IC Continuity Test
Key Takeaways
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The IC continuity test ensures the electrical continuity of all the pins in the IC.
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The IC continuity test can be performed on an IC under test using a multimeter.
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The matrix alignment of pins in a ball grid array or surface mound IC package makes it necessary to find advanced methods for IC continuity tests in PCB boards.
With the growth of the semiconductor industry, the density of circuits within integrated circuits (ICs) has increased. Even with the increase in density, the number of input-output pins remains unchanged, which is one of the reasons for the increased complexity in IC packages.
To ensure the reliability of ICs, IC testing is introduced at every stage of the production process. The IC continuity test plays a crucial role, as it ensures the IC under test is functioning well.
What Is the IC Continuity Test?
The IC continuity test can be performed to test the electrical continuity of the pins within the IC as well as to check the connection of the IC with other components in a circuit board.
IC Continuity Testing Within the IC
The IC continuity test helps to identify short circuits, open circuits, and pin-to-pin shorts. Consider an IC with two pins with the same functionality. The redundancy in pins can be considered an electrical short. If, say, pin 4 in an IC is the duplicate of pin 2, then the two pins can be regarded as electrically shorted.
If there is no connection between two pins (for example, pins 2 and 1), they are electrically open. Through the IC continuity test, the electrical connectivity between the pins can be verified.
IC Continuity Testing Between ICs and Other Components
In circuit boards, ICs are connected with other components. Pins share electrical shorts with one terminal of the components at which they are connected. If there is an open circuit between a pin and the intended component terminal, circuit operation is affected. The IC continuity test helps identify connections between IC pins and other components.
IC Continuity Testing Procedure
The IC continuity test can be performed on an IC under test using a multimeter. While testing continuity using a multimeter, you must do a visual inspection to make sure the pins aren’t touching each other.
Review the datasheet to understand the pins and the internal connection between them. There is no need for an external power supply.
How Does IC Continuity Testing Using a Multimeter Work?
The multimeter sends a small current through the probes. If there is continuity between the pins that are touching the probes, the current from one probe reaches the other probe through the IC under test and confirms continuity by producing a beeping sound.
IC Continuity Test Using a Multimeter |
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Step 1 |
Set the multimeter to the continuity setting. The continuity setting is indicated by a diode symbol in the meter. |
Step 2 |
Keep one probe of the multimeter on one IC pin and the other probe on other pins (one at a time). |
Step 3 |
Review the relevant document to identify the electrical shorts between IC pins and the electrical open connections. |
Step 4 |
When the probes are placed on two IC pins with internal connections, the multimeter produces a beep. The beep confirms the continuity or electrical short between the IC pins under test. |
Step 5 |
When the probes are placed on two IC pins with no internal connections, the multimeter produces no audible sound. No sound confirms the discontinuity or electrical open circuit between the IC pins under test. |
Step 6 |
Repeat the above steps for all the relevant connections per the IC datasheet pin diagram. Listen for the beep from the multimeter to confirm continuity or discontinuity. |
IC Continuity Testing and Package Complexity
As the complexity of IC packaging increases, the conventional IC continuity test becomes obsolete; advanced methods for continuity testing in PCB boards will soon be necessary.
Cadence’s suite of design and analysis tools can help you ensure IC continuity in your PCBs. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.