PCB Glossary

The PCB printed circuit glossary is designed to give you definitions to some of the words and phrases you will come across in doing business with PCB Circuits. While not exhaustive, it provides useful information about PCB circuits, circuit board design, and circuit board construction.

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PRINTED CIRCUIT BOARDS (PCB) GLOSSARY

The copper pad area that remains after a hole is drilled through the pad, measured from edge of hole to edge of pad.

Your inner and outer layer pads should be at least 0.018″ larger than the finish hole size (0.010” for vias). If your design has any pad to trace junction minimum requirement, add that to the above numbers [0.018″ pad + 0.002″ junction should have 0.020″ pad]. This will provide a 9mil annular ring for component pins, 5mil annular ring for vias.

The ratio of the length or depth of a hole to its pre-plated diameter (Example. 0.062″ thick board 0.0135″ drill = aspect ratio of 4.59:1).

Based on the aspect ratio calculation a different product level will be determined.  Below is the maximum aspect ratio allowed for each Product:

Product Maximum aspect ratio
ValueProto 6 : 1
PCBExpress 8.5 : 1
PCBpro 10 : 1
Custom > 10 : 1

Designer tip: Minimizing the aspect ratio of the holes improves through hole plating quality and minimizes the chance of via failures.

The long standing industry standard base PCB thickness is 1/16 inch (0.062″). In addition to the 0.062″ thickness the following thicknesses are also available for “Run as Sent” products: 0.031″, 0.047″, 0.093″, and 0.125″. Overall thickness tolerance is generally within +/- 10% of the given thickness (for 2 and 4 layer boards) and 14% for 6 layer boards.

Additional thicknesses are available through PCBpro and Custom.  Please select the “other” in the thickness dropdown menu and input your custom thickness.  Include all layer thickness requirements on your drawing or “readme”.

Technical information on our laminate materials.

The cutoff time for receiving orders and files for is 4:00 pm (PST) Monday through Friday. The lead time starts the following business day, unless a “hold” occurs.

A clearance (or isolation) is a term used to describe the space from a power or ground layer to a plated through hole. To prevent shorting, ground and power layer clearances need to be a minimum over the finished hole size of 0.020” for our PCBpro and Custom multilayer PCBs and 0.025” for PCBExpress and ValueProto (run as sent) PCBs .

In order to build your printed circuit board correctly, we must be able to identify the correct orientation of your design. Component, layer 1, or ‘top’ layer should read in facing up. All other layers should line up as though looking through the board. Please use layer designators, pass through marks, or correct reading layer text.

The outline or cut line for the printed circuit board made from a single continuous line. This line may not contain any broken/overlapping lines and/or improperly drawn arcs. The outline describes the shape of the board and is required for creating the route program.  Please inspect your outline layer in Gerber format prior to submission.  We will be able to use any outline layer contained on any Gerber layer to create the rout path. For board sizes that are different than the order form, your order may be placed on hold for clarification.

The electrical result of manufacturing a circuit board to meet characteristic impedance specifications. Combination of copper thickness and line width as well as the dielectric thickness and properties of the base material all contribute to the impedance value. The following is a good resource for calculation of impedance: http://www.mantaro.com/resources/impedance_calculator.htm.

Characteristic impedance extends the concept of resistance to AC circuits, describing not only the relative amplitudes of the voltage and current, but also the relative phases. When the circuit is driven with direct current (DC) there is no distinction between impedance and resistance; the latter can be thought of as impedance with zero phase angle.

This is total thickness of copper on the board surface. The value is determined from the copper foil thickness, plus plated copper, minus copper removed during surface preparation. Copper weight is measured in oz /sq foot. 1 oz / sq foot = 0.0012” minimum thickness (height). We offer finished copper weight of 1-oz., 2-oz., and 3-oz.  For multilayer PCBs we offer (1 oz and 2 oz copper layers).

If you need a different finished copper weight, please complete our Custom PCB Quote form.

