Almax-RP screen prints conductive inks onto semiconductor substrates including glass and silicon wafers to make electrochemical sensors for our customers. We print conductive inks such as conductive silver, silver/silver chloride, carbon, and Prussian blue. These inks are thermally cured onto the wafer substrates to make the functional electronics and electrodes. The wafers are diced after printing is completed to separate the individual sensors on the wafer substrates. At this point the finished sensors are ready for use. Screen printed electrodes on glass and silicon wafers are used for DNA analysis, drug detection, and other complex bio-sensing applications.
What Semiconductor Substrates Can Almax Print On?
Choosing the correct wafer substrate will depend on the final application. Glass wafers are great for applications that require a chemically inert substrate. Sapphire wafers have a very high thermal conductivity and a sapphire wafer substrate is a good choice for any application that will have to sink a lot of heat. N-type (P doped) and P-type (B doped) silicon wafers are electrically conductive. Screen printed electrodes on N-type or P-type wafers will perform very differently than electrodes on electrically insulating plastic or glass substrates. This changes electrode performance and allows our customers to pursue a whole new field of sensing applications.
How Do We Choose Conductive Inks for Your Electrodes?
After your team has identified the correct wafer substrate that you need for your application, it is important to choose the correct conductive inks. Printing silver/silver chloride (Ag/AgCl) on wafer substrates is very popular for a variety of applications. Most commonly, Almax prints an ink that is between 10%-40% AgCl onto glass and silicon wafer substrates. Conductive carbon is also used in a lot of electrochemical sensing applications. We often use conductive silver to print the interconnect circuitry between electrodes because of its low resistance when compared to Carbon and Silver/Silver Chloride. Specialty conductors like Gold, Platinum, & Prussian Blue can be printed when the final application calls for it.
How Does Almax Support the Semiconductor Industry in Arizona?
Almax is uniquely set up to support our customers who need conductive printing on wafers. Our location in Arizona has access to many different wafer substrates, and we can usually prototype your electrochemical sensor in 2 weeks or less. Our factory in Arizona can process over 1000 wafers a day. We are set up to work with 51mm, 100mm wafers, 200mm wafers, and 300mm wafers in Arizona. This allows us to support the growing semiconductor industry in the southwestern United States. Our ISO13485 certified factory in Dongguan, China handles any orders that exceed our onshore production capabilities.
Almax’s standard screen printing processes allow us to print features as small as 250um (0.010″). For applications that require finer lines and smaller features, Almax-RP can print with specialized equipment and tooling. Please allow three to four weeks lead time for any projects requiring features smaller than 250um (0.010″). This extra time allows us to order the specialized screens that will be required to print very fine lines.
What Does Almax Need to Start Manufacturing Your Custom Screen Printed Electrodes on Glass and Silicon Wafers?
To get started on your project, please contact our team today. We will need drawings that show the required printing on your wafer substrate. Acceptable drawing formats are 2D CAD (preferred), PDF, and vector AI files. Please specify wafer diameter, wafer material, types of conductive ink to be printed, and any other special features on the wafer like drill holes, or die lines. Our team will contact you within 1 business day after we receive your drawings.