Easily measure the hydrogen peroxide concentration in acidic etching baths for PCB manufacture
18 June 2003
Manufacturing / Production Technology, Hardware & Services
The PCB manufacturing industry uses etching baths based on sulphuric acid for various production processes, such as the manufacture of through-hole plating for multiplayer PCBs (black-hole method) the 'microcleaning' stage and for pre-treatment (pre-etching) during track formation. In most cases, the etching baths consist of an approximately 8,5% sulphuric acid (H2SO4) solution, with a hydrogen peroxide (H2O2) component of about 25 g/litre.
The concentration of hydrogen peroxide, in particular, is decisive for the quality of the product, and should be kept as nearly constant as possible. Depending on the number of boards being processed, this concentration diminishes as a result of dispersal and decomposition.
It is usual practice that several times a day, depending on the throughput and the operational life of the plant, technical staff carry out laboratory tests (titration of a sample with a potassium permanganate solution) to determine the hydrogen peroxide concentration. The disadvantage of this method is that isolated manual dosing causes overdosing of hydrogen peroxide at some times, and insufficient dosing at other times. In order to achieve a consistent rate of etching, and with it a consistent PCB quality, the hydrogen peroxide concentration should be kept constant by continuous automatic dosing.
ASSTech Process Electronics & Instrumentation says that the new Jumo Corrotode, can fulfil this task of measuring the hydrogen peroxide concentration. The Corrotode is a potentiometric sensor (CPPS = corrosion potential-based potentiometric sensor) with an output signal covering a voltage range of several hundred mV. Evaluation and control are performed by a transmitter with integrated control contacts. An attached dosing pump supplies hydrogen peroxide from a reservoir.
For more information contact Anastas Schnippenkotter, ASSTech Process Electronics & Instrumentation, 011 794 7057.
Further reading:
Outscale your competition
Manufacturing / Production Technology, Hardware & Services
Attendees will be able to explore the benefits of AMD Kintex UltraScale+ Gen 2 FPGAs in high-performance Pro AV, test & measurement, industrial, and medical applications.
Read more...
MTN SA Foundation drives youth pathways into the digital economy
Manufacturing / Production Technology, Hardware & Services
The MTN SA Foundation, in partnership with Helios Towers and Datacomb Development Hub, has launched the MTN–Helios Towers 12-month ICT Learnership Programme, a pathway that takes young South Africans from digital training into real workplace experience.
Read more...
Downstream demand, system reliability, and the expanding role of engineering-led distribution
Manufacturing / Production Technology, Hardware & Services
[Sponsored] As South Africa’s semiconductor demand continues to be shaped by downstream system deployment rather than upstream fabrication, the importance of engineering-led distribution will continue to grow.
Read more...
The impact of harsh environments and ionic contamination on post-reflow circuit assemblies
MyKay Tronics
Manufacturing / Production Technology, Hardware & Services
There is well documented historical proof that post-reflow circuit assemblies, when subjected to harsh environments, are particularly vulnerable to failure mechanisms, but modern electronic assemblies are far more susceptible to this phenomenon.
Read more...
Engineering copper grain structure for high-yield hybrid bonding in 3D packaging
Testerion
Editor's Choice Manufacturing / Production Technology, Hardware & Services
The way copper grains are sized and distributed forms the metallurgical foundation of hybrid bonding, enabling lower bonding temperatures, greater reliability, and stable grain structures throughout integration.
Read more...
Understanding solder dross: causes and control strategies
Truth Electronic Manufacturing
Editor's Choice Manufacturing / Production Technology, Hardware & Services
Dross formation is an inevitable consequence of wave soldering. It occurs when molten solder comes into contact with oxygen, forming metal oxides that float on the surface of the solder bath. Over time, this oxidation byproduct accumulates and must be removed to maintain solder quality and process consistency.
Read more...
Non-destructive techniques for identifying defects in BGA joints – TDR, 2DX, and cross-section-SEM comparison
MyKay Tronics
Manufacturing / Production Technology, Hardware & Services
This whitepaper reports the results of a comparison of the following techniques: TDR, automatic X-ray inspection (AXI), transmission X-ray (2DX), cross-section/SEM, and Dye & Pry.
Read more...
Implications of using Pb-free solders on X-ray inspection of flip chips and BGAs
MyKay Tronics
Manufacturing / Production Technology, Hardware & Services
With the move to Pb-free soldering, most of the attention has been paid to reflow temperatures, component compatibility, and reliability concerns, but the implications for inspection, particularly X-ray inspection, are equally important and often underestimated.
Read more...
The causes of solder balls in robotic soldering
Manufacturing / Production Technology, Hardware & Services
Solder balls (also known as solder splatter) are a major concern in many production sites as they may potentially cause shorts, leading to long-term impacts on product reliability.
Read more...
Material challenges for superconducting quantum chips
Manufacturing / Production Technology, Hardware & Services
To achieve the scalable and repeatable production of superconducting circuits for quantum technology products, players in the industry are leveraging semiconductor fabrication techniques.
Read more...
printer friendly version