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USB Flash Drive PCB: The Ultimate FAQ Guide

Table of Contents

If you have any question on USB flash drive PCB, you will find the answer right here.

So keep reading to learn more.

What Is A USB Flash Drive PCB?

A USB flash drive PCB is a circuit board that can easily store and connect your data.

For instance, you can use it to store videos, photo, or documents and also connect it to devices such as computers while transferring the data.

 USB Flash Drive PCB
A USB Flash Drive PCB

What Are The Main Layers Within A USB Flash Drive PCB?

Some of the primary layers you will find in a USB flash drive PCB entails the following:

  • Silkscreen layer

On this layer, you will find numbers, logos, symbols, etc. which will help you know the components.

The information also helps you when conducting repairs on the circuit board.

  • Substrate layer

This layer will use fiberglass material to enhance the rigidity of the USB flash drive PCB.

Besides, you will use fiberglass as it gives the USB flash drive PCB strength which in turn minimizes any breakage.

  • Copper layer

Depending on the type of circuit board, the copper layer can be a full copper coating or a copper foil.

For instance, a single-sided USB flash drive PCB has a single copper conductive layer on one side while the other side has electronic parts.

For a double-sided USB flash drive PCB, you have copper layers and components on both sides of the circuit board.

  • Solder mask layer

This layer will sit on top of the copper layer and give the USB flash drive it’s color.

The solder mask layer will prevent short circuits from occurring as the copper layer will not contact the surrounding environment on the USB flash drive PCB.

Besides, it also helps fabricators as they will know where to solder various components on the USB PCB.

This happens since it illustrates the correct placement of the electronic components during soldering.

USB Flash Drive Has Different layers
USB Flash Drive Has Different layers

How Will You Manufacture A USB Flash Drive PCB?

Here is the manufacturing process of a USB flash drive PCB:

  • Design

In this stage, the designer will use PCB design software to design a compatible USB flash drive PCB.

Examples of software they might use include KiCad, Altium Designer, Eagle, etc.

After approval, the designer sends the design to manufacturers as a Gerber file since it is a standard.

  • File to film

The manufacturers apply plotters to form photo films of the USB flash drive PCB since they are accurate and offer more detailed films.

This results in the production of plastic sheets with blank ink to represent the photo negative of the circuit board.

The clear internal areas do not have conductive materials while blank ink represents the presence of conductive copper within the inner layer.

However, the outer layers will apply the opposite pattern as you will etch out the black areas.

This process happens for all layers that you will use within a USB flash drive PCB.

  • Inner layer printing

This stage is where you make the actual USB flash drive PCB and the whole process happens in a dust-free environment.

Also, you will pre-bond a copper layer on the sides of the board.

Clean panels receive photo resist which hardens in the presence of UV light to ensure an accurate match from photo films to photoresists.

Afterward, you use alkaline solutions to wash the board to eliminate unhardened photoresists.

Then you will dry the board.

  • Eliminating surplus copper

This entails using strong chemical solutions to remove excess copper while desired copper will remain intact below the hardened photoresist.

The next stage entails removing the hardened resist using a solvent to reveal the copper below.

  • Layer alignment

In this stage, you use registration holes to align the internal layers to the external layers.

Technicians use an optical punch machine that accurately punches holes to the registration holes.

Besides, you will conduct an automatic optical inspection to ensure there are no defects.

  • Bonding

In this stage, you will bond all layers together by conducting layer-up and bonding processes.

Bonding happens on steel tables composed of metallic clamps to secure the layers hence inhibiting shifting when aligning.

  • Drilling

This entails using drills to bore holes with diameters of up to 100 microns.

Also, you use x-ray locators to precisely identify the area you are to drill.

The holes are where you will place vias and mechanical mountings.

  • Plating

This involves fusing layers by employing chemical depositions.

The chemical paths deposit thin copper on the panel which then fills the holes you drilled earlier.

  • Imaging the outer layer

This entails imaging external panel layers with photoresist opposite to the process you did on the inner layers.

