CN102856239B

CN102856239B - Predetermined element is placed in the apparatus and method of target platform

Info

Publication number: CN102856239B
Application number: CN201210029462.7A
Authority: CN
Inventors: 孔-琛·陈
Original assignee: WENTAIKE INDUSTRY CO LTD
Current assignee: WENTAIKE INDUSTRY CO LTD
Priority date: 2006-07-31
Filing date: 2006-07-31
Publication date: 2018-03-30
Anticipated expiration: 2026-07-31
Also published as: CN102856239A

Abstract

The invention discloses a kind of apparatus and method that predetermined element is placed in target platform.Present invention relates generally to package technique.According to the present invention, alignment and the Detection Techniques that element placement precision is improved in assembling are described.More specifically, present invention resides in various Detection Techniques by element combination alignment mark and on target platform combine reference marker and detect with Further aim platform element place the degree of accuracy method and structure.Composition array can detect the skew of offset component to form one group of sensor of multisensor probe in assembling.

Description

Predetermined element is placed in the apparatus and method of target platform

The present invention is to be based on application number 200610109038.8, and the applying date is on July 31st, 2006, applicant " Wen Taike Industrial Co., Ltd ", the divisional application of entitled " apparatus and method that predetermined element is placed in target platform ".

Technical field

Present invention relates generally to package technique, more specifically, the present invention is included by using various Detection Techniques right Fiducial mark note is attached on element and reference marker is attached on target platform and element is detected and improved on target platform and is put Put the structures and methods of the degree of accuracy.

Background technology

Electronic device has developed for many years.With complexity and the speed of service increase of integrated circuit (IC), have super Cross hundreds of or even 1,000 quantity of device of number of pin be continuously increased, this is not uncommon.For example, high speed design Need more power and ground pin.This differential pair instead of device input and output pin (I/O) place it is single-ended Signal, to meet signal integrity requirement.In addition, as system on chip comes true, increasing pin is added to To support more functions in device I/O.In a word, many (if not all of) in these pins tends to increase encapsulation Number of pin in device or element.

With the increase of number of pin, the lead pin pitch of device tends to reduce and limit the increase of package dimension.Reduce Lead pin pitch, particularly if lead pin pitch is less than 0.5mm, to element is accurately placed in into target platform (such as, printed circuit Plate (PCB)) on place apparatus propose challenge.

Traditional Surface mounted devices are as a reference point to incite somebody to action using rectangular co-ordinate at the center of Target Weld area pattern Element is placed on PCB.The degree of accuracy for carrying out monitoring element placement is not fed back.There is no appropriate feedback, the degree of accuracy that element is placed It is uncertain.In fact, element place the degree of accuracy by encapsulation profile the defects of, element contact array from preferable grating position Deviation, PCB encapsulation with reference to the defects of, the aging of place apparatus and the influence of inherent tolerance etc..As accumulated error approaches The spacing dimension of contact array, element is properly placed on PCB to the problem of being very big.

It is not difficult to encounter component placement problems during assembly line is installed on surface, particularly places thin space element.If for example, BGA elements are inaccurately placed on PCB, then BGA contact arrays can be caused to be offset from preferable weld zone pattern position, cause to weld Connect deficiency or solder is bridged to pad adjacent on PCB.It is dull and costliness to correct doing over again for these problems.For highly dense Doing over again for the high pin number element of high price spent on PCB is worse.

Moreover, the chip of high-end high number of pin is contained on motherboard by manufacturer commonly using socket.This causes user The element of correct speed class or middle execution speed upgrading can be selected at the scene.However, for user or manufacturer, do not have There is easy method to monitor whether chip is correctly inserted on socket or whether chip contacts well with the jack in socket.

It can be seen that, it is necessary to place the degree of accuracy and technology for detecting contact condition for detecting and improving element.

The content of the invention

Present invention relates generally to package technique, describe alignment that the degree of accuracy that element is placed is improved in assembling and Detection Techniques.More specifically, the present invention includes being attached on element alignment mark by using various Detection Techniques and reference Mark is attached on target platform and detects and improve the structures and methods that element places the degree of accuracy on target platform.Form battle array Row can detect the deviation of displacement component to form one group of sensor of multisensor probe in assembling.Only by example Mode, apply the present invention to by packaging be placed in for electronic system manufacture electronic substrate.It should be appreciated that The present invention has broader application.

In a specific embodiment, the invention provides a kind of technical solution, for IC or packaging, There is one group of one or more alignment mark in predetermined area of space on IC or packaging.According to the embodiment, encapsulation Device can be packaged in the integrated circuit in such as plastics (for example, epoxy), ceramics (for example, aluminium dioxide) or other materials Device, packaging contain multiple I/O contacts and multiple weld pads for being connected to I/O contacts.Packaging can be that more IC are stacked Device, more encapsulation stacking devices or multi-chip carrier.Packaging, which can also be, is laminated with anisotropic conductive elastomer (ACE) Film is as IC-components of interconnection interface for external connection, etc..This group of alignment mark monitors that the packaging exists Placement in target substrate or platform, whether it is precisely placed to such as print with the multiple external connections judged on device Circuit board, motherboard, ceramic wafer, bare die IC or other packagings and element target substrate or platform on weld zone pattern Place.If packaging is not placed accurately, alignment mark can also be used for obtaining feedback with the inclined of adjusting means position From.For simplicity, IC and packaging are referred to as element.

In a specific embodiment, alignment mark is the reference zone on element, and external probes can use should The accuracy that element of the alignment mark monitoring on target platform is placed.The alignment mark being incorporated on element can be in element On as direct alignment mark connection surface region from the top to the bottom conducting path, or can be as indirect alignment The different conducting paths that two surface regions are connected at the bottom of element of mark.Except being used as conducting pathway in element Footpath, alignment mark can also be the simple surfaces mark on element, and this depends on used detection method.Alignment mark Structure can be simple geometry or one group of geometry.

For each alignment mark on element, reference marker can be added to target platform and place reference for element. In a specific embodiment, the present invention is provided to such as printed circuit board (PCB), motherboard, ceramic wafer, bare die IC or other envelopes Device and the technical solution of component object substrate or platform are filled, it is one or more by combining one group at the domain of predetermined partition Reference marker, place and refer to for element.Reference marker can be connected to the other with reference to mark of same target platform with conducting path Note.It is connectable to the earth terminal in target platform, or it can be simply the surface markers on target platform, and this takes Certainly in used detection method.

In a preferred embodiment, the present invention is provided to improve the probe technologies solution of element placement precision.Visit Head can be single-sensor probe or can be sensor array.Single-sensor probe be capable of detecting element place precision and The state of element contact conditions on target platform.It is made up of sensor array and becomes the probe of multisensor probe, Neng Goutong Cross by one or more alignment marks on element the probe positions of aligned reference marker and adjust offset component Skew.Multisensor probe is capable of the skew of detecting element and to feed back the information to place apparatus inclined to correct the position From.Although single alignment mark can compensating element offset error, two alignment marks can correct the azimuthal error of placement.Probe It can be the combination of Resistance probe, capacitance probe, optic probe or these probes.Resistance probe is used for on/off measure, and electric capacity is visited Head is used for opposed area overlapping between measurement sensor surface and object reference, and optic probe, which is used to measure, comes from object reference Reflection.Reference probe is contact probe head.Capacitance probe and optic probe are non-contact probes.It is effective on multisensor probe The scope of sensor can be automatically determined by sensing the size of target reference marks.

In a specific embodiment, the present invention is provided to be directed at member on target platform under various Detection Techniques The method of part.

This method includes the region that the element including one or more alignment marks is placed on target platform.Target platform On region contain object construction and one group of reference marker by probe monitors, whether mesh has been accurately placed in judgment component Mark in structure.On PCB, object construction is element weld zone pattern.It is corresponding for each alignment mark on element Reference marker can be included on weld zone pattern.Top alignment mark relative to the contact array in component base sky Between relation should match spatial relationship of the reference marker relative to the contact array on weld zone pattern.This method is additionally included in mesh The method of multisensor probe is directed in case of marking on a map, the effective range of this group of multisensor is determined, adjusts and popped one's head in relative to alignment Position of components.

