Mon - Thur 7.30-15.30   Fri 7.30-14.00

What is plasma cleaning?

Blog, Plasma, Plasma cleaning

Plasma cleaning is a process of using plasma energy to clean and modify the surface of a substrate like a circuit board assembly.

It is a highly effective surface cleaning and treatment process before application of conformal coatings and is gaining more popularity due its highly effective performance.

Plasma cleaning is a process of using plasma energy to clean and modify the surface of a substrate like a circuit board assembly. It is a highly effective surface cleaning and treatment process before application of conformal coatings and Parylene.
Plasma cleaning is a process of using plasma energy to clean and modify the surface of a substrate like a circuit board assembly. It is a highly effective surface cleaning and treatment process before application of conformal coatings and Parylene.

What is Plasma?

Plasma is the energy-rich gas state (also known as the fourth state of matter) that can be used to modify the surface of a product to improve its performance.

Plasma technology is based on a simple physical principle.

Matter changes its state when energy is supplied to it. Solids become liquid. Liquids become gas.

If additional energy is then fed into a gas by means of electrical discharge it eventually ionises and goes into the energy-rich plasma state, plasma is created.

This modification can be improving the adhesion of a conformal coating or change the surface characteristics of the board.

How is Plasma used for improving the performance of coatings with printed circuit boards?

For electronic circuit surfaces, plasma treatment can be used in two highly effective ways.

That is it can:

  • Clean the surface of the circuit board. The surface will be free of residues and 100% contamination free including release agents and additives.
  • Activate the surface of the circuit board assembly. This will allow easier bonding and better adhesion of conformal coatings.

These properties make it an interesting technique for improving the surface performance of an electronic circuit board.

In fact, plasma treatment can clean, activate or coat nearly all surfaces. These surfaces include plastics, metals, (e.g., aluminum), glass, recycled materials and composite materials.

This means the plasma process can be highly effective on many different products.

For electronic circuits, plasma treatment can be used in two highly effective ways. First, it can clean the surface of the circuit board. Second, it can activate the surface of the circuit board assembly to allow easier bonding and better adhesion of conformal coatings and materials like Parylene.

For electronic circuits, plasma treatment can be used in two highly effective ways. First, it can clean the surface of the circuit board. Second, it can activate the surface of the circuit board assembly to allow easier bonding and better adhesion of conformal coatings and materials like Parylene.

What are the typical plasma processes available for surface treatment?

There are traditionally three types of plasma treatment:

  1. Low-pressure plasma
  2. Corona treatment
  3. Atmospheric pressure plasma

Low-pressure plasma

These plasmas are generated in closed chambers in a vacuum (10-3 to 10-9 bar).

They can be used in conjunction with Chemical Vapor Deposition (CVD) coatings like Parylene before application.

Corona treatment

Corona treatment (corona process) is a physical process involving high voltage and is mainly used for treatment of films.

This is normally not suitable for electronic circuit boards.

How is the plasma applied to a circuit board to clean and activate the surface?

For materials like liquid conformal coatings then atmospheric pressure plasma is an excellent process for cleaning surfaces and improving adhesion and surface energy performance of circuit boards for conformal coatings.

Atmospheric plasma is generated under normal pressure. This means that low-pressure chambers are not required.

The plasma is created with clean and dry compressed air and does not require forming gases. It is possible to integrate plasma directly into manufacturing processes under normal pressure conditions.

Typical plasma components used for cleaning surfaces on circuits are:

  • Plasma jets (nozzles) to apply the plasma to the surface of the circuit board. They could be controlled by a robotic system.
  • The plasma generators that create the plasma to clean or supply the coatings as required. They provide output power and, in conjunction with complete pretreatment stations, assume various control functions.
  • The process monitoring that controls the nozzles, the movement of the system and the quality of the output.

These three parts form the plasma cleaning process.

For Chemical Vapor Deposition (CVD) coatings like Parylene then low-pressure plasma can be used in the chamber before application.

These plasmas are generated in closed chambers in a vacuum (10-3 to 10-9 bar).

Want to know more about plasma cleaning and conformal coating performance?

Contact us now to discuss what we can offer you in terms of cleaning fluids from our Surclean range of materials.

Give us a call at (+44) 1226 249019 or email your inquiries at sales@schservices.com

How to clean “no clean” flux residues and get it right

Blog

Cleaning the residues left behind by a no clean flux process is one of the most difficult tasks when considering cleaning.

After all, the residues left on the circuit board are not formulated to be cleaned away easily.

How do you clean no clean flux residues if you need to?

Whether a flux residue can be cleaned effectively depends on the cleaning materials saponification factor and its compatibility with the residues.

