-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueEngineering Economics
The real cost to manufacture a PCB encompasses everything that goes into making the product: the materials and other value-added supplies, machine and personnel costs, and most importantly, your quality. A hard look at real costs seems wholly appropriate.
Alternate Metallization Processes
Traditional electroless copper and electroless copper immersion gold have been primary PCB plating methods for decades. But alternative plating metals and processes have been introduced over the past few years as miniaturization and advanced packaging continue to develop.
Technology Roadmaps
In this issue of PCB007 Magazine, we discuss technology roadmaps and what they mean for our businesses, providing context to the all-important question: What is my company’s technology roadmap?
- Articles
- Columns
Search Console
- Links
- Media kit
||| MENU - pcb007 Magazine
Estimated reading time: 5 minutes
Contact Columnist Form
Happy’s Essential Skills: Using Web Resources
The World Wide Web has become essential for information and communications. For problem solving, new process investigations and general information, it beats about any other source of information. But it is surprising how many engineers know how to do a thorough information search using the internet. In most cases, a Yahoo or Google search is all that is needed, but for technical information, you have to also use more detailed search methods or even special search engines.
Contents
Most of the material on the Web is in HTML format, and can be viewed by any Web browser (for example, Netscape or Internet Explorer). However, on some sites you may need to have the latest versions of these browsers in order to take advantage of all the facilities, and other sites will ask you to download ShockWave, Java, Flash or similar plug-ins. You will also need Adobe Acrobat Reader to handle the PDF versions of documentation; if you don’t yet have this utility, it is available for free download at www.adobe.com.
Problem Areas
A number of issues with the Web confront the user, especially with a fast-moving subject like printed circuits and lead-free electronics assembly.
- Few sites cover all aspects of lead-free implementation, partly because this is an area where consultants can earn fees, and there is too much emphasis on soldering and similar technology issues.
- Whilst some sites take a balanced view, there are a lot of hidden agendas out there. For example, if you followed certain threads in sources such as IPC’s TechNet you might get the impression that the lead-free transition makes no engineering sense! Many would argue that this view is right; it lacks the essential corrective input, but the industry is compelled to go down the route regardless.
- Although the amount of lead-free solder used has demonstrably increased, there are too many companies (especially in Japan) that say that they have “gone lead-free, when they actually mean that they have a single lead-free line.
- The age of the original material on which a webpage is based is often not clear, and some seemingly new material may be quite old.
- There is a lot of plagiarism, which means that errors tend to be copied right along with the good information.
- Unless you are experienced at using search engines, the irrelevant detail can be overwhelming.
One conclusion is that you should be directed to specific sources, at least in the initial stages, and that the questions you are asking should have summary answers that would allow you to check your findings.
Search Engines
Most engineers working in electronics are familiar with search engines, and probably have their own preferences. Remember, however, that it is very easy to get swamped with information, so keep refining your search until you get a manageable and relevant list to browse. Some suggestions:
- Experiment with alternatives, especially when American and English spellings are different.
- Use two or more search terms; these words are usually inferred as being combined with a logical AND, so that the search will be for items containing all the terms.
- Enclose a group of words with straight quotation marks (as in "speed reading") to search for the exact phrase.
- Put a minus (-) sign in front of the search term. This will often allow you to screen out unwanted material.
- Sometimes, a specific search engine may return more results for technical searches than others. An example of one of these is WebFerret.com (Figure 1).
Figure 1: WebFerret, a search engine specifically for technical information.
Improving Search Results
One of the difficulties of web searching is that it gives results that depend crucially on your selection of the keywords and search terms. For example, if you are looking for the implications of the transition to lead-free electronics, you might find this expressed as “lead-free electronics has a number of implications for…” as well as “the implications of moving to lead-free are…” In other words, the search terms can occur in either order and with varying amounts of space between them.
The normal way of dealing with this is to look for both terms anywhere in the document, but this can result in too many hits. A useful feature would be to be able to search for specific words within a small (preferably specifiable) number of words of each other, where the keywords could appear in either order. This type of search is referred to as a “proximity search.” Altavista and MSN are claimed to support a “NEAR” operator: When checked, an Altavista Boolean search for "lead-free" NEAR "pad design" produced 116 results, but then "lead-free" AND "pad design" gave the same number of hits. This compared with 8,950 hits for "lead-free" + "pad design" in Google, indicating that NEAR in Altavista may not work and that Google definitely has more links . . .
There is a way round, referred to as the Google API Proximity Search (GAPS), that lets you look for two words or word groups within one, two or three words of each other: the search ‘"lead-free" within 3 words of "pad design"’ reduced the number of hits to four, which shows the principle, even if it was a bit too effective! However, when I tried "lead-free" within three words of "implications," my search yielded 41 hits of reasonable quality.
Page 1 of 2
More Columns from Happy’s Tech Talk
Happy’s Tech Talk #34: Producibility and Other Pseudo-metricsHappy’s Tech Talk #33: Wet Process Management and Control
Happy’s Tech Talk #32: Three Simple Ways to Manage and Control Wet Processes
Happy’s Tech Talk #31: Novel Ultra HDI Architectures
Happy’s Tech Talk #30: The Analog Computer
Happy’s Tech Talk #29: Bend-to-Install Semi-flex FR-4
Happy’s Tech Talk #28: The Power Mesh Architecture for PCBs
Happy’s Tech Talk #27: Integrated Mesh Power System (IMPS) for PCBs