Because alignment mark can be in device manufacture or component encapsulation process relative to the spatial relationship about contact array In accurately control, so spatial relationship fixed between the contact array being able to ensure that in alignment mark and device or encapsulation. This allows the encapsulation (tilting encapsulation) or not fine along the line between adjacent tube core in physical contours with small gradient The bare die of ground heartcut can also be used to assemble.Because in assembling, element is placed and at this moment can relied on to fiducial mark The position of note, rather than the geometric tolerances by encapsulation profile.In a specific embodiment, the invention provides one kind side Method, the corresponding contact region that physically substandard device or encapsulation can be arranged on PCB or target platform.Often exist Cause the physically substandard device of misalignment issues will to be no longer abandoned in assembling.In the die separation of device or In the molding of the encapsulation of element, bigger tolerance means higher element yield.

Many benefits can be obtained by way of the present invention is better than traditional technology.This technology can easily use according to The technique for relying conventional art.In certain embodiments, it this method provide and improve yield, reduce to do over again and improve and place accuracy Means.In addition, this method provides the technique compatible with traditional technology, without to traditional equipment and technique progress Substantial modification.The present invention is to ultra-fine contact spacing and more than hundreds of or the device of even 1,000 contact especially has With.

Moreover, the invention provides a kind of method, it is used as monitoring by the use of anisotropic conductive elastomer (ACE) and interconnects boundary The placement of the device of face encapsulation.For various application scenarios, it can make non-soldered ball base packaging group efficiently and with precision It is attached to target platform or PCB.Anisotropic conductive elastomer contains only elastic insulated with being embedded in for certain direction conduction electric current A large amount of tiny conductive metal pipes of silicone resin film.It is used as in the test jack of high density and high number of pin interconnection with There is provided it is excellent contact, repeatability and the high frequency characteristics in IC device detections.Interconnected as interface for device and encapsulation It is feasible.The device or element for being laminated with ACE can be mounted directly in target substrate.Fixture cover can be used for device It is clamped together without device is welded in target substrate, if accurate placement technique can be obtained.This alignment skill Art can make the assembling of the ACE lamination devices in electronic system become feasible.

According to the embodiment, one or more of these advantages can obtain, and throughout the specification will in further detail Description.The various additional objects, features and advantages of the present invention can be by referring to following detailed description and accompanying drawing more Add full understanding.

Brief description of the drawings

Figure 1A is the example of preferable encapsulation；

Figure 1B is the example for tilting encapsulation；

Fig. 1 C are the examples of the substandard encapsulation with contact array deviation grid；

Fig. 2 shows the placement of the grid deviation element on weld zone pattern, after the placement all contacts on element from Weld zone pattern shift identical offset；

Fig. 3 shows that the element with one group of conducting path is placed on target platform, and the target platform has the weldering of matching Area's pattern and reference marker are connect, for checking placement precision and contact conditions；

Fig. 4 shows the different configuration of alignment mark, wherein all points tested as contact array in identical Side, this is the simplification figure of indirect alignment path and indirect alignment mark；

Fig. 5 is shown with single detection probe to check the example of placement precision and element contact conditions；

Fig. 6 is shown with the example that four probes are used for the position skew that detecting element is placed；

Fig. 7 shows the general test probe being made up of test point array, the skew placed for detecting element, is popping one's head in On work test point can in the process (on-the-fly) determine；

Fig. 8 shows the use on one group of S/R latch, to track the position of work test point and by test probe The example at the center of center alignment target reference marker, this group of S/R latch can be replaced by one group of writeable latch.

Fig. 9 is shown with two groups of latch to determine the direction of offset component and displacement, and state is by the first of binary system pair One group of latch that position represents, the overlap condition between alignment mark and reference marker is represented, state is by the second of binary system pair Another group of latch that position represents, represent the position of work test point；

The center that Figure 10 is shown with three groups of latch so that small alignment mark restricted publication of international news and commentary entitled to be marked, the in tuple the 3rd Position represents the effective range of the work test point for being directed at smaller test point；

Figure 11 is shown on being understood using the chart of general test probe amendment offset component.Wherein, pair on element Quasi- label size is less than the size of reference marker；

Figure 12 is the simplification figure for showing test probe, and the test probe is laminated with anisotropic conductive elastomer (ACE) work For interconnection interface, to improve the contact conditions between test point and alignment mark or between test point and reference marker；

Figure 13 shows to combine the example of the azimuthal error during two alignment marks are placed with compensating element on element；

Figure 14 shows the simplification figure of the series connection alignment chain on target platform；

Figure 15 is the simplification figure of capacitance sensor, and it is with protection body come the electric field of focus sensor；

Figure 16 is the simplification figure for showing one group of capacitance sensor, and the sensor group is right for non-contact electricity to be formed into array Accurate multisensor capacitance probe；

Figure 17 is the example on being stacked using electric field technique of alignment with monitoring element；

Figure 18 is illustrated that the different application of electric technique of alignment, for the object alignment that will be marked with four sensor alignments To the second object marked with four triangular references；

Figure 19 shows the transparent light path on element, can act as optical alignment marks, if with target platform The reflective pad matched somebody with somebody combines, and it can be used for the precision for improving element placement；

Figure 20 is the simplification figure for showing photodetector array, and the photodetector array forms in an array manner, with Form the multi-detector optic probe for element alignment；

Figure 21 is a kind of simplification figure of optical configuration, and the optical configuration has four photoelectric detectors and four I/V amplifications Device, for adjusting the skew of offset component.

Embodiment

According to the present invention, alignment and the Detection Techniques that the degree of accuracy that element is placed is improved in assembling are described.More specifically Ground, the present invention include being attached on element alignment mark by using various Detection Techniques and reference marker being attached to target The structures and methods that element places the degree of accuracy are detected and improved on platform and on target platform.So that array forms and forms pass more One group of sensor of sensor probe, can detect the deviation of displacement component in assembling.Only by the mode of example, this is sent out It is bright to be applied to for packaging to be placed in the electronic substrate for electronic system manufacture.It should be appreciated that the present invention is with wider Application.The further detail below of the present invention can find in the specification of the whole present invention, and in more detail under Face.

Alignment mark

According to preferred embodiment, alignment mark is the reference zone on element, and external probes can use alignment mark Monitor the degree of accuracy that the element on target platform is placed.The alignment mark being attached on element can be as directly to fiducial mark The conducting path in the connection surface region on element from the top to the bottom of note, or as indirect alignment mark in member The bottom of part connects the different conducting paths of two surface regions.Although conducting path from top to bottom needs not be forthright Footpath, but the straight path of the top and bottom position matched from the top to the bottom or on element, it is easier to visually and alignment mark The position of the bottom contact of association.Can be contact or difference on contact array in the surface region of the conducting path of bottom Accessing points.Except the conducting path in element, alignment mark can also be the simple surfaces mark on element, and this depends on institute The detection method used.The structure of alignment mark can be simple geometry or one group of geometry.

Alignment mark on element can be single alignment mark or one group of alignment mark.Normally, one to fiducial mark Note is enough.If the size of element is larger or can require orientation adjustment to improve the placement degree of accuracy, added to element Second alignment mark.It is tangential inclined from preferable weld zone pattern for the distal contact in big element if the error in orientation Defection is significant.For small element, because the consequence of the error in smaller orientation is inapparent.

Depending on Detection Techniques, when probe, which is used for monitoring element, places the degree of accuracy, probe can be direct with alignment mark Contact or be not directly contacted with.If Resistance probe is used for monitoring the position of alignment mark, it needs directly to contact.If electric capacity Probe is used for monitoring the position of alignment mark, then unwanted directly to contact.In both cases, alignment mark is electric alignment Mark, because conduction electric current flows through alignment mark, in addition to one is DC electric current and another is AC electric currents.If optics is visited Head is used for the reflection for monitoring the surface from alignment mark, then then alignment mark is optical alignment marks.Thus, in element Top surface on reflect, conductive mark can use as electric alignment mark or as optical alignment marks, this is depended on How alignment mark constructs and using which kind of Detection Techniques.

