pcb board assembly file requirements as follow

Pcb Board Assemply File Requirements

Assembly will need a few files in order to start your assembly job.

Remember: Please combine the following files into a single .zip file. You can then upload it to us via our website http://www.pcbgogo.com/c when you are placing an order or email it to me by eva@pcbgogo.com after you’ve ordered. Make sure to put your order number in the subject field. Ex: “Files for order ####-####.”

Bill Of Materials (BOM)

Your BOM describes what parts are required to be placed, and where they should go. A BOM can be provided in a number of formats: .xls, .xlsx, .csv, and tab-delimited. All of these formats can be read and created in Microsoft Excel.

Your Bill of Materials for a Kitted order should include:

• Line / Item #
• Quantity Per (# of instances of a single part number)
• Reference Designator
• Part Number (Digi-Key part numbers are ok)
• Part Description
• Package (QFN32, SOIC, 0805, etc.)
• Type (SMT, through-hole, fine-pitch, or BGA / leadless)

Gerbers

Assembly will require the Gerber files generated by your CAM350 program  (the same files you used for PCB Fabrication). At a minimum, assembly needs the silkscreen, copper (trace), and solder paste (or stencil) layers.

Centroid

Also known as Insertion or pick-and-place or XY data. This is the machine file in ASCII Text format, which should include: X, Y, Theta, side of board (top or bottom), and reference designator. If you cannot generate this file, Screaming Circuits can generate it for you from the Gerber files for an extra charge.

Assembly Drawings, Instructions or Photos

Generally these are not required for assembly, but they do help to ensure all special PCB assembly instructions are carried out properly. If you are requesting any non-standard processes or have ambiguous placements on your board, we strongly recommend you provide any and all drawings, instructions, and photos you have.

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pcb board assembly

In assembly the bare board is populated with electronic components to form a functional printed circuit assembly (PCA), sometimes called a “printed circuit board assembly” (PCBA).In through-hole technology component leads are inserted in holes. In surface-mount technology (SMT) the components are glued on pads or lands on the surfaces of the pcb board . In both component leads are then mechanically fixed and electrically connected to the board by soldering.

There are a variety of soldering techniques used to attach components to a pcb board. High volume production is usually done with SMT placement machine and bulk wave soldering or reflow ovens, but skilled technicians are able to solder very tiny parts (for instance 0201 packages which are 0.02 in. by 0.01 in.)by hand under a microscope, using tweezers and a fine tip soldering iron for small volume prototypes. Some parts may be extremely difficult to solder by hand, such as BGA packages.

Often, through-hole and surface-mount construction must be combined in a single assembly because some required components are available only in surface-mount packages, while others are available only in through-hole packages. Another reason to use both methods is that through-hole mounting can provide needed strength for components likely to endure physical stress, while components that are expected to go untouched will take up less space using surface-mount techniques.

After the pcb board has been populated it may be tested in a variety of ways:

• While the power is off, visual inspection, automated optical inspection. JEDEC guidelines for pcb board component placement, soldering, and inspection are commonly used to maintain quality control in this stage of pcb board manufacturing.
• While the power is off, analog signature analysis, power-off testing.
• While the power is on, in-circuit test, where physical measurements (for example, voltage) can be done.
• While the power is on, functional test, just checking if the pcb board does what it had been designed to do.

To facilitate these tests, pcb board may be designed with extra pads to make temporary connections. Sometimes these pads must be isolated with resistors. The in-circuit test may also exercise boundary scan test features of some components. In-circuit test systems may also be used to program nonvolatile memory components on the board.

In boundary scan testing, test circuits integrated into various ICs on the board form temporary connections between the PCB traces to test that the ICs are mounted correctly. Boundary scan testing requires that all the ICs to be tested use a standard test configuration procedure, the most common one being the Joint Test Action Group (JTAG) standard. The JTAG test architecture provides a means to test interconnects between integrated circuits on a board without using physical test probes. JTAG tool vendors provide various types of stimulus and sophisticated algorithms, not only to detect the failing nets, but also to isolate the faults to specific nets, devices, and pins.

When boards fail the test, technicians may desolder and replace failed components, a task known as rework.

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any pcb board quote and information,pls contact me via eva@pcbgogo.com

The Pcb Board Manufacturing Process

Printed circuit board processing and assembly are done in an extremely clean environment where the air and components can be kept free of contamination. Most electronic manufacturers have their own proprietary processes, but the following steps might typically be used to make a double sided printed circuit board.

