The application requires the priority of following patent application for all purposes and following patent application is by quoting simultaneouslyEnter the application: in No. 61/805,445 U.S. Provisional Application (the attorney docket 92580- that on March 26th, 2013 submits010500US-871209)；In No. 61/829,034 U.S. Provisional Application (attorney docket that on May 30th, 2013 submits92580-010600US-871209)；In No. 61/820,123 U.S. Provisional Application (agent that on May 6th, 2013 submitsReference Number 92580-011600US-871209)；And in No. 14/222,575 United States Patent (USP) Shen that on March 21st, 2014 submitsPlease (attorney docket 92580-010510US-903808).No. 14/222,575 above-mentioned U.S. Patent application is for allPurpose requires above-mentioned temporary patent application, i.e., the 61/805th, the 445 U.S. Provisional Application (generation submitted on May 26th, 2013Manage people Reference Number 92580-010500US-871209)；In the interim Shen in No. 61/829,034 U.S. that on May 30th, 2013 submitsPlease (attorney docket 92580-010600US-871209)；And No. 61/820,123 beauty submitted on May 6th, 2013State's provisional application (attorney docket 92580-011600US-871209), priority and these U.S. Provisional Patent ApplicationsIt is incorporated by reference into No. 14/222,575 above-mentioned U.S. Patent application.
Summary of the invention
The present invention relates to MEMS(microelectromechanical systems).
Embodiment of the present invention may include wafer scale centrifuge (WLC) system and the side using the system testing MEMS deviceMethod.Wafer scale centrifuge (WLC) system may include basic centrifuge system and pacify with the joining box of the basis centrifuge systemFill hub part.This method may include that smooth and continuous accelerating curve is applied to two or more by basic centrifuge systemA MEMS wafer.In a specific embodiment, accelerating curve may include the constant DC acceleration of long duration.Two or moreEach of multiple MEMS wafers can have the one or more MEMS devices being formed thereon.Two or more MEMSWafer can be set in two or more wafer keeping box, and wherein wafer keeping box configuration is on boxlike installation hub part.The partyMethod may also include the one or more target MEMS wafers of identification, this may include one that identification is located in one or more MEMS wafersThe static friction of a or multiple MEMS devices.
Other embodiments of the invention be may include pallet grade centrifuge (TLC) system and be set using system testing MEMSStandby method.Pallet grade centrifuge (TLC) system may also include basic centrifuge system and be connected with the basis centrifuge systemThe boxlike installation hub part connect.This method may include being applied to smooth and continuous accelerating curve by basic centrifuge systemTwo or more MEMS components.Equally, the constant DC acceleration of long duration can also be applied.These components may include by scribingPart, packed part or processed part etc. pallet, configure in tray box or carrier etc..These palletsBox or carrier are configurable on box installation hub part.This method may also include the one or more target MEMS components of identification or portionPoint, this may include identifying these MEMS by the static friction of one or more of scribing or part processed.
Wafer scale centrifuge (WLC) and pallet grade centrifuge (TLC) are provided which continuous, lossless method with by silicon in palletAll MEMS devices on wafer or packed part are exposed to g power (g-force), and wherein the g power is sufficiently high, to cause to moveContact between part.If any given bare die (die) on wafer is still detained after g power is removed, thenIt can be detected by chip and detect the bare die and remove the bare die from product population.Similarly, if being set to tray box or carrierIn any given packed MEMS portion be still detained after g power is removed, then then can detect inspection by chipIt surveys these parts and removes these parts from product group.
Embodiment of the present invention may include a kind of system and the method using the system testing MEMS device.In embodimentIn, the present invention provides a kind of systems of test equipment under high gravitational conditions, and wherein the system includes having rotating memberCentrifuge.Operation power can be applied to equipment, and wherein the equipment may be coupled to rotating member.The system may include rotation controlDevice may be coupled to centrifuge.The rotating control assembly can be configured to make to rotate structure in response to controlled per period revolutionPart rotation.The system may also include analytical equipment, be used to monitor related with controlled per period revolution from equipmentOne or more signals.Those of ordinary skill in the art will appreciate that other variations, modification and substitution.