Reference marker

For each alignment mark on element, corresponding reference marker can be added to target platform and be placed for element With reference to.Alignment mark and the spatial relationship of contact array should match on target platform reference marker and associate on element The spatial relationship of weld zone pattern.Reference marker can be a part for the element contact weld area pattern on target platform.Take Certainly in Detection Techniques and application requirement, reference marker can with or need not can directly be contacted with the bottom of alignment mark.At one Under particular situation, if reference marker is simply the surface markers on target platform, and if alignment mark is also Simple surfaces mark, and at this moment then the tip position of the alignment mark on element can select in such a way so that its A point in the midpoint of contact array on matching weld zone pattern or corner point, to eliminate to additional reference on target platform The needs of mark.

The uncertainty that element is placed

A useful aspect is to place the accurate physical contours for being no longer dependent on element surely in technique of alignment at present, also not Dependent on the grid degree of accuracy of the contact array from element edge.If for example, molding process cause in the encapsulation of completion it is small Tilting so that the contact array in encapsulation is no with the edge encapsulated parallel well (tilt and encapsulate), under traditional technology, Especially when package dimension is larger and array pitch size is smaller, it is difficult to which the encapsulation is correctly positioned in into weld zone pattern On；The encapsulation (encapsulation that grid deviates) offset for contact array from preferable grating position, and so.Traditional place apparatus As a reference point so that element is placed on it using the rectangular co-ordinate at weld zone pattern center, this is based on hypothesis element Physical contours are that do not have defective, and its contact array is accurately with respect to all sides of element according to the rating of machine of encapsulation Edge positions.

Figure 1A shows the example of preferable encapsulation.It, which has, does not have defective physical contours (for example, not having defective encapsulation wheel Exterior feature is 101) and all package contacts are on drawn grating position.Figure 1B shows to tilt the example of encapsulation, wherein contact battle array Row are not parallel to encapsulation physical contours, and favour preferable grating position (for example, being taken turns by encapsulation as viewed from the profile of encapsulation The preferable grating position 102 that exterior feature determines).Fig. 1 C show different examples (the contact array deviation lattice of a substandard encapsulation The encapsulation of grid), wherein contact array moulds without correctly center, and thus shown as viewed from encapsulation profile from ideal Grating position deviates (for example, skew 103 relative to preferable grating position).Encapsulation is not to be inconsistent physically in Figure 1B and Fig. 1 C Close specification, it is difficult to used in traditional surface installation assembling.The defects of accompanying drawing is exaggerated, to show the concept.

Fig. 2 shows to will deviate from the example that grating element 200 is placed on Target Weld area pattern 208.Fig. 2 is shown in weld zone The substandard element that contact array deviates grid is placed on pattern, after placement, all contacts are all from weld zone figure on element Case (for example, with the Target Weld area pattern 208 shown in broken circle in figure) deviates identical offset.As indicated, in element 200 Contact array 209 (contact array for deviateing grid on element) on (contact array deviates the element of grid) has in lower left There is bias 207.After the placement, all contacts 200 on element 200 will have from the phase of Target Weld area pattern 208 Same bias 207.This is different from tilting the placement encapsulated, the deflection or inclined in the placement for tilting encapsulation at the contact of turning From more than at center.

Alignment mark is added into element to significantly decrease due to the harmful effect for the defects of encapsulating profile, and even if Encapsulation profile still conforms to specification, can also eliminate by contact array from preferable grating position (for example, preferable contact grating position 201) contact position caused by deviation is uncertain.Alignment mark can be placed in element contacts array or outside.In phase For at the predetermined spatial relationship of element contacts array manufacture, rather than based on element physical contours or from package edge away from From opening position.

Alignment mark eliminates dependence of the equipment to the preferable physical contours of element.Thus, rule in production before Some physically substandard elements, such as in physical contours with small inclined encapsulation, there is the preferable grid position of deviation The encapsulation for the contact array put or bare die (being cut along the line between adjacent tube core without feeling relieved well), can For system assembles.The further detail below of the structure and the operation of alignment mark are described as follows.In whole this specification, also carry For some methods and modification.

Use the element alignment of Resistance probe

In this embodiment, alignment mark is to be incorporated in element or envelope with the predetermined spatial position relative to contact array Fax guiding path in dress.Conducting path can be from the top surface (test signal can be applied at this) of element to the bottom of element Portion surface (matching on target platform, which is got an electric shock, to be put or can be connected to reference to pad following).Conducting path and target on element It is the degree of accuracy that is paired, being placed with monitoring element that matching on platform, which refers to pad,.If element is properly placed on target and put down On platform, matching be will appear under the lower surface of conducting path with reference to pad, and electricity is conducted when voltage is applied to the top surface of element Stream will be detected.

Fig. 3 shows the example that element 300 is placed on target platform 310.Fig. 3, which shows to place on target platform, has one The element of group conducting path, the target platform have the weld zone pattern and reference marker of matching.Element 300 is in contact array Have at 309 multiple external connections and as alignment mark one or more conducting paths (for example, as electric alignment mark Conducting path) 302,303 hermetically sealed 301.On target platform, weld zone pattern (Target Weld area pattern) 308 and one Group is previously fabricated with reference to pad 306,307.If element 300 is aligned with weld zone pattern 308, will passed with reference to pad 306,307 Under the lower surface of guiding path 302,303.The figure is only example, should not unduly limit the model of claim herein Enclose.One of ordinary skill in the art will be recognized that many modifications, modifications and substitutions, and such as element can have insertion From the top to the bottom as alignment mark conducting path bare die, be sealed in weldering heap ceramic material encapsulation or plastics Integrated circuit in encapsulation or for outside interconnection but without the device for being laminated with one layer of ACE film of weldering heap, or these combination Deng.

Conducting path in element 300 can be straight tube or the conductive trace 303 of any irregular shape, in the component from Top extends to surface.One or more conducting paths can combine in the component.The outside associated with conducting path 302,303 Accessing points 304,305 can be simple circular pad.The shapes of other pads is such as square, rectangle, triangle, trapezoidal or these shapes Combination be possible.Resistance probe is placed on outside access point 304,305, and the state of the degree of accuracy is placed with monitoring.Conducting pathway Footpath can be metal, doped semiconductor path or other detectable entities.

In figure 3, one group with reference to pad 306,307 it is previously fabricated on target platform, carry out induction element as object reference Placement.With reference to pad can be simple circular pad, but other shapes are such as square, rectangle, triangle, trapezoidal, one group of ground connection Point and these combination may also.Reference pad 306,307 on target platform 310 is referred to as " reference marker ".For on element Alignment mark, corresponding reference marker can be added on target platform.The position of reference marker on target platform 310 with Such a mode manufactures so that spatial relationship between the reference marker 306,307 and weld zone pattern 308 on target platform With the spatial relationship between the alignment mark 302,303 and contact array 309 on element 300.

The size of reference marker is by such as element profile, contact array, target platform, equipment precision, mechanical aging sum Determined according to the variable of the place system of the defects of storehouse round-off error etc..The uncertain needs of placement with larger accumulation are larger Reference marker.The size of reference marker should be enough big so that alignment mark should at each element initial placement At least partially in the border of target reference marks.It is the reference mark based on being stored in placement database that starting element, which is placed, The placement of the coordinate of note or Target Weld area pattern.Moreover it is preferred that the size of alignment mark is identical with the size of reference marker Or the size less than reference marker, because it can influence the degree of accuracy of element placement, this will be explained below.

Except up-down structure (test point associated with conducting path is on the top surface of element), as shown in figure 4, also Can with the phase homonymy of contact array 409 at there are two test points (test accessing points) 411,412.Fig. 4 shows have indirectly The element 400 of alignment mark.Two additional traces (connection trace) 406,407 are added to target platform in that case 410, the test point 411,412 associated with conducting path (for example, transport element 402) is connected on target platform 410 Outside access point 403,404.The power and earth terminal of Resistance probe can be applied to two outside access points 403,404, with inspection Whether whether survey has conduction electric current, be correctly positioned on Target Weld area pattern 408 with judgment component.With positioned at The conducting path of two test points of contact array phase homonymy is referred to as alignment path indirectly.Its contact point is indirect alignment mark.

If several paths of alignment indirectly on different elements are connected to the serial daisy chain on target platform, its energy It is enough in the contact conditions of all elements in monitoring chain or checks that whether all elements are also appropriate when the system is in use Position.This be for the electronic system equipped with solderless element (element of interconnection interface is used as such as using ACE) it is useful, In this case, the indirect alignment path for the element of all ACE bases connects into the quasi- chain of single pair or several shorter chains.Supply Voltage and detector, such as LED diodes, are connectable to each chain, to monitor the connection shape of all solderless elements in chain State.

