Backside contact

After the cleaning procedure, deposit an A1 layer with a thickness of about 300 nm by, e.g., an electron-beam evaporation process anneal the contact at 420°C for 15 min to create an Ohmic backside contact. 

In US-A-4570329 a method for fabricating a backside contacted mosaic detector array is claimed. A cold weldable metal is used both as a means for fastening the array to a circuit board and as a means for providing electrical contacts. This arrangement allows closer detector packing compared with arrays using over the edge contacts. The detector array is claimed separately in US-A-4695861. 

A new area of concern for electrical stability arises because of the increasing use of conductive adhesives as replacements for solder. Some conductive adhesives show unstable electrical-contact resistance when used on non-noble metal surfaces such as copper or tin-lead solder. Although stable on gold, palladium, platinum, and silver surfaces, the same adhesives were found to be unstable on tin, tin-lead, copper, and nickel surfaces.The unstable resistance and increase in resistance in temperature-humidity exposures have been attributed to the growth of an oxide layer separating the filler particles from the substrate at the interface, a mechanism similar to that for the loss of backside contact in die-attach materials. 

A further problem relates to encapsulation. The ion-sensitive gate area is exposed to the analyte solution, but all other parts of the sensor must be insulated from the solution. In most cases encapsulation is carried out by hand using epoxy resins, but it is impossible to produce ISFETs at low cost by this technique. Both photolithographic methods [159], [160] and an electrochemical method [161] have been proposed for the solution of this problem. One very promising development is the backside-contacted ISFET [162]. TTie electrical contacts in this case are protected from the analyte solution by means of O-rings, thereby circumventing the need for resins. 

Release coatings are important components of pressure sensitive adhesive (PSA) products such as tapes and labels [1]. Release materials are coated onto the backside of PSA tape backings (often called low adhesion backsizes or LABs in this form) to provide the desired tape roll unwind force. They are also coated onto various substrates to form release liners for PSA products such as labels and transfer tapes. Typically the thickness of the release coating is less than 1 p,m, and often times less than 0.1 jLm. Release coatings can be thought of as the PSA delivery system, providing a controlled unwind or release force and protecting the adhesive from contamination and unintentional contact until it is applied. 

Providing the backside with an electrolyte contact, which is forward biased or alternatively reverse biased and intensely illuminated. 

TapCT The C-terminus of the mammalian nuclear RNA export factor NXFl/2 (also known as Tap) contains a sequence region with significant similarity to UBA-like domains. This region is also found in the yeast RNA export factor Mex67. A three-dimensional structure of this domain is available and confirms its similarity to the UBA domain [68]. This UBA-like domain does not appear to bind to ubiquitin but rather to the Phe-Gly repeat motif found in a number of nu-cleoporins. The interaction surface of the UBA-like TapCT domain with a Phe-Gly-containing loop was mapped by an NMR/X-Ray combination technique and shown to be different from the ubiquitin-binding mode the Phe-Gly loop binds on the backside of the UBA-like domain and is in contact with helices a2 and a3 [68]. 

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