Dielectric seal

Poly(vinyl halide) Acrylic N-methylol acrylamide in acrylic Dielectric sealing Yannich and Katz U.S. Pat., 4,684,689, 1989 National Starch... 

It was apparent that voids were created in the top/bottom of the dielectric seal during processing of the samples that contained the microstrip transmission line. For this reason, a majority of the testing was performed on samples containing the coplanar transmission line. 

Baseline TDR measurements were made for two samples in their entirety and then the two samples were ablated. In one case a laser was used to make a cut perpendicular to the direction of the track formed by the dielectric seal material. In the second sample, a dicing saw was used to cut through the top plate of the sample and remove a portion of the dielectric seal. After the samples were ablated, a second set of TDR measurements were made for comparison with the baseline. In both cases, there were no visible differences between the baseline and the second measurement. 

In a third sample, two dicing saw cuts were made perpendicular to the track direction and parallel to one another as shown in Figure 4-9, allowing a section of the ceramic top plate and a print of the dielectric seal material to be removed. In this sample, TDR measurements comparing the same sample in cases both with the ceramic lid in place and with the lid removed showed a visible phase-shift in the time-domain signal. 

A first seal over the longitudinal channel is achieved by oxidizing at least partially the cross structures. Otherwise, a dielectric seal is arranged to overlie the thermally oxidized cross structures, thereby forming a more complete seal and a substantially planar top surface to the silicon substrate. 

Most advantageously, the dielectric seal is formed by the low pressure chemical vapor deposition of a dielectric layer. The silicon is boron-doped silicon layer that is formed by boron diffusion (52). 

Because of their adhesive properties, EMA copolymers are used in extrusion coating, coextrusions, and laminating applications as heat-seal layers. EMA is one of the most thermally stable of this group, and as such it is commonly used to form hot and dielectric seals, as well in multiextrusion tie layer applications. 

Dielectric sealing can be used on most thermoplastics except those that are relatively transparent to high-frequency electric fields. This method is used mostly to seal vinyl... 

PASTES. Conductor, resistor, dielectric, seal glass, polymer and soldering compositions are available in paste or ink form. They are used to produce hybrid circuits, networks and ceramic capacitors. The materials are often called thick film compositions. 

Automotive interior door panels often use PVC latex as a binder for a high-loft fabric bonded to a backing board. This is then covered with vinyl-coated fabric, and the entire assembly placed in a dielectric sealing press, where it is both heat-sealed and embossed. PVC latex-coated paperboard stock also finds use in various packaging applications. When PVC latex is used to saturate, rather than coat, paper-board, the products are suitable for preparation of molded mats. 

As a tme thermoplastic, FEP copolymer can be melt-processed by extmsion and compression, injection, and blow molding. Films can be heat-bonded and sealed, vacuum-formed, and laminated to various substrates. Chemical inertness and corrosion resistance make FEP highly suitable for chemical services its dielectric and insulating properties favor it for electrical and electronic service and its low frictional properties, mechanical toughness, thermal stabiUty, and nonstick quaUty make it highly suitable for bearings and seals, high temperature components, and nonstick surfaces. 

Electrical. Glasses are used in the electrical and electronic industries as insulators, lamp envelopes, cathode ray tubes, and encapsulators and protectors for microcircuit components, etc. Besides their abiUty to seal to metals and other glasses and to hold a vacuum and resist chemical attack, their electrical properties can be tailored to meet a wide range of needs. Generally, a glass has a high electrical resistivity, a high resistance to dielectric breakdown, and a low power factor and dielectric loss. 

In the electronics industry. Pis find wide appHcations as a dielectric material for semiconductors due to thermal stabiHty (up to 400°C) and low dielectric constant. Pis are being considered for use in bearings, gears, seals, and prosthetic human joints. The intended part can be machined or molded from the PI, or a film of PI can be appHed to a metallic part. Because of their superior adhesion, dielectric integrity, processing compatibUity, and lack of biological system impact. Pis have been used in many biological appHcations with particular success as body implants. 

The elements thus formed are then inserted into a sheet steel container, vacuum dried and impregnated, with suitable non-PCB dielectric, which may be an oil dielectric or epoxy resin. The capacitor shell is then hermetically sealed, in oil dielectrics, to avoid any leakage of dielectric during operation. 

RF (radio frequency) welding Utilizes specific bands of radio frequency waves which are directed through specially constructed tooling to form localized melting/joining of certain dielectric thermoplastic materials. Can be used to form hermetic seals. Also known as high frequency or dielectric welding. 

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