Alignment mark is combined on element can not only detect the degree of accuracy that element is placed on target platform, and can Compensating element position is offset after the placement.However, it is that the construction of test probe and the signal detected to test probe enter Capable is handled to determine the function of alignment mark.Single test probe, i.e. single-sensor are popped one's head in, and can detect laying state and boundary Face contact conditions, and test probe more, i.e. multisensor is popped one's head in, and is capable of offset direction and the degree of detecting element placement, this It will be explained below.

Fig. 5 is shown with single-spot testing Resistance probe to check the example of the placement degree of accuracy and element contact conditions.Fig. 5 shows Go out using single test point Resistance probe 520 to monitor the example of the alignment of the element 500 on target platform 510.It is assumed that bag Element 500 containing two alignment marks 501 and 502 is aligned with the weld zone pattern on target platform 510, at this moment, there is one Reference marker 503 and 504 corresponding to group.The feed end 521 of conducting path from probe 520 is put down by alignment mark 501 to target Reference marker 503 on platform 510 and formed.Second conducting path from alignment mark 502 to target platform 510 on reference marker 504。

In order to avoid two reference markers 503,504 test when it is floating, two reference markers 503,504 should be connected to Inner plane 507 on target platform 510, inner plane 507 are connected to known reference voltage or by the ground connection of surface contact 505 508.Different methods is that two reference markers internally link together.After placing element, it can be come with application probe Test connectivity.If for example, the feed end 521 of probe 520 to be applied to the top surface of alignment mark 501, and it will be grounded End 515 is applied to the top surface of alignment mark 502, then, if element 500 is aligned well on target platform 510, shape Into the current loop of closure, pass through alignment mark 501, reference marker 503, interior trace to detect from the test lead 521 of probe Or inner plane 507 is back to reference marker 504, alignment mark 502, and the final conduction electric current to earth terminal 515 of popping one's head in.To the greatest extent Pipe shows two alignment marks, if azimuthal error possibility in element placement is little, an alignment mark is with regard to enough.Figure Soldered ball 509 is also show in 5.

Or if being connected to inner plane 507 with reference to pad 503,504, reference voltage or ground connection 508 are applied to surface contact 505, then, under reference voltage or it will be grounded with reference to pad 503,504.Because test lead 521 is applied to member in this case The top surface of alignment mark on part 500, so, if two grounding connections are together, then closed circuit passes through from probe Resistance mark, corresponding reference marker, to system earth, then pop one's head in and be grounded and formed.

As shown in figure 5, test probe 520 can contain resistance 522, light emitting diode 523, sound buzzer or galvanometer 524, the state placed with instruction.The maximum current of probe and alignment mark is flowed through in resistor limitation.Light emitting diode provides can Whether see signal correct to indicate to place.Sound buzzer allows users to hear.Galvanometer shows the electric current by probe Amount.Probe can be arranged in the place apparatus for monitoring laying state.It can also be for artificially checking member by user Part places the probe of the degree of accuracy and contact conditions.

Fig. 6 shows to improve the use of four probes of the degree of accuracy that element is placed, wherein can be detected using four probes The position skew that element is placed.More detection probes are that compensating element placement skew is indispensable.In this example, using with Test point A, B, C and D 4 Resistance probes.Circular reference marks (reference marker on target platform) 602 with big broken circle Show.And circular alignment mark (deviateing the alignment mark on the element of target location) 601 is shown with big solid line circle.In order to Make diagram simpler, it is assumed that the size of electric alignment mark 601 is identical with the size of the reference marker 602 on target platform, and It is assumed that all four test points of environment of the probe with matching reference marker 602 in the placement.If selection is square Reference marker is as an example, then all four points should be able to match party on probe after probe positions are aligned with reference marker Four angles of shape reference marker.

The deviation placed for compensating element, it is necessary first to by will probe upper all test point A, B, C and D be moved to or Close to the border of target reference marks 602 relative to the position alignment probe positions of reference marker.Then, element is moved into simultaneously And the coordinate of Target Weld area pattern is placed according to the information for being stored in placement database.If element is placed and offset, Alignment mark 601 on element will be only partially overlapping with the target reference marks 602 on target platform.4 Resistance probes It is overlapping that this part can be detected.For example it is assumed that skew be to the left inferior horn and only test point C in lower right-hand corner with being aligned Mark 601 contacts.At this moment, only test point C detects the electric current for flowing through alignment mark 601 to ground connection reference marker 602.Survey Pilot A, B and D do not detect electric current.Because they are in the perimeter of alignment mark 601, and the region is non-conductive 's.Using the test result as feedback, place apparatus can thus know element place skew.Position of components is to upper right Skew can correct placement skew, i.e., from electric current by test point by the direction that alignment mark 601 detects to not detecting electricity The direction of stream.This process continues until that the alignment mark 601 on element is moved to the position contacted with all test points.So Afterwards, element positions exactly.

If after placing, alignment mark 601 detects conduction electric current in two test points (for example, two left test points) Position.So, alignment mark, also element should be offset to the right is able to detect that electric current until it reaches all four test points Position.In this case, test probe, reference marker and alignment mark are all aligned, and element is precisely placed.Place apparatus In test probe and the pick-up head of element can be independently adjusted.

In the beginning that each element is placed, regulation test probe alignment target reference marker, which is to ensure that, places the degree of accuracy not Can be less.In this specific case, there is no element between probe and reference marker, be by making probe contacts reference marker And complete, which probe conduction the skew from the center of probe to the center of target reference marks can be by monitoring and true It is fixed.By not detecting that sense of current offsets probe positions to test point, probe can be aligned with target reference marks.This It is alignment probe step.

More test probes have in monitoring element placement tests the more performances of probe than single.Single test point resistance Probe can be used for detecting placing the degree of accuracy and contact condition, and testing probe can be used for detecting and providing relevant skew more The feedback of the deviation of element.

Fig. 7 shows the general test probe being made up of the array of test point 701.The general test probe is by test dot matrix Row composition, it is used for the position skew of detecting element placement.By making the probe contacts target reference marks and being surveyed to each Pilot applies voltage so which conduction electric current observed, and work test point on Resistance probe can be determined in the progress of work Scope.If it is more than the size of the reference marker 700 on target platform by 701 detectable area of test lattice array, then Position skew will be activated to detect by only testing a subgroup of lattice array.The survey to be activated in the placement of each element The subgroup of pilot array can be automatically determined in the progress of work in a similar way.This can be visited by reducing test Head, it is assumed that it is Resistance probe, is contacted with reference marker 700, then apply a voltage to test point all in array 700 with It is conductive to observe which test point.

If all conductive test points are close beta points in array, then selection close beta point detection electric current, with It is easy to position of components to adjust.Those nonconducting test points with what broken circle represented (for example, do not detect electric current in array Do not work test point 703) it will be ignored in current element placement.Wait to be actuated to be easy in the array of position of components regulation Close beta point subgroup is work test point (for example, the work test point 702 for detecting electric current represented with solid line circle).In place It is invalid test point 703 to put those ignored test points in regulation.

Due to from the center of more test probes known to sonde configuration, being enclosed if this work test point can be reoriented to Around the center at the center of more test probes, then probe designs can be simpler.This can be by being moved to new position by probe Put until all internal work test points are realized in the middle section of test probe more.In this new position, test probe Center be aligned with the center of target reference marks and the foreign range for the test point that works matching reference marker border.

If partially electronically conductive test point more test lattice arrays edges, probe size it is either too small otherwise probe position Put and do not alignd with reference marker.It is assumed that probe size is too small, i.e. the size less than target reference marks, it can cause due to not The uncertainty that position of components caused by small alignment probe reference marker center can be adjusted.Preferably, test probe Scope compatibility or the size more than reference marker.If probe position do not alignd with reference marker, should adjust until The center of the center alignment reference marker for the test point that worked in array.

One group of asynchronous set can be implemented in the electronics group of test probe and reset (SR) latch, a S/R latch is used In each test point on probe.The subgroup of monitoring element placement, setting SR locks are actuated to corresponding to the upper test point of probe The subgroup of storage with represent for each element place work test point position.Whole group S/R latch is in each element Place and reset when starting.Writeable latch also can be used in implementing S/R latch function.

