WO2017196638A2

WO2017196638A2 - Alignment system and method of using the same

Info

Publication number: WO2017196638A2
Application number: PCT/US2017/031146
Authority: WO
Inventors: Ted JOHNS; Mark Kosmowski; Ridian PRODANI; Brian Johansen
Original assignee: Electro Scientific Industries Inc
Current assignee: Electro Scientific Industries Inc
Priority date: 2016-05-13
Filing date: 2017-05-04
Publication date: 2017-11-16
Anticipated expiration: 2018-11-13
Also published as: TW201810505A; WO2017196638A3

Abstract

An alignment system includes a substrate fixture configured to receive a substrate, a guide structure positionally fixed relative to a substrate fixture and at least one actuated clamp. The substrate fixture may be configured to receive a substrate. An actuated clamp may include a clamp, an actuator coupled to the clamp and positionally fixed relative to a substrate fixture that is configured to receive a substrate, and an encoder operative to generate and output encoder data indicative of the position of the clamp. The actuator may be operative to move the clamp relative to the substrate fixture. The guide structure and the actuated clamp can be arranged such that a substrate received by the substrate fixture is pressable between the clamp and the guide structure when the clamp is moved relative to the substrate fixture by the first actuator.

Description

ALIGNMENT SYSTEM AND METHOD OF USING THE SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/336,472, filed May 13, 2016, which is incorporated by reference in its entirety.

BACKGROUND

L Technical Field

Embodiments of this application relate generally to systems and methods for performing alignment and, more particularly, to systems and methods for performing alignment using an electro-mechanical system.

II. Technical Background

Vision-based alignment is a technique that is very commonly used for detecting and correcting positional and part tolerance issues related to planar substrates during machining of the substrates. Typically an imager (e.g., an image sensor employing CMOS or CCD technology) and some type of illumination source are used to capture an image with a strongly contrasted edge (light vs. dark). Vision algorithms are then employed to locate this edge. By finding multiple edges of the planar substrate, the system control system software can then calculate offset, scale, and rotation of the part.

While useful, vision-based edge alignment techniques have several limitations. For example, known vision-based edge alignment techniques only work with a single size of substrate, unless at least one of the imager and the illumination source is mounted on some type of staging mechanism, which can add significant cost. Vision-based edge alignment techniques work well when the substrate is formed of an opaque material, but can be can be difficult to apply to transparent substrates such as glass or sapphire. Also, the precision with which an edge of a substrate is found is determined by the quality of the imager and any lenses used; so getting a highly precise image of the edge of a part can require expensive imagers and optics. Lastly, using a moving (non-fixed) imager to find multiple edges or to adjust for different substrate sizes takes time, which results in additional overhead time and lowers cycle time for machining the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an edge alignment system according to one embodiment of the present invention.

SUMMARY

In one embodiment, an alignment system can be characterized as including a substrate fixture configured to receive a substrate, a guide structure positionally fixed relative to a substrate fixture and at least one actuated clamp. The substrate fixture may be configured to receive a substrate. An actuated clamp may include a clamp, an actuator coupled to the clamp and positionally fixed relative to a substrate fixture that is configured to receive a substrate, and an encoder operative to generate and output encoder data indicative of the position of the clamp. The actuator may be operative to move the clamp relative to the substrate fixture. The guide structure and the actuated clamp can be arranged such that a substrate received by the substrate fixture is pres sable between the clamp and the guide structure when the clamp is moved relative to the substrate fixture by the first actuator.

In another embodiment, an apparatus for processing a substrate can include the alignment system described above. In yet another embodiment, a method of processing a substrate using a machine tool having a processing head, and at least one component associated with the processing head, can include acts that include: receiving reference data describing at least one geometric characteristic of a feature associated with a reference substrate; loading a substrate onto a fixture, the loaded substrate corresponding to the reference substrate; pressing the loaded substrate between at least one first structure and at least one second structure; after pressing, obtaining data indicative of the position of the at least one second structure; and forming the feature in the loaded substrate, wherein forming the feature includes controlling an operation of the at least one component based, at least in part, on the reference data and the obtained data such that at least one geometric characteristic of the formed feature corresponds to the at least one geometric characteristic of the feature associated with the reference substrate.