Making the substrate

• 1 Woven glass fiber is unwound from a roll and fed through a process station

  

  The above illustrations show an enlarged section of a pcb board .

  where it is impregnated with epoxy resin either by dipping or spraying. The impregnated glass fiber then passes through rollers which roll the material to the desired thickness for the finished substrate and also remove any excess resin.

• 2 The substrate material passes through an oven where it is semicured. After the oven, the material is cut into large panels.
• 3 The panels are stacked in layers, alternating with layers of adhesive-backed copper foil. The stacks are placed in a press where they are subjected to temperatures of about 340°F (170°C) and pressures of 1500 psi for an hour or more. This fully cures the resin and tightly bonds the copper foil to the surface of the substrate material.

Drilling and plating the holes

• 4 Several panels of substrate, each large enough to make several printed circuit boards, are stacked on top of each other and pinned together to keep them from moving. The stacked panels are placed in a CNC machine, and the holes are drilled according to the pattern determined when the boards were laid out. The holes are deburred to remove any excess material clinging to the edges of the holes.
• 5 The inside surfaces of the holes designed to provide a conductive circuit from one side of the board to the other are plated with copper. Non-conducting holes are plugged to keep them from being plated
  

  or are drilled after the individual boards are cut from the larger panel.

Creating the printed circuit pattern on the substrate

The printed circuit pattern may be created by an “additive” process or a “subtractive” process. In the additive process, copper is plated, or added, onto the surface of the substrate in the desired pattern, leaving the rest of the surface unplated. In the subtractive process, the entire surface of the substrate is first plated, and then the areas that are not part of the desired pattern are etched away, or subtracted. We shall describe the additive process.

• 6 The foil surface of the substrate is degreased. The panels pass through a vacuum chamber where a layer of positive photoresist material is pressed firmly onto the entire surface of the foil. A positive photoresist material is a polymer that has the property of becoming more soluble when exposed to ultraviolet light. The vacuum ensures that no air bubbles are trapped between the foil and the photoresist. The printed circuit pattern mask is laid on top of the photoresist and the panels are exposed to an intense ultraviolet light. Because the mask is clear in the areas of the printed circuit pattern, the photoresist in those areas is irradiated and becomes very soluble.
• 7 The mask is removed, and the surface of the panels is sprayed with an alkaline developer that dissolves the irradiated photoresist in the areas of the printed circuit pattern, leaving the copper foil exposed on the surface of the substrate.
• 8 The panels are then electroplated with copper. The foil on the surface of the substrate acts as the cathode in this process, and the copper is plated in the exposed foil areas to a thickness of about 0.001-0.002 inches (0.025-0.050 mm). The areas still covered with photoresist cannot act as a cathode and are not plated. Tin-lead or another protective coating is plated on top of the copper plating to prevent the copper from oxidizing and as a resist for the next manufacturing step.
• 9 The photoresist is stripped from the boards with a solvent to expose the substrate’s copper foil between the plated printed circuit pattern. The boards are sprayed with an acid solution which eats away the copper foil. The copper plating on the printed circuit pattern is protected by the tin-lead coating and is unaffected by the acid.

Attaching the contact fingers

• 10 The contact fingers are attached to the edge of the substrate to connect with the printed circuit. The contact fingers are masked off from the rest of the board and then plated. Plating is done with three metals: first tin-lead, next nickel, then gold.

Fusing the tin-lead coating

• 11 The tin-lead coating on the surface of the copper printed circuit pattern is very porous and is easily oxidized. To protect it, the panels are passed through a “reflow” oven or hot oil bath which causes the tin-lead to melt, or reflow, into a shiny surface.

Sealing, stenciling, and cutting the panels

• 12 Each panel is sealed with epoxy to protect the circuits from being damaged while components are being attached. Instructions and other markings are stenciled onto the boards.
• 13 The panels are then cut into individual boards and the edges are smoothed.

Mounting the components

• 14 Individual boards pass through several machines which place the electronic components in their proper location in the circuit. If surface mount technology is going to be used to mount the components, the boards first pass through an automatic solder paster, which places a dab of solder paste at each component contact point. Very small components may be placed by a “chip shooter” which rapidly places, or shoots, the components onto the board. Larger components may be robotically placed. Some components may be too large or odd-sized for robotic placement and must be manually placed and soldered later.
• 15 The components are then soldered to the circuits. With surface mount technology, the soldering is done by passing the boards through another reflow process, which causes the solder paste to melt and make the connection.
• 16 The flux residue from the solder is cleaned with water or solvents depending on the type of solder used.