The method that Fig. 8 is shown with this group of S/R latch so that test probe to be aligned with the center of target reference marks.Fig. 8 The method example shown is position and the more test points of the upper group that will pop one's head in using one group of S/R latch tracking work test point Center (center 802 of probe) alignment target reference marker center (center 801 of reference marker).This group of S/R latch energy It is enough to be replaced by one group of writeable latch.In order to which more test point Resistance probes are aligned into reference marker 803, in contact reference marker Afterwards, S/R latch set is made if corresponding test point conduction, SR locks if corresponding test point detects no electric current Storage still resets.Counter can be used for scanning row and column all on this group of S/R latch, to find which and which Row detect " 1 " of maximum quantity.The intersection point of highest row and column is the midpoint of reference marker.There is highest number for finding The line number word of " 1 " and linage-counter, column counter, comparator, the register of column of figure of amount, and select these logic lists One group of multiplexer of input of member etc., it can be used for realizing this kind of function.This is only an example, without that should be not Suitably limit the scope of the present invention.By by the line number word of " 1 " with maximum quantity and column of figure and at center probe Line number word and column of figure compare, can determine displacement (that is, the center of probe needed for the alignment probe reference marker center To the skew 804 at reference marker center).Probe thus can correspondingly offset and be aligned with the center with reference marker.Resetting After the probe of position, S/R latch is reset, to record new conducted state for all test points on probe.Set at this stage S/R latch contain the information of this work test point being aligned with the center of reference marker.

For quasi-element, another group of transparent latch can be added in probe electronics device, to track probe every time Fade to the instant conduction status of all test points during new position.The content record of transparent latch alignment mark and reference marker Between overlapping conditions.Its content compares the content with S/R latch.If two groups of content matching, element are accurately right Standard is on Target Weld area pattern.

Fig. 9 is shown with two groups of latch to obtain the direction of the element of skew and displacement.One group of latch, its state table Show first in binary system pair.First in binary system pair be this group of transparent latch situation, its represent alignment Overlapping conditions between mark and reference marker.Another group of latch, second of its state representation in binary system pair.Two enter Second is the situation of this group of S/R latch in system, and it represents the position of work test point.In fig.9, shown with reference 901 Go out the center of probe, test point and reference marker, reference marker is shown with reference 902 and shown with reference 903 Without the part of consideration.

By comparing the content of this two groups of latch, or the value of binary system pair, the direction of the element of error bit can be derived With regulation displacement.For more simplicity of explanation, it is assumed that the size of alignment mark is identical with the size of reference marker.In first " 1 " represents the alignment mark region overlapping with reference marker." 1 " in the second numeral represents the position of work test point.It is logical Cross with reference to " 11 " area (being known by simple AND logics) in figure 9, inside reference marker scope, there are 3 row on right side Comprising be entirely " 01 ", and upside only have two rows include be entirely " 01 ".Place apparatus thus knows three, right side The skew of two positions of skew and upside of position can correctly reset bit unit.The position of test point containing " 01 " can Known by simple special OR doors.This diagram is only example, should not inappropriate limitation the scope of the present invention.

Although for the element of skew, larger reference marker can extend the scope of regulation, if test probe is sufficient Enough big, i.e., if the scope of the upper all test points of probe is more than the size of reference marker, less alignment mark can be also correct Ground works.In order to support less alignment mark, the 3rd group of latch can be attached in probe electronics device, to represent work Effective subrange of test point, at this moment, will be with reference to small alignment mark in alignment.3rd group of latch is used as enabled mask, Draw and effective " 01 " scope is determined in the offset displacement of element.

Example shown in Figure 10 uses three groups of latch, the center that small alignment mark restricted publication of international news and commentary entitled is marked.Two enter First expression element alignment mark position of tuple processed.Second represents work test point position.3rd represents that work is surveyed The subrange of pilot, for less alignment mark." 1 " in a high position determines that 01x's is effective in Position displacement of component Up, down, right and left border.In Fig. 10, the center 1002 of probe and reference marker is shown and with attached with reference 1001 Icon note 1002 shows reference marker.In Fig. 10, the 3rd in binary system tuple represents the size of matching alignment mark Subrange in reference marker." 1 " of the 3rd, such as binary system tuple " 111 " and " 011 ", represent work test point subgroup Position, as smaller alignment mark target.Although the work test point determined by the size of reference marker is whole Individual scope is used for detecting the presence of alignment mark, and still, the subrange for the test point that works is used as the mesh for small alignment mark Mark." 11 " of tuple front two, i.e., " 11x " as shown in Figure 10 example represent the weight between alignment mark and reference marker Folded region.Tuple " 011 " represents the region that alignment mark is not aligned with reference marker.In the subrange of Figure 10 target, There are two row to contain " 011 " on the right side of " 111 ", there are two rows to contain " 011 " on the upside of " 111 ".Thus, the upward position of element and The skew of two positions to the right can also be completely by alignment mark reference marker, even if alignment mark is less than reference marker.

The actual subrange of the work test point associated with smaller alignment mark can be by referring to being stored in placement data In storehouse the diameter information of alignment mark or by using with place apparatus associated images sensor with the progress of work measure pair The diameter of fiducial mark note.

Figure 11 is shown with general test probe to correct the diagram of the position of offset component.In this illustration, it is first Alignment mark 1101 on part reflects the position (occurring needing the skew adjusted) of element, and less than the ginseng on target platform Examine mark 1102.Before starting to place each element, the scope of the work test point on probe should predefine, i.e., logical Cross to pop one's head in and be moved to the top of reference marker 1102, make there is no element therebetween, and apply voltage to all test points with It is conductive which is observed.Because the center of test probe is, it is known that so one group of work test point can be selected, make probe and reference The center of mark 1102 is aligned, and makes outermost test point close to the border of reference marker 1102.In fig. 11, non-source test on probe Point (do not work test point) 1104 represents that work test point is represented with solid line circle and solid stain with broken circle, wherein, with hollow Solid line circle represents the work test point 1103 that no electric current flows through, and represents to detect that the corner that electric current flows through works with solid stain Test point 1105.The diameter of the imaging sensor measurement alignment mark inside place apparatus, or reference can also be used to be stored in The diameter information of the alignment mark in database is placed, dynamically to obtain in work test point to be used for smaller alignment The subrange of mark alignment reference marker.

After starting element placement, the alignment mark 1101 on element is completely or partly located in reference marker 1102 and limited Work test point in the range of.Offset it is assumed that starting element is placed, and assume that only one corner work test point 1105 (is being schemed Shown in 11 with solid stain) detect electric current.Then place apparatus can using the subgroup for the test point that works as target to the right and to Upper offset alignment mark, until alignment mark and (the big broken circle in Figure 11 centers of whole subgroup 1106 of work test point 1106 It is shown) matching.In fig. 11, the center work test point matched with the size of smaller alignment mark is shown with reference 1107 1106 subrange.Thus, even if alignment mark is less than reference marker, element can also be precisely directed to Target Weld area figure Case.

On the contrary, if the region of alignment mark is more much bigger than the region of reference marker, the degree of accuracy placed will reduce.This It is because the scope of the work test point limited by small reference marker is fairly limited.Because can not obtain enough feedbacks with Its center is moved to by the big alignment mark in tutorial element to be aligned with limited group of work test point, so element adjustment is handled It can not continue.Detected for resistance, the effect using single test probe be similar to using the effect of larger alignment mark, It is wherein very narrow by singly testing the region of probe covering, similar to smaller test probe or the effect of smaller reference marker.No How is pipe, and in the case where singly testing probe, smaller reference marker is able to detect that the higher placement degree of accuracy, except non-reference The size of mark is too small to be unable to detect.

After initial placement, element is placed in outside reference marker.Any work test point is not in this case Conducting electric current can be detected.This shows that the setting of placing element is incorrect, or underestimates during element is placed under worst condition Skew, makes big tick marks go to outside undersized reference marker.So as to easily monitor incorrect system Setting or operating mistake.

