you for your support.

Copy and paste the following code for a text link:

<a href="http://www.electronics-tutorials.com/basics/soldering.htm" target="_top">visit Ian Purdie VK2TIP's "Soldering Practices" Page</a>

and it should appear like this:
visit Ian Purdie VK2TIP's "Soldering Practices" Page

 

rate this page for me

recommend this page to a friend

Please send me your valuable comments and suggestions! Tell your friends, tell a news group, tell the world!

Absolutely essential to keeping abreast of new and updated electronics tutorials is our comments or subscribe to our highly regarded FREE monthly newsletter form. Unsubscribe any time you like.

Related topics on soldering

tools for constructing electronic projects.

Weller Soldering Hints [PDF file]

Weller Consumer Soldering Tools

Kester Solder

Products offered for the scrolling printers




the author Ian C. Purdie, VK2TIP of www.electronics-tutorials.com asserts the moral right to be identified as the author of this web site and all contents herein. Copyright © 2000 - 2001, all rights reserved. See copying and links. These electronic tutorials are provided for individual private use and the author assumes no liability whatsoever for the application, use, misuse, of any of these projects or electronics tutorials that may result in the direct or indirect damage or loss that comes from these projects or tutorials. All materials are provided for free private and public use.
Commercial use prohibited without prior written permission from www.electronics-tutorials.com.


Copyright © 2000 - 2001, all rights reserved. URL - www.electronics-tutorials.com/basics/soldering.htm
Updated 27th September, 2001
webmaster@electronics-tutorials.com






Click Here!