DETAILED DESCRIPTION

Example embodiments are described herein with reference to the accompanying drawings. Unless otherwise expressly stated, in the drawings the sizes, positions, etc., of components, features, elements, etc., as well as any distances therebetween, are not necessarily to scale, but are exaggerated for clarity.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be recognized that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range, as well as any sub-ranges therebetween. Unless indicated otherwise, terms such as "first," "second," etc., are only used to distinguish one element from another. For example, one node could be termed a "first node" and similarly, another node could be termed a "second node", or vice versa. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Unless indicated otherwise, the term "about," "thereabout," etc., means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.

Spatially relative terms, such as "below," "beneath," "lower," "above," and "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature, as illustrated in the FIGS. It should be recognized that the spatially relative terms are intended to encompass different orientations in addition to the orientation depicted in the FIGS. For example, if an object in the FIGS, is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. An object may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly. Like numbers refer to like elements throughout. Thus, the same or similar numbers may be described with reference to other drawings even if they are neither mentioned nor described in the corresponding drawing. Also, even elements that are not denoted by reference numbers may be described with reference to other drawings.

It will be appreciated that many different forms and embodiments are possible without deviating from the spirit and teachings of this disclosure and so this disclosure should not be construed as limited to the example embodiments set forth herein. Rather, these examples and embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the disclosure to those skilled in the art.

I. Overview

Embodiments of the present invention provide an alignment system that is cost effective and addresses the limitations, noted above, associated with known vision-based alignment techniques. The alignment system can be incorporated into a machine tool (e.g., a numerical control (NC), computer numerical control (CNC) machine tool, etc.) adapted to process (e.g., cut, engrave, drill, erode, heat, melt, ablate, mark, discolor, crack, etc.) a substrate to thereby form one or more features (e.g., holes, trenches, vias, openings, indicia, cuts, etc.) on or within the substrate (according to reference data stored in a computer-readable medium that describes, among other things, one or more geometric characteristics of one or more features associated with a reference substrate). Examples of geometric characteristics include a location where a feature located on or within a reference substrate (e.g., relative to one or more edges of the reference substrate), the size of each of such feature, the shape of each such feature, or the like or any combination thereof.

Examples of suitable machine tools within which the edge alignment system can be incorporated include laser processing systems, waterjet systems, routing or milling systems, and the like. Examples of substrates that may be processed include, panels of printed circuit boards (PCBs) (also referred to herein as "PCB panels"), PCBs, flexile printed circuits (FPCs), integrated circuits (ICs), IC packages (ICPs), electronic or optical device substrates, cover glass articles (e.g., for use in smartphones, tablet computers, laptop computers, etc.), device housings (e.g., for watches, computers, smartphones, tablet computers, wearable electronic devices, or the like or any combination thereof), or the like. In some embodiments, the alignment system can be characterized as a set of one or more (e.g., two, three, four, etc.) actuated clamps. Each actuated clamp includes an actuator and an encoder (e.g., a linear encoder). The actuator is operative to move an associated clamp so as to press a substrate, which is to be processed, against one or more stationary guide structures. This enables repeatable placement of multiple sizes of substrates in operable proximity to a processing head (e.g., a laser scan head, a waterjet cutting head, a router head, or the like) of the machine tool. Generally, each stationary guide structure is coupled to a fixture (also referred to herein as a "substrate fixture"). The substrate fixture may, optionally, be carried by one or more motion stages operable to move the fixture along or about one or more axes.

The machine tool may further include components associated with the processing head. It should be recognized that the nature of such "associated components" will vary based on the nature of the machine tool. Examples of such "associated components" may include actuators for moving the processing head along a plane extending over the substrate, or in a direction towards or away from the substrate. Other examples of "associated components" (e.g., when the machine tool is provided as a laser processing apparatus) may include actuators for deflecting (e.g., by reflection, diffraction, refraction, etc.) laser light (e.g., manifested as a series of pulses, or as a continuous or quasi-continuous beam, of laser energy). Thus, when the machine tool is provided as a laser processing apparatus, "associated components" may include one or more beam positioning components such as a galvanometer-driven mirror, a fast-steering mirror (e.g., a mirror moveably coupled to a piezoelectric actuator, electro strictive actuator, voice-coil actuator, etc.), an acousto-optic deflector, an electro-optic deflector, or the like or any combination thereof. To the extent that the machine tool includes any stage operable to move the fixture (and, thus, the substrate) either with or relative to the process head, such stage(s) can be considered as "associated components" as well.

