High reliability pcb

Fundamental Characteristics of a High Reliability Printed Circuit Board

Ensuring PCB Reliability: 14 Critical Characteristics for High Performance

Just like in other electronic components, high reliability is the desire and goal for many designers and final users of Printed Circuit Boards (PCBs).  Since all the components are mounted on the PCB, it is expected that the PCB delivers some consistency and efficiency over time depending on operating conditions like temperature and humidity levels. Reliability is, therefore, crucial for any PCB regardless of its use and the stage (assembly stage or manufacturing) where it is used. Consequently, it is important to determine the reliability of PCB materials through testing and through observing the data sheets provided by the manufacturer. Moreover, testing the reliability of a PCB is more critical since all the components are mounted on it.

Please join us as we discuss the 14 most important characteristics of a highly reliable PCB. We are experts in the PCB having served millions of customers for over 15 years in PCB assembly, PCB design, PCB fabrication, and PCB manufacturing. Please visit us today at RUSHPCB.CO.UK and get to know the range of products and services we offer.

  1. Hole wall with copper thickness of 25 microns

Importance

  • Enhances the reliability of a Printed Circuit Board
  • Improves the resistance of the z-axis expansion where PTHs (Plated Through Holes) are metalized and drilled through the material thickness to form ground connections and form signals.

Risks involved if that is not done

  • Blow holes or outgassing causes problems in the electrical conductivity during the assembly process (the cell walls break or inner layer separation)
  • Future possibilities of failure when the PCB is loaded. In this case, we recommend the use of less than 20% copper IPCClass2.
  1. Absence of welding repairs or breaks in line repair

Importance

  • Adhering to these standards ensure that the circuitry is perfect hence increasing reliability and securing.
  • No maintenance is required since welding is done perfectly and there are no repairs needed.
  • Risks like electrical shock due to open circuits are eliminated.

Risk involved if that is not done

  • High chances of failure especially under load conditions since there are repairs involved especially in the panel’s circuitry layout.
  1. Failure to adhere to IPC cleanliness specifications

Importance

  • The cleanliness of a PCB is improved thus its reliability increases appreciably

Risk involved if that is not done

  • The solder resist layer and the residue on the PCB introduce the risk of ionic residues leading to risk of pollution, corrosion of welding surfaces hence low reliability due to bad solders or electrical faults
  • Increases the probability of the occurrence of failure hence low reliability
  1. Controlling the life of treatment surfaces

Importance

  • Increases solderability since the surfaces are well treated
  • High reliability
  • Reduces the risk of moisture intrusion

Risk involved if that is not done

  • The metallurgical processing of old boards changes over time thus solder problems occur
  • Moisture intrusion might lead to delamination during use or during the assembly process or in the inner layer and hole wall separation.
  1. Ensuring CCL tolerances adhere to IPC4101ClassB/L requirements

Importance

  • Controlling the thickness of the dielectric layer reduces the electrical performance’s expected deviation hence high reliability

Risk involved if that is not done

  • Sub-standard electrical performance/ apparatus hence the failure rate increases leading to low values of reliability.
  1. Using internationally recognized base like IEE for the PCB

Importance

  • Improves the performance and reliability of a PCB
  • The calibrations are made according to an international standard hence measurements and operations can be done by an expert from any part of the world.

Risk involved if that is not done

  • Poor mechanical properties lead to underperformance of a PCB hence the expected results like high performance cannot be achieved
  • Frequent breakages, delamination and warpage problems.
  • Impairment of the electrical characteristics of a PCB leading to poor impedance performance.
  1. Defining the mechanical features of the PCB like holes and shapes

Importance

  • It enables the control of the quality of the PCB since the PCB’s dimensions can be improved making it fit to perform the required function

Risk involved if that is not done

  • Assembly problems like alignment or fit which should never occur in professionally designed boards may occur
  • The size of the deviation increases thus increasing the probability of the occurrence of loading shock
  1. Defining solder material and ensuring compliance to the IPC-SM-840ClassT standards

Importance

  • Using a perfect solder material ensures that the resistivity of the solder is high hence the conductivity of the components is not affected. We at RUSHPCB ensure that we use the best solder material which is RoHS.

Risk involved if that is not done

  • Using poor quality solder can lead to anti-corrosion, adhesion and hardness flux problems leading to development of a solder resistive layer in the PCB hence corrosion of the copper circuit
  • Poor insulation characteristics can lead to an electrical short-circuits leading to damage of the PCB components or electrical shock.
  1. Definition of the repair and appearance requirements

Importance

  • Although this is not commonly defined, defining it ensures intensive care and security in the manufacturing process.

Risk involved if that is not done

  • Multiple repairs, abrasions and damage of the PCB can occur such that the aesthetic properties of the PCB are fully destroyed
  • A high risk of electrical shock and short-circuit
  1. Solder resist layer with a thickness similar to that recommended by NCAB

Importance

  • Improvement in the electrical insulating properties of the PCB thus reducing the electrical resistance
  • Reduction of risks of flaking or the loss of adhesion.
  • Higher capacity to fight a mechanical force regardless of its magnitude

Risk involved if that is not done

  • Higher anti-corrosion, hardness flux and adhesion problems leading to problems in the circuit board
  • Corrosion of the copper circuit due to solder resist layer
  • Formation of thin solder due to poor insulation properties hence higher chances of a short circuit leading to an arc or accidental conduction.
  1. Use of peelable gums models and brands like PetersSD2955

Importance

  • Peelable gums can be avoided by the use of better brands. it leads to destruction of the aesthetic features of the PCB

Risk involved if that is not done

  • The peelable glue might melt, foam or solidify such that the adhesive strips down making it ineffective
  1. Requirements of the plug hole depth

Importance

  • High quality jack assembly process reducing the risk of failure

Risk involved if that is not done

  • Hole in the plug may be insufficient due to Immersion Gold Process chemical residue causing weldability issues.
  • The solder balls might splash out during the assembly process leading to a short circuit
  1. The PCB does unit rejection of process plate

Importance

  • Efficiency can be improved by the use of an experience PCB manufacturer, fabricator and designer like RUSHPCB.

Risk involved if that is not done

  • Boards with defect require special assembly procedures thus if one is not sure, the rejection unit (x-out) board should be indicated or avoid putting in isolation due to lagging to avoid wastage of resources
  1. Using NCAB approval procedures for each single order

Importance

  • Implementing the program helps ensure that all specifications are adhered to

Risk involved if that is not done

  • Failing to adhere to specifications might cause deviation in the final assembly

We at RUSHPCB ensure that our boards are highly reliable and of high depending on the specifications of the customer. We love all our customers thus our prices are very fair and this has made us thrive in this industry and experience tremendous growth over years. Please visit us today at RUSH PCB Ltd and place your order today.