Packaging

• 17 Unless the printed circuit boards are going to be used immediately, they are individually packaged in protective plastic bags for storage or shipping.

contact us:

quick turn pcb board make at http://www.pcbgogo.com/c
any quote and information about the pcb board prototype, pls feel free to contact me by eva@pcbgogo.com

pcb printed circuit board prototype TG value

The glass transition temperature (Tg) is an important normative dimension in PCB board for the base material that determines the temperature at which the resin matrix converts from a glassy, brittle condition into a soft, elastic one.

The pcb board Tg value of the base material sets here an upper boundary, at which the resin matrix decomposes and a subsequent delamination occurs. The pcb board Tg is thus not the value of the maximum operational temperature, but rather that which the material can endure for only a very short time. A guideline for a continuous thermal load is an operating temperature approximately 25°C below the Tg.

When the glass transition temperature (Tg) is over 170°C, it is referred to as a high Tg material.

High Tg materials have the following properties:

• high glass flow temperature value (Tg)
• high temperature durability
• long delamination durability
• Low Z axis expansion (CTE)

make pcb board prototype at http://www.pcbgogo.com/c

any quote and information, pls contact eva liang by mail eva@pcbgogo.com

the step when you place an order in PCBGOGO.

the step when you place an order in PCBGOGO.

firstly, you register an account in http://www.pcbgogo.com/c

secondly,we have a instant quote system so that you could make a price quote after import you inquirement abour the pcb board you need .

thirdly, you need to upload pcb gerber file of the pcb board after you import the pcb board inquirement.

fouthly, our order audit will check you gerber file.

fifthly, you can make a payment after the pcb board order have been passed the audit.

and then our factory will handle you pcb board ASAP.

sixthly, you goods made yet will be shiped.

more information, pls contact eva liang via mail: service01@pcbgogo.com

make prototype pcb board at http://www.pcbgogo.com/c

prototype pcb board capability in pcbgogo

prototype pcb board capability in pcbgogo

you can make pcb board as follow:

layer: 1-10 layer pcb circuit board

board thickness: 0.4/0.6/0.8/1.0/1.2/1.6/2.0/2.4 mm

finished coppper thickness: 1 oz, 2 oz, 3 oz.

suface finish: HASL with lead . HASL lead free. Immersion Gold

make pcb board prototype at http://www.pcbgogo.com/c

more information,pls contact eva liang via mail: service01@pcbgogo.com

fast prototype pcb board production.

fast prototype pcb board production.

what urgent pcb board production can you choose in pcbgogo?

1. 24-hour urgent pcb board production time
2. 48-hour urgent pcb board production time
3. normal pcb board production time——3-5days

more information,pls contact eva liang via service01@pcbgogo.com

make pcb board at http://www.pcbgogo.com/c

what advantage do the prototype pcb board manufacturer have ?

what advantage do the prototype pcb board manufacturer have ?

when you place an order in a prototype pcb board manufacture, what service will you be provide?

firstly, you order will be handle at once.you can received you pcb board in a week from quick turn prototype pcb board manufacturer in china.

secondly, the prototype pcb board is fast production as well as high quality. all of pcb board is made by 94v0 fr-4 glass fiber material.

thirdly, we focus on fast production and high quality but also prompt delivery.we have signed a contact with DHL delivery. the DHL will ship the pcb board to you ASAP.

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how to make a prototype pcb board order online ?—— PCBGOGO

how to make a prototype pcb board order?.

firstly, you need to have you pcb board design file,such as gerber file .

secondly,you enter into the pcbgogo website and import your pcb board detail in the quote system (we have a automated instant quote system)

thirdly,you upload you pcb board gerber file in the pcbgogo website.

finally, you need to make a payment by paypal or cash after the audit .

and then you pcb board order have been place in the pcbgogo system. and the pcb board will manufacture soon. you can find all the production in process by you account. and the pcb board will ship to the address in serveral day.

make pcb board at http://www.pcbgogo.com/c

eva liang from pcbgogo.

customized pcb printed circuit board ——PCBGOGO

Today I’m going to show you how to make your very own customized PCB (printed circuit board). All you need are some materials and tools like a: PCB board, A bottle of Ferric Chloride, A mini drill, A small container, A bottle of thinner and Some plastic tweezers. Making your own circuit board only takes a snap, what you need is 30-45 minutes of time. I thought of posting this Instructable since there are only few articles out here in the site about making a customized circuit board.

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