  • Plating

This entails electroplating the board with a thin copper layer.

  • Etching

Tin will protect the copper you want during this phase as you eliminate surplus copper using chemical solutions.

  • Application of solder mask

Here, you will clean and cover the panel with epoxy ink before passing the board in UV light to remove unhardened parts.

  • Surface finish

This entails adding a chemical plate to the panel to give it additional solder-ability.

Besides, there are different surface finish you can apply and this depends on several factors.

  • Silkscreen

This entails applying inkjet markings on the surface of the board with important information regarding the circuit board.

After that, you will coat and cure the PCB.

  • Electrical test

This ensures that the board is fully functional and that it meets the original design.

  • Profiling

This entails cutting the board from the original panel to size.

Which Transmission Lines Can You Find In A USB Flash Drive PCB?

These include the following:

  • Stripline

This transmission line is surrounded by other dielectric materials that suspend between double layers of the ground plane on the USB flash drive PCB.

  • Microstrip line

This transmission line routes to external layers of the USB flash drive PCB.

Also, the dielectric materials will separate it from single ground planes.

What Components Will You Find Within A USB Flash Drive PCB?

Components Of A Flash Drive PCB
Components Of A Flash Drive PCB

The components within a USB flash drive PCB include the following:

  • Capacitors

These parts operate by releasing energy when other parts need it within the USB flash drive PCB.

They perform this task by temporarily storing an electric charge.

  • Resistors

They operate by resisting current flow by releasing power in form of heat.

  • Potentiometers

These parts act as variable resistors.

  • Inductors

When electric current passes through inductors, they generate and store energy as magnetic fields.

  • Diodes

These parts operate by allowing the flow of current in one direction that is to the cathode from the anode.

Also, they produce light when an electric current passes through them.

  • Transformers

These parts operate by increasing or decreasing voltage as they transfer electrical energy between circuits.

  • Silicon-controlled rectifiers

These parts are like diodes and transistors and operate as two transistors.

  • Transistors

These are semiconductors that operate by amplifying or switching power and electrical signals.

  • Integrated circuits

This is an electronic component that you create on small semiconductor materials.

They operate by performing similar functions as large circuits that you make from individual parts.

  • Crystal oscillators

They operate by providing clocks in several circuits that need an accurate time element.

  • Sensors

They operate by detecting environmental changes and producing electrical signals that relate to that change.

The electrical signals they produce then move to other parts on the USB flash drive PCB.

  • Switch and relay

These parts control the flow of current by either opening or closing the circuit.

What Is The Purpose Of Vias In A USB Flash Drive PCB?


Vias will offer a conductive path that allows the electrical signal to pass from one USB flash drive PCB layer to another through plated holes.

The vias enable designers to decrease the trace route distance for it to form a complete connection.

Besides, they come in various forms such as:

  • Through-hole via

This is a common via that you will use on USB flash drive PCBs.

Here, you will drill a hole through the circuit board

  • Blind via

This via starts on the top or bottom side of the USB flash drive PCB but will not go all the way through to the other side.

  • Buried via

This via will connect internal USB flash drive PCB layers and ar important for boards with dense routing.

  • Via-in-pad

These come as microvias of standard through-hole vias with unique positioning on surface mount pads.

  • Microvia

These holes are smaller than 6 mils and entail using laser drills to make them.

They will join two close layers and you can use them on the surface or within the USB flash drive PCB stack-up.

How Will You Test The Quality Of A USB Flash Drive PCB Assembly?

Testing the quality of USB flash drive PCB entails using the following processes:

  • Functional testing

This test will determine whether the USB flash drive PCB is functional.

For instance, you will check to see if it adheres to the project specifications.

You may also check it once it is installed on the customer side to ensure that it complies with standards of quality.

  • In-circuit testing

In this test, you’ll look at component placement and how they sit on the PCB of a USB flash drive.

In addition, an electrical probe test may be used to check for resistance, capacitance, shorts, open ends, and other issues.