The voltage which causes tracking after 50 drops of 0.1% ammonium chloride solution have fallen on the material. The results of testing at 3 mm thickness are considered representative of the material’s performance in any thickness. Tracking is an electrical breakdown on the surface of an insulating material. A large voltage difference gradually creates a conductive leakage path across the surface of the material by forming a carbonized track. Performance Level Categories (PLC) were introduced to avoid excessive implied precision and bias. Tracking Index (V) PLC 600 and Greater 0 400 through 599 1 250 through 399 2 175 through 249 3 100 through 174 4 <100 5

The cut line will be used to program the router path and it represents the circuit board outside edge. The tolerance on route dimension is +/- 0.010″. It is recommended to keep outer layer copper 0.010” and inner copper 0.020” from the cut line to avoid exposing copper at the board edge.

This option will date the date code ww/yy to be added to the circuit board for increased traceability. Our standard process will add this in the silk screen, can be added in the copper layer if no silk exists or there is insufficient room.

As part of the PCBpro (NRE) Service, we conduct an engineering design review with a personalized report listing any DFM violations. We inspect the files, readmes, print notes and fab drawings.  We insure that any requirements that are present in this documentation have been selected in ordering.  Any discrepancies will put the order on hold for clarification.  (Please provide any deviations to the documentation in a readme or other such file to keep your order off of hold).  We will perform small edits to the files to make the manufacturable with the highest yields.

The standard retention of quality documents (evidence of test, and inspection) for our product lines is as follows:

Run as Sent (i.e. ValueProto and PCBExpress): Minimum of 90 days

Engineering Review (i.e. PCBpro and Custom):  Minimum of 7 years

*UL orders will retain the documentation for a minimum of 2 years.

PCB1STOP orders do not require drawings or prints. If a drawing is provided with your “Run as Sent” order, the order form will override any details or notes on the drawing that deviate from PCB1STOP Circuits online capabilities and inspection criteria. The order form placed for each “Run as Sent” order is the governing document for orders that meet this criteria.  For PCBpro and custom orders however we will inspect all of the files and documentation present in your order.  If there are discrepancies between the order form and the documentation the order will be placed on hold for clarification.

This is an example of an Excellon drill file format. It will have both X & Y coordinates along with tool sizes.  This will be viewable in any text editor (notepad). This is the file that governs your finished hole sizes and locations.

A Sample Excellon File format:

M48 INCH
LZ T01C0.015
T02C0.031
T03C0.034
T04C0.037
T05C0.052
T06C0.058
%
T01
X00165Y-03805
X0018Y-03235
X00265Y-00704
X00281Y-01349
X00302Y-03816

Text files describing drill tool number, corresponding size, quantity of holes, and if the holes are to be plated or non- plated. (see “Plated through holes (PTH) – Non-Plated through holes (NPTH))

Electrical continuity (opens) and Isolation (shorts) testing of Circuit Boards. A net list is created from the customer supplied gerber files and then electrically compared to the finished pcb. The soldermask layer acts as the mask to determine what points can be tested. In general, endpoints of all of the nets are programmed for testing unless they are covered in soldermask, in which case the closest testable point to the endpoint is tested. The standard testing parameters used are 100 Volts, Isolation Resistance of 10 M Ohms, Isolation Distance 0.050”, and Continuity Resistance of 50 Ohms.

PCB1STOP Circuits uses flying probe (fixtureless) technology to conduct our electrical testing. We recommend testing all surface mount boards and multilayer orders.

It’s not possible to accurately test boards that have silkscreen on pads. It is highly recommended that the silkscreen clip option be selected on electrically tested orders.

A trace that is surrounded by ground fill. These types of features have different manufacturing characteristics that do not behave as traces grouped in tight runs do. The etching of this type of feature is typically slower and as a result we request that a minimum of 0.010” spacing be used from trace to ground fill.

RoHS compliant surface finish, that is also very planar (flat) and durable. ENIG is recommended for tight pitch, ICs and BGA type of technology.  It provides a good solder joint, allows parts to sit very flat, will withstand multiple reflow cycles as well as storage of PCBs.

Electroless Deposition – The deposition of conductive material from an autocatalytic plating solution without the application of electrical current.

Immersion Plating – The chemical deposition of a thin metallic coating over certain basis metals that is achieved by a partial displacement of the basis metal.

