TWI793956B - MEMS PROBE MANUFACTURING METHOD - Google Patents

Abstract

A method for manufacturing microelectromechanical probes, comprising step a) coating an adhesive layer on the surface of a substrate; step b). coating a seed layer on the adhesive layer; step c). coating a seed layer on the seed layer A photoresist layer with a thickness of 15 to 35 microns; step d). The photoresist layer is formed into a mold cavity with a plurality of probe arrangement patterns by a photolithography method through a photomask; step e). An electroplating method is used to make a conductive Deposition of permanent material to form a probe-shaped metal layer; step f). Apply laser etching to remove the photoresist around the metal layer; step g). Use an adhesive positioning member to fix the metal layer (probe) ; Step h). Applying laser etching to vaporize the adhesive layer; and Step i). Detaching the probe from the positioning member. Since the present invention uses laser etching to remove the photoresist first and then vaporize the adhesive layer, the manufacturing process does not consume time and electricity, and there is no accumulation of debris on the surface of the probe; therefore, the microstructure produced by the present invention Electromechanical probes are quality and cost-effective.

Description

MEMS PROBE MANUFACTURING METHOD

The invention relates to a manufacturing method of a probe, especially a manufacturing method of a micro-electro-mechanical probe through micro-electro-mechanical process and laser etching.

Press, in the general semiconductor manufacturing process, before the wafer processing is completed but not cut and packaged, the electrical characteristics of the IC in the wafer stage must be tested with a probe card. In addition to the test report, the results can be fed back to the front-end process for fine-tuning. In order to ensure the yield rate of wafer processing; at the same time, it is also possible to eliminate defective products first to avoid waste in the later packaging process, thereby achieving the effect of reducing costs and increasing production capacity. When testing, the probes on the probe card are in contact with the pads (Pad) or bumps (Bump) on the IC chip to form a test circuit; and the signal sent by the tester is transmitted through the probe. Insert the chip, and then send the chip feedback data back to the testing machine for analysis and judgment, so as to detect whether the function of each die on the wafer is normal.

In recent years, with the high integration of semiconductor chips, the bonding pads on the chip have become thinner and the spacing has become smaller. Since the probes on the probe card in the test device must be reduced accordingly, the application of micro-electromechanical process The probes made were born accordingly. Second press, Microelectromechanical Systems (MEMS for short) is an industrial technology that integrates microelectronics technology and mechanical engineering. micron to millimeter.

Press again, Taiwan Invention Patent No. 202009496 "Manufacturing Method of MEMS Probe for Semiconductor Inspection Using Laser", that is, the micro-electromechanical process is used to make the probe; the method includes: 1. Depositing a sacrificial layer on the substrate; 2. Coating a photoresist on the sacrificial layer; 3. Forming a photoresist pattern; 4. Forming a metal layer; 5. Removing the photoresist; 6. Etching to remove the sacrificial layer but retaining the support portion; 7. Fixing the probe with the adhesive part; 8. Cutting off the supporting part with laser; 9. Detaching the probe from the adhesive part. 1A shows a substrate 910, and a sacrificial layer 920 is first deposited on the substrate, and then coated with a photoresist 930; FIGS. , and then deposit the conductive material to form the metal layer 950, remove the photoresist to form the cavity 960; then remove the sacrificial layer 920 by etching but retain the support portion 970, so that the metal layer 950 is supported; finally, use the bonding parts 980 fixes the metal layer 950 of the probe. 2A-2B show that the support portion 970 is cut off by laser, and finally the probe 990 is separated from the adhesive member 980 . The above steps must be divided into two stages, and the sacrificial layer 920 and the supporting portion 970 are removed by etching successively. Since the sacrificial layer 920 and the supporting portion 970 are both conductive materials, this etching operation requires a long time and a large amount of power. Moreover, During the etching process of the support part 970, residues often remain to make the surface of the probes lose smoothness, thereby affecting the accuracy of subsequent wafer detection; subject of thought.

