Gemini Tec Ltd - Privacy Policy Notice & GDPR Policy

This document concerns private information collected and stored by Gemini Tec Ltd from its customers, suppliers and professional service providers. We only collect basic personal data comprising of name, email addresses, phone numbers and who employs you. Personal data is data related to an identifiable individual and not to the company or organisation they represent.

Why we need your data.
We need to collect this data to be able to process customer orders for products and services provided by Gemini Tec Ltd and to comply with legal requirements to retain details of financial transactions. Our dominant business is relationship based and our customers typically place repeat orders for products or services many times and on trade credit terms. We need to be able to contact customers to discuss their orders to provide a high quality efficient and responsive service without the need to repeatedly input and process the same contact information.

From time to time we need to send important information concerning our holidays, those of our key suppliers or major changes in the marketplace which are likely to impact our business with you (for example changes in exchange rates which affect the prices of our products and services).

We may also need to contact you to invite you to subscribe to new information services we may provide in the future, for instance a technical blog which offers technical advice in the preparation of electronic and PCB designs.

How we store your personal data.
Personal data is held in encrypted databases with blue-chip service providers within the EU and also
held in backups at our own premises as well as stored securely offsite. The principal communications channel used by our customers and suppliers is unencrypted email and we are not able to protect personal information sent by these means.

What we won't do with your data.
We do not share personal data with third parties except as is necessary to fulfil orders for products or services purchased from us. We may share personal data with our trusted providers of professional services for example book-keepers, accountants and legal advisers or where it is necessary for you to interact directly with a partner business to successfully execute an order. We never sell or release bulk private data to any outside organisations.

How long we keep your data.
We are required under UK tax law to keep your basic personal data (name, address, contact details) for a minimum of 6 years following any financial transaction after which time it will be destroyed. If you have agreed to receive information circulars we will keep basic contact information until you notify us that you no longer wish to receive this information.

What are your rights.
If at any point you believe the information we process on you is incorrect you can request to see this information and have it corrected or deleted. If you wish to raise a complaint on how we have handled your personal data, you can contact us to have the matter investigated using any of our published communications channels.

To comply with GDPR, a Subject Access Request can be requested via email, addressed to the company (This email address is being protected from spambots. You need JavaScript enabled to view it.). These requests will be charged per subject access request. Gemini Tec Ltd will aim to provide the relevant data within 14 days of receiving the request.

Gemini Tec will always verify the identity of anyone making a subject access request, prior to handing over any information.

If you are not satisfied with our response or believe we are processing your personal data not in accordance with the law you can complain to the Information Commissioner’s Office

Gemini Tec use the very latest processing technology available to manufacture customer PCBA products. We operate with two Asscon vapour phase reflow ovens, providing customers with seamless PCBA processing from early prototype through to batch production. Gemini Tec are the first UK CEM to operate the latest in-line vapour phase reflow oven, manufactured by Asscon of Germany.

Vapour Phase Reflow at Gemini Tec

We have listed out some of the FAQ's about this technology:


Why use vapour phase reflow, instead of other popular reflow methods? 

Assemblers in progressive companies such as Gemini Tec recognise the advantages of this soldering method as the simplest and most reliable method of soldering. It allows for the processing of ALL types of components and PCBA's without many hours of complicated calculations to create thermal profiles, which are often a compromise between the solder paste and the component make up.

Vapour phase reflow is a repeatable process, without external factors that drive the process window. 


How does it work? 

A Galden liquid boils to deliver a layer of saturated vapour which contains no oxygen or other gasses. As the PCBA is immersed into the vapour zone, the vapour condenses onto the PCBA and transfers its corresponding heat in a linear method. 


Vapour phase reflow was popular in the 80’s, but went out of favour due to chemicals that contained CFC’s, is this still the case? 

The fluid used in today’s vapour phase machines do not contain any harmful CFC’s. The chemical is environmentally compatible, non-corrosive and extremely stable.


Are vapour phase machines expensive to run, which pushes up manufacturing costs? 

No, the chemical running costs of a typical machine is around 70p an hour or a little over 1p a minute. Our Asscon vapour phase oven also consumes much less power, running at at 2.5kW p/h VS the equivalent convection oven running at 20kW p/h. The investment into the process is alot higher than a typical convection reflow oven, but ROI is seen very quickly through finished yields and removal of other hidden costs.  