Files that are not specifically used in your design, and or an incomplete file set can add delays in terms of holds to your order. Insure that your submitted files are complete and do not contain extraneous files. When ordering a 4-layer board with Soldermask and one side Silkscreen, send in 7 gerber layers and an excellon drill file.

We can output the Gerber RS274X and Excellon Drill files from your Eagle.brd file at no additional charge. Gerbv is a free gerber viewer that will allow you to preview the production files as interpreted by our plotting software.

The Industry standard format for files used to generate artwork necessary for circuit board imaging. PCB1STOP’s preferred Gerber format is RS274X, which places aperture information in the header of each gerber layer file (see Aperture information). If files are not saved in RS274X, PCB1STOP will need one aperture list sent with the files. When your software outputs more than one aperture list we may place your order on hold until we receive your instructions or correctly formatted files.

We can output the Gerber RS274X and Excellon Drill files from your Ivex .brd file at no additional charge. If you choose this option, we will hold your order until you approve the Gerber files generated. Gerbv is a free gerber viewer that will allow you to preview the production files as interpreted by our plotting software. It is highly recommended that you add text to the top layer of any IVEX file to insure that the orientation of your design is correct. Using layer designators is another option.

You can output the Gerber RS274X and Excellon Drill files from your Protel file at no additional charge. Gerbv is a free gerber viewer that will allow you to preview the production files as interpreted by our plotting software.

A patterned arrangement of printed circuitry and components that utilizes flexible base material with or without flexible cover lay.

Flexible circuit boards are often used as connectors in various applications where flexibility, space savings, or production constraints make the use of rigid circuit boards impossible. In addition to cameras, a common application of flexible circuits is in computer keyboard manufacturing; most keyboards made today use flex circuits for the switch matrix. Contact our Support Team and we may be able to recommend a source for Flex parts.

A software tool used to view PCB design output prior to submitting it for fabrication.  Do not just assume that the Gerber files will resemble your design file.  There are quite a few places for errors to occur in the output of Gerbers.

A little extra time spent setting up your software outputs, and confirming they load correctly into a Gerber viewer will insure a working board that will be shipped when you need it.  Gerbv is a free to use Gerber viewer.

Edge connectors electroplated with nickel (Ni) and hard gold (Au), good for wear type applications available for PCBpro and Custom products. (Approx. 200 u” Ni / Min. 30 u” Au). Utilizing industry standard tie-bar plating protocol to allow electro plating of Ni and Au after etching and soldermask application. Price is calculated on the distance (linear inches) between the outside edges of the outermost connector contacts.

Designer tip: May not be suitable for applications where multiple finger lengths are required.

With your Au selection, a standard 30-degree bevel will be added to your edge connector. We can also bevel at 15 or 45 degrees upon request. For multi-layer boards please insure adequate inner layer back set to allow for the bevel requested.

Gold finger connectors typically have the leading edge beveled in order to ease insertion to the mating connector.When this happens, inner planes can have exposed copper if they aren’t pulled back from theedge sufficiently. We will pull your inner layer copper back as shown at the right above in order to avoid having exposed copper at this location. Exposed copper can cause a direct short across all terminals of your connector as it is inserted

The process of adding solder to the exposed copper features of the circuit board. The ratio of Tin to Lead in the deposit is approximately 60%/ 40%. Finished boards are dipped in a molten solder bath and passed through a high pressure stream of hot air to remove excess solder, resulting in a uniform solder layer being applied to all exposed copper surfaces.  HASL is not an ideal choice of surface finish for tight pitch or for ICs and BGAs.  There will be variations in solder height from pad to pad and planarity is not a strength of HASL.  Please select Immersion silver or ENIG for these designs.  Not a RoHS compliant finish.

Cutting of the circuit board to match the outline layer provided. There must be a continuous board outline for our “Run as Sent” products. Selection of Individual Route will result in boards NOT be delivered in a multi-board panel suitable for automated assembly.

Our inspections and conformance criteria are setup based upon “IPC-A-600 Class II.” The inspection methods that we use to insure the quality of your orders can be accessed on our inspections guidelines page.

These are usually solid copper planes of a multi-layer board connected to power or ground.