The reason is that the main purpose of the present invention is through micro-electro-mechanical process and application of laser The etching method is used to increase the production speed of the probes and improve the quality of the probes, thereby ensuring the reliability and benefits of the wafer inspection process.

To achieve the above object, the present invention includes steps a) coating an adhesive layer on the surface of a substrate; step b). coating a seed layer on the adhesive layer; step c). coating a seed layer with a thickness of A photoresist layer of 15 to 35 microns; step d). Make the photoresist layer form a mold cavity with a plurality of probe arrangement patterns through the photolithography method of the photomask; step e). Use an electroplating method to make a conductive Material deposition to form a probe-shaped metal layer; step f). Apply laser etching to remove the photoresist around the metal layer; step g). Use an adhesive spacer to fix the metal layer (probe); step h). Applying laser etching to vaporize the adhesive layer; and step i). Detaching the probe from the spacer.

Explain the meaning of some terms in the previous paragraph, where the "substrate" in step a) is only used for the probe process, and the material coated on it can be removed in subsequent processes without damaging the substrate or Gasification disappears; therefore, the substrate is a reusable material; and, step b). Referring to a seed crystal layer, the "seed crystal" refers to the formation of The crystal nucleus is used to accelerate or promote the growth of crystals corresponding to its crystal form or its three-dimensional configuration; in other words, the seed crystal is a small single crystal that can be placed in a saturated or supersaturated solution to grow a large crystal. Also, a photoresist layer is mentioned in step c). The "photoresist" is also called photoresist, which is a light-sensitive mixed liquid composed of three main components: photosensitive resin, sensitizer and solvent. .

According to the features disclosed above, the material of the substrate in step a) of the present invention includes any one of ceramics, glass, metal, plastic and semiconductor wafer.

According to the features disclosed above, the adhesive material mentioned in step a) of the present invention can be a metal, or a combination of colloid and metal; and the aforementioned metals include copper, chromium, tungsten, nickel, nickel-chromium alloy, nickel-copper alloy , nickel-cobalt alloy, nickel-alloy, lead, and gold; and the aforementioned colloid includes any one of acrylic glue, epoxy resin, polyimide, and PET.

According to the features disclosed above, the positioning member described in the step g) of the present invention can be an adhesive film.

According to the features disclosed above, the laser etching described in step f) and step h) in the present invention can use a laser light source to provide a laser beam; and use a vibrating mirror to scan the module and place the laser On the transmission path of the light beam, it has an X-Y optical scanning lens and an optical reflective lens, and through the reflection of the optical reflective lens and the focusing of the X-Y optical scanning lens, the focus of the laser spot and the corresponding angle shift are realized , make the laser beam deflect and focus on the desired irradiation point, and project the laser beam onto a workpiece to generate a response beam, and the response beam will be further collected and collected by the X-Y optical scanning lens The reflection of the optical reflective mirror is used for analyzing the irradiation status of the laser beam; in addition, a vision module is set on the transmission path of the laser beam and the response beam, so that the vision module can be used to inspect the laser beam The beam is projected on the position to be irradiated and the relative position of the corresponding beam; a translation stage is used, which is set on the opposite side of the laser light source, and has a working platform and at least two axial directions of X and Y. A displacement mechanism; thereby, the substrate described in step f) and step h) and the attachments on it are placed on the work platform, and then the vision module is used to inspect and drive the X-Y optical scanning lens and The displacement mechanism is cooperatively displaced, so that the laser beam is correspondingly projected on the desired irradiation point, and then the laser etching operation is completed.

According to the characteristics disclosed above, the wavelength of the laser beam in the present invention can be 355nm˜1070nm.

In the present invention, an adhesive layer, a seed layer, and a photoresist layer are sequentially coated on the surface of the substrate; and a mold cavity with a plurality of probe arrangement patterns is formed in the photoresist layer by photolithography; The metal layer is deposited by electroplating; finally, the laser etching method is used to remove the photoresist and then vaporize the adhesive layer; since the laser etching process does not consume too much time and power, and the surface of the probe is not Any debris accumulation; therefore, the MEMS probe produced by the present invention has quality and cost-effectiveness.

