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Commercial Laboratory Equipment
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different sites, including to contract manufacturing to use manufacturing
resources most efficiently. DFi provides the ‘‘hooks’’ in the design that allow
future changes that reduce the cost of components, improve the yield, and
ease the assembly effort.
Although Keithley buys components, it fabricates and manufactures most
of the electrical and electronic subsystems that go into its products. These
are custom designs because of the special nature of low-level measurements.
Keithley assembles but does not fabricate its own PCBs for its products.
Control and cleanliness in the assembly of PCBs are very important to avoid
interference in low-level signals and very sensitive physical measurements.
For circuits that do not have quite the stringent requirements on control,
Keithley will go to a contract PCB fabricator to build some boards if
Keithley’s facilities are busy.
Keithley works with vendors to fabricate and manufacture the mechanical
elements of subsystems and enclosures, too. Keithley will then assemble
most subsystems on site (Figure 6.7). Branding and the nature of custom
design tends to keep much of the assembly in-house.
Keithley assembles its circuit boards and its products. The primary
reason, again, is quality control to achieve instruments that consistently
function correctly while measuring low-level signals. Parts of the assembly
and manufacturing environment are inspection and test; Keithley personnel
inspect subsystem and final assemblies and perform both manufacturing
tests with dedicated test rigs and BIT, if BIT is incorporated in the product.
FIGURE 6.7
Keithley personnel assembling a product. (Used with permission, Keithley Instruments, Inc.)