semi合集-English.pdf - 第5459页
SEMI PR9-0705 © SEMI 2005 3 6.3.6 Volume s should be minimized (i nternal, connecti ng, inter f ace/interconnect ion, dead volumes), give relation to time and pr ocess response , give dry-down const raints. 6.3.7 Surface…
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5.2.9 Wafer Level Sealing — bonding of wafers by anodic, silicon direct, eutectic, or adhesive means.
5.2.10 Macrosealing — sealing on components at the macroscale.
5.2.11 Static Seals — seals that operate with non-moving surfaces.
5.2.12 Dynamic Seals — seals that operate with moving surfaces.
5.2.13 high-purity — of a system, subsystem, or component used for the control of chemicals (gases or liquids),
designed and constructed in such a manner that it does not introduce significant impurities, particulate or molecular,
into the flow stream it controls or regulates.
NOTE 1: Such systems, subsystems, or components are designed and constructed such that, if an impurity is introduced into the
flow path, it can be readily purged to an insignificant level.
5.3 leak — a path (or paths) in a sealed system that will pass tracer gas when a pressure differential, a concentration
differential, or diffusion path exists. There are two leak mechanisms: a mechanical passage and a material through
which gas can diffuse or permeate. A leak may have both mechanisms operating in parallel.
5.4 leakage, inboard — leakage from outside to inside occurring when the internal pressure is less than the external
pressure acting on a component or the concentrations of a given component are different inside and outside
generating a non-zero chemical potential. Inboard leakage is typically determined by introducing a tracer gas around
the exterior of the piping system or component under test.
NOTE 2: Inboard leak tests are easier tests to conduct to high sensitivity levels, but are typically not indicative of pressurized
operating conditions. It is difficult to correlate an inboard leak test to the performance of a component, subsystem, or system
when under internal pressure. Also, the internal collapsing forces created by external pressure may mask leaks which may exist
under pressurized operating conditions.
5.5 leakage, internal — leakage occurring within a component across a flow barrier, such as the seat of a closed
valve.
5.6 leakage, outboard — leakage from inside to outside occurring when the internal pressure is greater than the
external pressure acting on a component. Outboard leakage is typically determined by introducing a tracer gas into
the interior of the piping system or component under test.
5.7 Microfluidic Subsystesm — a “microfluidic subsystem” in a fluidic system may contain one or many MEMS
components. The subsystem contains control and signaling elements. The subsystem, in turn, is attached fluidically
to a larger system or subsequent process. e.g. mass flow controller for fluid delivery, lab-on-a-chip.
5.7.1 Fluidic Adapter — a physical interconnecter that fluidically links a microfluidic component to another micro-
or macro-scale fluidic device.
6 Design Guidelines
6.1 Purpose — Define basic design criteria for micro-fluidic interconnections, considering factors such as fluid
type, pressure, flow rate, surface conditions, materials and their compatibilities, etc. Establish a recommended
standard scaling rule for dimensions of such interconnections.
6.2 Scope — Micro-sealing connections as defined in ¶5.2.3 above, for applications in two pressure ranges: below
one atmosphere and 0–125 psig, and in three temperature ranges: <0 C, 0–100 C, and >100 C.
6.3 Define Design Parameters
6.3.1 Overall dimension and weight constraints: MEMS component, subsystems,
system, fittings, manifolds.
6.3.2 For different materials used to join parts check that the differences in thermal expansion coefficients are
acceptable for the temperature range that the component or system will be used in.
6.3.3 For different materials used to join parts check material chemical characteristics are compatible (see materials
§7 below).
6.3.4 Fluid types to be used with MEMS, define gases and liquids, reference SEMI F79 (Gas Compatibility with
Silicon). List all materials in wetted path.
6.3.5 Electrical configuration, digital or analog IEEE standards?
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6.3.6 Volumes should be minimized (internal, connecting, interface/interconnection, dead volumes), give relation to
time and process response, give dry-down constraints.
6.3.7 Surface roughness requirements.
6.3.8 Design for shock and vibration criteria, Reference MIL-STD 810.
6.3.9 Leak integrity: permeability, across the seat, and inboard. Reference SEMI F1.
6.3.10 Accuracy, repeatability, control range requirements.
6.3.11 Purging capability, number of times of full scale should flow for purging, turnover requirement.
6.3.12 Direction of flow
6.3.13 Upstream filtration requirements, particle requirements, moisture, other contamination characteristics.
Reference SEMI E49 for high purity and ultrahigh purity systems.