First, please refer to FIG. 3 , which is the process flow of the "method for manufacturing microelectromechanical probes" of the present invention, including: step a). Coating an adhesive layer S10: coating an adhesive material on the surface of a substrate to form An adhesive layer; Step b). Coating a seed layer (seed layer) S20: coating a single crystal seed material on the adhesive layer to form a seed layer; Step c). Coating a photoresist layer S30 : Coating a photoresist material on the seed layer to form a photoresist layer with a thickness of 15 to 35 microns; step d). Forming a probe arrangement pattern S40: using a photolithography method through a photomask, Form the photoresist layer into a mold cavity with a plurality of probe arrangement patterns; step e). Form a probe-shaped metal layer S50: use an electroplating method to deposit a material that is conductive and the same as the single crystal seed on the aforementioned In the mold cavity of the step, a metal layer in the shape of a plurality of probes is formed; step f). Removing the photoresist S60: applying laser etching to irradiate from the front side of the substrate to remove the photoresist around the metal layer; step g). Fixing Probe S70: Use an adhesive positioning member to adhere to the surface of the metal layer, so that the probe is fixed on the positioning member; Step h). Vaporization of the adhesive layer S80: Apply laser etching to irradiate the adhesive from the back of the substrate layer to vaporize and disappear the adhesive material; step i). Detaching the probes S90: detaching the probes from the positioning member one by one.

As mentioned above, the material of the substrate described in step a) S10 of the present invention includes any one of ceramics, glass, metal, plastic and semiconductor wafer. Also said adhesive material can be a metal, or a combination of colloid and metal; and the aforementioned metals include copper, chromium, tungsten, nickel, nickel-chromium alloy, nickel-copper alloy, nickel-cobalt alloy, nickel alloy, lead and any one of gold; and the aforementioned colloids include any one of acrylic glue, epoxy resin, polyimide and PET.

Shown in Fig. 4～5, it is the status diagram of carrying out and finishing operation of step g of the present invention; Because in the process of step a～f, the probe 14 of metal layer has been formed on the surface of substrate 11, and probe 14 and substrate There is an adhesive layer 12 between 11, and the photoresist that originally existed around the metal layer has been removed; therefore, once the substrate 11 is to be detached in the subsequent manufacturing process, the probes 14 are bound to fall off messily and cause damage; therefore step g That is, a sticky positioning piece 13 is used to adhere to the surface of the metal layer, so that the probe 14 is fixed on the positioning piece 13; the positioning piece 13 in the present invention can be an adhesive film, but it is not limited thereto.

As shown in FIG. 6 , it is a schematic diagram of the operation of vaporizing the adhesive layer in step h of the present invention; it uses laser etching to irradiate the adhesive layer 12 from the back of the substrate 11 to vaporize and disappear the adhesive material; in the present invention, the laser The etching device is a large-area laser beam scanning device 100, because the scanning head of the device will project a laser beam with a wavelength of 355nm~1070nm to irradiate the adhesive layer 12, and a plurality of probes 14 are attached. The substrate 11 is placed on the stage of the device, and the back of the substrate 11 faces upward, and by the relative movement of the scanning head and the stage or a fixed-moving method, the adhesive layer 12 will be moved area by area. Vaporizes and disappears when irradiated by a laser beam.