Is condensation soldering different to vapour phase soldering? 

No, they are the same. The same fluids are used and heated to their boiling point to create a vapour, which allows the solder to reflow in an inert atmosphere. The only differences are to the individual manufacturer’s machine design.


Can PCBA products be overheated, much like a convection oven? 

No, the maximum board temperature is equal to the boiling temperature of the liquid used, i.e.200ºC. for SnPb or 230ºC for lead-free materials. Irrespective of how long the PCBA and solder material remains in the vapour, irrespective of board thickness the temperature can never exceed that of the relative vapour. 

So if your PCBA is 0.5mm thick or at 2.4 thick with 18 layers using 2oz copper ground planes, both will get the sufficient heat required and neither will overheat. The laws of physics dictates the process is impossible to overheat the PCBA.


What about oxidation? 

Vapour phase reflow produces a 100% inert/oxygen free soldering environment that eliminates oxidation problems. The vapour is heavy (in comparison to steam or air) and therefore displaces lighter gases, which are found above the vapour. In this method, the vapour creates a protective gas atmosphere even without the use of nitrogen, which is a highly expensive soldering process. 


Does vapour phase reflow cause tomb-stoning? 

The ability to completely pre-heat the board, according to the material/component requirements (see previous answer), and create a very gradual temperature rise will help avoid thermal stress and tomb-stoning.


Higher technology boards are high in mix and use components with small process windows, such as µBGAs, CSPs and flipchips. A uniform reflow is crucial, so how can vapour phase provide this? 

During conventional reflow to ensure any hidden central joints are heated sufficiently, the temperature may have to be raised as much as 50ºC above the melting point of the alloy. Overheating of the external solder connections causing permanent heat related damage. With vapour phase the heat is drawn by conduction from a saturated vapour onto the PCB. The heat is distributed evenly throughout, irrespective of whether components have a high or low thermal mass. Reflow temperature differentials across the assembly are always less than 5ºC, as the delta T of vapour phase is only 5°C


How does vapour phase cope with lead free solder paste? 

The temperatures that is required for lead free materials are more extreme. Typically this is +10% for wave soldering and +20% for reflow, these additional temperatures add even further risk of damage by excessive heat. Vapour phase is the only reflow process that allows you to change to lead free (for example: SnAg 3,5 with a melting point of 221ºC) without any danger of overheating the board or its components by using a liquid with a boiling point of 230ºC.


Is the solder wetting of lead free materials a concern? 

Lead free alloys do not wet as well as SnPb, an inert atmosphere will be more important to employ the best possible soldering conditions to help overcome this problem. When using convection reflow the use of a nitrogen atmosphere will improve solder joints, but this adds excessive cost and is a process that is not widely adopted in the UK over concerns with the long-term reliability.  

Vapour phase reflow soldering automatically provides a 100% inert atmosphere, without adding nitrogen (and without adding additional cost), to guarantee the best possible soldering conditions along with the best possible long term reliability with every use.


What about the problem of pop-corning during production? 

As plastics are hygroscopic, humidity will get into the body of these components (e.g. BGAs). When reflow soldering this can lead to high pressure of the moisture trapped inside the components which is converted into steam and forced out under pressure during reflow. This can cause delamination of the substrate or 'pop-corning'.

The higher the reflow temperature needed for lead free alloys results in a greater the risk of pop-corning, therefore a maximum reflow temperature of 230ºC is the optimum process. And with no risk of heating the PCBa's above a maximum of 230ºC, vapour phase reflow provides a vastly reduced risk of pop-corning. All MSL related materials used at Gemini Tec are subject to baking prior to use, when required. We also have in house vacuum sealing machines and automated control over exposure time and labelling materials.  


Gemini Tec support a wide range of customers and applications from prototype to medium volume production, our investment in processing technology, allows us to support complex and demanding PCBA products where reliability and conformance is essential.


If we can help you with more technical questions or if you need our expertise, please contact us to arrange a site visit. +44 (0) 1252 333 444

We provide contract manufacturing services best suited to complex and high mix surface mount electronic products.

Our service is agile and responsive to support customers from initial PCB design and rapid prototype & NPI orders, before transitioning to small to medium production. Our typical manufacturing batch sizes range from 2 to 5000 units per run, and we support customers with annual volumes of C15K per year. 