Besides, after thoroughly inspecting the design and construction of the USB flash drive PCB, you will undertake in-circuit testing.

  • Automated Optical Inspection [AOI]

When doing a visual examination, experts can still miss certain faults; hence, automated optical inspection eliminates this problem.

The AOI method evaluates the final design of the USB flash drive PCB to an original blueprint and highlights any flaws.

  • X-ray inspection

Several densely-populated elements may be present in complex USB flash drive PCB designs.

Because metallic parts absorb certain x-ray elements, an x-ray examination will aid in verifying solder junctions inside thick regions.

This permits you to see the USB flash drive PCB’s interior parts, connectors, and solder joints.

  • Visual testing

This procedure comprises visually inspecting the circuit board with certified workers.

Furthermore, it is less expensive and simpler to execute than other sorts of testing procedures.

The specialists will look for scratches, joint faults, inadequate mask application, soldering joints, and other physical problems on the USB flash drive PCB.

Functional And In Circuit Testing Are Some Tests Done To Determine Quality Of PCB
Functional And In Circuit Testing Are Some Tests Done To Determine Quality Of PCB

What Colors Are Available For A USB Flash Drive PCB?

A USB flash drive PCB can come in various colors such as:

  • Green
  • Red
  • Blue
  • White
  • Black
  • Yellow
  • Purple
A Green USB Flash Drive PCB
A Green USB Flash Drive PCB

What Silkscreen Printing Methods Are Available For A USB Flash Drive PCB?

These include:

  • Direct legend printing [DLP]

This pricey approach makes use of acrylic paint and inkjet projectors.

It includes the use of CAD programs as well as the exposure of the pigment to UV light.

  • Liquid photo imaging [LPI]

This approach is suitable for screen printing lines that are thicker than 4 mils.

To cure the laminate, you must first coat it with epoxy and then subject it to ultraviolet light.

  • Manual screen printing

This approach can be used if the registration tolerances are less than 0.005″ or if the line width exceeds 0.007″.

Also, this technique necessitates the use of stencils with traces and text information.

Manual screen printing, on the other hand, is challenging to master yet simple to perform.

What IPC Standards Are Important During The Assembly Of A USB Flash Drive PCB?

These include:

  • IPC-A-600

The Acceptability of Printed Boards is represented by this standard.

When the USB flash drive PCB arrives from the manufacturers, the standard scrutinizes it.

  • IPC/WHMA-A-620C

This is the Cables and Wire Harness Assemblies Requirements and Acceptance.

This guideline will be used by CM during the connection manufacturing process.

  • IPC 7711/7721C

Rework, Modification and Repair of Electronic Assemblies is the basis of this standard.

Using the knowledge in this guide, you will mend USB flash drive PCBs to this IPC requirement.

  • IPC-A-630

This IPC represents the Acceptability Standard for Electronic Enclosure Manufacture, Inspection, and Testing.

The CM will resort to this guideline during the fabrication and assessment of the box constructions.

What Types Of USB Flash Drive PCB Exist In The Market Today?

There are various kinds of USB FLASH DRIVE LED PCBs and they are suitable for a variety of applications.

The available types include the following:

  • Single-sided USB flash drive PCB

There is only one substrate on this type of USB flash drive PCB.

It also shields the substrate by using an electrical conductor like copper.

The copper sheet normally has a solder mask on it, while silkscreen coatings are used to designate the electronic parts on the USB flash drive PCB.

The circuitry will be on one face of a single-sided USB flash drive PCB, while the electrical components will be on the other.

Furthermore, this sort of PCB is less expensive to produce than all the others.

Single Sided USB Flash Drive PCB
Single Sided USB Flash Drive PCB
  • Double-sided USB flash drive PCB

The component will be fused to both faces of the substrate, which you will coat with conductive materials.

Furthermore, they are more common than a single-sided USB flash drive PCBs.

Surface mount technology will link the electronic components from one side of the board to the other.

Besides, this method will occupy less space.

