See "write enable".
See "write enable".
A slice or flat disk, either of semiconductor material or of such a material deposited on a substrate, in which circuits or devices are simultaneously processed and subsequently separated into chips if there is more than one device.
A package whose size is generally equal to the size of the semiconductor device it contains and that is formed by processing on a complete wafer rather than on an individual device.
NOTE 1 Because of the wafer-level processing, the size of a wafer-level package may be defined by finer dimensions and tighter tolerances than those for a similar non-wafer-level package.
NOTE 2 The package size will change with changes in the size of the die.
A signal indicating that the device addressed by the central processing unit has not yet completed its data transfer. (Ref. IEC 824.)
A measure of the permeability of plastic film or metallized plastic film material to moisture.
See "write enable".
An imperfection or deviation from the designed construction that affects reliability.
The adhesion or weld of a thin wire, usually aluminum, to a package bonding surface, usually a plated leadframe post or finger, using an ultrasonic wire-bonding process. The wedge bond includes the compressed (ultrasonically bonded) area of the wire and the underlying bonding surface. For bonding to an aluminum alloy die bond pad, there is no wedge bond-bond pad intermetallic because the two materials are of the same composition; the two materials are recrystallized together by the ultrasonic energy of the welding process.
The formation of a relatively uniform, smooth, unbroken, and adherent film of solder to a basis metal. (Ref. IPC‑T‑50.)
A spontaneous columnar or cylindrical filament, usually of monocrystalline metal, emanating from the surface of a finish.
NOTE Whiskers are not to be confused with dendrites, which are fern-like growths on the surface of a material, formed as a result of electromigration of an ionic species or during solidification.
The number of whiskers per unit area on a single lead or coupon area.
Measurable changes in whisker length and/or whisker density after exposure to a whisker test condition for a certain duration or number of cycles.
The straight-line distance from the point of emergence of the whisker to the most distant point on the whisker.
A piece of metal of specified size and shape that is plated or dipped with a tin finish for the purpose of measuring the propensity for whisker formation and growth.
The number of data lines used in parallel transmission.
NOTE For digital data, width is usually expressed in bits, bytes, or words.
A hole formed by etching through an oxide or insulating layer on a semiconductor for the purpose of diffusion into or deposition onto a selected area of the semiconductor.
Work in progress or work in process.
The total amount of interconnect of a net (specified in units of either length or capacitance).
A character string or a binary element string that it is convenient to consider as an entity. (Adapted from ANSI X3.172.)
NOTE For memories, it is common practice to use the term "word" generically for any number of bits that occupy a single address location.
A device that has a parallel data interface of 16 bits or more (usually in multiples of 16 bits), possibly with additional bits appended to provide parity or error-detection capability.
The peak reverse voltage excluding all transient voltages.
See "write protect".
To make a permanent or transient recording of data in a storage device or on a data medium. (Ref. ANSI X3.172.)
The corruption of data in one location caused by the writing of data at another location.
The input that, when true, causes the data present on the D or the DQ pin(s) to be written into the address cell(s) of the device. For devices that have one WE per byte, the WEs are designated LWE and UWE. For devices that have more than two bytes and one WE per byte, and for all modules that have multiple WEs, the WEs are numbered beginning with 0.
The output signal used to reflect the status of the write-protect switch on the memory card. If the memory card write-protect switch is present, this signal will be asserted by the card when the switch is enabled, and deasserted when the switch is disabled. If the memory card has no write-protect switch, the card will connect this line to ground or VCC, depending on the condition of the card memory. If the card can always be written, the pin will be connected to VSS. If the card is permanently write-protected, the pin will be connected to VCC.
An operation in which the data to be written is introduced through the serial port and is then transferred internally to the memory array data bus for writing into the cells. At the same time, the "tap pointer" is set. This is a counter that defines the starting point in the serial register into which data is entered. Data is entered serially from this point, with wraparound when the end of the register is reached. The contents of the full serial register are transferred in parallel. In addition to the normal write transfer, numerous other types of special write transfers are defined in JESD 21-C.
See "write transfer".
See "water vapor transmission rate".
A 4-arm bridge forming a diamond, all of whose arms are predominantly resistive, with three resistors of known values in three of the arms and the unknown resistor in the fourth.
NOTE 1 A voltage source, e.g., a battery, is connected across two opposite points of the diamond and a current-detecting instrument (e.g., a galvanometer) is connected across the other two points. The values of one or two of the known resistors are varied until no current flows through the galvanometer. The bridge is then balanced and the value of the unknown resistor can be calculated in terms of the other three.NOTE 2 A method using the Wheatstone bridge for monitoring resistance of solder bumps in electromigration tests has greater sensitivity to resistance change than other methods. Net resistance changes due to electromigration of only the solder bumps, excluding the Al or Cu traces, can be deduced by this method.
The portion of a chamber, used for stress testing, that meets the calibration requirements.
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