In a specific embodiment, rotating member may also include and the joining power source of equipment.The power source can beBattery, capacitor etc., and can be configured to provide operation power to equipment.Rotating member may also include and the joining communication of equipmentSource.The communication source can be configured to the signal from equipment being supplied to analytical equipment.Communication source may include such source such as Wi-Fi, wireless, optical, bluetooth, near-field communication, microwave, laser etc. and combinations thereof.In addition, analytical equipment may include being configured toThe communication sink of signal is received from the communication source.
In a specific embodiment, equipment includes the accelerometer based on MEMS, is configurable on and equipment shown in Fig. 9On similar installation unit.Installation unit can spatially be configured to for the accelerometer based on MEMS being oriented to give birth to by centrifugeAt centripetal force at predetermined angle.Cube is installed by rotation, all axis of mounted accelerometer can be tested.Controlled is everyPeriod rotation may include the controlled per period revolution changed over time.In this case, analytical equipment can be configured toThe gravity changed over time for being applied to equipment is determined in response to the controlled per period revolution changed over time.Analytical equipmentIt may be additionally configured to the gravity in response to changing over time and one or more signals from the accelerometer based on MEMS determineStiction associated with the accelerometer based on MEMS.In a specific embodiment, the one or more signal can with it is multipleFormer power is associated, and wherein the recuperability is associated with the accelerometer based on MEMS.
In embodiments, the present invention provides the methods for determining defect equipment under the gravitational conditions.This methodIt may include that equipment is attached to the rotating member of centrifuge and operation power is applied to equipment.When being applied with operating work in equipmentWhen rate, the rotating member of centrifuge can have controlled rotation speed.The rotation speed can be associated with gravity.In embodimentIn, this method may include relative to gravity slewing, to apply gravity with specified angle.By with different orientation arrangementsEquipment, equipment can be tested on six all axis.Then, when being applied with operation power in equipment and by gravityWhen, one or more signals from equipment, which can be received in, to be calculated in equipment.By using equipment is calculated, in response to thisOr multiple signals and gravity, equipment can be determined as defect or be not defect.
In a specific embodiment, this method may include connection power source to rotating member and equipment, to mention to equipmentFor operation power.The power source can be selected from battery, capacitor etc..
In a specific embodiment, this method may include applying adjustment factor when being applied with operation power in equipment to settingIt is standby, and output response is believed in the one or more of adjustment factor when being applied with operation power in equipment and by gravityNumber.In addition, the one or more signal can be exported from the joining communication source of centrifuge.The one or more signal can be from logicalBelieve mechanism output, wherein the communication agency is selected from Wi-Fi device, wireless device, Optical devices, blue-tooth device, near-field communication dressIt sets, microwave device, laser aid etc..
In a specific embodiment, equipment may include the accelerometer based on MEMS, and the method for controlling rotation speedStep may include the timely rotation speed for changing rotating member.In response to one or more signals and rotation speed and and accelerationCounting associated static friction source can determine in calculating equipment.In addition, the one or more signal can be associated with recuperability,In the recuperability it is associated with the accelerometer based on MEMS.
Other embodiments of the invention can be related to test the various equipment based on MEMS with detection quality.
With reference to specific embodiment and attached drawing, each other purpose of the invention, feature and excellent can be more fully understoodPoint.
Specific embodiment
The present invention relates to MEMS(Micro-Electro-Mechanical-Systems, microelectromechanical systems).MoreBody, embodiments of the present invention provide the method and knot for improving the integrated MEMS device including inertial sensor etc.Structure.
Embodiments of the present invention, which are provided, to be contacted for stimulation MEMS in a controlled manner to be detected for static frictionAnd possibly screen the solution of the MEMS device of wafer form.This method can be applied to from wafer to complete packing deviceMEMS device in any development phase.
