2 oz Copper PCB

In this guide, you’re going to learn everything about 2 Oz copper PCB.

It compares 1 Oz PCB to 2 Oz PCB, benefits, applications, design, and quality standards, amongst others.

So, if you want to be an expert in 2 Oz copper PCB, read this guide.

What is a 2 Oz Copper PCB?

A 2 oz copper PCB is a printed circuit board whose copper weight per square foot amounts to two ounces.

To make this circuit board, copper of two-ounce weight is flattened to form an even surface with square dimensions of one foot.

The resulting thickness of this board type is about 2.8 mils or 70 micrometers.

 2 Oz copper PCB assembly

What is the difference Between the 1 Oz Copper PCB and the 2 Oz Copper PCB?

You find the major difference between the two copper board types is the copper weight used and subsequently the thickness.

The 1 oz copper PCB is made from a flattened copper weight of one ounce over a square foot.

Two ounces used for the 2 oz copper board.

 1 Oz copper PCB

Additionally, you find that a 2 oz copper PCB can conduct more current than a 1 oz copper PCB.

Therefore, you find that the 2 oz copper PCB is used in applications with larger current demands.

How much Space is Required between Copper Paths for the 2 Oz Copper PCB?

The minimum required spacing conditions for the 2 oz copper PCB is7 mils or 0.178 mm.

Space requirements are important considering board management.

They allow for the effective placement of components while enabling easy maneuverability when soldering.

Do 2 Oz Copper PCBs use Vias?

Yes, they do.

You find the through-hole vias, the buried vias, and the blind vias as the types of vias available for the 2 oz copper PCB.

While they both are used differently, they derive the following benefits to the 2 oz copper board.

• They ensure efficient board space management
• Vias allow an increased component density on a 2 oz copper board
• You find wire management is effective with the use of vias
• Using vias reduces the size of a 2 oz copper board allowing for use in miniaturized devices

Are Vias Closed in 2 Oz Copper Boards?

Yes, they are.

Vias are closed to prevent solder material from trickling into them.

Smaller vias are less likely to be filed up with solder than large vias.

Since most vias are conductive, allowing a solder presence within them can result in shorts.

You also find that component connection are interfered with.

However, vias are not merely closed up using a cap or filling them.

The care process has to be undertaken in sealing vias.

The caps might be affected by temperature changes and air movement within the vias tunnels.

 2 Oz copper PCB

How are Vias Sealed in 2 Oz Copper Boards?

Sealing vias involves three approaches that are frequently used.

Vias can be tented, or plugged, or filled.

However, precise instructions have to be used to seal vias to prevent malfunctions.

· Tenting of Vias

Tenting vias is the least costly method of sealing vias.

To tent vias, you use a solder mask to cover the hole of the vias.

However, the solder mask is not entirely dependable and so tenting is mostly recommended for via holes with small diameters.

You find tenting useful in inhibiting the accumulation of foreign particles such as dust into the vias hole.

Additionally, it prevents the formation of unintended board connections that could result in shorts and even board failure.

· Plugging of Vias

Viashole can be plugged with a non-conductive material such as a mask.

A mask is inserted into the vias hole while the annular ring of the vias is covered in the process too.

Plugging is commonly found on 2 oz copper boards where components are surface mounted.

The most common board design featuring plugged vias is the ball grid array.

In this instance, the vias openings are located very close to the ball grid landings.

Plugging prevents the solder residue from trickling into the holes and thus weakening the weld.

· Filling of Vias

You can fill vias with either conductive material or non-conductive material.

Conductive material allows thermal and electrical transfer between boards or layers.

A thermal transfer could be to dissipate heat energy from high power components.

An electrical transfer is needed where you have a component presence on both board sides.

A major limitation of using conductive material as a vias filler is the mismatch of the thermal expansion coefficient.

The conductive material is usually metallic while the walls of the vias are composed of laminated materials.

Metals have higher thermal expansion coefficients than laminates.

Non-uniform expansion can result in cracking of the material confluences.