In order to improve the durability of test probe and ensure that alignment mark and reference marker contact are good, as shown in figure 12, Anisotropic conductive elastomer (ACE) 1205 can be layered in the surface of general Resistance probe 1200 as interconnection interface 1201, contacted for test point with alignment mark and reference marker.Test probe shown in Figure 12 is laminated by anisotropic conductive Elastomer (ACE) is used as interconnection interface, to improve the contact conditions between test point and alignment mark, reference marker.At this In figure, each test point is made up of the contact tube 1202 inside probe 1200.The diagram is only example, is not considered as pair The limitation of the scope of the invention.For example, probe be shown as it is circular but it is also possible to be other shapes, such as square, rectangle, triangle, Trapezoidal, other irregular shapes or even flexible cable.Further, although test point in figure with regular array (with test probe The test lattice array 1203 of association) show, but the test point of array can need to place with any configuration according to application.

In order to solve azimuthal error in element placement, two alignment marks can be combined in the opposite sides of element.Have Deflection error is more prone in big contact array or the element of hyperfine contact pin.

Figure 13 shows to combine the example of the azimuthal error during two alignment marks are placed with compensating element on element.It is assumed that Element tilts counterclockwise after initial placement, and assumes that the size of alignment mark is identical with the size of reference marker.In figure Two big solid line circle represents two alignment marks 1301,1302 on element.The two alignment marks 1301,1302 are connected in figure Imaginary solid line shows the imagination orientation of element after initial placement.Two corresponding reference markers 1303,1304 on target platform Shown, connected by imaginary dotted line to represent preferable target bearing with big broken circle.The intersecting acute angle of solid line and dotted line be Azimuthal error after initial placement.If without displacement error, crosspoint is the center C of element 1300.It is assumed that two surveys Probe header is used for monitoring the placement of the element containing two alignment marks, but if for detection every time, prevents equipment can The center of writing task test point and test probe, then one just enough.

Before placing element, probe must be aligned with target reference marks.For Resistance probe, this is by connecing probe Reference marker is touched to determine work test point relative to the scope and coordinate at reference marker center and to complete.Then, with spy Head motion upwards, component pick is placed at Target Weld area pattern.If element places no azimuthal error, two right Fiducial mark remember 1301,1302 by be exactly in reference marker 1303,1304 top and with work test point commensurate in scope. If azimuthal error, then a few thing test point outside the scope of alignment mark and will be not turned on electric current on probe. If the component pick-up head in component can carry out Angle Position regulation, by monitoring that the conduction state of work test point can obtain Know the direction of regulation, i.e. by the way that element or alignment mark are not detected into the side of electric current rotates to work test point.

In fig. 13, two alignment marks 1301,1302 on element are in upper right and lower left position.If orientation counterclockwise Error occurs after element is placed, then the work test point 1305 for the detection conductive current of upper detection will be in left-hand side Tilt and the work test point 1307 conductive for the detection of bottom detection will tilt in right-hand side.By by element from work Test point detects that a lateral side for not detecting electric current of electric current rotates, i.e., rotationally clockwise, the orientation of element Error can be corrected.But if current sense test point appears in phase homonymy in detecting twice, for example all on a left side Hand side, then displacement error is had occurred and that and element should be offset to the right to correct displacement error.Specifically, in fig. 13, Shown with reference 1306 and the work test point of electric current is not conducted in the outside of alignment mark, is shown with reference 1307 The work test point of the conduction electric current gone out inside alignment mark, with reference 1308 show do not have in the outside of alignment mark Conduct the work test point of electric current and the test point that do not work on probe is shown with reference 1309.

Technique of alignment can adjust according to the needs of application.For example, if place system is crooked in itself so that one The placement error in individual direction is bigger than other direction, then rectangular reference can be selected to mark, and it is larger its long side is corresponded to skew Direction.Preferably, probe size is bigger than reference marker size, is surveyed to be directed at probe and work to be automatically determined on probe The scope of pilot.Preferably, the size of reference marker is more than the size of alignment mark, or size is close.

Resistance detection needs direct contact measurement, in the case where needing to move the element of placement on target platform, The pollution of scolding tin may be caused around Target Weld area pattern.Be laminated with ACE does not have this ask as the element of interconnection interface Topic.The element for being laminated with ACE interconnection interfaces is also good with the weld zone pattern contacts on target platform.

, can also be on the weld zone patterned surfaces upper strata on PCB in order to avoid there may be the harmful effect of scolding tin pollution Folded a thin layer solder, this is similar with the soldered ball material in PCB manufacturing processes in encapsulation.Then can cancel in the installation assembling of surface Soldering paste printing step, thus without soldering paste pollute.

Figure 14 shows the series connection alignment chain 1401 on target platform, between being directed at path 1402 indirectly and having on element The upper and lower alignment 1403 of the combination in alignment path is connect, and also show signal or voltage source 1404 and surveillance device 1405.From Pushing up downward alignment mark and Indirect Electro alignment path can combine and be used in combination in identity element.It is top-down right Fiducial mark, which is remembered, can improve the degree of accuracy of placement, and chain can be concatenated into by being directed at path indirectly, to monitor connecing for all elements in chain The state of touching, as shown in figure 14.This is particularly useful for being assembled into electronic system with the element for being laminated with ACE interconnection.

Use the alignment of capacitance probe

Electricity alignment can also be realized using non-contact method.Except using Resistance probe measure opening at direct contact point/ Powered-down resistance, moreover it is possible to capacitance probe with non-contacting method quasi-element.

Figure 15 is shown by Lion Presion of St.Paul, the capacitance sensor example of Minnesota manufactures, the electricity Hold the electric field that sensor carrys out focus sensor 1502 using protection body 1503.In order to improve accuracy of measurement, it is necessary to autobiography in future The electric field of sensor is limited in the space between the surface of sensor and reference target.Single conductor is kept and sensor itself Identical voltage, the conductor are used as protective around the side of sensor and below.It is single when AC signals are applied to sensor Individual circuit applies identical excitation voltage to the protective.Because there is no voltage difference between sensor and protective, institute There is no electric field between them.Except sensor, the side of capacitance probe 1501 or any other conductor below and protective and It is not that sensor forms electric field.Only not protected sensor front end forms the electric field to reference target.Caused by sensor Electric field is the projection of its size and shape.For example, circular sensor can be to reference target project cylindrical shape electric field.In Lion In Presion capacitance sensor, cylindrical electric field can be extended up to 30% at the effective range of sensor diameter 40%.

Because AC signals are applied to sensor surface, AC electric currents will flow through gap institute shape between sensor and object reference Into electric capacity.The capacitance size that the size of current flowed through is depended between sensor and object reference, i.e., by gap size and table Overlapping degree between face determines.If sensor is directed at reference target completely, the electric capacity formed in gap is maximum, AC electricity Flow highest.If sensor is completely outside reference target, without overlapping surface region and related electric capacity, as long as joining Examine beside target without external conductor in ranges of sensors.

As shown in figure 16, the capacitance sensor of one group of protection can be formed array, forms what is surveyed for non-contact electrical resistivity survey Multisensor capacitance probe 1600.Sensor 1601 in array can also need optionally to start according to application.For example, figure 16 show the probe of nine sensors.But be used to place detection if only the sensor at four angles of activation probe, then it turns into The capacitance probe of four sensors.

It is aligned for detection, the definite electric capacity by upper each sensor detection of popping one's head in is not subject matter.This be because For in alignment applications, capacitance sensor does not measure the precise intervals between parallel body, so accurate capacitive reading is not It is necessary.The relative capacity determined by the region overlapping degree between detecting head surface and object reference region plays key effect. If disturbing the measurement of relative capacity in the range of sensor electric field without external conductor, when being used to measure the placement degree of accuracy The effective range of multisensor capacitance probe is more than the scope of single sensor.

Be applied to the upper all effective sensors of probe because AC is excited, all the sensors will sensor and object reference it Between monitor identical electric capacity, thus if probe is aligned with reference target completely, the AC electric currents of formed objects will be measured.If Misalignment be present, then the electric current of the part effective sensor conducting overlapping with reference target is maximum in detection zone of popping one's head in, and joins Examine the electric current that the part effective sensor outside target will turn on very little.By the phase for comparing AC electric currents in effective sensor array To size, the direction of skew can be known.The skew can by under capacitance probe alignment element aligns mark or pass through to Effective sensor detects smaller AC senses of current movement offset component to adjust.It need not pop one's head in this process and mesh Mark platform or the probe of element contact.

