PCB panel parameters

 PCB panel parameters

The primary reason for having your boards delivered in an array is to make automated assembly faster and less expensive. Running an array of boards through a pick-and-place machine is far more efficient than sending them through one at a time. Arrays are also desirable because they allow the addition of tooling rails, tooling holes, and fiducials, all of which help your assembler.panel parematers.

Array
An array is combining a single PCB multiple times or different pcb composed to make a larger array of connected boards.Other terms used to describe an array are: panelized, stepped out, palletized and rout and retain.
 

 

PCB Tooling Rail
Tooling Rails are the ‘frame,border’ for the array. They provide stability and make it easier to handle the arrays throughout the assembly process. Tooling holes and fiducials are usually added to the tooling rails. The rails could be on all four sides of the array or only on two sides. If you only have it on two sides, then you can usually get a few more pieces up on the panel, which will help the per board cost. Available options for panel borders: 5.00 mm – 7.00 mm – 10.00 mm – 20.00 mm To make a stable panel we propose a minimum border of 2 x 5 mm in X and Y.

Fiducials
Fiducials are copper spots on the rails with the same finish as the rest of the board, which aid automated pick-and-place assembly equipment by providing a uniform reference point. The ideal size is .040” and will not be covered with mask to make it easier for assembly equipment to see. Typically, three fiducials are needed on an array and are placed on the rails. Some manufacturers may require fiducials on each individual board as well. However, for the most part, there are pads or other features on the individual boards that can be used to provide additional alignment targets.

Tooling Holes
Tooling Holes are non-plated holes added to the rails in the four corners to aid in alignment and orientation when assembling the board . They are typically .125″ in diameter but can be drilled to your required specification.tabs and bits.

Scoring
Scoring or V-cut is making a small V groove along the length of the board where they will be separated. The groove is typically 1/3rd on top, 1/3rd on bottom leaving 1/3rd of the material remaining in place to hold the boards together. The score will be made along the shared board outline. Scoring is performed only parallel to the x- and y-axes, not diagonally. Because scoring runs all the way across the array in a straight line, the board outline should be straight for scored arrays.

Break-rout tabs
If your design has an irregular shape, then tab routing may be required. Break-rout tab arrays will leave a small tab on all four sides of the board attached to the other boards or the rails. Small tabs of material will remain to hold the boards in place. This type of array is not as stiff as the scored array, but can be easier to break apart. Tabs are typically one on each side of every board and usually .050” wide. Our default is to add a 0.1″ (2.54mm) gap between the boards to allow the router bit to pass between them. To make separation easier, we can add small non-plated holes to the tabs called ‘mouse bites’ to perforate the tab. If you desire a smooth edge on your PCB’s, these areas will need to be sanded after the boards are removed from the array. The minimum ( and standard) clearance between PCB’s for break-routing is 2.00 mm. Any larger value is OK.

X Outs
An X out is when one of the individual boards on the array does not pass the test and is marked out with a marker. Some manufacturers will allow a certain percentage of X outs on the order, while others may require there be no X outs on any of the arrays. By having no X outs, it will make the board cost a little more since the PCB manufacturer may need to make a larger number of arrays in order to meet the order requirements depending on their yields.

Stencils
If we setup the array for you, your assembler will need to receive the arrayed Gerber files so a stencil can be made with the exact spacing of the final design. We will be happy to send you the files but please be aware that we also make stencils! Simply contact your sales rep for more information.

The Difference between ED Copper and RA Copper

Flexibility in the copper comes from multiple factors. Of course the thinner the copper, the more flexible.  In addition to the thickness (or thinness), copper grain also affects flexibility. There are two common types of copper that are used in the PCB and flex circuit markets. Electro Deposited (ED) and Rolled Annealed (RA).

Differences between  Electrolysis Deposition Copper Foil and Roll Anneal Copper Foil

1. Electrolysis Deposition Copper Foil (ED copper)

Formation: Melt copper into dilute sulfuric acid, it becomes bluestone solution.
Through a high electric field, copper attach on the metal drum. With the rolling of metal drum, thin copper foil finally formed.

Advantage: Low cost, ED copper has better conductivity than RA copper.
Shortage: Unsuitable for small lines; bad bending resistance.


2. Roll Anneal Copper Foil (RA copper)

Formation: Roll copper block many times, and then do the annealing treatment with high temperature. The shape of its crystal is lamellar structure.

Advantage: Soft, smooth surface, suitable for flexible PCB and small lines.
Shortage: high cost

Because of different performances, RA copper and ED copper are used in different products which tend to different product requests. For example, the flex board needs to be bendable a lot, so obviously, RA copper will be a good choice. Otherwise, we could use ED copper with high electrical conductivity. 

Whatever, you should select copper according to your circuits' requests (final board performance, cost, function...)

For further info,Please visit our website at www.kingcredie.com.

Step Plated PCB

Technical specifications

1.Selective copper plating required

2.Via fill and over plate

3.10mil Rogers 4350B

4.ENIG

Methods and Processes

During the traditional PCB production process, we need use the film for image transfer. When the image transfer, we need make sure that the film affix to the copper clad, or it will cause ultraviolet rays refraction and short or open circuits because the failed conductor pattern transfer. Because the copper thickness of the selective area is thicker than the other areas, it is hard to ensure the accuracy of the image transfer. During the circuit process, we are not able to use the normal processing. In fact, this problem will also happen during soldermask and screen printing processes. KingCredie apply a special way which called the secondary plating. We can meet the customers’ requirement by plateing the pads of the selective areas, and we use the advanced LDI exposure machines. So we cancel the film directly and ensure the precision of the soldermask and circuit.

About us


Founded in 2005, King Credie Techonlogy Ltd. Has been providing high quality, both quick turn and mid-production PCB services to the industries.Our continuous efforts and determination make us one of the leaders in both qualities and services.In recent years, King Credie Technology Ltd. has diversified our services to include PCB design, PCB and FPC R&D, quick turnkey and volume assembly (PCBA) to better serve all industries; our sales, as well as our reputation, have grown globally. We specialize in multilayer fabrication.

We would be thrilled if you were to send us details of your circuit drawings so that we can then provide you with a detailed quotation. Our quotation will describe the cost and the expected completion of your order. 

Our goal is to continue to improve, be the best manufacturer in our industry and provide our customers a great business experience.

We hope that you will consider our services so that we can help you achieve your goals too.:)