In many MEMS devices, silicon structure is designed to move due to given accelerate, or moves as side effect,And it is contacted when reaching end of travel with another surface.Problem is, stimulates MEMS device to reach the usual side of contact pointMethod includes mechanically percussion mechanism.Under wafer form, these methods are unavailable, and these methods are moved in view of complicatedIt is not reproducible in the case where state shock-testing.
Wafer scale centrifuge (Wafer Level Centrifuge, WLC) and pallet grade centrifuge (Tray LevelCentrifuge, TLC) continuous, non-destructive mode is provided which to expose all Silicon Wafers in pallet or be sealedThe MEMS device on part is filled, so that g power is sufficiently high to cause the contact between movable part.If be removed in g powerAny given bare die on wafer is still detained afterwards, detects and removes from product group then the bare die can be detected by chip.ClassAs, if any given packed MEMS portion being arranged in tray box or carrier after g power is removed still is detained, thisA little parts can be detected by chip and detect and also remove from product group.
Alternative is packed part shock-testing or centrifuge, this is very expensive and time-consuming.
Fig. 1 is the picture of conventional centrifuge.The centrifuge is the G-5005 type centrifuge of OKTEK.Embodiment party of the inventionFormula may include this centrifuge, be exposed to rotary centrifugal force (RCF) for will be up to 48 " wafers with being designed to provideUnique platform custom hardware.Other existing centrifuge models etc. can be used in WLC system as described herein.TheseWLC system is designed to easy to use and safe.For example, the existing centrifuge of repacking can be efficient and may be onlyNeed cross head driver.
Fig. 2 is the picture with traditional wafer keeping box of wafer.The wafer keeping box is 2 slot type titanium wafer cassettes, toolHave the Delrin(Delrin for crystal round fringes protection) hub part.These wafer keeping box can be used in one or more of WLC systemIn a embodiment.
Fig. 3 is the picture of traditional wedge-shaped center hub part.The center hub part can be the wedge-shaped center hub part of pin joint, canIn one or more embodiments of WLC system.Tenon joint type (dovetail) center hub part of these types can provide boxQuick insertion and removal, allow operation readiness and to minimize the risk of operator's setup error.Releasedly by boxThe other similar mechanisms for being fastened to drive hub part can be also used in the position of tenon joint type hub part.
Fig. 4 is the picture of wafer scale centrifuge (WLC) system of embodiment according to the present invention.Here, two wafersKeeping box is configured in a vertical manner on central tenon joint type hub part, which is attached to basic centrifuge.It is makingIt makes, hub part and box are critically balanced.
In specific embodiment, wafer is loaded in face of the top (landing pad side) of tenon joint type mounting rack.This is by g powerIt is located in the +Z direction about the MEMS device on wafer.Every side of WLC system needs to match with the wafer of identical quantityTo ensure balance appropriate.Do not make component appropriate balance that there can be safety hazard.Rotating wafer (spinning wafer) can wrap2 or 4 wafers or even number wafer are included to ensure to balance.
Fig. 5 is to show embodiment according to the present invention to use the schematic diagram of the method for WLC test manufacture MEMS device.The figureShow producer and many wafers be provided to test reception device, these wafers can be with one formed thereon orThe MEMS wafer of multiple MEMS devices.Test trigger can initiate WLC test processes, independently of CP trigger.Then pass throughWLC test/Screening Treatment wafer becomes fully enclosed product.
The embodiment of method may include some or all of following steps:
One or more wafers are inserted into one or more wafer keeping box.Wafer keeping box can be pre-installed in centrifugationIt is mounted in centrifuge in machine or after wafer is inserted into it.
Controlled accelerating curve (programmed curve, such as smooth, continuous, step-by-step movement are applied to Silicon Wafer, pulse etc.).
One or more wafers are removed from box (before or after removing box from centrifuge).