Once placed in operable proximity to a processing head, the substrate can be considered to be "loaded" into the machine tool. In one embodiment, the actuator of each clamp is driven in "force mode," with a well-calibrated force limit, so that the clamp stops pushing the substrate when the substrate is properly pressed against a guide, and so that the clamp presses against the substrate with a sufficiently-low force to avoid undesirably deforming the substrate. This force limit will typically be calibrated differently for different types of substrates. The encoder is operative to generate and output one or more signals (also referred to herein as "encoder data") indicative of the position of the clamp. After each clamp is actuated to properly press the substrate against one or more guides, encoder data output by each associated encoder can be read or otherwise processed (e.g., by a computer or other processor associated with the machine tool) to determine the position of the substrate, the location of edges of the substrate, the size of the substrate, or the like or any combination thereof. The encoder data - either unprocessed, or processed as discussed above - can be input to any suitable edge alignment calculation algorithm (e.g., executable by a computer or other processor associated with the machine tool) to generate correction data, which can be used to modify the reference data. Specifically, the correction data can be used to modify reference data in terms of one or more geometric transformations (e.g., translation, rotation, scale, shear, or the like or any combination thereof), so that the location, size, shape, etc., of features ultimately formed on or within the loaded substrate (e.g., relative to the edges of the loaded substrate) will correspond to the relative locations, sizes, shapes, etc., represented by the reference data. Other examples of geometric transformations that may be applied to modify the reference data include one or more transformations such as a displacement transformation, an isometric transformation, a similarity transformation, an affine transformation, or the like or any combination thereof.

Generally, correction data describing how to modify reference data to account for translation of the loaded substrate (relative to the reference substrate) can be generated by an alignment system having a single actuated clamp. Correction data describing how to modify reference data to account for translation and scale of the loaded substrate (relative to the reference substrate) can be generated by an alignment system having two actuated clamps. Correction data describing how to modify reference data to account for translation, scale and rotation of the loaded substrate (relative to the reference substrate) can be generated by an alignment system having three actuated clamps.

Generally, the loaded substrate will correspond to the reference substrate. As used herein, the loaded substrate corresponds to the reference substrate if it has a shape that is the same as the shape of the reference substrate, and corresponds in size to the reference substrate. Thus, the loaded substrate may be smaller than or larger than the reference substrate, or may be the same size as the reference substrate. In some embodiments, however, the loaded substrate will have a shape that is different from the shape of the reference substrate. For example, both the reference substrate and the loaded substrate may define a rectangular shape (e.g., in the X-Y plane), with or without corners that are rounded, but any of the length or width of the rectangular shape of the loaded substrate may be greater than or less than (e.g., + 1%, + 2%, + 3%, + 4%, + 5%, + 6%, + 7%, + 8%, + 9%, + 10%, + 15%, etc., or between any of these values) the length or width of the rectangular shape of the reference substrate.

The machine tool may further include a controller communicatively coupled (e.g., over one or more wired or wireless communications links, such as USB, Ethernet, Firewire, Wi-Fi, RFID, NFC, Bluetooth, Li-Fi, or the like or any combination thereof) to various components of the machine tool (e.g., the processing head of components associated therewith, one or more substrate stages, or the like or any combination thereof), as well as to the encoder (and, optionally, to the actuator) of each actuated clamp. The controller may be operative to receive encoder data and process the encoder data as discussed above. In one embodiment, the controller may be operative to modify reference data as discussed above, and control the processing head (or components associated therewith) in accordance with the modified reference data. Generally, the controller includes one or more processors configured to generate the aforementioned control signals upon executing instructions. A processor can be provided as a programmable processor (e.g., including one or more general purpose computer processors, microprocessors, digital signal processors, or the like or any combination thereof) configured to execute the instructions. Instructions executable by the processor(s) may be implemented software, firmware, etc., or in any suitable form of circuitry including programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), field-programmable object arrays (FPOAs), application- specific integrated circuits (ASICs) - including digital, analog and mixed analog/digital circuitry - or the like, or any combination thereof. Execution of instructions can be performed on one processor, distributed among processors, made parallel across processors within a device or across a network of devices, or the like or any combination thereof. In one embodiment, the controller includes tangible media such as computer memory, which is accessible (e.g., via one or more wired or wireless communications links) by the processor. As used herein, "computer memory" includes magnetic media (e.g., magnetic tape, hard disk drive, etc.), optical discs, volatile or non-volatile semiconductor memory (e.g., RAM, ROM, NAND- type flash memory, NOR-type flash memory, SONOS memory, etc.), etc., and may be accessed locally, remotely (e.g., across a network), or a combination thereof. Generally, the instructions may be stored as computer software (e.g., executable code, files, instructions, etc., library files, etc.), which can be readily authored by artisans, from the descriptions provided herein, e.g., written in C, C++, Visual Basic, Java, Python, Tel, Perl, Scheme, Ruby, etc. Computer software is commonly stored in one or more data structures conveyed by computer memory.

