{"id":2454,"date":"2023-05-11T05:48:52","date_gmt":"2023-05-11T05:48:52","guid":{"rendered":"https:\/\/35.94.173.37\/blog\/?p=2454"},"modified":"2026-06-29T16:07:04","modified_gmt":"2026-06-29T16:07:04","slug":"in-circuit-and-functional-ate","status":"publish","type":"post","link":"https:\/\/www.apexwaves.com\/blog\/in-circuit-and-functional-ate\/","title":{"rendered":"In-Circuit and Functional ATE"},"content":{"rendered":"\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<figure class=\"wp-block-audio\"><audio controls src=\"https:\/\/www.apexwaves.com\/blog\/wp-content\/uploads\/2023\/05\/In-Circuit-and-Functional-ATE.mp3\"><\/audio><figcaption class=\"wp-element-caption\"><strong><em>Click here to listen to this post.<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">When it comes to verifying the functionality and performance of products during manufacturing, <strong>Automatic Test Equipment (ATE)<\/strong> is an irreplaceable tool. Two of the most prominent types of ATE used in product testing and field servicing are in-circuit and functional ATE. This article will take a look at how both of these types work, as well as the advantages and disadvantages of both.<\/p>\n\n\n\n<!--more-->\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left has-black-color has-text-color has-link-color wp-elements-144234f7a49f3290abb53f514b6b515b\" style=\"font-size:25px\">In-Circuit ATE<\/h2>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\"><strong>In-circuit test fixtures<\/strong>&nbsp;use a \u201c<strong>bed-of-nails<\/strong>\u201d interface to test the individual components on an assembled printed circuit board (<strong>PCB<\/strong>) to determine their value and to identify any manufacturing defects. The board under test (BUT) is forced down on the bed-of-nails, which is so named because of the various spring loaded pins that resemble nails. These pins are maintained by a pneumatic or a vacuum force, and they can be arranged into a variety of patterns.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">Both the passive and active values of the individual components of the PCB are sequentially measured in-circuit, and these values are checked against stored standards (or a software model of the PCB) to isolate faulty ones. Some faults that an in-circuit tester may identify include, but are not limited to; short circuits due to poor soldering\/layout, incorrect wiring, missing components, incorrect orientation of components, faulty components, and open-circuited tracks.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">Any faults discovered through the in-circuit testing are isolated and reported in a printout display. Depending on the number and type of components on the PCB, the entire process is completed within a few minutes.<\/p>\n\n\n\n<p class=\"has-text-align-left has-black-color has-text-color has-link-color wp-elements-3d37a5872e36c4ad1bd12e36305250bd\" style=\"font-size:20px\"><strong>How it Works:&nbsp;<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">Stimulus signals are routed to the appropriate test points on the board-under-test via the switching unit and the bed-of-nails interface fixture.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">Responses are routed to the measuring device (which is controlled by the computer) from the interface fixture and the switching unit. Results are fed to the computer for calculation, comparison, and processing.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">Test results can be recorded on a disc and printed out in a \u201c\u2018repair ticket\u201d that indicates the faulty components. By tabulating the frequency of fault incidences, potentially bigger problems such as possible faulty component batches, repeated assembly faults, or process errors can be addressed.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">A good general-purpose in-circuit tester should have measurement capabilities, facilities that make it easy to change the bed-of-nails interface fixture, and the capability to directly program both program modification or program generation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left has-black-color has-text-color has-link-color wp-elements-13c733f535b37ffa9541168b1090d83e\" style=\"font-size:25px\"><strong>Advantages of In-Circuit Testing<\/strong><\/h2>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 Low initial cost<\/p>\n\n\n\n<p class=\"has-text-align-left\">\u2013 Easy to operate and program<\/p>\n\n\n\n<p class=\"has-text-align-left\">\u2013 Incredibly effective when it comes to isolating production faults<\/p>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left has-black-color has-text-color has-link-color wp-elements-662a439245ffa7703e098f537a842472\" style=\"font-size:25px\"><strong>Disadvantages of In-Circuit Testing<\/strong><\/h2>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 An individual bed-of-nails fixture is required for each type of board to be tested, resulting in high interface costs.<\/p>\n\n\n\n<p class=\"has-text-align-left\">\u2013 A vacuum or pneumatic power source is required for successful operation<\/p>\n\n\n\n<p class=\"has-text-align-left\">\u2013 It does not test the dynamic performance of the components.<\/p>\n\n\n\n<p>&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><img decoding=\"async\" src=\"https:\/\/www.apexwaves.com\/blog\/wp-content\/uploads\/2023\/05\/pexels-miguel-a-padrinan-343457-2-1024x1024.jpg\" alt=\"Closeup of green circuit board\" class=\"wp-image-2054\"\/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left has-black-color has-text-color has-link-color wp-elements-a374a49f522015a2bdd9cf496fbaef00\" style=\"font-size:25px\">Functional ATE<\/h2>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">A&nbsp;<strong>functional tester&nbsp;<\/strong>is used to assess the performance of the test board under typical working conditions. Functional testers use an edge connection to access the board-under-test, which simplifies and lowers the cost of interface connector design In comparison to the bed-of-nails fixture. Depending on the board\u2019s architecture, extra connections could occasionally be required using chip probes or connectors.