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CAM Procedures
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CAM Procedures - Free PCB File Check-(Design for manufacturability)


CAM Based Quoting: Design for Manufacturability Check

For customers that do not have the printed circuit board specifications available, we will extract the pertinent

information from Gerber data supplied with a request for quote. While we may find some design issues that might

cause your PCB order to be put on CAM hold during this review, because we do not perform our complete CAM

procedure at this time there may be some issues that are not identified until after your order is placed. Please

review the quote carefully for notes regarding the files submitted and to insure that the boards' specifications are

correct.

After Your Order is Placed - CAM Normalization Process:

During the normalization procedure the Gerber files submitted with each order are standardized so that they can

be processed through our automated panelization step as well as through our PCB manufacturing processes.

The Basic Steps of the Normalization Process are:

1.      Re-naming the files to our standard naming convention

2.      Checking to insure that all necessary files are present.

3.      Importing Gerber and NC drill files into our CAD system.

4.      Reviewing that the boards' specifications in the order match the data supplied (based on information in

          Gerber files, non-Gerber prints and other document files).

5.      Preparation of files for Custom Spec orders, there are basic modifications that are made to most every

         set of files received by Advanced Circuits. These modifications are required for our Custom Spec process

         and are not intended to alter the functionality of your design in any way. The following is a listing of some

         of the changes made.

Outer Layers:

1.      Pads are removed for non-plated holes. (Unless pads are greater than .050 larger than the hole size. If

          these holes are placed directly into a copper plane a clearance is created in the plane to avoid exposed

           copper)

2.      Text outside of outline is removed.

3.      The board outline is removed from artwork if present.

4.      Pads are added for all holes that do not have pads for Standard Spec orders as all holes are plated under

          this program.

5.      Copper extensions for gold fingers will be added to connect to gold bus bar.

Inner Layers:

1.      We will add a .020" clearance border around negative inner layers for the outer edge of the board.

          Clearances will be increased to .020" (.010” per side) over the hole size when possible around a drill  hole

          and around the edge of a cutout.  If all of these cannot be done without impacting the connectivity of the

          planes the order will be placed on hold. This is done to accommodate the inner layer clearance

          requirement at least 0.010" from the edge of a hole to any adjacent copper on the inner layers, and to

          prevent exposed copper.

2.      Clearances that are smaller than the hole size are assumed to be intended as direct connections to the

           plane and will be removed.

3.      On boards with edge fingers that will be beveled a .150" clearance will be added along the edge that

          will be beveled. This is required to avoid exposed copper along the beveled edge.

4.      Text outside of outline is removed.

5.      Non-functional pads on positive layers removed.

6.      The board outline is removed from positive artwork if present.

Drill Files:

1.      Non-plated holes are identified and labeled

2.      Drill files are saved in a standard format.

3.      Double drill hits (duplicate drills), and any drill hits with smaller drill hits inside them will be removed.

4.      Drill chart tolerances that are all blank, or +/- 0.0 will be ignored and the order type tolerances will be

           used instead.

Rout Files:

1.      We are unable to use CNC rout files for extracting data

2.      Board outlines on .GKO (Gerber Keep out) layers will need to be verified as the actual outline.

3.      The largest diameter routing bit is 0.093" (used to produce 0.100" spacing), using this bit reduces routing

        costs by allowing multiple panels to be simultaneously routed.

4.      The cutting path that the machine takes is called the NC route path; normally you need not to worry

         about it. You want to relay to manufacturing any specific cutting requirements you might have.

5.      With regard to the board and slot outlines. We would prefer to have these included in the Gerber files

      (solder mask and drill/fab files) with a line width .005" or 0.010". This line width will not affect the board

      price as the board outlines are disregarded when the minimum trace width is determined.

Solder mask:

1.      Clearances are increased to meet a minimum of .005 swell. Standard Spec orders are increased globally

           to achieve this. If copper is exposed an FYI is sent and order will continue to process. Custom Spec

           orders with random clearance issues will be placed on-hold.

2.      Text outside of outline is removed.

3.      The board outline will be added to this layer if not already present. This will be used for reference during

          production


The Following are the Options that KINGRON has available regarding via holes:


"Exposed Vias"

1.      These will be processed with a clearance in the solder mask image that is equal to or greater than the via

            pad size plus .005" solder mask swell.

2.      If you have a requirement other than this we can accommodate clearances as small as the finished hole

          size plus .005" Please include any specific requirement in the fabrication notes and/or order

          documentation.

3.      These can be quoted and ordered with our standard parameters.

4.      Unless prior arrangements have been made the boards will be built based on the solder mask image files

         submitted.

5.      Most design software packages have accommodations for including or excluding the vias from the

          solder mask images.

"Tented Vias"

1.      These will be processed with no clearance in the solder mask image for the the vias.

2.      This will result in the pads being covered with solder mask and the holes may be open, partially plugged

         or completely plugged.

3.      As we do not have dry film solder mask available we cannot offer vias tented in such a way as to

         guarantee that all of the holes will be completely covered.

4.      These can be quoted and ordered with our standard parameters. Unless prior arrangements have been

          made the board will be built based on the solder mask image files submitted.

5.      Most design software packages have accommodations for including or excluding the vias from the

          solder mask images.

