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PCBs Manufacturing – The Most Detailed Introduction(Helpful)

PCBs Manufacturing standard stands for Institute for Printed Circuits, currently known as Association Connecting Electronics Industries. It was founded in 1975 to set the standards for bare PCBs and finished PCB assemblies.

The PCB manufacturing classes are IPC Class-I, Class-II, Class-III, and Class-III/A. Class-I is the basis of PCB manufacturing quality.

As well as Class-III/A is the strictest. All three classes belong to the IPC-6011 standard. The significant difference between classes is their level of qualification.

1.PCBs ManufacturingBrief Introduction

Below is a brief introduction to the different classes:

1.1 PCBs ManufacturingClass-I

Class-I PCBs are in the “Limited Life Expectancy” group. Or the electronics assemblies. Those are expected to be used in a low-reliability environment.

These PCBs are used in general electronic products, circuits, and gadgets. Such as where the function of the product is sufficient to accept it. An LED light, flashlight, TV remote, etc. They are examples of Class-I PCBs.

1.2 Class-II

Class-II PCBs are in the “reliability products category.” But reliability is not considered critical. These types of PCBs are used in dedicated products. Such as personal computers, laptops, tablets, smartphones, etc.

1.3 PCBs ManufacturingClass-III

Class-III PCBs are highly reliable products. It does not compromise over reliable operation of the product.

Examples are electro-medical equipment, military equipment, electronic monitoring parts of automotive, etc.

1.4 Class-III/A

This is another type of PCB for which the manufacturing and inspection criteria are the strictest. Their main applications are aerospace, military airborne systems, and missile systems.

2.PCBs ManufacturingIPC PCBs Manufacturing standard

These classes define the level of inspection. As well as acceptance of the user. In general, all PCBs’ manufacturing requirements are approximately the same.

But require tighter tolerances for inspection. That eventually results in enhanced product reliability. The parameters are controlled throughout the manufacturing process and final review.


The faults occur in any of the produced items. They ensured traceability, and if noticed that PCB may be destroyed.

This practice makes sure that all of the PCBs are ‘fault-free. And comply with the tolerances specified by the respective class.

Generally, any manufacturer can claim that he makes class II or III PCBs. But the coupons and the certificates provided for each PCB are verified.

Another third-party laboratory confirmed them. So that certifies the reality about claimed class. 

Because manufacturing qualifies and certifies each PCB’s manufacturing is the manufacturer’s sole responsibility.


So it is upon the manufacturer. He does manage to qualify each PCB for the respective class; either he makes more than the requested PCBs or destroys the unqualified PCBs.

Or makes every product by controlling the features to its maximum and class category.

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Fig. 1:- Class-II vs. Class-III PCBs

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Fig. 2:- PCB inspection stage for class-II,class-III

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Fig. 3:- A comparison and list of IPC Manufacturing standard manufactured PCBs.  Inspection parameters

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Emma Lu
Our professional engineering support saves our customers a lot of trouble and loss. >>>>>> After you place the order, our engineer will conduct technical reviews to make sure the parts can be mounted well/correctly on the boards. We will check if the component packages match well with the Gerber footprints, if the part numbers you provided match well with the descriptions, and if the polarity is clearly marked. >>>>> When your design is ready, please send your Gerber and BOM so we can quote and start!