The stimulating method is incorporated in probe of wafer production stream, such as determines which is in the MEMS device of wafer scaleWith/do not have static friction problem, and by MEMS device and without the wafer separate of static friction problem.
Embodiments of the present invention may include wafer scale centrifuge (WLC) system and use the system testing MEMS deviceMethod.Wafer scale centrifuge (WLC) system may include basic centrifuge system and the box installation for being connected to basic centrifuge systemHub part.This method may include to one or more MEMS wafers by basic centrifuge system using controlled accelerating curve(for example, smooth and continuous accelerating curve, the curve of piecewise-linear, static acceleration, long-time constant acceleration etc.).OneEach of a or multiple MEMS wafers can have one or more MEMS devices formed thereon.Two or moreMEMS wafer may be provided in two or more wafer keeping box, two or more wafer keeping box are configured in box installationOn hub part.This method may also include the one or more target MEMS wafers of identification, it may include pass through probe of wafer or other electrical measurementsTrial sets the static friction for identifying one or more MEMS devices in one or more MEMS wafers.
Other embodiments of the present invention include disc centrifuge (TLC) system and use the system testing MEMS deviceMethod.Disc centrifuge (TLC) system may also comprise basic centrifuge system and the box installation for being connected to basic centrifuge systemHub part.This method may include to two or more MEMS components by basic centrifuge system using smooth and continuous accelerationCurve.These components may include the scribing being configured in disc type cassette or disc type carrier etc., encapsulation or processed partDisk etc..These disc type cassettes or carrier are configurable on box installation hub part.This method may also comprise the one or more targets of identificationMEMS component or part may include the static friction in the one or more for identify these MEMS scribings or part processed.
Fig. 6 is the schematic diagram for acting on the power on the wafer in centrifuge for showing embodiment according to the present invention.TheseEquation shows force vector ApzAnd AnIt is equal.
Z g force vector between the bare die of wafer center and the bare die of edge does not have difference.
However, there are bigger differences for Y g power.It is zero tangential force in wafer center.At crystal round fringes, tangential force is10.16K, higher than the g power 13% in Z-direction.
For the general equation of the angular speed under desired g power are as follows:
Fig. 7 is rotary centrifugal force (the RCF)-angular speed relationship schematic diagram for indicating embodiment according to the present invention.
Fig. 8 is the simplified stream for showing the method using WLC system manufacture MEMS device of embodiment according to the present inventionCheng Tu.This method uses the WLC system with the basic centrifuge system for being connected to box installation hub part, such as outlined below:
801. provide wafer scale centrifuge (WLC) system with the basic centrifuge system for being connected to box installation hub part；
One or more MEMS wafers are inserted into one or more boxes by 802.；
One or more boxes are connected to box installation hub part by 803.；
804. pairs of MEMS wafers apply controlled accelerating curve；
805. remove one or more MEMS wafers from one or more boxes；
806. determine one or more MEMS devices with physical problem on wafer；And
807. execute other required steps.
As shown, this method has series of steps, these steps are changeable, modification, replacement, reset, expand, reductionOr any combination of them.That is, this method repeats any of above step.These steps can individually carry out or withOther descriptions or even without description the step of combination carry out.These steps can be carried out in the order shown or in other sequencesSuddenly, if necessary.Other processing steps can also be used using the combination of hardware and software to carry out these steps.It can also makeThese steps are carried out with other processing of the realizations such as hardware or software.Certainly, many other modifications may be present, modify and replaceIt changes.Other details of this method can be found in the whole instruction and in greater detail below in description.
In one embodiment, the present invention provides the methods for using WLC system testing MEMS device.As shown in figure 8,This method can begin at step 801, provide WLC system.In step 802, one or more MEMS wafers can be inserted into oneOr multiple boxes, each MEMS wafer have at least one MEMS device formed thereon.In specific embodiment, oneOr multiple wafers may include two or more wafers (even number wafer), and can be inserted into (even number in two or more boxesA box), box is configured on box installation hub part in a manner of accurate balance.Each MEMS wafer may include top or landing padSide.In step 803, these boxes can be connected to the box installation hub part of WLC system.MEMS wafer and box may be configured so that eachThe top surface of MEMS wafer installs hub part to box.Box is either vertically or horizontally mounted on box installation hub part.