Designer tip: Make any clearances on these layers 0.020″ for PCBpro and custom 0.025″ for “Run as Sent” (diameter) over the finished hole diameter. Using these clearance guidelines will help you avoid shorts caused by manufacturing variations. (See “Clearances”)

 

Please clarify the correct polarity of your plane layers. The options for polarity are “positive” and “negative”. Positive images show all copper features as features on the gerber plot. Negative images show all features to be removed from the copper.

Designer tip: Any splits in planes should be at least 0.010” wide.

Routing layers composed of signal traces that are contained below the surface layers of your board. These layers are connected to the surface layers by plated through holes and/or vias.

We may remove any pads that are not connected to traces on your internal signal layers in order to expedite the imaging process on Full-Featured Orders. Many customers upload their files with these non-functional pads already removed, which expedites the tooling process. If for any reason, you do not wish these pads to be removed, please clarify this by listing it as a drawing note, or in a “readme” file.

The specified thickness and makeup of the different layers contained in a multi-layer printed circuit board. We offer a variety of specified standard constructionsfor many layer counts and copper thicknesses.  We also allow you to specify a layer stackup (choose non-standard construction).

We do not require you to map the layers from your files during the order process to help save you time.  In order to be sure we build the layers in the correct order, provide a readme with the layer order or name the files in a logical manner.  For example:

copper_top.grb
inner1.grb
inner2.grb
copper_bot.grb
silk_top.grb
silk_bot.grb
smask_top.grb
smask_bot.grb
paste_top.grb
paste_bot.grb
ncdrill.txt
drill_dwg.grb
fab_dwg.grb (not needed if PCB1STOP Circuits manufacturing and inspection criteria are acceptable) May cause delay in processing your order.

The number of conductive layers required for your PCB order.

Designer tip: Text such as company name, logo, or part number that is correct reading on the top copper layer will insure the layers are oriented correctly. This orientation text can be placed inside or outside of the board outline. Text placed outside of the board outline will be used for reference only and deleted prior to manufacture. (see “Component Side”)

You can instantly quote PCBs with up to 20 layers online.  For more than 20 layers a Custom Quote will need to be generated.

Some Customers require a manufacturer’s lot code to be placed on the board for future tracking purposes. A drawing can specify the location, what layer and if it is to be in copper, solder mask opening, or silkscreen (PCB1STOP’s default). The lot code will be your order number and will be applied to the PCBs.

The limitations of a specific manufacturing process that is aimed at consistently producing product with a sufficiently high yield. These specific capabilities may be different for every PCB manufacturer, please follow these in the design portion of your project to help avoid problems down the road.

PCB1STOP Circuits manufacturing capabilities will provide more information.

Trace width and the space between traces are used to define the complexity of your design. We use this information for pricing and to properly align your order in our manufacturing products. The smaller or more tightly packed the features of your board are, the more difficult it will be to manufacture. When ordering your boards you will need to know the minimum trace size as well as the minimum copper to copper spacing present in your design.

“Run as Sent”  product has the capability of 0.005” trace/space while PCBpro can be ordered with 0.004” trace/space. If you need smaller traces or spaces please complete our request for custom quote form.

Due to processing considerations, for our customer’s design files that use cross hatching, our limit for online orders is .010” line/ .010” space cross-hatch pattern.

Designer tip: For traces embedded in ground plane we recommend a minimum spacing from trace to plane of 0.010”

See our manufacturing capabilities chart for more information.

A hole in a printed board that does not contain plating or other type of conductive reinforcement. Generally used for mounting of components to a circuit board or a circuit board to a larger portion of a project.

We recommend that you include a drill drawing to identify the non-plated holes in your design.  Non-plated holes are NOT guaranteed through our ValueProto product line.

Non-Plated holes should maintain a minimum clearance of 0.010” from any conductive surface.

Refers to the cost of creating a new PCB design, which is paid up front with the first order. Contrast with “production cost,” which is ongoing and based on the quantity of material produced. For example, in the semiconductor industry, the NRE is the cost of developing the circuit design and photomasks; the production cost is the cost to manufacture each board.