"Plugged Vias"

1.      These will be processed with an additional process that will fill the vias with a solid material that will

           prevent solder and air flow thought the vias.

2.      The entire via cavity may not be completely filled.

3.      These orders will require a custom quote.

"Filled Vias"

1.      These will be processed with an additional process that will fill the vias with a solid material that will

           prevent solder and air flow thought the vias.

2.      The entire via cavity will be filled.

3.      These orders will require a custom quote.

Silkscreen:

1.      We increase any text widths below 0.005" to a minimum of .005".

2.      A silkscreen clip layer (Corresponding solder mask layer) is created to eliminate ink on pads. We do not

          add via clearances if the via holes are tented.

3.      The board outline is removed from artwork if present.

4.      Text outside of outline is removed.

Solderpaste:

1.      We delete outside text and panelize if design is ordered as an array.


Panelization arrays: Tab-Route/Score:


What is scoring?

Scoring is a "v" groove cut into the top and bottom surfaces of an array configuration of multiple

PCB's or a PCB with removable rails or frame. The cut depth is set such that the material left is

the lesser of .018" or 1/3 of the finished thickness. When this process is used the printed circuit

boards are typically set up side by side and end to end with no gap between the edges. This

results in the v-grove cutting into the area of the boards, so a .015" clearance between the edge

of the boards and any conductors is required.


How do I indicate score lines?

When placing an order that requires scoring please indicate this requirement by checking the

score option on the order form. If the CAD files supplied with the order already have the boards

step and repeated, indicate the locations of the score line in the fabrication or panel print. If you

are supplying the CAD data as a 1-up image please supply a drawing with the array configuration

that you would like including tooling holes, fiducials and step and repeat requirements.

Our standard score angle is 30 degree (blade angle total), but we can also do a 60 degree angle

at a premium price.

We can set up your scored array for you (Standard and Custom orders), If
we have:

1.      Your single board files (1-up files)

2.      The total number of board in the array and if the number of board in the X direction and the Y direction.

(boards will be placed edge to edge (0 mils between)

3.      The width of the Top, bottom, left, and right rails (standard is 0.5"), if required.

4.      Select scored array on your order.

What is tab routing?

A tab route is used to create arrays, often called "route and retain". The customer can place more

than one board (same or different design) up in a given area in an array or panelized

configuration. This is typically for the convenience of the customer or for assembly requirements

that utilize pick and place machines to load components. The PCB's are then separated by

breaking or cutting the tabs. Tabs are usually 0.100" in width and are placed with at least 1 on

each side of the boards. The tabs are usually .050" is width.

How do I tab rout my board?

We can set up your array for you (Standard and Custom orders), If we have:

1.      Your single board files (1-up files)

2.      The total number of board in the array and if the number of board in the X direction and the Y direction.

          (Please allow 0.100" between your individual boards for tab rout spacing)

3.      The width of the Top, bottom, left, and right rails (standard is 0.5"), if required.

4.      Select tab route array on the order.

When placing an order that requires tab routing please indicate this requirement by checking the

tab rout option on the order form. If the CAD files supplied with the order already have the boards

step and repeated, indicate the locations of the tabs in the fabrication or panel print. If you are

supplying the CAD data as a 1-up image please supply a drawing with the array configuration that

you would like including tooling holes, fiducials and step and repeat requirements.


Tab Rout Spacing:

Please allow 0.100" spacing between your individual pcb boards for tab rout spacing.


·         Artwork, drills and rout will be panelized as required when an array is ordered. Additional tooling holes

 and fiducials will be added upon request.

Unless an array setup is specifically requested the following standards will apply:

·         For tab-rout orders .100" spacing will be added between boards.

·         No spacing between score boards will be added unless there are routing requirement that would

      necessitate additional spacing.

·         .500" rails will be added around entire array.

·         Score lines will extend to the end of the array.

·         Jump scoring will require a minimum of .250" spacing before the start of the score line and .250" past

   the score line.

·         Tooling holes or fiducials will be added per customer specification, in the absence of any specification

   these will be added based on our standard configuration.


If perforated tabs (mouse bites) are requested we will use a .060 tab with two .018 holes in each

tab. The edge of the perforations (mouse bite) holes will be on the edge of the outline.

The files are then saved and stored on our network.

CAM Panelization Process:

During the panelization process the files prepared during the normalization process are copied to

fill our 18" x 24" production panels.

The basic steps of this process are:

1.      Importing Gerber and NC drill files into our CAD system

2.      Step and repeating the images into the usable area (16" x 22") of our production panels.

3.      Adding the panel identification and tooling features to the border of the panels.

4.      Saving the Gerber images of the panel artwork (conductor layers, solder mask images and legend

images) and sending them to the photo department for laser photo plotting.

5.      Saving the NC drill files and placing them on our network so that they will be available for the CNC

 controllers to retrieve

6.      Creating the NC rout programs that are used to add slots, large holes and cut the individual boards from

 the production panels. These are then placed on our network so that they will be available for the CNC

 controller to retrieve.

7.      Preparing the data files used for our Quality Assurance steps. The reference data that is used for

 Automation Optical Inspection (APQI) and Electrical Test (ET) are prepared and placed on our network so that

 they will be available when needed during production.