Saponification is the ability of the no clean residues to be softened to the point of being able to be dissolved by the alkali content (the saponifier) of the cleaning chemistry. The higher the saponification factor of the cleaning fluid the easier it is to clean the residues.

So the key here is to ensure that the saponifier completely dissolves the residues.

What happens if the residues are only partially dissolved?

A no-clean residue that is only partly cleaned away may be far worse for a printed circuit board assembly (PCBA) than a no-clean residue left untouched.

One of the reasons is because lead free flux activators are more active than those in earlier leaded flux formulations.

In a no clean flux, when un-cleaned, the residues are locked up in the carrier resin matrix. They are stable (benign) at normal operational temperatures and therefore will not leach out dangerous residues and cause corrosion problems.

However, if the protective matrix around the residue is partially removed by an inadequate cleaning regime, then the activators could be exposed.

This may lead to a corrosion process starting on the circuit board. Further, this process could be accelerated in the presence of heat, power on the boards in service or high relative humidity.

So how do you clean “no-clean” residues?

It is important when considering cleaning “no-clean” residues on a circuit board that you consider three points:

  1. Can you actually clean the residue to be cleaned effectively?
  2. Have you matched the cleaning chemistry with the relative degree of difficulty and the available process?
  3. Have you validated the whole process by careful testing?

Consider these three points and it may help you be successful. Not considering these three points could easily lead you to having real problems in the long term.

Want to know more about cleaning no clean fluxes or cleaning circuit boards? 

Contact us now to discuss what we can offer you in terms of cleaning fluids from our Surclean range of materials.

Give us a call at (+44) 1226 249019 or email your inquiries at sales@schservices.com

The ABCs of Atomic Layer Deposition (ALD)

Blog, Uncategorized

What is ALD?

Atomic Layer Deposition (ALD) belongs to the family of Chemical Vapour Deposition methods (CVD).

It is a deposition process at a nano-scale level within an enclosed vacuum chamber.

The deposition process forms ultra-thin films (atomic layers) with extremely reliable film thickness control.

This provides for highly conformal and dense films at extremely thin layers (1-100nm).

What coatings are deposited in ALD?

ALD principally deposits metal oxide ceramic films.

These films range in composition from the most basic and widely used aluminum oxide (Al2O3) and titanium oxide (TiO2) up to mixed metal oxide multilayered or doped systems.

How does ALD work in practice?

The ALD deposition technique is based upon the sequential use of a gas phase chemical process.

Gases are used to grow the films onto the substrate within a vacuum chamber.

The majority of ALD reactions use two chemicals called precursors. These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner.

Through the repeated exposure to alternating gases there is a build up of a thin coating film.

Where is ALD used?

ALD is used in many different areas including:

  • Micro-electronics
  • Semiconductors
  • Photovoltaics
  • Biotechnology
  • biomedical
  • LEDs
  • Optics
  • Fuel cell systems
Advantages and disadvantages of ALD

Advantages

  • Self-Limiting. The ALD process limits the film thickness. Many other processes like Parylene are dependent upon amount of dimer and will continue to deposit successive polymer layers until it is completely used up.
  • Conformal films. ALD film thickness can be uniform from end to end throughout the chamber. Other coatings like Parylene can have a varied coating thickness across the chamber and the devices being coated.
  • Pinhole free. ALD films can be pinhole-free at a sub-nanometer thickness. Parylene and some other materials are only pinhole-free at micron levels.
  • ALD allows layers or laminates. Most other films including Parylene are single component layers.

Disadvantages

  • High purity substrate. This is very important to the quality of the finish similar to many other vapour deposition processes.
  • ALD Systems can range anywhere from $200,000 to $800,000 based on the quality and efficiency of the instrument. This tends to be 3-4 times the prices of a Parylene system.
  • Reaction time. Traditionally, the process of ALD is very slow and this is known to be its major limitation.
  • Masking challenges. The ALD masking process must be perfect. Any pinhole in the masking process will allow deposition beyond the masking barrier.
What are some of the ALD coatings that can be deposited?

A wide variety of chemistries are possible with Atomic Layer Deposition.

They include:

  • Oxides
  • Nitrides
  • Metals
  • Carbides
  • Sulfides
Want to know more about Atomic Layer Deposition (ALD) coatings?

Contact us now!

Call us on +44 (0) 1226 249019, email your requirements on sales@schservices.com

What is Plasma coating?

Blog, Plasma, Plasma coating

Plasma treatment of the surface of a circuit board before conformal coating

Plasma coating is the application of a nano-coating material onto a surface via a plasma.

Using a jet nozzle the material is supplied to the plasma. Next, the plasma excites the material and this increases the coatings reactivity.

This extra reactivity allows the material to optimally cover the surface of the substrate and bond much tighter.

The plasma coating process can be adjusted individually to the substrate. It can be used to coat different materials like metals, glass, ceramics and plastics.