Non-conductive material involves the use of material with poor electrical transfer properties.

For plated vias, the use of non-conductive filler does not hamper their conductivity as well.

Using non-conductive material offers support to the seal over the vias hole.

What Factors Influence the Current Carrying Capacity of the 2 Oz Copper PCB?

 1 Oz PCB vs 2 Oz PCB

You find that the thickness of the 2 oz copper PCB is the major influence on its current-carrying capabilities.

However, other interventions can be made to increase the amount of current conducted by the 2 oz copper board.

You can increase the width of the copper trace to allow the transfer of larger current values.

However, this measure results in a large board area which limits its density.

Additionally, minimizing the temperature variations on the 2 oz copper board is effectual to its ability to conduct current.

How much do 2 Oz Copper Boards Cost compare to other PCBs?

Copper weighted printed circuit boards have increasing costs with an increase in the weight of copper.

You, therefore, find 2 oz copper PCBs costing more than 1 oz copper PCBs.

Additionally, costs increase due to the increased difficulty in manufacturing a heavier copper PCB.

What Steps are used in the Fabrication of 2 Oz Copper Boards?

To fabricate a 2 oz copper PCB, several different processes have to be carried out.

The processes are carried out for large production cycles and single boards.

With each process, a design objective is achieved.

The fabrication sequence can be described as follows:

• 2 oz copper is prepared alongside other material requirements such as the FR – 4 and reinforced glass.
• Designs are prepared by using computer programs and fed as an instruction to machines
• The prepared material layers are plotted with the required designs using a photo-plotter.
• The inner layers are prepared with materials depending on their application needs
• The fabricated layers are taken to a lamination process to bind them together
• Holes are drilled at the designated points for guiding later processes such as component placement
• Plated through-holes are then made to provide inter later conductivity
• The outer layer is then worked on to finality for the sake of component placement
• Inspection of works is carried out to identify any errors and faults
• The solder mask is laid to coat the copper traces
• A surface finish is applied to the boards
• A legend for the circuit board is printed
• The finished 2 oz copper board is taken for testing
• Successful testing of the board is followed by packaging

Are 2 Oz Copper PCBs available in Multilayers?

Multilayer PCB

Yes, they are.

You can find 2 oz copper PCBs in multilayer formation for up to 20 layers.

Multilayers allow for miniaturization without hampering on the product quality by reducing board composition.

You, therefore, find that performance can be improved through increasing circuit board density by using multiple layers.

How does the Multilayer differ from the Double-sided Board of a 2 Oz Copper PCB?

The double-sided board and multilayer board only differ in the number of layers.

Both the board types have additional components populated layers other than the surface layer.

The double-sided type has both substrate surfaces coated with 2 oz copper to create essentially a two-layer construction.

You find double-sided boards enlisting the use of bias to provide conductive transfers over both surfaces.

With the double-sided layer, the copper paths can be closely spaced by alternating the paths across the two surfaces.

Multilayers are characterized by a configuration of more than two layers.

You find the multilayer with a strong core structure fabricated from 2 oz copper and FR – 4.

The inner layers are furnished from reinforced glass materials.

When multiple layers have been furnished, they are combined through lamination.

The lamination process involves high temperature and pressure treatment that causes the layers to be held together.

The new single and rigid structure is taken for further processing.

How are Components attached to the 2 Oz Copper PCB?

2 Oz copper PCB

The 2 oz copper boards can be surface mounted or have components mounted through-holes.

This means that you can find 2 oz copper PCBs supporting both these types of components.

Through-hole mounted components have leads attached to them for connecting with the board.

The leads are typically wire extensions of the components.

These wires are inserted into holes that are drilled on the board providing a connection.

Through-hole components provide reliability as their connection is strong and able to endure rough handling.

Furthermore, you find through-hole mounted products can easily be replaced without destroying the board.

Surface-mounted components lack leads in the definition of wire extensions.

You instead find surface mounted components with contact surfaces at the base such as ball grid array.