In step 804, it is carried out in WLC system once, controlled acceleration can be applied to MEMS wafer by WLC systemIt writes music line.In step 805, after the processing in WLC system, one or more MEMS wafers are moved from one or more boxesIt removes.In step 806, the MEMS device with physical problem on these wafers is then identified.These physical problems may includeStatic friction problem in MEMS device.Other steps can be if necessary additionally carried out.
In one embodiment, MEMS is tested using wafer scale centrifuge (WLC) system the present invention can provide a kind ofThe method of device, the WLC system include basic centrifuge system and the box installation hub part for being connected to basic centrifuge system.The partyMethod may include providing two or more MEMS wafers, and each MEMS wafer is filled with one or more MEMS formed thereonIt sets.Two or more MEMS devices are configurable in two or more wafer keeping box.In one embodiment, it may be presentEven a or four MEMS wafers, it is therein that each there are one or more MEMS devices formed thereon.
These wafer keeping box are configurable on box installation hub part.It is brilliant that box can be the 2 slot type titaniums with Delrin hub partCircle box, but other wafer cassettes can also be used.In specific embodiment, the MEMS wafer in wafer keeping box can accurately be put downThe mode of weighing apparatus configures on hub part.Wafer keeping box can be installed vertically or horizontally.Box installation hub part may include the joggle of pin jointFormula central box installs hub part.
In specific embodiment, each of two or more MEMS wafers include top or landing pad side.When installing MEMS wafer and wafer keeping box, configuration may include positioning MEMS wafer so that each of in wafer keeping boxThe top surface of wafer installs hub part to box.These wafer keeping box can also be configured so that from the g power phase for applying accelerating curveThe direction Z+ is oriented in for one or more MEMS devices in each MEMS wafer.
Controlled accelerating curve can be applied to MEMS wafer by basic centrifuge system, and can recognize one or moreA target MEMS wafer.Controlled accelerating curve may include smooth accelerating curve, static acceleration curve, continuous accelerationIt writes music line, step-type accelerating curve, pulse acceleration curve, long term constant accelerating curve or other curves.More specificallyGround, the MEMS device that one or more shows static friction can be identified in MEMS wafer.It can be in identifying processing using eachKind processing, including chip detection, probe of wafer, conventional detection production etc. and their combination.
Fig. 9 is mounted to the customization 8DUT(measured device of multiaxis test block) it is centrifuged the picture of plate.The DUT test board can wrapInclude the PCB(printed circuit board being arranged on installation cube), it may be configured for 8 equipment (showing on circuit boards),This 8 equipment can be MEMS device, MEMS package part etc..In various embodiments, according to application and/or equipment rulerIt is very little, the equipment of different number can be mounted on test board (for example, 2,4,6,10 etc.).
Figure 10 is the picture with embodiment according to the present invention, the centrifuge measuring system of customized modification.Such asShown in figure, the bluetooth transceiver being battery powered is installed in the center of hub part.Two DUT boards are installed in opposite end.As shown in figure 9, these DUT boards can be customized 8DUT centrifuge plate.The configuration provides the appearance of 16DUT in single runAmount.These DUT boards can be configured in various positions through the installation cube for making to be equipped with the PCB with MEMS device aboveBody rotation or all 6 axis for realizing stimulation relative to the direction of the centripetal force generated by centrifuge plate system by changing plateLine (- x ,-y ,-z ,+x ,+y ,+z).
Figure 11 is the measured device (DUT) of embodiment according to the present invention or the picture of centrifuge measuring system.DUT canTo be wafer, bare die, encapsulation chip, active package chip etc..As shown, the fixing shell including revolving part or arm can coupleTo calculating equipment.Fixing shell can be basic centrifuge instrument or system, the G-5005 type of all OKTEK as shown in Figure 1Centrifuge.Similar to Figure 10, DUT test board and battery may be coupled to the end of rotating arm.