Having generally described the alignment system and an operation thereof above, the construction of an alignment system according to one embodiment will now be discussed in greater detail below.

II. Example Embodiment of an Alignment System

Referring to FIG. 1, an alignment system according to one embodiment of the present invention is provided as alignment system 100, which includes a substrate fixture 102 and three actuated clamps: a first actuated clamp including a first clamp rail 104a, a first actuator 106a and a first encoder 108a; a second actuated clamp including a second clamp rail 104b, a second actuator 106b and a second encoder 108b; and, optionally, a third actuated clamp including a third clamp rail 104c, a third actuator 106c and a third encoder 108c. The substrate fixture 102 may, optionally, be secured to one or more substrate stages (e.g., one or more motion stages) configured to move the substrate fixture 102 along the X-axis, along the Y-axis (e.g., orthogonal to the Y-axis), along a Z-axis (e.g., orthogonal to the X- and Y-axes), about the X-axis, about the Y-axis, about the Z-axis, or the like or any combination thereof.

Generally, each of the first, second and third actuators 106a, 106b and 106c, respectively, can be positionally fixed relative to the substrate fixture 102. For example, each of the first, second and third actuators 106a, 106b and 106c, respectively can be fixed to the substrate fixture 102. The first, second and third actuators 106a, 106b and 106c, respectively, are operative to move respective ones of the first, second and third clamp rails 104a, 104b and 104c relative to the substrate fixture 102. For example, the first actuator 106a is operative to move the first clamp rail 104a along the X-axis, the second actuator 106b is operative to move the second clamp rail 104b along the Y-axis, and the third actuator 106c is operative to move the third clamp rail 104b along the X-axis. The alignment system 100 also includes a first guide structure 110a (e.g., a rail) and a second guide structure 110b (e.g., a rail) positionally fixed relative to the substrate fixture 102. For example, each of the first and second guide structures 110a and 110b, respectively can be fixed to the substrate fixture 102. The rail of the first guide structure 110a defines a guide surface extending along the Y-axis, and the rail of the second guide structure 110b defines a guide surface extending along the X-axis. Although each of the first and second guide structures 110a and 110b, respectively, are illustrated as provided as a single rail, it will be appreciated that any of the first and second guide structures 110a and 110b may be provided as a set of pins (e.g., aligned such that a plane tangent to the set of pins extends along the X-axis, in the case of the second guide structure 110b; or aligned such that a plane tangent to the set of pins extends along the Y-axis, in the case of the first guide structure 110a).

Generally, the actuated clamps and the guide structures are arranged such that substrates of one or more sizes can be accommodated therebetween and over the substrate fixture 102. For example, FIG. 1 illustrates an example in which a relatively small substrate 101a or a relatively large substrate 101b can be accommodated on the substrate fixture 102, between the guide structures (i.e., first and second guide structures 110a and 110b) and the actuated clamps (i.e., the first, second and, optionally, third actuated clamps). The first actuated clamp and the first guide structure 110a are arranged relative to one another such that, when actuated, the first actuated clamp presses the substrate in a direction along the X-axis, against the first guide structure 110a. The second actuated clamp and the second guide structure 110b are arranged relative to one another such that, when actuated, the second actuated clamp presses the substrate in a direction along the Y-axis, against the second guide structure 110b. When included, the third actuated clamp is arranged relative to the first guide structure 110a such that, when actuated, the third actuated clamp presses the substrate so as to rotate the substrate (e.g., in a plane extending in the X- and Y-axes) about an edge of the first guide structure 110a. Although the third actuated clamp is illustrated as being operative to rotate a substrate about an edge of the first guide structure 110a, it will be appreciated that the third actuated clamp may be arranged so as to be operative to rotate a substrate about an edge of the second guide structure 110b. III. Conclusion