The laser etching described in step f) and step h) in the present invention uses a large-area laser beam scanning device 100, as shown in Figure 7, comprising: a laser light source 20, which is a laser The light emitting machine 21 is used to generate a laser beam L1 as the irradiation light source of the workpiece M (i.e. the substrate and the attachment on it); a translation stage 30 is arranged on the opposite side of the laser light source 20, which has a A working platform for placing the workpiece M, and a displacement mechanism capable of two axial displacements of X and Y; in the present invention, the displacement mechanism further includes a Z-axis displacement function, so that the working platform can cooperate with the laser beam L1 The projection focal length is used to raise and lower its height; a galvanometer scanning module 40 is arranged above the translation stage 30 and on the transmission path of the laser beam L1, which has an X-Y optical scanning lens 41 and optical mirrors 42. The laser beam L1 is reflected by the optical reflector 42, and its horizontal projection direction is turned downward, and then focused by the X-Y optical scanning lens 41, thereby realizing the focus of the laser spot and generating the corresponding Angle shift, the laser beam L1 is deflected and focused on the desired irradiation point of the workpiece M, then the workpiece M will generate a photoluminescence response beam R1, which is collected by the X-Y optical scanning lens 41 The reflection of the light and the optical mirror 42 makes the response beam R1 transmit in the horizontal direction for analysis of the laser beam irradiation condition. A vision module 50, having a first beam splitter group 51, is located on the transmission path of the laser beam L1 and the response beam R1, so that the vision module 50 can be used to inspect the laser beam L1 projected on the desired The position and spot state of the irradiation point and the response beam R1; and drive the X-Y optical scanning lens 41 to coordinate with the displacement mechanism of the translation stage 30 to make the laser beam correspondingly projected on the desired irradiation point, and then Complete the laser etching job.

Please refer further to Fig. 8, which is the state of laser etching in the present invention; wherein, the workpiece M (i.e. the substrate and the attachment thereon) is placed on the working platform 31, and the laser light machine 21 sends out a laser beam L1 is refracted by the optical mirror 42, so that the laser beam L1 in the horizontal direction turns to the working platform 31 below, and the vision module 50 is used to check and adjust the setting state of the relevant components, and then drive the translation stage 30 The working platform 31 carries out the displacement of the desired irradiated area, and after the irradiated area is positioned, the optical mirror 42 of the galvanometer scanning module 40 is used to deflect the angle so that the laser beam L1 is projected on the desired irradiated area one by one. On the point, in this operation, the irradiation area can be divided into 9 irradiation points; in the figure, each square represents the irradiation field of view area S of the X-Y optical scanning lens 41 after the displacement of the translation stage 30, through which the optical mirror The individual deflection of 42 will cause the laser beam L1 to be projected on the desired irradiation point P one by one from the first point in the upper left corner to the ninth point in the lower right corner, and the corresponding photoluminescent light beam R1 of each point will be irradiated , the light received by the X-Y optical scanning lens 41 and the reflection of the optical mirror 42 are then monitored by the vision module 50; The stage 30 will be moved to the new irradiation field of view area S again, and the irradiation of each irradiation point P will be repeated one by one; in this way, the laser etching operation will be completed continuously and one by one in each irradiation field of view area S.

As shown in FIG. 9 , it is a schematic diagram of the state of completing the step of vaporizing the adhesive layer in the present invention; since the probe 14 is fixed on the positioning member 13, and the adhesive layer 12 between the probe 14 and the substrate 11 is fixed area by area. The laser beam is irradiated and vaporized and disappears, so the probe 14 is separated from the substrate 11 , but it is still fixed on the positioning member 13 at this time.

To sum up, the technical means disclosed in the present invention do have the requirements of invention patents such as "novelty", "progressiveness" and "suitable for industrial use". I pray that the Jun Bureau will grant patents to encourage inventions without any obligation. sense of virtue.

However, the drawings and descriptions disclosed above are only preferred embodiments of the present invention, and modifications or equivalent changes made by those who are familiar with the art according to the spirit of this case should still be included in the scope of the patent application of this case.