Using world class processing technology we supply populated PCBA products or fully manufactured and tested products, ready for distribution. Gemini Tec Controller Unit IMG 1396  

  • PCB assembly services for rapid NPI orders.
  • PCB assembly services for small to medium volume production.
  • Conformal coating. 
  • Cable assemblies.
  • Functional test and validation.
  • Box build manufacturing.
  • PCB layout with Altium design tools.

We work closely with our customers to add value when adopting a sub-contract manufacturing process. We help overcome the various challenges during the prototype/NPI phase ahead of fully optimised production orders.

We deliver consistent product quality and conformance, with all our manufacturing completed at our Hampshire UK based facility.

Facility Highlights:

  • Highly organised with digital integration.
  • IPC Class 3 build standards.
  • Superbly equipped with PCBA processing technology.
  • Impeccably clean environment.
  • Secure with full IP protection. 

Download a short overview about our sub-contract PCB manufacturing services here: G-Tec CEM Services.pdf


Contact us in confidence to discuss your requirements in more detail, or arrange a visit to our production facility. Tel +44 (0) 1252 333 444

Since 1980 Gemini have used Barco scanning hardware and software to reverse engineer 'Artworks' into electronic data that can be cleaned and optimised for re-manufacture. we have vast experience in re-engineering physical medium back further into CAD data for a wide range of customers including OEM's and PCB manufactures.

Artwork films and physical PCB's and PCBA's can be re-engineered into Gerber data, with optimum accuracy for file storage. This service proves invaluable for supporting legacy products, where a identical replacement is required. Our service includes full BOM re-engineering and the re-manufacture of prototypes for validation. 

The re-engineering of films to Gerber data is a cost effective and accurate solution for long term digital storage and product support.

  • Experienced engineers conversant with circuit board production.
  • Full Gerber/DPF re-creation suitable for any tooling system, using BARCO Graphics.
  • Scanning of bare PCB boards to Gerber data
  • Scanning of PCB's and converted to CAD data.
  • Scanning of populated PCB's to Gerber data.
  • Scanning of artworks to Gerber data.
  • Scanning of diazo films to Gerber data.
  • Perfect layer-to-layer registration, snapped to the drill centres.
  • Re-engineered data eliminates manufacturing problems.

If you need technical assistance with re-engineering data contact us for more details. Tel +44 (0) 1252 333 444

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Quality of the products we manufacture:

Gemini Tec Ltd has held a recognised ISO9001 approval for over 35 years and use well proven systems and procedures to support its diverse customer base.

We manufacture PCB and surface mount products to IPC-A-610 class 2 & 3 (Level 3, default condition) with all our technicians trained and individually certified to the recognised IPC standards. To ensure our capability is fully compliant, we have qualified in-house trainers and instructors to deploy the requirements of the IPC & J-STD conditions across our entire manufacturing process.

We provide products that meet IPC CH-65A & J-STANDARD 001-D standards, suitable for medical applications. Cleaning of PCB assemblies is completed by using the latest ultrasonic & vapour cleaning or by aqueous board washing, all supported with a full ionic contamination testing capability.

Our manufacturing process supports RoHS (Lead Free) and Non-RoHS (Leaded) assemblies, we produce in accordance with AS9100 requirements with fully traceable parts and assemblies.

You can download a copy of our latest ISO 9001:2015 certification here: pdfG-Tec_ISO9001-Cert-AJA.pdf


Quality of the service we provide:

After more than three decades in business, Gemini Tec remains committed in delivering a professional service that people continue to recommend. Our reputation was built on providing technology products and services for time critical orders.

We maintain this position by investing in our loyal staff, technical capability and infrastructure. Our ability to react and implement information quickly allows us to offer the fastest manufacturing service for rapid prototypes. Our extensive manufacturing capability allows us to support customers with small to medium volume production orders.

To ensure our continued success we instill a culture that appreciates and understands the needs of our customers. We are focused on delivering a manufacturing service that adds commercial value and exceeds our customers expectations.


Privacy Policy:

We are fully conversant with handling sensitive data & customer IP, which extends to using any personal information you provide us. We never disclose or sell information to external companies and its use is solely to provide our service and relevant material to you. In line with GDPR requirements we have a brief policy: Click Here


We always prefer to talk in person, feel free to contact us about your requirements for PCB design, complex PCB assembly or outsourced manufacturing services. Tel +44 (0) 1252 333 444