METHODS OF SEPARATING GOOD PROBE STRUCTURES FROM DEFECTIVE PROBE STRUCTURES IN AN ELECTROCHEMICAL FABRICATION SYSTEM
20240017990 ยท 2024-01-18
Inventors
- Duy P. Le (San Francisco, CA, US)
- Rulon J. Larsen (Colorado Springs, CO, US)
- Jeffrey A. Thompson (Van Nuys, CA, US)
- Uri Frodis (Los Angeles, CA, US)
- Dale S. McPherson (Kissimmee, FL, US)
- Kleun Kim (Los Angeles, CA, US)
- Mahmood Samiee (Glendale, CA, US)
- Nina C. Levy (Los Angeles, CA, US)
- Dennis R. Smalley (Newhall, CA)
Cpc classification
B81C99/003
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Electronic test probes formed in a batch have a plurality of multi-material layers wherein at least one of the materials is a sacrificial material and at least one other material is a structural material. Successfully formed or good test probes are separated from unsuccessfully formed or bad test probes
Claims
1. In a method for operating an electrochemical fabrication system to manufacture electronic test probe structures, of the type including: (A) receiving parameter data for manufacturing the electronic test probe structures, wherein each probe structure has a compliant probe body of a first material and a contact tip made of a second material different from the first material; (B) operating the electrochemical fabrication system based on the parameter data to: (i) deposit a structural material; (ii) deposit a conductive sacrificial material; and (iii) seize the deposited structural and sacrificial materials, to form a plurality of successive layers on a substrate in the electrochemical fabrication system, with, each successive layer adhered to a previously formed layer; (C) after forming the successive layers, separating at least a portion of the conductive sacrificial material from the structural material to reveal the plurality of probe structures; (D) with the plurality of probe structures on the substrate, comparing, by inspection or testing, a parameter of each probe structure to the parameter data; (E) identifying probe structures on the substrate not compliant to the parameter data as being in a first group of probe structures and identifying probe structures compliant to the parameter data as being in a second group; the improvement comprising: (F) while the probe structures are on the substrate, adding a secondary material only to the probe structures in the first group; (G) physically separating the first group of probe structures and the second group of probe structures from the substrate; and (H) physically separating the first group of probe structures from the second group of probe structures using the secondary material.
2. The method of claim 1 further including assembling the probe structures in the second group with other components to create devices and scrapping the probe structures in the first group.
3. The method of claim 1 wherein the parameter data includes a mechanical and/or electrical property of the probe structures.
4. The method of claim 1 wherein the parameter data includes a limit on geometry distortion.
5. The method of claim 2 wherein probe structures missing any feature specified in the parameter data are identified as being in the first group.
6. The method of claim 1 wherein the secondary material is added by electroplating.
7. The method of claim 1 wherein the secondary material is a magnetic material.
8. The method of claim 7 wherein step H is performed using a magnet.
9. The method of claim 1 wherein the probe structures in the second group are formed of non-magnetic material.
10. The method of claim 1 wherein the secondary material comprises: a polymer, a photoresist, parylene, a curable monomer or oligomer, and/or a wax.
11. The method of claim 10 wherein the secondary material is coated with a hydrophobic material.
12. The method of claim 11 further including immersing the first and second groups of probe structures into a liquid, to separate them via a buoyancy differential.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] Electrochemical Fabrication in General
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[0042] In
Definitions
[0043] Structural material as used herein refers to a material that remains part of the structure when put into use.
[0044] Primary structural material as used herein is a structural material that forms part of a given build layer and which is typically deposited or applied during the formation of that build layer and which makes up more than 20% of the structural material volume of the given build layer
[0045] Secondary structural material as used herein is a structural material that forms part of a given build layer and is typically deposited or applied during the formation of the given build layer but is not a primary structural material as it individually accounts for only a small volume of the structural material associated with the given layer. A secondary structural material will account for less than 20% of the volume of the structural material associated with the given layer.
[0046] Sacrificial material is material that forms part of a build layer but is not a structural material. Sacrificial material on a given build layer is separated from structural material on that build layer after formation of that build layer is completed and more generally is removed from a plurality of layers after completion of the formation of the plurality of layers during a release process that removes the bulk of the sacrificial material or materials. In general sacrificial material is located on a build layer during the formation of one, two, or more subsequent build layers and is thereafter removed in a manner that does not lead to a planarized surface. Materials that are applied primarily for masking purposes, i.e. to allow subsequent selective deposition or etching of a material, e.g. photoresist that is used in forming a build layer but does not form part of the build layer) or that exist as part of a build for less than one or two complete build layer formation cycles are not considered sacrificial materials as the term is used herein but instead shall be referred as masking materials or as temporary materials. These separation processes are sometimes referred to as a release process and may or may not involve the separation of structural material from a build substrate.