Capacitance sensor is generally calibrated to the target of ground connection.The body or external receptacle of capacitance probe should be with being electrically connected to It is grounded to improve the probe degree of accuracy.Reference target is also required to properly grounded.The incorrect ground connection of reference target will reduce probe Sensitivity and accuracy.Fortunately, although many targets are not directly grounded, there is very big electric capacity between ground by its environment, Such as component pick-up head.In the case of AC excitations, bulky capacitor eventually makes object reference shorted to earth.Thus, it will be put down in target It is beneficial that reference marker on platform, which is connected to ground plane or the alignment mark at element surface is connected into local ground plane, but Not necessarily, as long as the electric capacity of target over the ground is quite big to the ratio between electric capacity of sensor with target.As two electric capacity are connected Situation is the same, and the ratio more than 10 makes the error of capacitance measurement be less than 10%.

During using capacitance probe quasi-element, the surface markers at the only top of element are related.On element crests The surface region of alignment mark determines the capacitance of capacitance sensor detection.No longer as resistance detect situation need from Element crests to bottom guiding path as electric alignment mark.However, the contact at the alignment mark and component base at top Rectangular co-ordinate relation between array should close with the coordinate between the Target Weld area pattern on reference marker and target platform System matches.It is assumed that aligned reference marker of popping one's head in, then can be by being visited in electric capacity with alignment mark under capacitance probe The lower mobile alignment mark of head, and all effective sensors above alignment mark detect the identical electricity more than certain minimum threshold The place of stream is monitored to complete.After alignment mark probe, the element of alignment can be reduced then downwards with standard Really it is placed on Target Weld area pattern.

Using non-contact detection, such as electric capacity detects, and is popped one's head in energy by alignment probe object reference and by alignment mark Enough complete independentlies.Thus, as long as probe detection range is large enough to the ginseng on the alignment mark and target platform on cladding element Mark is examined, then size relationship therebetween is not so important in contact detects for another example.Thus, utilize non-contact detection, tool The element for having big alignment mark remains able to be precisely directed on less reference marker.

Electric technique of alignment can also be used to monitoring and encapsulate the chip-stacked degree of accuracy, wherein it is possible to from the top of encapsulation chip Portion inserts guiding path as electric alignment mark to bottom.Electric technique of alignment can also be used for monitoring that bare die stacks accurate Degree, wherein the guiding path in bare die from the top to the bottom can be formed using ion implanting, diffusion or other methods.

Figure 17 is shown with the example of the stacking of electric technique of alignment monitoring element, being capable of monitoring element using electric technique of alignment The degree of accuracy of stacking.Several modifications are shown in this example to illustrate the application under different situations.The degree of accuracy of stacked elements can By the bottom for the top and bottom element alignment mark that probe (sound end 1701) is directly placed in crown member alignment mark And learn.Wherein, the crown member being placed is shown with reference 1702, shown using reference 1703 as will quilt The base member of the target platform of alignment, and electric registration signal is shown with reference 1700.If the element stacked will It is placed on seating surface 1704, then the ground connection reference point that the alignment mark of base member bottom can be connected on seating surface (earth terminal 1705) is with generation from probe to the monitoring path of ground plane.Or it can be combined a pair on element to be stacked Electric alignment mark, they may be coupled to the guiding path in seating surface for two alignment mark tops in probe monitors laminated components The stacking precision in portion.Ringlet represents the contact pin to other laminated components or seating surface in the figure.Electric current is also show in figure Meter 1706 and signal source 1707.

Figure 18 is shown with another application that two objects are aligned by electric alignment methods together.Figure 18 is illustrated that use Electric technique of alignment, the object marked with four sensor alignments is registered to the second thing with four triangular reference marks Body.Four triangular reference marks can be four single triangles, can also be close together to form single triangle.At this In individual example, 4 sensor groups into array be incorporated in the first object (for example, four sensors pair on the first object 1801) fiducial mark remembers, 4 triangle sets into array be attached in the second object as reference target (such as on the second object Four triangles as four single reference targets 1802) be used for monitor alignment the degree of accuracy.Four can with reference to triangle To be divided into four reference markers, (such as four triangles on the second object can also being engaged togather shown in being formed Shape is close together to form single reference target 1803).Four sensors can be using contact measurement one group of Resistance probe or Using one group of capacitance probe of non-contact method.

The structure works in a similar manner.It is assumed that the second object is deviateed in lower section to the first object to the left so that on the first object Two left side alignment sensors associated with the second object a quarter triangular reference mark outside.If it is assumed that The scope of sensor array and the commensurate in scope of referential array, then sensing electronic equipment can be produced to right hand side direction skew the The instruction of one object.But after the first object is offset to right hand side, two lower right sensors will then fall on the second object Reference marker region (triangle C, D) outside, and now two upper sensors are still with reference in the range of triangle.It is logical Cross upwards, i.e., having been detected by sense of current to sensor moves the first object, and four alignment sensors can be moved then To in the range of reference marker, two objects finally give alignment.

It is aligned using optic probe

If the reference marker on the alignment mark and target platform of element crests is high reflectivity, optic probe energy It is enough in element alignment.Figure 19 shows that the transparent light opening on element 1900 can act as optical registration mark.If put down with target The reflective pad 1904 of matching on platform combines, then its degree of accuracy that can be used for improving element placement.As shown in figure 19, to fiducial mark Note can also be the transparent light path 1901 on element, and it makes laser beam (for example, incident light 1902) to pass through following reference Mark and reflected (for example, reflected light 1903) from the reference marker.On element crests reflective surface mark or element Light path can be used for optical registration mark.

In optical detection, it is not necessary to be grounded the alignment mark on element or light path, it is not required that by target platform Reference marker is grounded.However, the space between the alignment mark at top and contact (contact point 1905) array of component base is closed System should match with the spatial relationship between associated welds area pattern on reference marker and target platform, this and other Detection Techniques It is identical.

Figure 20 shows the array of one group of photoelectric detector 2001 or optical diode composition, is formed for the more of non-contact detection Sensor optical is popped one's head in, and also show the imaginary line 2002 being grouped again for representing photoelectric detector.The sensing of array Device can be selectively grouped according to resolution requirement.For example, Figure 20 shows the probe of 16 sensors.But if the reflected beams Border defocus and slightly fuzzy, then can be by 16 on optic probe or if the size of the reflected beams is quite big Individual photoelectric detector is re-arranged to four groups to form the optic probe of four sensors.Resetting sensor can be by again Setting is transported to the input signal in probe electronics and completed.In another example, if it is possible to which incident beam is carried out Regulation and focusing, then it need to only select four sensors of center probe accurate to increase alignment as the sensor of interest of alignment Degree, although the gamut of all 16 sensors is used as effective sensor to increase the hunting zone of incident beam.

If the general test probe for testing sensor array composition is Resistance probe, it is measured at each contact Connection resistance or DC electric current.If capacitance probe, then it measures the AC electric currents at each test sensor, and the electric current is anti- The overlapping region reflected between the surface of each sensor and object reference.If optic probe, then examined in each photoelectricity Survey and photoelectric current is detected at device, the electric current represents the position of the reflected beams.

Using optical alignment, when element places beginning, probe positions must be with the center of the reference marker on target platform Alignment.In optical alignment, reference marker can be simple reflective pad.Chi of the diameter of incident beam preferably with reference marker It is very little to be consistent.Otherwise, no matter too big or reference marker the size of the size of incoming laser beam is too big, can all produce uncertainty. Detector side, incident beam should be focused on correctly to ensure it in the range of photoelectric detector.Referred to by alignment probe After the center of mark, element is moved into and is placed at weld zone pattern.Next by the position of alignment mark and probe Position alignment.For non-contact detection, the final precision that element is placed is determined by the indirect alignment methods of two steps.Depending on light Such as how optical means collimates beam, and the relative size of alignment mark and reference marker weighs not as under resistance detection event Will.

Figure 21 shows a kind of example of optical pickup, probe that it contains four photoelectric detectors of band and for detecting partially Move the related I/V amplifiers of Component Displacement.Each I/V amplifier includes current-to-voltage convertor and voltage amplifier.With Light incides the photoelectric detector (such as photodiode 2101) on probe and produces electric current, and the electric current is then amplified by I/V Device amplifies.The circular light beam (reflecting bundle 2102) from object reference reflection is also illustrated in figure.If element is aligned with reference to mesh completely Mark, then the reflected beams are by the center of optical pickup.