These nano coatings can be made to be hydrophobic (water repellent) and hydrophillic (water absorbant) depending on your requirements.

Examples of plasma coating applications include:

  • Improvement of barrier characteristics of plastics for packaging
  • Improved paint application with long-term stability and resulting high flexibility in manufacturing
  • PT Release coatings, for injection molding tools, allow a high number of process cycles without the components having to be stressed with release agents that contain silicone.
  • PT Bond coatings assuring long-term adhesion in the adhesive joint.
  • Corrosion protection coatings that offer extremely high corrosion protection with long term resistance to corrosive electrolytes (especially for aluminum alloys) because of their good barrier effect

 

Want to know more about plasma coating and protecting your products?

Contact us

Call us on +44 (0) 1226 249019, email your requirements on sales@schservices.com

The ABCs of plasma cleaning for conformal coating

Blog, Plasma cleaning

The ABCs of plasma cleaning for conformal coating

Plasma cleaning is a process that is gaining more popularity in thin film applications due its highly effective performance on cleaning and modifying surfaces.

It is also a highly effective surface cleaning and treatment process before application of conformal coatings.

Plasma circuit treatment of circuit board narrow

What is Plasma?

Plasma is an energy-rich gas state that can be used to modify the surface of a product to improve its performance. This modification can be improving the adhesion of a conformal coating or changing the surface characteristics.

Plasma technology is based on a simple physical principle.

Matter changes its state when energy is supplied to it. Solids become liquid. Liquids become gas.

If additional energy is then fed into a gas by means of electrical discharge it eventually ionises and goes into the energy-rich plasma state, the fourth state of matter.

Plasma is created.

How can Plasma be used for cleaning printed circuit boards?

 

Plasma treatment can clean, activate or coat nearly all surfaces. These surfaces include plastics, metals, (e.g., aluminum), glass, recycled materials and composite materials. This means the plasma process can be highly effective on many different products.

For electronic circuit surfaces, plasma treatment can be used in two highly effective ways.

That is it can:

  1. Clean the surface of the circuit board to be 100% contamination free. The surface will be free of residues and contamination including release agents and additives.
  2. Activate the surface of the circuit board assembly to allow easier bonding and better adhesion of conformal coatings. It can change the surface energy of the surface to ensure complete adhesion is possible and in some cases it can make materials bond where it was previously impossible.
  3. These properties make it an interesting technique for improving the surface performance of an electronic circuit board.

What are the typical plasma processes available for surface treatment?

There are traditionally three types of plasma treatment:

  1. Low-pressure plasma
  2. Corona treatment
  3. Atmospheric pressure plasma

Low-pressure plasma

These plasmas are generated in closed chambers in a vacuum (10-3 to 10-9 bar).

They can be used in conjunction with Chemical Vapor Deposition (CVD) coatings like Parylene before application.

Corona treatment

Corona treatment (corona process) is a physical process involving high voltage and is mainly used for treatment of films.

This is normally not suitable for electronic circuit boards.

Atmospheric pressure plasma

Atmospheric plasma is generated under normal pressure. This means that low-pressure chambers are not required.

The plasma is created with clean/dry compressed air (plant air) and does not require forming gases. It is possible to integrate plasma directly into manufacturing processes under normal pressure conditions.

This is an excellent process for improving adhesion and surface energy performance of circuit boards for conformal coatings.

How is the plasma applied to a circuit board to clean it?

Typical plasma components used for cleaning surfaces on circuits are:

  • Plasma jets (nozzles) to apply the plasma to the surface of the circuit board. They could be controlled by a robotic system.
  • The plasma generators that create the plasma to clean or supply the coatings as required. They provide output power and, in conjunction with complete pretreatment stations, assume various control functions.
  • The process monitoring that controls the nozzles, the movement of the system and the quality of the output.
  • These three parts form the plasma cleaning process.

What sectors is plasma treatment used?

different technologies that have been plasma cleaned or treated

There are many sectors that plasma cleaning is used for improving conformal coating performance.

They include:

  • Automotive
  • Telecommunications
  • Mobile phone and Tablets
  • Aerospace
  • Military
  • Transport
  • Consumer goods
  • Life sciences
  • LED Coating

Want to know more about plasma cleaning and conformal coating performance?

Contact us

Call us on +44 (0) 1226 249019, email your requirements on sales@schservices.com.

 

0
  • Your current order total is £0.00 — you must have an order with a minimum of £75.00 to place your order.
0
Your Cart
Your cart is empty
Continue Shopping
  • Your current order total is £0.00 — you must have an order with a minimum of £75.00 to place your order.
Calculate Shipping
  • Your current order total is £0.00 — you must have an order with a minimum of £75.00 to place your order.

Conformal Coating UK