These components are attached to landing pads on the PCB through soldering.

Surface mounting allows for components to be made smaller.

Smaller components utilize less board space.

This is useful in the miniaturization of devices.

Additionally, you find that surface mounting allows for larger board densities.

What are some 2 Oz Copper PCB Specifications?

You the following specifications common for the 2 oz copper PCB:

• A layer count of up to 20 layers
• Panel size of about two feet by two and a half feet
• A 2 oz copper thickness options in material composition
• A minimum copper trace spacing of 7 mils
• Holes of at least 0.15 mm diameter
• Provision of vias for multilayer boards
• Impedance control
• Liquid photo-imagable mask in a variety of colors such as green, blue, and yellow
• Surface finish options of hard and soft gold, immersion or organic solder preservative

How is 2 Oz Copper PCB Board Traces made?

There are two approaches to making the conductive trace of the 2 oz copper board.

These traces provide a circuit path for electrical components.

You find the additive approach and the subtractive approach used in this instance.

· Subtractive Approach

This approach is carried out through an etching process.

In this case, the parts of the copper not in the trace pattern are removed.

The result of this procedure is that you are left with the desired trace patter.

It is this removal of the undesired copper that derives the subtractive definition.

· Additive Approach

This approach can be carried out through several processes.

Plating, conductive paste screening, or insertion can be used.

With the additive approach, the required copper weight is added to the substrate surface in line with the pattern design.

What are some of the Components used on 2 Oz Copper PCB?

You find several different components on a 2 oz copper PCB.

These components can be classified as active and passive components.

Active components include diodes, transistors, and integrated circuit chips.

Passive components include capacitors, resistors, and inductors.

· Electronic Diode

The electronic diode allows the unidirectional flow of current.

This component is useful in protecting circuits from revere voltages.

· Electronic Transistor

This component is used in the amplification and switching of electrical signals.

There are many electronic transistors on a printed circuit board.

These components serve up electrical signals to other passive components ensuring proper functionality.

· Integrated Circuit Chips

These components are varied and with different uses.

They are composed of miniaturized components grown on a die and interconnected to execute a given function.

You can find integrated circuit chips that are used as memory storage for example.

· Electronic Capacitor

The electronic capacitor stores small amounts of electrical charge and discharges them for defined use.

An electronic capacitor can be used to power intermittent light functions among others.

The charge stored by electronic capacitors is derived from a voltage source.

Are Adhesives used in 2 Oz Copper PCB?

Yes.

You will find adhesive useful in 2 oz copper PCBs as they are used to join materials during layering.

There are several adhesives used such as polyimide adhesives, polyester adhesives, acrylic adhesives, and epoxies.

Polyimide adhesives are one of the most common adhesives types flavored for their superior thermal resistance.

Polyester adhesives are synthetic and cost relatively lower than other adhesive types.

Acrylic adhesives are structurally similar to anaerobic adhesives that form tough bonds on polymerization.

Where are 2 Oz Copper PCBs used?

You find several uses of the 2 oz copper PCB.

Printed circuit boards of this copper weight are used in applications requiring medium current requirements.

Some of the uses include:

• Medical equipment such as wireless controllers, pacemakers, and drug delivery systems use 2 oz copper PCBs.
• Handheld units used in telecommunication have components furnished on 2 oz copper boards.
• The automotive industry uses these printed circuit boards in their display screens and music systems.
• Consumer electronic appliances such as televisions and sound systems utilize these printed copper boards.

How is Etching Carried Out in the Manufacture of 2 Oz Copper PCB?

The etching is a process where a design or pattern is created on a surface by using chemical solvents or other means.

In etching, parts that are not part of the design are extracted to leave a desired shape or form.

To perform the etching process a pattern has to be separately developed before application.

Etching in 2 oz copper PCB is carried out in two ways:

· Chemical Etching

In chemical etching, sulfate and chloride compounds are used in the process.

The most commonly used are ammonium sulfate and ferric chloride.