[0047] Primary sacrificial material as used herein is a sacrificial material that is located on a given build layer and which is typically deposited or applied during the formation of that build layer and which makes up more than 20% of the sacrificial material volume of the given build layer. In some embodiments, the primary sacrificial material may be the same on each of a plurality of build layers or may be different on different build layers. In some embodiments, a given primary sacrificial material may be formed from two or more materials by the alloying or diffusion of two or more materials to form a single material.
[0048] Secondary sacrificial material as used herein is a sacrificial material that is located on a given build layer and is typically deposited or applied during the formation of the build layer but is not a primary sacrificial material as it individually accounts for only a small volume of the sacrificial material associated with the given layer. A secondary sacrificial material will account for less than 20% of the volume of the sacrificial material associated with the given layer.
[0049] In batch fabrication of structures or parts wherein good and bad parts are distinguished with the bad parts being cut up or destroyed so that only parts that are believed to be good remain whole. In a first embodiment, destruction occurs after all layers are formed. In a second embodiment, the final layer of the build is provided with a protective coating such that upon destruction, debris, from destroyed parts, does not become deposited on good parts. In a third embodiment, destruction of failed parts occurs during layer build up and possibly at the end of layer build up. In some embodiments, destroyed parts may be separated from good parts prior to supplying the good parts to a customer while in other embodiments some or all of the destroyed parts may be shipped with the good parts with the knowledge that the destroyed parts cannot be inadvertently used in place of good parts.
[0050] Each embodiment of the invention includes the fabrication of a plurality of parts or structures from a plurality of multi-material layers with each layer including at least one structural material and at least one sacrificial material. In the most preferred embodiments, though not necessarily all embodiments, each layer is planarized to set an upper boundary level for the layer while a planarization of the materials associated with the prior layer sets the lower boundary level for a current layer. In the most preferred embodiments, each successive layer is adhered to a previously formed layer during its formation. In some embodiment variations, layer formation is by one of the processes set forth herein above (e.g. selective deposition of a first material, blanket deposition of a second material, and thereafter the two materials are planarized). In some embodiment variations one or more part layers may be formed from three or more materials (e.g. two structural materials and one sacrificial material or three or more structural materials and one or more sacrificial materials). In still other embodiments, layer formation may vary from layer to layer, while in still other embodiments, some or all layer formation may be by other methods (e.g. laying down sheets of material, cutting the sheets into desired cross-sectional patterns and bonding the sheets together either before or after cutting, etc.). In the most preferred embodiments, inspections or tests are performed after selected process steps during the formation of layers (e.g. once per layer or multiple times per layer). When problems are found, individual parts or regions are flagged as bad or failed. If too many problems occur on a single layer or if too many problems have accumulated from the formation of a plurality of layers, a decision may be made to erase one or more layers and reform them to improve overall yield. However, if failures have not met a reform threshold, failed regions are simply flagged and building is allowed to continue.
[0051] In the embodiments, at some point in the process, data associated with flagged parts or regions is converted into data associated with destruction paths (e.g. cutting paths) that will be used in destroying the bad parts. After formation of one or more layers, and in the most preferred embodiments after formation of all layers, destruction path data is used to direct a destruction tool onto the surface of the last formed layer with a desired depth of destruction such that bad parts are unambiguously distinguished from good parts. In different embodiments, the destruction tools may take on any of a number of effective forms. For example, in some embodiments, a pulsed or CW laser beam of appropriate power, diameter, wavelength, pulse width, and the like may be directed onto appropriate locations on the surface of a last formed layer to provide ablative cutting of bad parts (e.g. using a YVO4 laser or a diode pumped doubled YAG laser (e.g. at 532 nm) or some other frequency multiplied solid state laser). In such embodiments, the laser beam may be moved over the surface while in others the surface may be moved under a fixed beam position. In such embodiments multiple passes of the beam may be used to achieve a desired cutting depth (e.g. two passes to a thousand passes or more). In other embodiments the destruction tool may take a physical form such as for example that of an appropriately operated punch, a mill bit, or a drill. In the most preferred embodiments, the size of the parts is small, e.g. less than 1 mm in height and less than several centimeters on an edge. In some embodiments the height of a part in the layer stacking direction may be less than 200 or even 100 um while the lateral dimensions may be on the order of 10 um to 10 mm. In such embodiments a cutting tool width may be appropriately sized for the circumstances. For example for the part sizes noted above the tool width may be on the order of a few microns to a few tens of microns while positioning accuracy of the tool or of the part relative to the tool may be on the order to microns to tens of microns.