<\/p>\n\n\n\n<p class=\"has-text-align-left\">The functional tester is able to quickly determine if the PCB is sound or faulty through the use of a basic&nbsp;<strong>Go\/No-Go test<\/strong>. A No-Go result indicates the presence of hardware failure. This failure could be caused by a variety of things; faults in PCB manufacturing, faulty ICs, faulty IC pin connections, or faults in assembly.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">The Go\/No-Go test may pinpoint the fault\u2019s location but it is often not accurate enough to allow for repairs. For greater accuracy, additional diagnostic tests must be performed to achieve this. These additional tests may involve monitoring and examining waveforms using a digitizing programmable oscilloscope, or by using a \u201croving probe\u201d in the case of a digital board-under-test.<\/p>\n\n\n\n<p class=\"has-text-align-left has-black-color has-text-color has-link-color wp-elements-15fd4c122af94d465b7835d98a51bd0d\" style=\"font-size:20px\"><strong>How it Works:<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">The functional tester utilizes an IEEE-488 instrumentation bus for interfacing the programmable instruments, and a peripheral bus for interfacing the peripherals to the microprocessor-based controller. Two memory stores are used: a permanent ROM store for the master program containing the basic programming requirements, and a RAM chip that stores the program dedicated for the particular board to be tested.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">The stimulus signals of the test are produced by the pulse of the signal generator under the direction of the controller, and they are then fed into the board under test via an edge connector interface. Output responses are picked up from the edge connector of the board and routed to one or more of the measuring devices via the interface.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">The controller receives the measured results, compares them with those expected from a good board, and indicates the results. Further detailed tests to identify the precise fault may be carried out manually, either under the control of the operator using the keyboard or under instructions from the tester by directing the operator to the steps to be taken.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-black-color has-text-color has-link-color wp-elements-6ab39716f43853c9e60cdcb2d8d47881\" style=\"font-size:25px\"><strong>ADVANTAGES OF FUNCTIONAL TESTING<\/strong><\/h3>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 Has a very high fault coverage (around 90 \u2013 98%) due to it verifying the actual operating specification of the board-under-test.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 Significantly faster than in-circuit testing because not every component has to be tested individually.<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 Edge connection is simple to design and cheap to make.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-black-color has-text-color has-link-color wp-elements-2e9af81d7bd9e8ee330ed8024b248696\" style=\"font-size:25px\"><strong>DISADVANTAGES OF FUNCTIONAL TESTING<\/strong><\/h3>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 Expensive<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 More complex to program<\/p>\n\n\n\n<p class=\"has-text-align-left has-text-align-left\">\u2013 Isolating the fault in a faulty board is difficult and time-consuming.<\/p>\n\n\n\n<p class=\"has-text-align-left has-black-color has-text-color has-link-color wp-elements-0a2a08c30b40e3ac6a5cb4d3520d2d23\" style=\"font-size:25px\"><strong>ADDITIONAL INFORMATION:<\/strong><\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-outline is-style-outline--1\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/www.youtube.com\/watch?v=_H-MilZuicI\">Creating ATE- NI YouTube Video<\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:25px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>When it comes to verifying the functionality and performance of products during manufacturing, Automatic Test Equipment (ATE) is an irreplaceable tool. Two of the most prominent types of ATE used in product testing and field servicing are in-circuit and functional ATE. This article will take a look at how both of these types work, as [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":2455,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[71,73,124,140,257,286,345,529,917],"class_list":["post-2454","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-circuits","tag-ate","tag-automated-test-equipment","tag-circuits","tag-components","tag-functional-ate","tag-in-circuit-ate","tag-manufacturing","tag-pcb","tag-test"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/posts\/2454","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/comments?post=2454"}],"version-history":[{"count":2,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/posts\/2454\/revisions"}],"predecessor-version":[{"id":3842,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/posts\/2454\/revisions\/3842"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/media\/2455"}],"wp:attachment":[{"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/media?parent=2454"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/categories?post=2454"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.apexwaves.com\/blog\/wp-json\/wp\/v2\/tags?post=2454"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}