In figure 21, optical pickup produces four different voltage VA, VB, VC and VD.Can with one group of comparator come Compare the voltage output from these I/V amplifiers.Can be by by the output voltage and predetermined threshold of each I/V amplifier Voltage compares and determines to adjust direction.Probe is represented by the high output voltage of comparator detection, object reference has overlay region Domain.Region also misalignment corresponding to the low output voltage expression detected as comparator.It is high defeated by the way that element is detected from comparator The position for entering voltage is displaced to the position of comparator detection low input, and misalignment can be corrected.If without comparator The voltage level of tsaoko intended threshold level (VT) is detected, i.e., is examined without relevant reflecting bundle by any four photoelectric detectors Survey, it represents that element dislocation or optic probe completely are not aligned with object reference at all.If all four voltage levels reach To intended threshold level, element is accurately aligned on target platform.

Alignment procedure

The program that element placement precision is improved using technique of alignment is summarized as follows.

A. placing element in assembly is prepared, some such as coordinates at the center of weld zone pattern or and target for information about Weld zone pattern associates on platform the coordinate of reference marker, probe construction, size of alignment mark etc. on element to be placed, Input the database of place system.These information are useful in automation is placed.

B. target platform is loaded into assembling equipment.Reference point on target platform is selected as origin, is deposited with matching Store up the origin of the coordinate system in database is placed.

C. probe can be the single-sensor probe for monitoring placement precision, or can be for correcting offset component The multisensor probe of skew.In order to correct the skew for the element do not placed accurately, it is necessary to which element is being placed in into target platform By the center of alignment probe target reference marks before upper.Probe can be Resistance probe, and its measurement passes through from probe sensor To fiducial mark meter, turned on by means of the ON/OFF of direct contact method to reference marker.Probe can be capacitance probe, its by means of The overlapping degree in region between non-contact method detection probe and object reference.Probe can also be optic probe, and it, which is measured, visits Optical registration between head and object reference.

By the coordinate for moving on to the reference marker according to placement database of popping one's head in, and if desired, probe positions are adjusted, All the sensors until detecting electric current are the internal sensors around center probe, in such manner, it is possible to realize probe pair The center of quasi- reference marker.For Resistance probe, probe must directly contact reference marker to declining.For non-direct contact Capacitance probe, probe need to move on to scope of no external conductive body in its field regime.For optic probe, probe needs Regulation height is so that the diameter of Beam matching object reference.

The internal sensor for detecting electric current determines the scope of the upper working sensor of probe based on the measurement by reference to mark. Using correct regulation, the center of Auto-matching reference marker is capable of at the center of these working sensors.Work on probe passes The center of sensor and scope are the new position and target of the alignment mark on element to be aligned.Multisensor probe can be member Part position adjustments provide feedback, and the probe is different from being merely capable of the single-sensor probe for detecting placement precision.

D. pickup device and it is placed on Target Weld area pattern.This placement is based on Target Weld area pattern The coordinate at center or the coordinate of reference marker.

E. the position alignment probe that regulating element pick-up head marks until element alignment.The direction of regulation is to make more to work Monitor detects sense of current.It is right in the presence of when alignment mark, all working sensor can detect it on popping one's head in Standard is achieved that.

Because the spatial relationship between the weld zone pattern on reference marker and target platform can be previously fabricated with matching Element alignment marks the relation between contact array, so, element being capable of alignment target weld zone pattern well.This Under technique of alignment, some substandard not serious elements can also be used in assembly.

F. can be carried out for the element with embedded indirect alignment path, all paths of alignment indirectly according to daisy chain Connection, to form the alignment chain of series connection or several shorter alignment chains.When system comes into operation, alignment chain can be used for detecting The connection status of all elements in chain.

The step of sequence described above, shows method according to embodiments of the present invention.When addition step, remove one or more steps When suddenly, or with different order providing one or more steps, other alternative schemes can also be provided, without departing from right herein It is required that scope.

This technique of alignment is not limited in assembling placing element on PCB, and it can also be used in various applications, such as be supervised Depending on chip package, wherein being considered as target platform to be mounted to the substrate that the tube core on substrate is considered as element and encapsulated.Finally, This alignment mark and Detection Techniques are applicable to more encapsulation stackings, bare die stacking, multi-chip carrier modular assembly, module Component, encapsulation card component and motherboard component, etc..Those skilled in the art will realize that many modifications, modifications or substitutions.

Claims

1. a kind of device including sensor array, operatively according to the alignment mark being presented on element and target platform by member Part is aligned with target platform, and described device is operatively put down the element and the target using the subgroup of the sensor array Platform is aligned, wherein the number of the subgroup of the sensor array is less than the number of the sensor array, the sensor array Subgroup be determined in the process in the following way during the element is aligned with the target platform：Described In the case of not having element between sensor array and the target platform, the subgroup of sensor array is selected, so that selected Subgroup be aligned with one in the alignment mark being presented on the target platform, and make the outermost side senser in the subgroup Close to the one border being presented in the alignment mark on the target platform.

2. device according to claim 1, wherein, described device is also operatively：

During first is aligned the sensor array is directed at relative to the center for the alignment mark being presented on the target platform Row；And

Based on the signal detected by a part for the sensor array relative to being presented on the element during second is aligned On alignment mark described in sensor array subgroup.

3. device according to claim 1, wherein, one in the sensor array includes direct feeler.

4. device according to claim 1, wherein, one in the sensor array is included from including capacitance sensing The non-direct contact sensor chosen in the group of device, optical sensor and photoelectric detector.

5. device according to claim 1, wherein, the sensor array is Resistance probe, and

Anisotropic conductive elastomer is layered on the surface of the Resistance probe.

6. device according to claim 1, wherein, the element is from including naked die integrated circuits, the integrated electricity of bare die The stacking on road, more IC stack device, more encapsulation stacking devices, multi-chip carrier and are laminated with anisotropic conductive elastomer (ACE) selected in the group of the IC-components of film.

7. device according to claim 1, wherein, the target platform from including printed circuit board (PCB), motherboard, ceramic wafer, Selected in the group of naked die integrated circuits and packaging.

8. device according to claim 1, wherein, present the alignment mark on the element with the element On contact array there is predetermined spatial relationship.

9. device according to claim 1, wherein, be presented on the alignment mark on the target platform with described Contact weld area pattern on target platform has predetermined spatial relationship.

10. a kind of method for being used to be placed into element by the device including sensor array on target platform, methods described Comprise the following steps：

The element is aligned with the target platform according to the alignment mark being presented on the element and the target platform；

The element is aligned with the target platform using the subgroup of the sensor array, wherein the sensor array The number of subgroup is less than the number of the sensor array；And

Determine the sensor array in the process in the following way during the element is aligned with the target platform Subgroup：In the case of there is no element between the sensor array and the target platform, the son of sensor array is selected Group, so that selected subgroup is aligned with one in the alignment mark being presented on the target platform, and make in the subgroup Outermost side senser close to being presented on one border in the alignment mark on the target platform.

11. the method according to claim 11, in addition to：

12. according to the method for claim 10, wherein, one in the sensor array includes direct sensing contact Device.

13. according to the method for claim 10, wherein, one in the sensor array is included from including capacitance sensing The non-direct contact sensor chosen in the group of device, optical sensor and photoelectric detector.

14. according to the method for claim 10, wherein, the sensor array is Resistance probe, and wherein described side Method also includes：

Anisotropic conductive elastomer is laminated on the surface of the Resistance probe.

15. according to the method for claim 10, wherein, the element integrates from including naked die integrated circuits, bare die The stacking of circuit, more IC stack device, more encapsulation stacking devices, multi-chip carrier and are laminated with anisotropic conductive elastomer (ACE) selected in the group of the IC-components of film.

16. according to the method for claim 10, wherein, the target platform is from including printed circuit board (PCB), motherboard, ceramics Selected in the group of plate, naked die integrated circuits and packaging.

17. according to the method for claim 10, wherein present the alignment mark on the element with the member Contact array on part has predetermined spatial relationship.

18. according to the method for claim 10, wherein the alignment mark being presented on the target platform with institute The contact weld area pattern stated on target platform has predetermined spatial relationship.