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[0053] Element 117 follows element 116 and calls for the performing of each fabrication step for production of each layer. The defining, performing, and/or controlling of operational steps, parameters and associated equipment for elements 116 and 117 may involve the use of a programmed computer in conjunction with manual or automated processing and inspection equipment. Element 117 also calls for the performing of inspections (e.g. visual) or tests (e.g. adhesion tests, hardness tests, composition tests, and the like) after selected steps to determine whether any specific parts or general build regions have been subjected to processing failures. It also calls for noting or recording the failed parts or regions (e.g. locations on a wafer where failures exist or are likely to exist). Finally to the extent desired, it optionally calls for the performing of one or more additional steps on the failed parts or regions prior to the completion of the fabrication of all layers. These additional steps may include for example the cutting or ablation of failed parts into two or more pieces or the complete removal of the failed parts.
[0054] Element 118 follows element 117 and calls for the performing of any post layer formation, pre-release processing including, for example: (1) optionally, applying a protective coating over the previously formed layers, (2) to the extent not already done, compiling a listing (e.g. including coordinates) for one or more removal locations or removal patterns for each failed part or for each part within a failed region, (3) cutting or ablating each failed part or each part in failed regions into two or more pieces or completely removing such parts, (4) if used and if necessary removing the protective coating. This processing of element 118 may be performed with the aid of a programmed computer in conjunction with manual or automated processing equipment.
[0055] Element 119 follows element 118 and calls for the release of at least a portion of the parts from the sacrificial material and/or from the substrate. Element 120 follows element 119 and calls for performing any secondary release processes and any other post release processes. For example, a post release process of element 120 may involve the physical separating or sorting of good parts from bad parts. Finally element 121 follows element 120 and calls for the shipping of the good parts and possibly the failed parts to a customer or the putting of the good parts to use (e.g. after assembly into a complete device). Any required separating or sorting may involve the use of manual or computer controlled automatic processing tools or equipment.
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[0057] Element 155 calls for the performance of the inspection(s) or test(s) and explicitly or implicitly results in the flagging of respective parts or regions as failed or passed. Element 161 makes an inquiry as to whether the just performed step sn is equal to the last step number Sn for the layer n. If no the process increments sn by one (element 162) and loops back to element 153. If yes the process moves forward to element 163 where an inquiry is made as to whether or not the current layer number n is equal to the last layer number N. If no the process increment n to n+1 (element 164) and loops back to element 152 in preparation for forming a next layer. If yes the process moves forward to element 171.
[0058] Element 171, if not already compiled, calls for the creation of a listing of modification locations for selected parts such that the modifications will result in the removal of the selected parts or the dissection of the selected parts into two or more pieces. This may involve a translation of identified specific failed parts to specific locations on those failed parts where the specific locations define the regions to actually be modified. In some embodiment variations, it may be necessary to designate complete modification paths (e.g. scanning paths for laser beams or cutting paths for mechanical elements). Element 181 follows element 171 and calls of the modification of the selected parts (e.g. ablation, cutting, or complete removal).
[0059] Element 191 follows element 181 and calls for the release of at least part of the parts from the sacrificial material and possibly from the substrate. Element 192 follows element 191 and calls for the optional separation of the modified parts (i.e. bad parts) from the whole parts (i.e. good parts). Element 193 follows element 192 and calls for the putting of the whole parts to use such as assembling them with other components to make one or more devices. The process ends with element 194 following element 193.
[0060] The process 150 of
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[0066] Element 251 calls for the starting of the process. Element 252 follows element 251 and calls for the setting of a process Step No., sn, equal to one. For each layer this process step number is associated with a specific process operation or set of operations that are to be performed to fabricate the layer of the parts. These process numbers and associated operations or steps may be fixedly defined in advance or may be variably defined and modified depending on the results of prior process steps, inspection steps or tests. Element 253 follows element 252 and calls for the performance of the operation(s) of step sn. Element 254 questions whether or not an inspection step will follow the operation(s) of step sn. If the answer is yes, the process moves to element 255. Otherwise it moves to element 261.
[0067] Element 255 calls for the performance of the inspection(s) or test(s) and explicitly or implicitly results in the flagging of respective parts or regions as failed (i.e. bad) or passed (i.e. good). Element 261 makes an inquiry as to whether the just performed step sn is equal to the last step number Sn for the layer n. If no the process increments sn by one (element 262) and loops back to element 253. If yes the process moves forward to element 263 where an inquiry is made as to whether or not the current layer number n is equal to the last layer number N. If no the process sets n=n+1 (element 264) and loops back to element 252 in preparation for forming a next layer. If yes the process moves forward to element 265 which calls for the formation of a protective coating over the last formed layer so that upon modification of selected structures removed structural material will not be deposited onto the good parts. In different embodiment variations, protective coatings may be formed in different ways and be formed of different materials. For example, the coating may be the same material as the sacrificial material (e.g. copper) and may be deposited by electroplating or electroless plating. In other variations it may be patterned or unpatterned photoresist.