11: Substrate 12: Adhesive layer 13: Positioning parts 14: Probe 20: Laser light source 21:Laser machine 30: Translate the stage 31: Working platform 40: Scanning mirror module 41: X-Y optical scanning lens 42:Optical reflective lens 50: Visual Mod 51: The first beam splitter group 100: with a large-area microphotoluminescent scanning device L1: laser beam M: Workpiece (i.e. the substrate and its attachments) P: irradiation point R1: Response Beam S: Irradiate the field of view

1A to 1C are schematic diagrams of the forming process of a conventional MEMS probe. 2A to 2B are schematic diagrams of the post-production process of a conventional MEMS probe. Fig. 3 is a block diagram of the manufacturing steps of the present invention. . Fig. 4 is the operation schematic diagram of step g of the present invention. Fig. 5 is a schematic diagram of the state of completing step g of the present invention. Fig. 6 is a schematic diagram of the operation of step h of the present invention. Fig. 7 is a schematic diagram of a laser etching device of the present invention. Fig. 8 is a schematic diagram of the operation of laser etching in the present invention. Fig. 9 is a schematic diagram of the state of completing step h of the present invention.

Claims (5)

A method for manufacturing microelectromechanical probes, comprising: step a). Coating an adhesive layer: coating an adhesive material on the surface of a substrate to form an adhesive layer; step b). Coating a seed layer (seed layer ): coating a single crystal seed material on the adhesive layer to form a seed layer; step c). Coating a photoresist layer: coating a photoresist material on the seed layer to form a A photoresist layer with a thickness of 15-35 microns; step d). Forming a probe arrangement pattern: using a photolithography method through a photomask to form a mold cavity with a plurality of probe arrangement patterns on the photoresist layer; step e ). Forming a probe-shaped metal layer: using an electroplating method to deposit a material that is conductive and the same as the single crystal seed in the cavity of the previous step to form a plurality of probe-shaped metal layers; step f). Remove Photoresist: use laser etching to irradiate from the front side of the substrate to remove the photoresist around the metal layer; step g). Fixed probe: use an adhesive positioning member to adhere to the surface of the metal layer to make the probe Fixing on the positioning member; Step h). Vaporize the adhesive layer: use laser etching to irradiate the adhesive layer from the back of the substrate to vaporize the adhesive material; step i). Separate the probes: separate the probes one by one The positioning part is separated; and the laser etching described in step f) and step h) is to apply a laser light source to provide a laser beam; and use a vibrating mirror to scan the module and place it on the laser beam On the transmission path, it has an X-Y optical scanning lens and an optical reflective lens, and through the reflection of the optical reflective lens and the focusing of the X-Y optical scanning lens, the focus of the laser spot and the corresponding angle shift are realized. Deflecting and focusing the laser beam on the desired irradiation point, and projecting the laser beam onto a workpiece will produce a Response beam, and the response beam will be further collected by the X-Y optical scanning lens and reflected by the optical reflector for the analysis of the laser beam irradiation situation; in addition, a visual module is set on the laser beam On the transmission path of the response beam, the visual module can be used to check the relative position of the laser beam projected on the desired irradiation position and the response beam; and a translation stage is installed on the laser light source On the opposite side, it has a working platform and a displacement mechanism capable of at least two axial directions of X and Y; thereby, the substrate and the attachments described in step f) and step h) are placed on the working platform Then, the vision module is used to inspect and drive the X-Y optical scanning lens to move in cooperation with the displacement mechanism, so that the laser beam is correspondingly projected on the desired irradiation point, and then the laser etching operation is completed. The manufacturing method of the MEMS probe as described in item 1 of the scope of the patent application, wherein the material of the substrate in step a) includes any one of ceramics, glass, metal, plastic and semiconductor wafer. The manufacturing method of microelectromechanical probes as described in item 1 of the scope of the patent application, wherein the adhesive material described in step a) can be a metal, or a combination of colloid and metal; and the aforementioned metals include copper, chromium , tungsten, nickel, nickel-chromium alloy, nickel-copper alloy, nickel-cobalt alloy, nickel-alloy, lead and gold; and the aforementioned colloids include acrylic glue, epoxy resin, polyimide and PET any of them. The manufacturing method of the MEMS probe as described in item 1 of the scope of the patent application, wherein, the positioning member described in the step g) may be an adhesive film. The manufacturing method of the MEMS probe as described in item 1 of the scope of the patent application, wherein the wavelength of the laser beam is 355nm~1070nm.

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