A hole in a printed board that does not contain plating or other type of conductive reinforcement. See ‘non-plated holes’

This is the total number of holes to be drilled in the board. Please be aware that your board price might change if the number of holes ordered is significantly different than the number of holes contained in your file set.

Custom Quote:

  1. Customer supplied info (P.O., print, readme)
  2. PCB1STOP generated Order form
  3. Customer Specific Specification

PCBpro:

  1. Order form
  2. Customer supplied info (P.O., print, readme)
  3. Customer Specific Specification

ValueProto and PCBexpress:

  1. Order form
  2. PCB1STOP Website

A portion of a conductive pattern usually, but not exclusively, used for the connection and/or attachment of components.  Can refer to a pad for a drilled hole (the copper surrounding the drilled hole on either side of the PCB) or a surface mount pad.

The name or number associated with your printed circuit board design. We use your part number throughout the entire order process for your convenience.  We require a distinct combination of part number and revision for each new part number ordered.

Printed circuit design software developed by PCB1STOP Circuits. This software is Free to download and use, it is integrated into the PCB1STOP Circuits manufacturing process.

A hole with plating on its walls that makes an electrical connection between conductive patterns on internal layers, external layers, or both, of a printed board.

PCBpro Product: All drill sizes will be treated as PTH unless NPTH is specified in the Drawing, Print, Drill file, drill tool description text file, or identified with a special note, for example “ 0.125 holes to be non plated” In addition, landless holes identified in the Gerber files will be treated as non plated: holes without pads, holes designated with a crosshair target, or holes with a significantly smaller pad (i.e. 0.125″ holes with 0.050″ unsupported pads).

“Run as Sent” Product: All holes in the drill file regardless of definition will be treated as plated holes. This means that they will have the hole size increased to accommodate plating, will be drilled at primary drill, and may or may not be plated (depending on presence of pads, proximity to copper features, or size of the drilled hole).

If drawing or tool description is different than the size specified within the drill file, we will use the drill file to determine finished hole size (For “Engineering Review” (NRE) these errors are reported for customer clarification before manufacturing can begin).

All orders placed as “1 layer” will be treated as single sided and the holes barrels will be non-plated.

The number of boards to be ordered.

To see the pricing matrix in the quote process, enter the approximate number of boards needed. The quantity can be changed at any step of the quoting process to meet your needs in terms of price and lead time.

ValueProto Product allows quantities up to 25 pieces. PCBExpress will allow up to 100 pieces and PCBpro will quote quantities up to 10,000 pieces. If you need larger quantities or would like to schedule out shipments, please use our request Custom PCB Quote form.

A text file included in the zip file, providing information needed to manufacture your order. Phone numbers or email addresses of designer or engineer contacts for this project should be included to expedite resolution of any potential manufacturing problems.

Below is a sample Readme:

PCB1STOP Order # (insert order number) ABC Company P/N AB C125 Rev A Please build a quantity of 100 pieces of this 6-layer board. We are requesting 1/2-oz. base copper weight, 0.062″ thick on FR4 material, green solder mask, and white legend. The Gerber files included in this zip are: File Name (description): SR125.CMP Layer 1 (component side) SR125.gnd Layer 2 (ground layer) SR125.IN1 Layer 3 (internal signal) SR125.IN2 Layer 4 internal signal) SR125.VCC Layer 5 (power layer) SR125.SLD Layer 6 (solder side) SR125.CSM (Component-side solder mask) SR125.SSM (Solder-side solder mask) SR125.TSK (Component-side silkscreen/nomenclature) SR125.BSK (Solder-side silkscreen) SR125.DRL (Excellon drill file) SR125.TOL (Drill tool description) SR125.APT (Aperture information) SR125.DWG (Drawing or print) Any technical questions can be referred to johndoe@abc.com (your email address). My contact number is 555-555-1234 (your number).

Readme files in “Run as Sent” orders will not be used in tooling of your order.

The number of iterations a particular part number has been through to reach the current level of development.  We require a distinct combination of part number and revision for all new PCB orders.

In order to assure that the correct files are used in manufacturing, please indicate your revision number as well as the part number. The part and revision number should be included in your drawings and readme. Please change revision in all locations of your files, drawings, and readme’s to avoid confusion. (Most of the missed changes occur in the document header, or a generic print that was not updated.)