[0068] Element 271 follows element 265 and if not already compiled, calls for the creation of a listing of modification locations for selected parts such that the modifications will result in the removal of the selected parts or the dissection of the selected parts into two or more pieces. Element 281 follows element 271 and calls for modification of the selected parts (e.g. by ablation, cutting, punching, micro-milling, micro-drilling). In some embodiments, failed parts may be completely destroyed or obliterated (e.g. by ablating or machining). Element 282 follows element 281 and calls for the optional removal of the protective coating.
[0069] Element 291 follows element 282 and calls for the release of at least part of the parts from the sacrificial material, from any remaining protective coating material, and possibly from the substrate. Element 292 follows element 291 and calls for the optional separation of the modified parts (i.e. bad parts) from the whole parts (i.e. good parts). Element 293 follows element 292 and calls for the putting of the whole parts to use such as assembling them with other components to make one or more devices. The process ends with element 294 following element 293.
[0070] The process 250 of
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[0073] Element 351 calls for the starting of the process. Element 352 follows element 351 and calls for the setting of a process step no. (sn) equal to one. For each layer this process step number is associated with a specific process operation or set of operations that are to be performed to fabricate the layer of the parts. These process numbers and associated operations or steps may be fixedly defined in advance or may be variably defined and modified depending on the results of prior process steps, inspection steps or tests. Element 353 follows element 352 and calls for the performance of the operation(s) of step sn. Step 354 questions whether or not an inspection step will follow the operation(s) of step sn. If the answer is yes the process moves to element 355. Otherwise it moves to element 356.
[0074] Element 355 calls for the performance of the inspection or test and explicitly or implicitly results in the flagging of respective parts or regions as failed or passed. Element 356 follows element 354 or element 355 and makes an inquiry as to whether or not modification of failed structures is to occur prior to the next process step. If the answer is yes the process moves forward to element 357. Otherwise it moves forward to element 361. Element 357 calls for the compilation, if not already made, of a listing of modification locations for selected structures. Information on depth of modification may also be obtained as the depth of cutting may be different for different parts as some may have undergone previous modification. Element 358 follows element 357 and calls for the modification of the selected structures. Such modification may occur in a number of different ways including for example, by ablation, cutting, punching, drilling, milling, or the like.
[0075] Element 359 follows element 358 and calls for the optional filling of any voids formed by element 358. This filling may occur in a blanket or selective manner and may use the same material as the sacrificial material or may be a different material. The filling may even be a dielectric particularly if the removal pattern does not result in electrical isolation of subsequent regions which are to receive electrodeposited material. Filling may be followed by further planarizations. In some variations initial planarizations may always set a level above a desired layer level so that any necessary subsequent planarizations are sure to leave the desired material at the layer boundary level. In such a case, further planarization may occur regardless of whether or not filling occurred.
[0076] Element 361 follows element 356 or element 359 and makes an inquiry as to whether the just performed step number sn is equal to the last step number Sn for layer n. If no, the process increments sn by one (element 362) and loops back to element 353. If yes the process moves forward to element 363 where an inquiry is made as to whether or not the current layer number n is equal to the last layer number N. If no the process increments n to n+1 (element 364) and, the process loops back to element 352 in preparation for forming a next layer. If yes the process moves forward to element 366 which makes an inquiry as to whether further modification of the parts is required (e.g. cutting of the last layer of the failed parts). If the answer is no the process moves forward to element 381. Otherwise it moves forward to element 371.
[0077] Element 371, if not already completed, calls for the creation of a listing of modification locations for selected parts such that the modifications will result in the removal of the selected parts or the dissection of the selected parts into two or more pieces. Element 381 follows element 371 and calls for the modification of the selected parts (e.g. cutting or complete removal by laser ablation).
[0078] Element 391 follows element 366 or element 381 and calls for the release of at least part of the parts from the sacrificial material and possibly from the substrate. Element 392 follows element 391 and calls for the optional separation of the modified parts (i.e. bad parts) from the whole parts (i.e. good parts). Element 393 follows element 392 and calls for the putting of the whole parts to use such as assembling them with other components to make one or more devices.
[0079] The process 350 of
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[0085] In view of the teachings herein, many further embodiments, alternatives in design and uses of the embodiments of the instant invention will be apparent to those of skill in the art. As such, it is not intended that the invention be limited to the particular illustrative embodiments, alternatives, and uses described above but instead that it be solely limited by the claims presented hereafter.