The foregoing is illustrative of embodiments and examples of the invention, and is not to be construed as limiting thereof. Although a few specific embodiments and examples have been described with reference to the drawings, those skilled in the art will readily appreciate that many modifications to the disclosed embodiments and examples, as well as other embodiments, are possible without materially departing from the novel teachings and advantages of the invention. Accordingly, all such modifications are intended to be included within the scope of the invention as defined in the claims. For example, skilled persons will appreciate that the subject matter of any sentence, paragraph, example or embodiment can be combined with subject matter of some or all of the other sentences, paragraphs, examples or embodiments, except where such combinations are mutually exclusive. The scope of the present invention should, therefore, be determined by the following claims, with equivalents of the claims to be included therein.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for processing a substrate, the apparatus comprising:

an alignment system including:

a substrate fixture configured to receive the substrate;

a first guide structure positionally fixed relative to the substrate fixture; and a first actuated clamp including:

a first clamp;

a first actuator coupled to the first clamp and positionally fixed relative to the substrate fixture, the first actuator operative to move the first clamp relative to the substrate fixture; and

a first encoder operative to generate and output encoder data indicative of the position of the first clamp,

wherein the first guide structure and the first actuated clamp are arranged such that a substrate received by the substrate fixture is pressable between the first clamp and the first guide structure when the first clamp is moved relative to the substrate fixture by the first actuator.

2. An alignment system, including:

a substrate fixture configured to receive the substrate;

a first guide structure positionally fixed relative to the substrate fixture; and

a first actuated clamp including:

a first clamp;

3. The apparatus of claim 1 or alignment system of claim 2, wherein the alignment system further includes:

a second guide structure positionally fixed relative to the substrate fixture; and a second actuated clamp including:

a second clamp;

a second actuator coupled to the second clamp and positionally fixed relative to the substrate fixture, the second actuator operative to move the second clamp relative to the substrate fixture; and

a second encoder operative to generate and output encoder data indicative of the position of the second clamp,

wherein the second guide structure and the second actuated clamp are arranged such that the substrate received by the substrate fixture is pressable between the second clamp and the second guide structure when the second clamp is moved relative to the substrate fixture by the second actuator.

4. The apparatus of claim 1 or alignment system of claim 2, wherein

the first actuator is operative to move the first clamp relative to the substrate fixture along a first axis; and

the second actuator is operative to move the second clamp relative to the substrate fixture along a second axis different from the first axis.

5. The apparatus of claim 1 or alignment system of claim 2, wherein the second axis is perpendicular to the first axis.

6. The apparatus or alignment system of claim 4, wherein the alignment system further includes:

a third actuated clamp including:

a third clamp; a third actuator coupled to the first clamp and positionally fixed relative to the substrate fixture, the third actuator operative to move the third clamp relative to the substrate fixture; and

a third encoder operative to generate and output encoder data indicative of the position of the second clamp,

wherein the third actuated clamp is arranged relative to the first guide structure such that substrate received by the substrate fixture is rotatable about an end of the first guide structure when the third clamp is moved relative to the substrate fixture by the third actuator.

7. The apparatus of claim 1, further comprising a machine tool operative to process a substrate received by the substrate fixture, the machine tool having a processing head.

8. The apparatus of claim 7, wherein the alignment system is operative to place a substrate received by the substrate fixture in operable proximity to the processing head.

9. The apparatus of claim 7, further comprising a controller coupled to at least one component associated with the processing head and at least one selected from the group consisting of the first encoder, the second encoder and the third encoder, wherein the controller is operative to control an operation of the at least one component associated with the processing head based on encoder data output by the at least one encoder selected from the group consisting of the first encoder, the second encoder and the third encoder.

10. The apparatus of claim 9, wherein the at least one component includes an actuator configured to deflect laser light.

11. The apparatus of claim 7, wherein the machine tool is a laser processing system.

12. A method of processing a substrate using a machine tool having a processing head and at least one component associated with the processing head, the method comprising:

receiving reference data describing at least one geometric characteristic of a feature associated with a reference substrate; loading a substrate onto a fixture, the loaded substrate corresponding to the reference substrate;

pressing the loaded substrate between at least one first structure and at least one second structure;

after pressing, obtaining data indicative of the position of the at least one second structure; and

forming the feature in the loaded substrate, wherein forming the feature includes controlling an operation of the at least one component based, at least in part, on the reference data and the obtained data such that at least one geometric characteristic of the formed feature corresponds to the at least one geometric characteristic of the feature associated with the reference substrate.

13. The method of claim 12, wherein loading the substrate onto the fixture comprises loading the substrate onto the fixture such that the loaded substrate is operably proximate to the processing head.

14. The method of claim 12, wherein controlling the operation of the at least one component includes:

modifying the reference data based on the obtained data; and

controlling the operation of the at least one component based on the modified reference data.

15. The method of claim 14, wherein modifying the reference data includes:

generating correction data based on the obtained data; and

modifying the reference data based on the correction data.