At present, there are two kinds of PCB board edge design: metallization and non-metallization. For non-metallization, manufacturers in the industry have matured, but the metallization technology is still immature. Nowadays, more customers’ production needs are turning to PCB metal edging. Therefore, the quality of PCB metal edging has become the focus of customers’ and manufacturers’ attention because its quality directly affects the use of products.

 What are the applications of edge plating in PCB?

Edge plating circuit boards are common in many industries, and edge plating is a common practice. You’ll find PCB edge castellation (or edge plating PCBs) applied in many cases, including:

· Improving current-carrying capabilities

· Edge connections and protection

· Edge soldering to improve fabrication

· Better support for connections such as boards that slide into metal casings

What is the process of PCB edge plating?

As you know, there are a great deal of challenges for a multilayer PCB manufacturer mainly in how to prepare the plated edges and the life span adhesion of the plated material, what’s more, it needs the precision handling in PCB manufacturing that is used for edge PCB soldering. We can make sure that the PCB edge castellation thoroughly prepares edges surfaces, which applies the plated copper for prompt adhesion and processes the circuit board to make sure the long-term adhesion between each layer.

Needless to say, we can control the potential hazard for plated through hole and edge plating with a controlled process during printed circuit board manufacturing for edge soldering. So the most important concern is the creation of burrs, which result in discontinuities in plated through hole walls and limits the life of adhesion of the edge plating.

The outer contours, to be metalized, must be milled before through-hole plating process, as the metallization of the edges take place during this fabrication step. After the deposition of copper, the intended surface finish is finally applied to the edges.

Fabrication Issues:

1. Copper Peeling -Plating over a large substrate surface can lead to the plated copper peeling due to a lack of adhesion strength. We address this by first roughening the surface through a combination of chemical and other proprietary means. Next, we employ direct metallization, which has a higher copper bond strength, to prepare the surface for plating.

2. Burrs -Often edge plating, especially on castellation holes, can result in burrs from the final machining process. We apply a modified, proprietary process flow that results in the burrs being polished down to the edge of the feature.

Fab Note:

1. The antenna position of the gold pad is too large, affecting customer soldering or signal transmission.

2. The inner edge pad is connected to the wires on the board, resulting in a short circuit.

3. The stamp hole is designed at the edging groove and must be handled in the 2nd drilling process.

4. Through the process-related manufacture of the individual PCBs as a panel, a continuous metallization of the outer edges is not possible. No metallization can be applied where the small panel bridges are located.

5. One request, the slide plating metallization can be covered with solder mask.

When purchasing edge plating boards, you must confirm with your PCB supplier the possibility of manufacturing PCBs with plating process, and extent to which the fabricator can edge plate the PCB. Your Gerber files or fab drawing should indicate in a mechanical layer where they need slide plating, and the surface finish they need on it. Most manufacturers prefer a selective ENIG as the only surface finish suitable for round castellation.

YMS Electronics Co., Ltd. is a professional manufacturer of high-precision multilayer circuit boards, module immersion gold circuit boards, automotive circuit boards, driving recorders, COB power supplies, computer motherboards, medical circuit boards, module bonding boards, blind hole impedance board, thermoelectric separation copper substrate, etc. RayMing provides top-notch quality assurance and punctual delivery, a high-tech enterprise with sales as a whole. If there is a demand for side-coated gold boards, please feel free to contact us!