The demand for Rogers materials is continuously on the rise. In With the wireless communications industry rapidly evolving, this type of demand is becoming extremely common. Nearly all radio frequency (RF) devices used for test equipment specify Rogers materials. With its impressive and efficient dielectric constant, Rogers PCBs allow for very little current impedance. As a result, it has become the material of choice for designers developing high speed circuits.  Sunstone offers a variety of Rogers materials (RO4000 series, RO5000 series and RO6000 series).

RoHS is the acronym for Restriction of Hazardous Substances. RoHS, also known as Directive 2002/95/EC, originated in the European Union and restricts the use of specific hazardous materials found in electrical and electronic products. All applicable products in the EU market after July 1, 2006 must pass RoHS compliance.

In an effort to support the RoHS initiative, PCB1STOP Circuits offers several options that comply with the directive. All of the laminate material, soldermask material, and silkscreen material supplied are compatible for assembly at lead free solder temperatures and do not contain (above the upper limits) any of the restricted materials. There are several options for surface finishes for RoHS compliance: Immersion silver, ENIG, OSP and electrolytic gold

RoHS compliance applies only to the printed circuit board “as shipped” and PCB1STOP Circuits retains no responsibility for RoHS compliance of the printed circuit board after any subsequent processing or component placement by our customers or their assemblers.

Marking ink used to identify components location during the assembly and troubleshooting processes. This can be placed on one or two sides of the printed circuit board depending on the board design and application.

Minimum line width for silkscreen legible printing is 0.006″. Any lines drawn smaller may result in missing or illegible marking on your boards.

White is the standard silkscreen color used. Yellow and black are also available.

Immersion silver is one of the RoHS compatible surface finish alternatives available.  Immersion is very planar (flat) and recommended for tight pitch components, ICs and BGAs.  Immersion silver is limited in its shelf life and sensitivity to UV light, handling, humidity, solvent exposure and heat exposure.  May not be an ideal finish for PCBs that are planned for longer term storage.  PCB1STOP recommends that any silver parts being stored to be vacuum sealed and stored in a controlled environment.

Printed circuit board with copper on only one side. Usually with through hole technology, the copper will be on the solder side, opposite any component placement. All through holes will be Non-plated. Solder pads should be oversized in order to provide adequate mechanical support for component leads. Pads that are too small can be easily torn from the pcb substrate.

With surface mount technology the copper layer is on the component side, or top of the board.

To avoid your job being put on hold, please use text to label your copper layer. This simple addition will avoid confusion about orientation of the copper and drill files.  If your copper layer is to be on the component side, with components placed on top of the board as designed, text should be right reading. If copper layer is the bottom layer, opposite your components, text should be left reading (reversed) as seen looking down through the board. (see “Component Side”)

The maximum overall single board X and Y dimension measured at the supplied board outline. Irregularly shaped boards are measured from the farthest extents of the board outline.

All dimensions can be input in either inches (Imperial) or millimeters (metric).

The following are the board size limits for each product:

ValueProto: 12″ x 14″

PCBExpress: 14″ x 18″

PCBpro: 16″ x 22″

Custom: > 16″ x 22″

Defined as the size of the smallest drilled hole present in the design.

Please make sure that all of your holes are present in your Excellon drill file.

Soldermask serves 2 basic purposes.  It protects the circuitry from solder during a wave solder process, keeps the solder from bridging gaps between nets, and it protects the copper from oxidation and corrosion.

PCB1STOP uses Tayio PSR BN-4000 liquid photoimagable (LPI) soldermask.

We recommend the following soldermask clearances for pads

  • “Run as Sent”: +0.006”to 0.010” (diameter).
  • PCBpro: +0.00 to 0.010” (diameter).

Please note: While we make every attempt to leave a soldermask “dam” between surface mount pads, fine pitch areas may be relieved in strips. Our manufacturing process needs at least 0.005″ (“Run as Sent”) or 0.004” (PCBpro) mask “dam” between pads in order to adhere to the board. Pad-to-pad spacing less than 0.013″ may not have soldermask between them.

Green is the industry standard default solder mask color. We have additional options for colors as well: red, black, blue, white and clear.