In a specific embodiment, revolving part can also comprise the power supply for being attached to the equipment.The power supply can be battery,Capacitor etc., and be configured to the equipment and operation power is provided.Revolving part can also include being attached to the deviceCommunication source.The communication source may be configured to provide the signal from the equipment to analytical equipment.The communication source may include such as Wi-The source of Fi, wireless, optics, bluetooth, near-field communication, microwave, laser etc. and combinations thereof.In addition, analytical equipment may include being configuredAt the communication control processor for receiving signal from the communication source.
In a specific embodiment, which includes the accelerometer based on MEMS.Controlled per period revolution can wrapInclude the controlled per period revolution changed over time.In this case, analytical equipment can be configured in response to controlledThe per period revolution changed over time determines the gravity changed over time for being applied to the equipment.Analytical equipment can also be matchedIt is set to the gravity in response to changing over time and one or more signals determination from the accelerometer based on MEMS and baseIn the associated stiction of the accelerometer of MEMS.In a specific embodiment, these one or more signals can with it is multipleFormer power is associated, wherein recuperability is associated with the accelerometer based on MEMS.
In embodiments, centrifuge measuring system can be configured to have multiple customized modifications, in order to which MEMS is setThe test of standby, package of MEMS part etc..Rotating arm can be by being electrically coupled to USB(universal serial bus) DAQ(data collection system)The optical switch of module controls.The USB DAQ module may be coupled to calculating equipment, such as desktop computer, tablet computer,Mobile phone etc..In addition, bluetooth transceiver can be set in fixing shell, and it is configured to transmit from DUT test boardData (as shown in Figure 9).Various software measurement tool LabVIEW etc. can be used to locate for data from bluetooth transceiverReason.
Figure 12 is the schematic diagram for showing the method for the measuring system of centrifuge of operation embodiment according to the present invention.MoreBody, the figure shows applied acceleration (acceleration of g) and the accelerating curve as time goes by and according to equipmentExport the relationship of (RBM) between the static friction energy found in DUT as time goes by.Indicate two key points: MEMSWhen detection quality (PM) and MEMS stop structure are contacted, and when PM is released.
In embodiments, the present invention provides the methods for determining defective equipment under high gravity.This method canRevolving part including equipment to be attached to centrifuge, and apply operation power to the equipment.The revolving part of centrifuge have byThe rotation speed of control, and the equipment has the operation power being applied thereto.The rotation speed can be associated with gravity.In realityIt applies in mode, this method may include that the equipment is rotated relative to gravity, to apply gravity with specified angle.By in not TongfangThe equipment is upwardly biased, the equipment can be tested on all 6 axis.Then, there is the operation applied with thereon in the equipmentPower and while by gravity, can receive one or more signals from the equipment in calculating equipment.It is set using calculatingIt is standby, in response to one or more signals and gravity, it may be determined that the equipment has zero defect.
In a specific embodiment, this method may include that the power supply that will be coupled is attached to revolving part and equipment, thus forThe equipment provides operation power.The power supply can be selected from battery, capacitor etc..
In a specific embodiment, this method can further include while the equipment has the operation power being applied theretoAdjustment factor is applied to the equipment, and has in the equipment and applies with operation power thereon and while by gravity, fromThe equipment output response is in one or more signals of adjustment factor.In addition, one can be exported from the communication source for being attached to centrifugeA or multiple signals.These one or more signals can be from Wi-Fi, wireless, optics, bluetooth, near-field communication, microwave, laserThe communication mechanism selected in is exported.
In a specific embodiment, which may include the accelerometer based on MEMS, and control the side of rotation speedMethod step may include the timely rotation speed for changing revolving part.Calculate can determine in equipment in response to one or more signals andRotation speed static friction associated with accelerometer source.In addition, one or more signals can be associated with recuperability,In, recuperability is associated with the accelerometer based on MEMS.
