How to perform Infrared inspection on PCBs?

Printed Circuit Boards are the rigid structures that have geometrical patterns etched on their surface. These patterns are made of copper or conductive material and replace the use of electrical wiring in electronics. Printing the circuits is less expensive than fitting wires and soldering them.

On the other hand, multi-layer boards with wiring make systems highly complex. If a defect occurs in an inner layer of the multilayer board, then all the other layers above that layer need to remove to reach that layer. This generates the need of proper inspection before lamination.

Among the various types of inspection techniques, infrared inspection uses heat and requires the use of current. The purpose of inspection is to find defects in printed circuit boards which if not corrected timely could lead to electrical failure.
Defects in the PCBs can result variations in temperatures. Inadequate or improper soldering at joint can cause electrical resistance. As a result, the temperature of the PCB increases and can be detected with the help of infrared camera.

The idea behind printed circuit board inspection with known standards is based upon the fact that heat emitted in the part of the PCB that is inspected is predictable. This idea behind inspection can be affected by the elements and methods used for printed circuit board fabrication. The substrate contains numerous electrical components, such as semiconductors, that generate heat of varying temperatures.

The idea of image subtraction involves the use of software that forms a perfect thermal profile which can be compared to the actual inspection results or even subtracted from them.  The outline can be loaded into the inspection camera or it can be used from computer system.

One main thing in various types of inspection is presence of current to facilitate necessary heat generation requirements. There are mainly two types of infrared inspections, active and passive.

In active infrared inspection of printed circuit board, the device is given energy as it would be serve the actual purpose and heat produced by different electrical units is measured. On the other hand, passive infrared inspection on printed circuit board involves the current directed on the tracks in the PCB to a heat sink.

Before conducting the printed circuit board infrared inspection, the professional inspectors properly examines the job and makes selection for the best inspection tools. During selection of equipment, the inspector considers various factors like color options, field of view, and limitation associated with the physical structure of the equipment. Each inspection techniques have its own set of issues and the selection of equipment plays major role. The selection of right equipment avoids re-testing.

The printed circuit board inspection enables defects to be detected before they become a major cause of failure.

Various techniques used for PCB assembly

The printed circuit board assembly (or commonly known as PCB assembly) is a process of connecting various electronic parts together on a printed circuit board to produce a comprehensive functional printed circuit unit. 

Before we start with the various methods to create PCB, lets’ have a quick look in what Printed Circuit Board is? PCB is a thing board where numbers of electrical components are attached through the etched copper pathways (conducting tracks) instead of wires. This conductive part of the board directs an electrical current to the various electrical units mounted on the board’s surface. 

Existence in industry:

The use of printed circuit boards is widely popular in various industries including for the fabrication of semiconductors used in computer microprocessors, for making sensors, such as missile wings sensors, in aerospace engineering. Furthermore, they are the widely used electronic equipment in military which is used in missiles and rockets. 

Almost every electronic device used today has a printed circuit board as an integral part of their construction. Most of the electronic things such as television, coffee machines, radio, iPods, washing machines,     mobile phones, games consoles, computers, alarm systems etc., have PCBs as the basic building blocks of their internal structure. 

Construction of PCBs:

Basically, there are three main construction techniques used to create PCBs that are discussed as follows:

Surface-mount assembly: SMT assembly involves the various electronic elements being joined directly to the printed circuit board surface. This method has several advantages over the traditional through-hole in the way that they can be used to create much smaller circuit boards.

Through-hole assembly: This construction method involves the electronic parts that have leads connected to them are pushed to the PCB by inserting through finely drilled holes. This job can be accomplished by using machines or can also be completed by hand. 

Electro-mechanical assembly: Also popular by the name box-build assembly, this method of construction is use the cable assembly, customized metalwork, moulded plastics, and wire harnesses to fabricate fully-functional printed circuit boards.

Many businesses rely on electronic assembly fabrication services to source their printed circuit board units. There are many advantages associated with hiring of such services, including:

• They save money as a lot of investment is required for PCB assembly unit. Furthermore, it saves large amount of money that would go for hiring labor, setting up required operations, upgrading machinery, managing inventory and maintaining various equipment etc. 
• Another benefit of hiring electronic assembly services is that you get your work done by the highly specialized work forces. The expert service ensures you the delivery of a product that will meet the modern industry standards.

SMT assembly is a latest technique of manufacturing electronic circuits in which the various parts are positioned directly on the board’s surface.

Consider These Tips While Choosing a PCB Manufacturing Company

The internet has made it easy for every individual to search any information at any time of the day. No matter, whether you are searching for online shopping stores or a advance PCB manufacturing company, the results will come in front of you in a few seconds.
But, the question is how to choose a reliable manufacturing company when thousands of options are available on the web? Here is a list of factors that one needs to take into account before selecting PCB manufacturers.

Use of Latest Technology

The technology is becoming more and more advance with each passing day. That is why; the design of electronic devices has become more complex.

Not, even a single electronic manufacturing company is interested in buying Printed circuit boards that are not designed according to latest standards and the technology that is widely used.

So, choose a firm that makes use of latest and innovative techniques to design a circuit board.

Openness to Customization

The structure and design of PCB’s vary from one device to the other. In simple words, each device has its own requirement for circuit boards.

Therefore, it is important to choose the company that is ready to work according to the requirement of devices and clients.

Experience

The firm should have years of experience in designing different types of circuit boards so that they can fulfill requirement of electronic device manufacturing companies in the best possible manner.

Different processes of PCB assembly process!

PCB assembly a very common term that most of us listen today; especially those people who are surrounded by electronic equipment and products. However, still there are few others who are not aware of it. So for them this article would help enlighten few facts about it:

Basically, PCB comprise of various components that are put together to enable the functioning of device. However, the whole process is quite complicated and long one which is needed to be carried out carefully by the manufacturing company. Various multi-stages are carried during the PCB assembly service that includes placing of components of board, soldering them, inspect and lastly test them for working.

The foremost and basic step that is followed by the manufacturer company is ordering of silicon and other semiconductors, further which are then transformed into electronic chips. These chips are then integrated onto a printed circuit board for its working or operation.

Now let’s have a detailed look at the different processes carried under PCB Assembly Services:

Solder Paste Printing: Once the chips are prepared they are needed to be pasted on the board, during the soldering method. Basically, during this process, binding of material is done on the board.

SMT pick and place assembly: On each assembly line, chips are placed appropriately or accurately on their designated places. This is done in order to have proper functioning of device.

Reflow/Through-hole curing: So as to bind the chips properly on the board, hole curing method is performed after soldering is done. This helps to bind the chips more firmly on the board.

Conformal Coating: After the chips are soldered and placed properly, boards are covered with a protective layer coating so that they are not affected by the harmful materials or other things. Usually, conformal selective coating is done by the machines that provides protective layer to the board.

AOI and AXI: In order to get assured that no mistakes are there on the board, inspection process is also carried out during the assembly process. This method is particularly known as Automatic Optical Inspection and Automated X-ray Inspection. After soldering and pasting is done, this method is vital to perform and therefore, PCB manufacturers never miss out to leave this process of inspection.

Reworking: During the inspection, if any defect is detected then that is corrected before the board is sent out for construction. During the reworking process, board is heated, chips are removed and replacement is made with the right chips or semiconductors. Once the chips are soldered then again the inspection process is carried out in order to ensure that now the replaced board is working properly.

Fabrication of printed circuited board and its assembling is a very cumbersome and challenging task. It is generally outsourced by business to the assembly service providers. So make sure to find out the most reliable company for PCB Assembly Manufacturing .