In this case, the pattern is traced on a protective stencil and applied on the copper surface.

The chemical solution is then applied over the surface eating away the unprotected surface.

Also, the remaining surface formation is in the shape of the desired trace pattern.

The desired copper trace can also be electroplated to with tin to act as a resist on the chemical etching agents.

· Laser Etching

Laser etching is a novel technique where the image pattern is directly transferred to the copper surface.

With this process, you find there is a reduced error as observed in the filming process. Also, eliminating transferred imaging simplifies the process.

When the desired trace pattern is directly transferred to the process, strong laser rays are used in the etching process.

The unwanted areas of the surface are precisely cut out leaving the designed copper conductive path.

What Design Assembly Methodology is used for 2 Oz Copper PCB?

The assembly process of the 2 oz copper PCB can be carried out using manual processes or automated processes.

· Manual Assembly

For the 2 oz copper PCB, you find some processes carried out manually.

A notable process carried out manually is the preparation of holes.

This includes the sealing procedure and padding of the holes that ensure good solderability.

It also ensures no entry of solder flows into the holes.

· Automated Assembly

Automated assembly is mainly observed during the placement of components.

Components are attached to the 2 oz copper board by robotic arms before the soldering process is carried out.

For surface mounted components an automated process called reflow is used in soldering.

What are the Limitations Faced in the Assembly Process?

The assembly process is a crucial one not just for the 2 oz copper but other board weights as well.

This process whether carried out manually or automatically is faced with the following limitations.

• The process is limited by the number of components that can be fixed in one single operation.
• The assembly process is inhibited by the size of the panel.
• The assembly process is much more complicated for double-sided board designs.
• The size of the components will greatly limit the assembly process.
• Whereas surface mounted components will be easier to assemble; through-hole mounted components pose a challenge.

What are the Quality Standards of 2 Oz Copper PCB?

Some of the standards provided for the fabrication of 2 oz copper PCB includes:

· ASTM-F1896

With this standard, the methodology of measuring resistivity for the conductive materialsin2 oz copper PCB is provided.

· BS-123100-003

A system of examining quality for rigid single-sided and double-sided 2 oz copper PCBs with non-plated holes.

· BS-CECC-23100-801

This standard defines a quality assessment system that is harmonized for single and double-sided 2 oz copper PCBs with non-conductive holes.

· DD-IEC/PAS-61249-6-3

The specification for glass-based completed woven fabric for 2 0z copper PCB construction.

PD-IEC-61189-3-301

Test procedures for 2 oz copper PCB, electrical materials used, assemblies, and interconnection.

IEC-61188-1-1

This standard is for PCBs such as 2 oz copper and their board assemblies.

It encompasses the design and use of the PCB with the required flatness needed for assembly.

How is 2 Oz Copper PCB Tested?

Testing a 2 oz copper PCB can be carried out by the use of the flying probe test.

Flying probes are attached to cameras and controllers with electrical and mechanical capabilities.

Computer programs are used to instruct the flying probes.

You find that the flying probes can identify misalignment of components and access their leads using vias as reference points.

As the probes examine the board, it connects with sensors to assist in error identification.

These include counters for measuring frequency and multimeters.

Flying probes test a single component at a time while also identifying short and open circuits.

Some of the measures undertaken in the testing process include:

Double sided 2 Oz pcb

· Testing of the Phase Difference

The phase difference measuring unit releases a signal of high-frequency.

The frequency is transmitted between the reference and signal lines determining the phased difference.

· Test of Stress Induced by High Voltage

This test targets the regions not covered by the phased difference measuring unit.

Here, pulses with large voltage values are transmitted to identify the resistance response.

Voltage values are typically over 250 V.

· Detection of Soft Shorts

When a high voltage is applied; parts with soft shorts can burn up in the process.

Detection of shorts allows the areas with sort shorts to be determined without damaging parts.

This can be done by beginning with low voltage values as you progressively make increments.

With the information in this guide, you can choose high quality and reliable 2 Oz copper PCB.