Extreme electronics production involves the circuit layout design, production and assembly of a series of key steps.
Once received the recognition from the OEM, word of mouth
Can improve reliability and security of electronic products, from these aspects: PCB layout design, PCB manufacturing and PCB assembly.
Electronic OEM customer service providers should fully explain the importance of the promotion board specifications, moreover, the supplier should be OEM license, so that you can use the update of the specifications of the file to continue production, which in any case is very important.
PCB design working current of a board design for 5 amperes, however, before the PCB layout simulation, had better add a buffer as the working current of the early warning.
As a result, once the board is exposed to extreme heat or harsh environment, its working current rise to 6 to 7 amperes, reaching the limit of its own specifications.
Of course, if the board design for 6 layer board, then you should consider giving the board to add two layers.
Once the signal path between different layers has a possibility of a crosstalk, then increase the two layer can provide more formation.
For the PCB layers is to ensure that the purpose of the signal and relaxed without crosstalk or mixed signal interference, and ensure that the signal SNR in the acceptable range.
The greater the stability of the strata, the better the signal is separated from each other.
On the contrary, if a signal has multiple power supply or separation layer on layer, the layer is not provide stable formation circuit used to limit the noise and crosstalk.
By adding the design of the current and to increase the number of strata, you can board the reliability of about 15% to 20%.
At the finish line on the road,
Especially the clock on a line)
Increase the shielding, can also will increase the reliability of the board by about 15% to 20%.
For rf circuit, increase the aluminum block can make sensitive signals from each other, make the signal transmission become clean.
Shield by preventing digital signal from point A to point B, so as to achieve the purpose of protecting sensitive signal, to ensure that the digital signal is not mixed with analog signals on the board, the signal integrity.
This helped create a clean signal, reduce the crosstalk method can provide more protection for the board.
Other major design include: add multiple redundant mode and high availability, components selection, feedback loop that monitoring circuit, analog/digital signal and extra protection and warning.
Has built-in redundancy of good design even when it is exposed to extreme environment, also can work effectively and reliably.
Under these conditions, many models or redundant functions are the same, compared with products of high quality and high reliability, the cost is not the biggest problem.
A module as the main signal generator circuit.
Once the original module fails, an identical signals generator or backup module inserted, secure a stable and continuous operation.
There are many different kinds of extreme environment application requires multiple modules, two typical example is the military/aerospace electronics and deep well drilling equipment, these products need to be redundant and accurate precision.
Under normal circumstances, the electronic components can be divided into military class and business class, choose the right types can satisfy the requirements of the extreme environment, it is very important.
Military types of electronic components at higher prices, because they made using the extremely strict tolerance and surface treatment technology, which can ensure they work in extreme conditions.
To achieve high reliability requirement, it is best to use the tolerance only 12% of the military class components.
Device packaging material selection is very important.
With silver or gold plated pins of the components can cope with more severe environment, low price, with components of lead alloy and copper alloy pin is more suitable for commercial applications.
So, it is important to study specification table, because components manufacturers usually don't particularly distinguish between military and commercial grade.
Therefore, EMS suppliers and contract manufacturers need to grasp the electronic circuit of professional knowledge, so that they can read a thick data table, understand the difference between military and commercial specifications, different operating ratings and tolerance, eventually make the products meet the requirements of extreme conditions.
In the design of circuit, extreme environment should take feedback loop into consideration.
Signal continuously testing and monitoring in the distance, a feedback loop will provide key data.
For highly complex system, the feedback loop can provide real-time information, to take timely corrective measures when necessary.
Leakage must not fall within the scope of design, reduces the product performance, reliability and repeatability in the bad environment.
Signal to noise ratio, electricity leakage and crosstalk must be strictly controlled, take extra care when design.
Circuit board production circuit board production and layout needs to be fully aware of the material selection.
In the extreme environments of the circuit board are used to determine the material, should choose high temperature resistant material, such as FR4 -
008 or the polyimide substrate, these materials can withstand higher temperatures, won't stratification in extreme environments, will not lead to membrane peeling resistance welding.
Product should be in the military specifications certified production circuit board factory, so that can ensure the optimal quality of circuit board.
Due to extreme environments are often faced with excess heat and temperature fluctuations, plate warping need special attention.
Warp will cut off the circuit connection, damage solder joints, resulting in application of failure.
Compared with conventional circuit boards PCB assembly, commercial application of the circuit board assembly needs more repeatability and reliability.
In order to achieve repeatability, reliability and flow control, use up more efficient than manual placement machine to place components.
The same applies to other automation steps in a circuit board assembly processes.
Using automatic optical inspection system, solder paste thickness tester, thermal analyzer and other assembly devices allow the operator to avoid some problems because of negligence, these problems will lead to the low product quality, reliability is low.
With the correct sound of machinery and equipment, assembly process repeatability is higher, higher reliability, product quality is more manageable.
After the simulation, different assembly step completion requires strict guidelines, the process is in a professional environment test in the laboratory.
First usually want to undertake a variety of tests, including the temperature cycle test, drop and vibration testing, mechanical strength test, etc.
All of these tests shall be conducted in the initial stage of product development, the problem is resolved at an early age.
Anyhow, want to extreme environment of electronic products, need to increase the cost of this OEM need to know.
Should choose can provide design, production and assembly of one-stop service contract manufacturers or EMS providers, because they can fully meet the bad environment of the high demand for electronic products, achieve the result of get twice the result with half the effort.
In addition, has the certification of electronic supplier have the ability to provide high quality PCB and assembly products, such as the IPC level 3, ROHS, etc.
Turn-key Electronics Manufacturing Services for Printed Circuit Boards and Assembly