The fundamental element in all types of electronic circuits is the Printed circuit board. Regardless of its design, either simple or complex designs. The wide use of the surface elements, in alliance with the need for multi-layer PCBs, causes a lot of hitches in recently designed PCBs. Irrespective of the appliances on the board, a perfect functionality of the PCB with no fault is vital.
The present age electronic circuits have many components and solder point interconnections. A little frailty on the board hugely affects the general performance of the elements. Thus, the need to diligently test pcb and inspect its element becomes very crucial. It is to ensure quality to the end product after the fabrication process.
A faulty design on the PCB or its assembling could result in product failure. Thus, producers have the task of ensuring that the product matches all safety standards. It will help improve end-users’ reliance on the quality of designed PCBs.
PCB being valuable hardware that is frequent in different types of electronic gadgets needs quality tests. It is to eliminate faults that could lead to product malfunctioning. An overlook during fabrication could mean recalling the faulty device for proper adjustments. Let’s get into details on how to test a pcb circuit board.
What is a PCB Test?
PCB testing starts with the awareness that it is the bedrock of all printed circuit assembly. The PCB being a high-standard device, should not attract an extra cost due to faults in the finished product.
In the PCB manufacturing process, the test pcb stage is very crucial. Without this, the PCB could have hidden faults not open during the production process. These faults might cause failures. To make sure the PCB functions perfectly, PCB testing is crucial.
PCB testing is a basic necessity in the PCB manufacturing industry. It deals with examining some specified benchmarks on the board. The PCB tests will reveal if the design meets the basis that qualifies its standard. Thus, end-users are confident about the integrity of the product.
Aims of PCB Test
The following are the reasons why performing the PCBs test becomes very crucial. They include:
To identify flaws
Through pcb board testing, probable faults become visible. It helps manufacturers locate where the faults or errors are on the board. It could either be in the functionality, manufacturing or any other elements. Manufacturers can rectify the faults immediately as required.
For cost efficiency
Defective PCB will result in double expenses. Designers would have to bid for a blueprint and mid-size fabrication. It will help to perform pcb board testing on the design that is a crucial step in the process.
Saving time
Performing PCB tests at the very early phase of the process saves time. Major issues become easily identified when it is still at the design stage. To meet the objectives above, the PCB has to go through the following tests. It will ensure the design meets standards.
Soldered Joints
Soldering tests of all the soldered joints are crucial to the PCB. It helps to ensure the firmness of the elements to the board.
Environmental Test
It is an important test required by the PCB. The test helps to confirm the PCB water absorption level if it meets standard or not. It is because the majority of the PCBs perform in a moist environment.
Disinfection Test
The disinfection test tries out the strength of the PCB to resistance. It analyzes the PCB before and after it has gone through some climatic conditions.
Copper plating
This is to test the volume of the copper applied as a cover to the supply conductive plate. The test examines the copper plating ductile and lengthening strength in particular.
Electrical connections
The test is critical in the PCB manufacturing process. It helps to confirm how the radiation level enables voltage leakage in the circuit.
Lamination
The focal point of this test is to know the solidity of the laminate as it dictates the life of the PCB.
Welding ability
This test is to confirm how firmly fixed the element could stand on the board. It also checks out the acceptance level of the wet solder on the surface of the board.
Hole wall standard
This will confirm that the hole walls on the PCB do not split or pull off while the PCB is functioning.
Types of PCB Test
The PCB fabricating test techniques are a vital part of the design process. There are various methods of testing PCB. They include:
Automated Optical Inspection (AOI)
It is a mechanical visual examination of the PCB. A high focus camera scans the PCB for the test to find out grief failures and standard faults. The manufacturing industry often uses this type of testing because it is contactless. It is also helpful in many phases of the manufacturing process.
X-ray Inspection
This type of PCB test is frequent in PCB examinations. It is a rare method that tests the integrity of the PCB and uncovers invisible faults. This method does not expose the board to any damage while undergoing testing. It is most suitable to test recent hi-tech PCBs with attributes of firmly packed elements.
In-Circuit Testing (ICT)
In-circuit testing discovers faulty elements due to solders mislaid or over soldering. It could also detect skewed components and soldering deformity. It is a hugely accurate device for testing PCB.
Visual Inspection
This is the easiest form of PCB testing. The test is reliant on the optical view of the examiner or aided by embroider. The examiner makes comparisons between the board and the design template. It is to ascertain common faults from the components on the board.
Flying Probe Testing
This practice of testing PCB focuses on finding faults such as skewed elements. It also uncovers inactive parts and energy scans for elements. The flying probe test machine performs the task.
Functional Testing
This type of testing is an all-inclusive examination process. It helps to decide if a fabricated board can move from the production table to the end-users. The test is to detect manufacturing faults. These faults influence the dependability, misplaced elements, and solder connections on the PCB.
Burn-in Testing
The burn-in testing type is a devastating method of testing the PCB. It prompts acute conditions that are above the design standard. The test shows the faults and verifies the load strength of the PCB when exposed to a harsh environment. The power supplied runs at a high temperature mostly on its highest functionality. This could be dangerous to the PCB.