Figure 13 is the schematic diagram for showing the method that embodiment according to the present invention explains DUT.The attached drawing is provided for solvingRelease the energy equation of the data in the centrifugation test process of one or more equipment.As previously mentioned, during the test by threeCrucial moment: test time started T0, landing time TTDWith release time TR.In T0Place, centrifuge is operated with 0RPM, thus az=0g.In TTD, there is the acceleration for ramping to the first acceleration at place, wherein az=a1.In TRPlace has ramp down to the second accelerationThe acceleration of degree, wherein az=a2.As shown, DUT is the equipment with the detection quality (PM) for serving as spring.Provide equationAnd contact the ENERGY E of PM to substrate surfaceTdThe ENERGY E of=F × d and storage in the springs=(1/2)K×d2.Herein,ETd=Es。
Figure 14 is the schematic diagram for showing the conservation of energy of DUT of embodiment according to the present invention.Shown by hereinIt is that landing energy is recuperability, recuperability is stored in the energy in spring.The equipment illustrates if not no static frictionIn the case of detection quality position.By static friction, static friction energy is subtracted equal to landing energy and is released energy.Ratio using the ratio equal to energy as static friction acceleration (a1-a2) and landing acceleration (a1).
Inherent static friction energy is defined as the static friction energy (that is, Van der Waals force) from pure surface physics.By otherFactor is added to inherent static friction energy to form total static friction energy.These factors may include that the pollutant of form membrane is (organicObject), contact surface treatment/topological structure, particle, surface hardness (impact can change topological structure if soft) etc..TheseOther factors can be changed quite greatly with the variation of manufacturing process, and many things can influence the static friction recovery of MEMS devicePotentiality.All of these factors taken together all shows need stiction nargin why.
Figure 15 is the schematic diagram for showing the static friction for DUT of embodiment according to the present invention and restoring to consider.Top is attachedIllustrating particle can be to the effect of the reduction of the spring energy stored.EsWith particle diameter dpSquare reduce.Central diagram showsOut due to the increase of the static friction energy of surface contamination.Bottom attached drawing shows the irregular static friction due to surface topologyThe reduction of energy, surface topology irregularly cause contact area to reduce.
If static friction energy or the unchanged property that releases energy, static friction limitation is set as E(stiction)/ETD<1.0 being sufficient.In other words, ETD>E(stiction).However, due to variability, it is therefore necessary to release energy and landing energyBetween have nargin, to ensure that live part will not be clung.In order to be similar to ensure that institute is required in the case where all changesNargin, experience static friction data and SEM particle from system described herein and measurement of centrifuge method can be used in weDimension data.
Figure 16 and Figure 17 is embodiment according to the present invention, for the calculating of energy variation estimation and static friction narginSimplify indicate.Returned energy is previously stored the energy in spring, and by reducing due to the factor vr of particle size.?In specific embodiment, SEM data of the factor from design and for metal bump equipment is estimated as vr=(1-(0.5/1.6))2=0.473.In addition, static friction energy passes through the factor v due to process variabilitysTo increase.In a specific embodiment,The factor is estimated as v from the experience variability data from measurement of centrifuges≈80/20=4.Using these factors (in Figure 16Show), final static friction nargin can be identified as E(stiction)/ETD=vr/vs=14%.Of course, it is possible to have other variations, modify and replaceGeneration.
Figure 18 is the schematic diagram for showing the user interface of analytical equipment of embodiment according to the present invention.Number from DUTAccording to that can be recorded and show on the screen, to allow user to be readily determined the quality of these equipment.
It will also be appreciated that example and embodiment described herein are for illustrative purposes only, and suggestThose skilled in the art carry out various modifications or change according to these examples and embodiment, these modifications or variation are included withinIn spirit herein and permission and the scope of the appended claims.