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6 Truths You Need to Know About Bare PCB Manufacturing

The moment we think about printed circuit boards, we usually think about their designs in addition to the applications in real life. We could even think about their specific parts selected for a particular use. 

 

However, there is a specific component that we mostly forget – the bare printed circuit board. Many of us are aware that the empty board is a printed circuit board that lacks any parts on it. But are you aware that during the bare PCB manufacturing process, you can create defects? 

 

Some of the most prevalent defects are shorts (under-etchings), opens (over etchings), and holes.

 

There are plenty of interesting questions and facts regarding the bare PCB manufacturing process.

 

This article summarizes these to help the audience understand more about stark board PCB production. 

General Steps For Making Bare PCB

The following are the general steps for creating bare PCB manufacturing.

1  Primary drilling- this is the first step for building a bare board PCB. Drilling is a slow process since every hole has needs proper drilling.  

2  Deburring- this is the second step, and it involves removing small pieces or raised edges of material that had remained attached to the workpiece after modification.

3  Addition to glue – this is the third step, and it involves adding glue to the PCB to hold its parts together.

4  Electroless copper plating – this process is used to plate holes to make vias and PHTs.

5  Application of solder mask – Soldier mask gets applied on both sides of the bare board to shield the copper surface and prevent solder-shorting components during assembly.

6  Screen printing – this is the process of pressing some ink on a stenciled mesh screen to come up with a printed design.

7  Production of multilayer bare board PCB – this is the last step. It involves the rolling out of the empty board after completing all the steps above.

bare PCB manufacturing process should produce a board like this.jpg

Test of Bare PCB

1. What is an empty board test?

Bare board tests are electrical tests conducted to check for isolation between the individual circuit patterns and stability between the interconnected pads.

2. Why is testing necessary?

Highly populated bare board PCBs that do not undergo testing have failed before applications where they find their use. Testing ensures that you avoid such errors at all times.

3. Benefits of bare board PCB testing

While many companies find these tests somewhat time-consuming, some benefits are associated with testing bare PCB manufacturing. Some of the benefits include the reduction of overall costs of repair, on-field testing, and maintenance. Also, testing ensures that the testing duration, total setup time, and expenses are highly minimal. Lastly, tests are highly effective for bare PCB manufacturing that have SMT and excellent line mounting technologies.  

Reduction of cost is one advantage associated with testing PCB empty board manufacturing.jpg

Possible Defects in Bare PCB Manufacturing

Some errors may occur when manufacturing printed circuit boards. Some of the most prevalent mistakes include the following:

1. Excessive or missing copper

The essential element used to make traces on a bare board PCB is copper. Copper is used based on the fact that it’s highly conductive, meaning that it can quickly transmit signals without losing some electricity along the way. However, either excessive or inadequate copper may cause defects on a bare board printed circuit board. Too much copper may bring about corrosion, while insufficient copper may bring about short-circuits to the board.

2. Short circuit problem

A short circuit is an electrical circuit problem that occurs when two or more wires that aren’t supposed to come into contact together touch each other. A short course may bring about very high currents that flow through the course. That’s not all. A short course also takes place the moment there’s a bypass of some electrical current. When it comes to the production of bare board printed circuit board production, short circuits are common problems that many designers face. However, to fix the problem, there’s a need to replace the wire. Otherwise, your bare board printed circuit boards won’t function as intended.

3. Extra holes

All bare board printed circuit boards have holes in them. Holes often referred to as through-holes, are those holes that go through the board entirely. Holes are the signals that carry conductive vias to establish interconnection between the layers of the printed circuit board. Unfortunately, having extra holes is another problem that may bring about defects during the production of bare board printed circuit boards. Extra holes may limit the space available in addition to the routing area aimed for signal tracing.

excessive gaps might be a problem during the bare PCB manufacturing process.jpg

Designing Bare Board PCB

When you are in the process of developing a bare board printed circuit board, you may think that arriving at the final step will be a tedious and somewhat arduous journey. But examined carefully, you’ll find that the process of designing them is relatively easy. The first step that you have to do is to design the layout of your bare board. You may do this by using software such as OrCAD or KiCAD. Others that you may use include Eagle or Altium Designers.

After you finish designing your layout, you will have to export your design to a format your manufacturer can handle. You will then have to convert this design to an output format by using extended Gerber. The extended Gerber encodes some of the most vital information, such as component notations, tracking layers, apertures, and so on.  

All the boards must undergo checks to ensure that all errors are detected. You will then have to plan on other aspects such as trace hole spacing, sizes of the holes, track width, and board edge spacing. After that, the file has to be forwarded for production by the boarding house.

The second and final step is where the designer outputs the schematic files that the manufacturer will use to create photo films. These films are used in imaging the printed circuit boards. To achieve this, a designer may use plotters to provide a detailed printed circuit board design. At this point, there will be a plastic sheet consisting of a negative film for the PCB.

The negative photo that results will be in some blank ink that represents conductive copper parts. It also consists of an outer layer covering areas that have non-conductive material. But to ensure that you achieve film correspondence, the holes will need some punching.

Using the right software matters a lot during bare PCB manufacturing process.jpg

Material Selection in Bare PCB Manufacturing

The primary material used in bare printed circuit board manufacturing is of immense importance. It is essential to factor in vital aspects such as the performance of the chosen materials such as adhesion, temperature resistance, flexibility, tensile strength, dielectric strength, flexibility, thermal factors, and many other physical factors. The performance of a bare board printed circuit board depends on the material chosen to manufacture it. Some of the most common materials used in the fabrication of empty board printed circuit boards include the following:

•  FR-4 – FR-4 is a common material used in the manufacture of bare board PCBs. This material is made of a glass-reinforced epoxy laminate sheet. This material is water and flame resistant.

•  PTFE (Teflon) – this is a kind of plastic material that doesn’t provide any resistance. It is preferred based on its high speed.

•  Metal – traditional materials such as copper, iron, and aluminIum still find their way in bare PCB manufacturing. They are preferred based on the fact that they provide excellent mechanical durability.

Copper always find its way in bare PCB manufacturing.jpg

Bare PCB Manufacturing Drilling

Drilling is one of the most expensive and time-consuming processes for the manufacture of empty board printed circuit boards. The empty board drilling process has to be carefully implemented because even the slightest error could bring about significant losses. The drilling process is one of the most critical and the bottleneck of bare printed circuit board manufacturing. The drilling process forms the foundation for vias.

There are two types of drilling technology. There’s laser drilling and mechanical drilling. Mechanical drills have do have less precision, even though they are easy to undertake. On the other hand, laser drills can drill smaller holes.

Drilling forms the foundation for vias during bare PCB manufacturing process.jpg

Summary

At times, bare boards might be challenging to manufacture. If you find yourself unable to produce bare boards on your own, then you can rely on us at WellPCB. For more than a decade and counting, we have been manufacturing high-quality bare PCB manufacturing to many customers.

We believe in quality and competitive pricing. If you need bare printed circuit boards for your next project, feel free to contact us. We can provide you with the technology, materials, and quality services that will leave you satisfied at the end of your project. We have a team of responsive customer care attendants ready to answer all your questions politely and professionally.

If you have any questions or concerns, at your earliest convenience, feel free to contact us for assistance. We at WellPCB are here for you.

Hommer
Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.

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