6.3.14 Attitude constraints
6.3.15 Design for reliability requirements, MTTF, MTTR
6.3.16 Temperature limits
6.3.17 Pressure (proof, burst, inlet) limits
6.3.18 Flow ranges
6.3.19 Scaling rule for dimensions of interconnections
1
6.3.19.1 Consider scaling rule to be different for different industrial applications. For example gas and liquid
cannot use the same scaling rule.
6.3.20 Adapter guidelines for smooth transition from Macro to Micro. This is for the case the MEMS system is to
replace an existing device, and there is a mismatch of the dimensions. A flexible transition may be considered if
space is limited.
6.3.21 Surfaces that come into contact with samples, process gasses, or chemicals must not adsorb or react with
them. Select components or tubing that is: 1) inherently compatible, 2) can be treated (water rinsed, O
2
ashing, acid
clean...) or 3) coated (Teflon
®
, SiO
2
, ...), to be compatible. Consider protein materials where the quantity of
biomaterial sticking to surfaces will be dependent upon the wetted surface area and how well the fluid adsorbs to the
surface.
7 Materials Guidelines
7.1 Purpose — Provide a Matrix of Materials Compatibility for commonly used materials and provide examples of
applying the matrix to designs.
7.2 Scope — Use of this guide is limited to materials types known to be commonly used such as: silicon, polymers,
glass, metals, ceramics and plastics.
7.2.1 This guideline applies to materials which may be used in fluidic devices in large or small form factors. It is
assumed the material is in the wetted flow path as either a thin surface film or bulk material. Standard temperature
(0ºC) and pressure (1 atm) are conditions considered in this table unless otherwise stated. Physical, mechanical,
thermal, microstructural, and electrical properties of materials can be found in materials selection handbooks or
material supplier datasheets. Breadth of details for chemical compatibility and materials properties varies widely
within these literature and care must be taken to consider relevant information. unlikely that a single source of
information would be suitable.
7.2.2 The intended use of the compatibility matrix is to provide a general resource to the user. Detailed research
into materials compatibility with specific chemicals is an important part of any product development program. In
depth research into materials and fluid analysis are beyond the scope of this guide and will be required in most
circumstances.
1 Hsu, Tai-Ran; MEMS and Microsystems Design and Manufacture; McGraw-Hill, 2002 Section 6.7.
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7.2.3 The reader is specifically requested to consult the Materials Safety Data Sheet (MSDS) and the
manufacturer’s recommended practices for any fluid or component prior to use and to follow the suggestions
prescribed. In addition, the acceptable degree of chemical and material incompatibilities are relative to conditions of
use. For instance, microscopic corrosion may be intolerable in one application yet may be quite tolerable in another.
A list of such considerations is well documented in materials selection handbooks
2
, 3 , 4
.
7.3 In Service Considerations are partially listed below.
7.3.1 Operating pressure
7.3.2 Operating temperature
7.3.3 Chemical environment: dry, moist, corrosive
7.3.4 Loads-magnitude, nature-tension, bending, torsion
7.3.5 Loads-nature-static, dynamic, impact
7.3.6 Mating part materials
7.3.7 Attachment points/ mechanisms
7.3.8 Presence of potential crevices
7.3.9 Allowable deflections /rotation
7.3.10 Allowable failure modes
7.3.11 Dimensional stability needed-short and long term
7.3.12 Frequency of assembly and disassembly
7.3.13 Insulation-thermal/electrical
7.3.14 Isolation-RF, thermal, electrical
7.3.15 Chemical Potential
7.4 Manufacturing Considerations are partially listed below.
7.4.1 Cost
7.4.2 Availability of material
7.4.3 Stock shapes-availability
7.4.4 Weldability
7.4.5 Formability
7.4.6 Expected consumption rate
7.4.7 Machinability
7.4.8 Achievable surface finishes
7.5 Assembly/Transport/Shipping consideration partially listed below.
7.5.1 G Forces-allowable shock and vibration
7.5.2 Allowable Moisture
7.5.3 Allowable Temperature
7.5.4 Allowable Pressure
7.5.5 Total Weight
2 Cheremisinoff, Nicholas, P., Materials Selection Deskbook, William Andrew Publishing/Noyes, 1996, p.p. 18-36.
3 Kutz, M, Handbook of Materials Selection, 2002
4 Ashby, MF, Materials Selection in Mechanical Design, 2000