  • Multilayer USB flash drive PCB

This type of USB flash drive PCB has more features than a double-sided USB flash drive PCB.

It consists of numerous layers of substrates separated by insulation material into individual sheets.

When it comes to saving space, the multilayer USB flash drive PCB outperforms its double-sided equivalent.

Multilayer USB flash drive PCBs have 3 or more layers and can be used in a variety of applications.

  • Rigid-flex USB flash drive PCB

This PCB combines the characteristics of both flexible and rigid USB flash drive PCBs.

Rigid-flex USB flash drive PCBs allow you to attach rigid and flexible PCBs, which are not possible with regular PCBs.

  • Flex USB flash drive PCB

This type of USB flash drive PCB uses a flexible substrate that can bend into any shape.

Furthermore, they are less expensive to produce than the rigid USB flash drive PCB.

  • Rigid USB flash drive PCB

This type of circuit board includes multiple stiff layers, making it ideal for manufacturing materials that are resilient to fracturing.

Fiberglass is the material you’ll use to construct a rigid USB flash drive PCB.

How Does SMT, Thru-Hole, And Mixed Technology In A USB Flash drive PCB Compare?

Here is how these compare:

This entails placing electronic parts directly on the surface of the USB flash drive PCB.

SMT lowers production costs since no drilling is necessary, thereby you can mount several components per unit time.

In this method, you will use physical leads to mount electronic components on the USB flash drive PCB.

It entails hooking the leads through pre-drilled holes into then soldering them on the other side of the printed circuit board.

  • Mixed Technology

In this method, you will use both surface mount technology and thru-hole technology when placing components on the PCB.

What Is The Cost Of A USB Flash Drive PCB?

The price will vary anywhere from 5 US dollars.

What Factors Affect The Cost Of A USB Flash Drive PCB?

Some of these factors include the following:

  • Available storage

USB flash drive PCBs that can handle a large storage capacity will cost more than those with a small storage capacity.

  • Number of layers

A USB flash drive PCB with many layers costs more than those with fewer layers.

For instance, multilayer USB flash drive PCBs cost more than single-sided USB flash drive PCBs.

  • Finishing

This is the final layer that you can apply to the USB flash drive PCB to increase its longevity.

Some surface finishes cost more than others.

For instance, you will spend more on ENIG [Electroless Immersion Gold] than HASL [Hot Air Solder Levering].

Other types of surface finish include:

  1. Immersion silver
  2. Organic Solderability Preservatives [OSP]
  3. Immersion tin
  4. Electrolytic gold or nickel
  5. Electroless Nickel Electroless Palladium Gold [ENEPIG]
  • Thickness of PCB

Since you will use many laminates and other materials to make thick USB flash drive PCBs, you will end up spending more.

  • Number of parts

Using several parts on a USB flash drive PCB will drive up the overall cost.

  • Customization

If you need to incorporate unique features and components on the USB flash drive PCB, you will end up spending more.

  • Type of material

There are various materials that you can use when fabricating a USB flash drive PCB.

Besides, they all have varying price ranges, for instance, polyimide material is expensive than FR-4.

  • Size of the circuit board

Large USB flash drive PCBs cost more than smaller versions since you are using more materials.

  • Assembly type

It is cheap to use Surface Mount Technology [SMT] than it is with thru-hole technology when assembling a USB flash drive PCB.

The Factors Above Affect The Cost Of A USB Flash Drive PCB
The Factors Above Affect The Cost Of A USB Flash Drive

What Quality Standards Does A USB Flash Drive PCB Comply With?

A USB flash drive PCB has to comply with a set of quality standards to ensure they are safe to use and are functional.

Some of these quality standards include:

  • CE certification
  • Restriction of Hazardous Substances [RoHS]
  • IATF16949 certification
  • Underwriters’ Laboratories [UL]
  • ISO 9001:2008 certification
  • Institute of Printed Circuits [IPC]

For any questions or inquiry about USB flash drive, contact Venture Electronics now.

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