Fixture, custom

Quite possibly the greatest daily irritant (and cost) in the operation of a typical test area today revolves around the cost of building test fixtures. Customers still hate to pay for them, and the creation of fixtures burdens the board shop with an entire manufacturing process that seems to add no value and that distracts from the main productive purpose of the factory. The only fully effective commercially available systems that require no test fixtures are flying-probe... 

Chartered Metal Industries Toolroom in Singapore produces a wide range of standard and customized products to support manufacturers in the metal industries. Their production includes high-volume, batch-run precision parts, prototype components, subassemblies, tooling, fixtures, and gauges. 

Buyers should also consider that for a whole variety of reasons it is a fact of life today that field representatives may not be a permanent fixture in the long-term treatment and management of any particular customer s cooling water plant. Good people often get promoted or move on to new... 

The layout or arrangement of in-store fixtures should be designed to move patrons around the pharmacy to obtain the items they need or desire. Ideally, customers should visit as many areas of the pharmacy as possible to increase the probability of impulse purchases. 

Since the early 1950s, petroleum coke markets have changed radically. Once treated only as a refinery by-product by refiners, petroleum coke is now a permanent feature of several end use markets that are influenced by a variety of economic variables. Many refiners have begun to commit corporate resources to marketing their petroleum coke in hopes of realizing incremental revenues. Marketing was formerly left to a few specialized marketers who contributed to market viability by developing new customers and new uses of petroleum coke that are now considered as permanent market fixtures. 

Figure 2 shows the specifically developed small size custom RIM machine for this application, including the metering unit, electrical controls, fixture for the vertical arrangement of the baseball bats to be filled, and also an up and down moving support on which the mixing head is installed. The operation of the machine is semiautomatic. 

Figure 2. Custom RIM metering and mixing machine with fixture, for the fill of aluminum baseball bats with a small amount of flexible foam.

Figure 2. Block Diagram of inlet systems for the FTMS including custom moisture analysis fixture.

Dynamic Z,S—End-loaded split specimens were also tested in the drop tower, but were mounted horizontally in a custom clamping fixture as shown in Fig. 2. This fixture consists of a side grooved Palmgren vise (Chicago, IL) mounted to a custom pedestal. The pedestal is constructed of 50 x 50 mm steel box tubing welded to 6.4 mm steel plates and is clamped to the drop tower base using 100 mm C-clamps. In this case, a hemispherically-tipped steel tup is attached to the drop tower sled and travels downward, striking the end of the specimen as shown in the schematic in Fig. 2. 

The RFS method makes use of the fact that carbon disc electrodes used in RDE spectrometers are porous and can be used as a filter to trap particles in oil samples. Early versions of the RFS fixture used standard disc electrodes with some success and acceptable sensitivity [5]. However, standard disc electrode geometry caused the process to be slow, and lack of manufacturing control of disc porosity resulted in poor repeatability. Due to its ease of use and inherent advantages, the RFS concept was recently revisited with the intent of further improving performance. The updated RFS technique uses custom ring-shaped graphite electrodes and a semi-automatic process to improve sensitivity and repeatability and to reduce sample preparation time. 

F. Adhesive Customization Together with Rapid Fixture and/or Cure On Demand Improve Process Efficiency... 

Fig. 6.25 Schematic showing cross-sectional view of the custom three-electrode fixture used for electrochemical characterization [39]. Reproduced by permission of The Electrochemical Society.

Today, powder coating is widely accepted, with thousands of installations in the factories of original equipment manufacturers (OEMS) and custom coating job shops. It is the preferred method for coating many familiar items such as lawn and garden equipment, patio and other metal furniture, electrical cabinets, lighting, shelving and store fixtures, and many automotive components. 

Pin ronting can be an economical process when a small generation of boards is profiled, or if the shapes reqnired are relatively simple. For pin routing to be effective, generally a very skilled operator is reqnired to fabricate the template and to route the boards. Outside machine shops can bnUd alnminnm ronte fixtures for each customer application however, lead times and costs per order mnst be considered. Pin routing is usually used by small shops not able to invest in the CNC eqnipment and its associated support, or as a specialty process, off-hne from CNC routing. 

Proposals have circulated for radical new measurement approaches to electrical testing. These have included the use of electron beams, laser-stimulated photoelectric effects, and gas plasma techniques in configurations similar to existing flying probers. In each case, the board is scanned without use of a custom test fixture. To date, all of these methods involve compromise of fault coverage, or add little or no fine-pitch performance beyond conventional methods. Relaxation of test criteria is not a relief available to most users. HDI product types demand increased fine-pitch capability. These finer trace and via geometries increase the risk of latent defects and increase interest in measurement methods most sensitive to precursor symptoms of such defects. As a result, none of these approaches has seen widespread adoption. 

Each dedicated, or hard-wired, test system presents some sort of standardized interface pattern of test points. This may consist of a universal grid s continuous array of points (bed of nails) or may be a connector pattern of some type. In the most primitive systems, a simple cable connector may be presented. Each of these types of eqnipment nses one or more types of customized test fixtures to connect this standard electrical interface pattern to the unique contact pattern of a particular product to be tested. 

Each fixtured system includes a measurement nnit that can be connected to any of some thousands of test points by a solid-state switching matrix. A central computer controls the measnrement unit and switching matrix. This compnter also controls the press (or vacuum mechanism), which can compress the prodnct against spring-loaded test points presented to the prodnct by a customized test fixtme. 

In a high percentage of assembly areas, good housekeeping will take care of contamination from the environment. It should be a common event on each shift to clean workstations, sweep floors, dust fixtures, empty trash, and so on. This not only prevents contamination, but it also helps to keep personnel morale at a higher level. After all, we all desire to work in a nice, clean environment. It will also serve as a positive point if visitors or possible customers visit the assembly area. 

Performance testers are often known as edge connector functional testers.They connect to the edge connectors of the board under test with mating connectors that are then adapted to the tester resources by a customized fixture called an adapter. In most cases, no other connections are made by the test fixturing to any internal nodes of the circuit. In essence, the board is tested in an environment that resembles its application environment to some degree. 

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