How to Test a Circuit Board
The Printed Circuit Boards are composite assemblies. This is due to the numerous elements and lots of solder joints found on the board. Individual elements ought to function at their maximal standards. However, a micro flaw can alter the general standard and performance of the circuit board.
The aim of PCB board testing is to identify its deformities. Each element and its electronic quality on the circuit board play a crucial role. The circuit testing process is in two ways, which are the Power off test and Power on Test. The power-off test comes up prior to applying power while the power on comes up when power is fully on.
Circuit testing is a very strong mechanism that aids in digging out faulty elements. This is through examining each separately. It is one of the most precise means of testing, which carries out layout verification. The faults found on the board can get replacements immediately. It is important before the PCB goes through the finishing line of production.
PCB board testing gained popularity because of its known all-inclusive examination process. It examines all the required components on the board. This process performs the test with concentrations on the following:
- Open Circuits
- Missing or wrong placement of elements
- Solder bridges
- Misperceived automatic components
- Electrical condenser and inductor elements
- Soldering and procedure issues
- Short circuits
- Element spacing, lead spacing, elements sixes, and land size.
- Utility of regulators in the circuit.
- Misunderstood correlative elements
- Jumpers/ electrical switches in the right position
- Existence/ inexistence of inactive elements
The circuit board testing does have some deficiencies. It does not expose diverse power relations missing. Furthermore, it does not uncover unnecessary power linkage and mechanical fasteners as well.
Components of Circuit Board Tester
The circuit board test system has so many varieties available. However, each is famous by capacity, style of reaction, and testing process. The Circuit board tester has elements that are common. Irrespective of the type of choice made, they include:
- Fixture
- Interface
- Software
- Analog Scanner
- Powered Analog tests
- Analog-digital opens
- Controller
The circuit board test is a dependable and superior test method. The test is to certify that the PCB carries out its functions brilliantly. Producers make honest efforts to use a standard PCB on their design. It is a fast and dependable testing procedure that conveys element-level failure detection.
Advantages of Circuit Board Testing
For guaranteed easy, quick, and swift discovery of the precise area of faults, circuit board testing is vital. It is an accepted method of performing testing due to the benefits it has accrued over time. They include:
- Finding errors out is less time consuming using the circuit board testing
- The interpretation of test pcb results is easy
- This method is an all-inclusive process in contrast to every other.
- The pcb board testing guarantees high coverage of manufacturing faults
- The most preferred pcb board testing procedure for mid-size and prolific through-hole regular fabrication
- Its maintenance cost is low
Disadvantages of Circuit Board Testing
Every procedure has its limitations, and circuit board testing is not an exception. The under-listed are the disadvantages of adopting the circuit board testing method
- Results can be inconsistent due to improper contact of test pins with the right test pads.
- Regular cleaning and replacements of the test pcb pins to fend off failure
- It is expensive testing each component on the board
- Detecting connector failures in high concentrated, small size SMT elements could be inconsistent.
Despite these setbacks, it still maintains the most preferred method in PCB assembly. Carrying out PCB testing helps producers examine the performance of the elements in no time.
Why PCB Testing is Essential
Every single electronic product needs adequate testing. Either correctly designed and skillfully manufactured, testing is essential. It could be susceptible to faults and malfunctions if not tested. Maintaining quality assurance and quality control during each manufacturing step is crucial. Most notable is the initial phase of the process.
When you test a circuit board, you help in probing challenges and reduce faults. Strategies that aid early detection are signal probity test, power integrity, and EMI.
PCB Components that require testing
Resistors
Resistors are vital components on the board. They are small electronic gadgets that supply voltage. These supplies are through transferring electrical ion flow. To perform testing of these elements, isolating the resistors comes first. It is to ensure that other components on the board will not alter the result. Digital or Analogue multimeters are the devices that help to measure the results. A high in the testing result indicates a problem with an open resistor.
Diodes
These are electrical gadgets that transfer current in a one-way direction. They contain photonic materials in the middle of the terminals. Primarily, diodes supply current in a single way direction. However, they obstruct current in the opposite direction.
Diodes are subtle elements, so caution is vital during the testing process. Testing diodes, there must be a disconnection at one end of the PCB. The digital or analog meter helps in finding the red and black meter check. There are minimal results expected in case of defects on the diode.
They are:
- Some defiance in meter reading indicates the diode is forward distorted
- There is leakage in the diode if the meter lodges two readings
Capacitors
Capacitors are fundamentally electronic gadgets that keep the energy as a dielectric field. They are heat proof materials laid between transmitting plates. To carry out a test pcb on the capacitors, disconnection of it at one end is essential. It is vital to ensure that power supplied from the DC equals the span capacitor to fend off device overload.
Conclusion
By now, you should know how to test a pcb circuit board. Pcb board testing has developed into a necessity in the manufacturing process. This is to ensure that the finished products meet the highest criterion. It is important to understand the type of testing required by each design. The quality and purpose of production determine the perfect type of test pcb.
Compactness, mounting system, and the elements on the design are other major determinants. A detailed understanding of this article will guide in taking the best testing method.