The sole purpose of a stencil is to transfer solder paste to a bare circuit board. A stainless foil is laser cut creating an opening for every surface mount device on the board. Once the stencil is properly aligned on top of the board, solder paste is applied over the openings (making a single pass, using a metal squeegee blade). When the foil is separated from the board, bricks of solder paste remain, ready for placement of the SMD. This process, as opposed to hand soldering methods, ensures consistency and saves time.

Foil thickness and aperture opening size control the volume of paste deposited on the board. Too much solder paste causes solder balling, bridging, and tomb-stoning. A lack of solder paste creates insufficient solder joints. All of which compromise the electrical functionality of the board.

Proper foil thickness is chosen based on the types of devices being loaded on the board. Component packages such as 0603 capacitors or 0.020” pitch SOIC’s, will require a thinner stencil than larger packages such as 1206 capacitors or 0.050” pitch SOIC’s. Stencil thickness ranges from 0.001” to 0.030”. The typical foil thickness used on the majority of boards is anywhere from 0.004” to 0.007”.

The pitch of the surface mount is defined as the dimension, in inches, from center to center of adjacent surface mount pads. (When the conductors are of equal size and their spacing is uniform, the pitch is usually measured from the reference edge of the adjacent conductors.) Standard pitch is >0.025″, fine pitch is 0.011″-0.025″, and ultra fine pitch is <0.011”.

A method of forming an array of PCBs for automated assembly, utilizing a routing bit. A 0.100” routing path is formed around the perimeter of your board, leaving a narrow, (usually 0.100” wide) tab of material attaching the PCBs to each other and to the panel border. Tab-route is available through PCBpro and Custom Quote Product lines and requires an NRE.

When this service is selected on the order form, we will step and repeat individual images to fill a 12″x14” (approximately) panel. These panels will have a standard space of 0.1” apart, with 4 (0.1”) tabs positioned at our discretion along the edges, and surrounded by a 0.5″ border.

If you have specific panel requirements such as “Perf” holes, Fiducials, or tooling holes, you will need to provide a detailed panel drawing with your board files.

In the printed circuit board production process there are process variation and equipment capabilities that can add some degree of error to a specific step.  Some of these are drill machine X & Y true positional tolerance, drill bit deflection, layer to layer registration, rout tolerances and plating allowances. The specific values will vary by board manufacturer.

The following tolerances have been calculated based on all of the tolerances that may affect the items and ask that printed circuit board designs allow for these processes (to list just a few see manufacturing capabilities for a complete list):

  • Outer layer pads should be 0.017” more than the drill holes (if you have to go a mil or two less try using teardrop shaped pads to limit the amount of breakout that could occur at the pad / trace junction).
  • Inner layer clearances should be 0.025” more that the drill holes.
  • Copper features should be 0.010 away from the rout line for outer layers, and 0.025″ for inner layers.

These are the conductors of the printed circuit board.”Run as Sent” product has the capability of 0.005” trace/space while Pcbpro can be ordered with 0.004” trace/space. If you need smaller traces or spaces please complete our request for Custom Printed Circuit Board Quote form.

Due to processing considerations, for our customers design files that use cross hatching, our limit for online orders is 0.010” line/ 0.010” space cross-hatch pattern.

Designers Tip: For traces embedded in ground plane we recommend a minimum spacing from the trace to the plane of 0.010”

PCB1STOP’s UL File Number E58527. We will mark your boards with our UL identification and 94V-0 flammability rating.

Rather than completing a route path around the board edge, the edges are “scored” to allow breaking boards apart after assembly. This is another way to palletize / panelize the boards (see Tab Routing).

This method creates two beveled scoring lines along the perimeter of your boards. This makes it easier to break apart the boards at a later date. You would receive your boards in panel form like tab routing (see Tab Routing). Be sure to check with your assembly house for any special needs they might have.

Holes for which are designed to move current from one side of the board to the other and not to have a component or lead inserted.

All files needed for the processing of your printed circuit board order must be compressed into a zip file. Due to the large amount of orders received, we are not able to accept individual layer files sent to us. Winzip or Pkzip can be downloaded online.