MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第409页

MIL-STD-883F METHOD 2032.2 18 June 2004 3 (6) Cont act window is an opening (us ually s quare) t hrough the oxide ( or ins ulati ng) layer for t he purpose of allowing c ontac t by deposi ted materi al to t he subst rate…

MIL-STD-883F

METHOD 2032.2

18 June 2004

e. Magnification. "High magnification" inspection shall be performed perpendicular to the element with illumination

normal to the element surface. Other angles at which the inspection can be performed, and at which the element

can be illuminated, may be used at the option of the manufacturer if the visual presentation is the same as used in

the originally specified conditions. "Low magnification" inspection shall be performed with either a monocular,

binocular, or stereo microscope with the element under suitable illumination, tilted at an angle not greater than 30°

from the perpendicular. The magnification ranges to be used for inspection are specified at the start of each

section and are called out at the start of each major criteria grouping.

f. Reinspection

. When inspection for product acceptance or quality verification of the visual requirements herein is

conducted subsequent to the manufacturer's successful inspection, the additional inspection shall be performed at

the magnification specified herein, unless a specific magnification is required by the acquisition document.

g. Exclusions

. Where conditional exclusions have been allowed, specific instruction as to the location and conditions

for which the exclusion can be applied shall be documented in the assembly drawing.

h. Format and conventions

. For ease of understanding and comparison, visual criteria are presented side-by-side in

a columnar format. Class H criterion are presented in the left column and class K criterion are presented in the

right column. When there are differences, the applicable parts of the class H criterion are underlined, for ease of

comparison and clarity, and the differences only are shown in the class K column. When there are similarities, the

phrase "same as class H" is used with no underlining of the class H criterion. If a requirement is not applicable to

either product class, this is indicated by "N/A." A note in the class H column is applicable to class K unless

otherwise specified in the class K column. A note in the class K column is applicable to class K only. Two kinds of

notes are used herein, regular notes (NOTE:) and precautionary notes (PRECAUTIONARY NOTE:). A regular

note is a integral part of a criterion. A precautionary note is not an integral part of the criterion but serves to alert

the user to a requirement of the General Specification for Hybrids, MIL-PRF-38534. The phrases "except by

design," "intended by design," "by design," or "unless otherwise specified by design" require that the element

drawing be referenced to determine intent. For inspections performed at 100X, the criteria of "0.1 mil of

passivation, separation, or metal" is satisfied by a "line of passivation, separation, or metal." Reference herein to

"that exhibits" is satisfied when the visual image or visual appearance of the element under examination indicates a

specific condition is present that does not require confirmation by any other method of testing. When other

methods of test are used to confirm that a defect does not exist, they shall be approved by the acquiring activity. In

the figures, cross-hatched areas represent metallization, blank areas represent resistor material and shaded areas

represent exposed underlying material. The letters "x", "y", or "z" represent the dimension of interest and the letter

"d" represents the original dimension. Most figures show the reject condition only.

i. Definitions

(1) Active circuit area

is all functional circuitry, operating metallization, or any connected combinations of these.

In the case of resistors, it includes all resistor material that forms a continuous path between two metallized

areas (usually bonding pads).

(2) Block resistor

is a solid, rectangularly shaped resistor, which, for purposes of trimming, is designed to be

much wider than would be dictated by power density requirements and shall be identified in the approved

manufacturer's precap visual implementation document.

(3) Bonding pad

is a metallized area (usually located along the periphery of the element) at which an electrical

connection is to be made by the user of the element.

(4) Bridging

is complete connection between circuit features not intended to be connected.

(5) Conductive substrate

is one that can conduct electricity. Copper or doped silicon, for example, are

conductive substrates. Alumina and quartz, for example, are nonconductive (insulating) substrates.

MIL-STD-883F

METHOD 2032.2

18 June 2004

(6) Contact window is an opening (usually square) through the oxide (or insulating) layer for the purpose of

allowing contact by deposited material to the substrate.

(7) Controlled environment

is one that has 1,000 or fewer (0.5 Hm or greater) particles/cubic foot in a controlled

environment in accordance with the requirements of ISO 14644-1 for a class 6 clean environment, except

that the maximum allowable relative humidity shall not exceed 65 percent.

(8) Corrosion

is the gradual wearing away of metal, usually by chemical action, with the subsequent production

of a corrosion product.

(9) Crazing

is the presence of numerous, minute, interconnected surface cracks.

(10) Crossover

is the transverse crossing of metallization paths, without mutual electrical contact, achieved by

the deposition of an insulating layer between the metallization paths in the area of crossing.

(11) Detritus

is fragments of original or trim-modified resistor or conductor material.

(12) Dielectric

is an insulating material that does not conduct electricity but may be able to sustain an electric

field. It can be used in crossovers, as a passivation or a glassivation, or in capacitors.

(13) Foreign material

is any material that is foreign to the element or any nonforeign material that is displaced

from its original or intended position in the element. It is considered attached when it cannot be removed by

a nominal gas blow (approximately 20 psig) or by an approved cleaning process. Conductive foreign

material is any substance that appears opaque under those conditions of lighting and magnification used in

routine visual inspection. Particles are considered to be embedded in glassivation when there is evidence of

color fringing around the periphery of the particle.

(14) Glassivation

is the top layer(s) of transparent insulating material that covers the active circuit area, including

metallization, but not bonding pads. Crazing is the presence of numerous minute cracks in the glassivation.

Cracks are fissures in the glassivation layer resulting from stress release or poor adhesion. The cracks can

form loops over metallized areas.

(15) Kerf

is the clear area in a trimmed resistor resulting from the removal of resistor material by the trimming

operation. In laser trimming, the kerf is bounded by the reflow zone (which is characterized by adherent,

melted resistor material), the scorched heat-affected zone (which is characterized by discoloration of the

resistor film without alteration of its physical form), and the undisturbed zone.

MIL-STD-883F

METHOD 2032.2

18 June 2004

(16) Mar is a nontearing surface disturbance such as an indentation or a buff mark.

(17) Metallization, multilevel (conductors)

is alternate layers of metallization, or other material used for

interconnection, that are isolated from each other by a grown or deposited insulating material. The term

"overlaying metallization" refers to any metallization layer on top of the insulating material.

(18) Metallization, multilayered (conductors)

is two or more layers of metallization, or other material used for

interconnection, that are not isolated from each other by a grown or deposited insulating material. The term

"underlying metallization" refers to any metallization layer below the top layer of metallization.

(19) Metallization, operating (conductors)

is all metallization (gold, aluminum, or other material) used for

interconnection. Bonding pads are considered to be operating metallization. Alignment markers, test

patterns, and identification markings are not considered to be operating metallization.

(20) Narrowest resistor width

is the narrowest portion of a given resistor prior to trimming; however, the

narrowest resistor width for a block resistor may be specified in the approved manufacturer's design

documentation.

(21) Neck-down

is tapering of a resistor line at a metallization interface. Resistor material taper is typically equal

on both sides of the line and is less abrupt than a void.

(22) Nicking (partial cut)

is incomplete or inadvertent trimming of a resistor adjacent to the one being trimmed or

of the next ladder rung of the same resistor.

(23) Nonplanar element

is one that is essentially three-dimensional.

(24) Original separation

is the separation dimension or space that is intended by design.

(25) Original width

is the width dimension that is intended by design.

(26) Oxide defect

is an irregularly shaped defect in the oxide characterized by two or three colored fringes at it

edges.

(27) Passivation

is the silicon oxide, silicon nitride, or other insulating material, that is grown or deposited directly

on the element prior to the deposition of metal.

(28) Passivation step

is a change in thickness of the passivation layer by design.

(29) Passive elements

are planar resistors, capacitors, inductors, and patterned substrates (both single-layer

and multilayer), and nonplanar chip capacitors, chip resistors, chip inductors, and transformers.

(30) Patterned substrate

is a substrate on which conductors, and components such as resistors or capacitors,

are formed using thick or thin film manufacturing techniques.

(31) Planar element

is one that is essentially two-dimensional with all points in a common plane.

(32) Protrusion

is a jutting-out of a circuit feature. Protrusion is typically caused by a photolithographic or

screening defect.

(33) Resistor ladder

is a resistor structure resembling a ladder in appearance that can be trimmed in incremental

steps. A coarse ladder structure is one in which trimming of a rung results in a large incremental resistance

change (one that can cause an out-of-tolerance condition to occur). A fine ladder structure is one in which

trimming of a rung results in a small incremental resistance change (one that can not cause an

out-of-tolerance condition to occur).