WO2009061154A1

WO2009061154A1 - Flexible tactile sensor module and method for manufacturing the same

Info

Publication number: WO2009061154A1
Application number: PCT/KR2008/006582
Authority: WO
Inventors: Kunnyun Kim; Kwang Bum Park; Dae Sung Lee; Nam Kyu Cho; Won Hyo Kim; Kang Ryeol Lee
Original assignee: Korea Electronics Technology Institute
Priority date: 2007-11-08
Filing date: 2008-11-07
Publication date: 2009-05-14
Also published as: KR20090047845A; KR100896465B1

Abstract

Provided is a flexible tactile sensor module and a method for manufacturing the flexible tactile sensor module. In the flexible tactile sensor module, a terminal having a flat cable shape and connected to an electrode line of a tactile sensor is formed together with the tactile sensor. Therefore, the flexible tactile sensor module can be conveniently used by inserting the flexible tactile sensor module into a connector socket connected to a control unit.

Description

FLEXIBLE TACTILE SENSOR MODULE AND METHOD FOR

MANUFACTURING THE SAME

Technical Field

[1] The present disclosure relates to a flexible tactile sensor module and a method for manufacturing the flexible tactile sensor module. Background Art

[2] Generally, tactile sensors are used to detect information about surrounding environments such as contact force, vibration, surface roughness, and temperature variation caused by heat conduction.

[3] Such tactile sensors can be used for fine surgical operations, medical diagnoses such as a cancer diagnosis, medical treatments, and other application fields such as robot application fields.

[4] FIG. 1 is a schematic sectional view illustrating a silicon tactile senor of the related art. The silicon tactile sensor is formed as follows. A groove 12 is formed in the bottom side of a silicon substrate 10 by removing a portion of the bottom side of the silicon substrate 10 using a micro electro mechanical system (MEMS) so as to form a rectangular diaphragm 11.

[5] A load block 14 is disposed on the top side of the diaphragm 11, and a tactile sensor detection part 15 is formed using a silicon piezo-resistor or a thin-metal strain gauge.

[6] As described above, the silicon tactile sensor includes a piezoresistive structure pattern on the diaphragm formed by etching the rear side of the silicon substrate. Therefore, when an object makes contact with the load block, the diaphragm is deflected, and thus the contact pressure can be detected by measuring a resistance variation of the detection part caused by the deflection of the diaphragm.

[7] FIG. 2 is a schematic sectional view illustrating a silicon tactile sensor array of the related art. A plurality of tactile sensors 21, 22, 23, and 24 are attached to the top side of a flexible printed circuit board (FPCB) 30, and electrode terminals of the tactile sensors 21, 22, 23, and 24 are bonded to electrode terminals of the FPCB 30 by using wires 29. Then, wire-bonded regions are sealed by a polymer elastic part 40. In this way, tactile sensors are arrayed.

[8] In the related art, however, as the number of the tactile sensors included in the silicon tactile sensor array, the wire bonding process between the tactile sensors and the FPCB becomes more complicated, and thus errors increase. Disclosure of Invention Technical Problem [9] Accordingly, the present disclosure is provided to reduce errors generating in proportion to the number of arrayed sensors that affects the complexity of a wire process. Technical Solution

[10] According to an aspect, there is provided a flexible tactile sensor module including: a strain gauge; an insulation layer enclosing the strain gauge; a first electrode line connected to an end of the strain gauge and extending to a surface of the strain gauge through the strain gauge; a second electrode line connected to the other end of the strain gauge and extending to the surface of the strain gauge through the strain gauge; and a support part including a first opening on which a portion of the strain gauge floats and second openings through which the first and second electrode lines are exposed, the support part disposed at a lower side of the insulation layer.

[11] According to another aspect, there is provided a method for manufacturing a flexible tactile sensor module, the method including: forming a first insulation layer on a top side of a substrate; forming a metal pattern on a top side of the first insulation layer; forming a second insulation layer on the top side of the first insulation layer to enclose the metal pattern; forming a strain gauge metal pattern and a first electrode line metal pattern sequentially on a top side of the second insulation layer; etching a portion of the first electrode line metal pattern to form a strain gauge, a first electrode line connected to an end of the strain gauge, and a electrode pad connected to the other end of the strain gauge; forming a third insulation layer on the top side of the second insulation layer, the third insulation layer exposing the electrode pad connected to the other end of the strain gauge, an end of the first electrode line, and a portion of the top side of the second insulation layer; forming a second electrode line extending from the exposed electrode pad to the exposed portion of the top side of the second insulation layer; forming a support part on a top side of the third insulation layer, the support part including a first opening through which a region including a top side of the strain gauge is exposed, and second openings through which ends of the first and second electrode lines are exposed; forming plating layers in the second openings through which the ends of the first and second electrode lines are exposed; and separating the substrate and the first insulation layer from a bottom side of the second insulation layer.

[12] According to another aspect, there is provided a method for manufacturing a flexible tactile sensor module, the method including: forming a first insulation layer on a top side of a substrate; forming a metal pattern on a top side of the first insulation layer; forming a polyimide layer on a top side of the first insulation layer, the polyimide layer exposing the metal pattern; forming a thin metal layer on a top side of the polyimide layer to enclose the exposed metal pattern; forming a second insulation layer on the side of the polyimide layer to enclose the thin metal layer; forming a strain gauge metal pattern and a first electrode line metal pattern sequentially on a top side of the second insulation layer; etching a portion of the first electrode line metal pattern to form a strain gauge, a first electrode line connected to an end of the strain gauge, and a electrode pad connected to the other end of the strain gauge; forming a third insulation layer on the top side of the second insulation layer, the third insulation layer exposing the electrode pad connected to the other end of the strain gauge, an end of the first electrode line, and a portion of the top side of the second insulation layer; forming a second electrode line extending from the exposed electrode pad to the exposed portion of the top side of the second insulation layer; forming a support part on a top side of the third insulation layer, the support part including a first opening through which a region including a top side of the strain gauge is exposed, and second openings through which ends of the first and second electrode lines are exposed; forming plating layers in the second openings through which the ends of the first and second electrode lines are exposed; separating the substrate and the first insulation layer from a bottom side of the second insulation layer to expose the metal pattern; and forming a plating structure on the exposed metal pattern for forming a load block.

[13] According to another aspect, there is provided a method for manufacturing a flexible tactile sensor module, the method including: preparing a structure including an insulation layer formed on a substrate, a plurality of strain gauges arrayed in the insulation layer, metal patterns disposed between the substrate and the insulation layer and respectively corresponding to the strain gauges, and first and second electrode lines respectively connected to both ends of the strain gauges and extending to a surface of the insulation layer through the insulation layer; attaching a support part to the insulation layer, the support part including first openings through which regions respectively including the strain gauges are exposed, and second openings through which ends of the first and second electrode lines are exposed; separating the substrate from the insulation layer of the structure to expose the metal patterns; applying solder paste to top sides of the exposed metal patterns by printing; placing a shadow mask above the insulation layer, the shadow mask including a plurality of openings; inserting solder balls through the openings of the shadow mask to bring the solder balls into contact with the metal patterns, respectively; and fusing the solder balls onto the metal patterns by a reflow process.

[14] According to another aspect, there is provided a method for manufacturing a flexible tactile sensor module, the method including: preparing a structure including an insulation layer formed on a substrate, a plurality of strain gauges arrayed in the insulation layer, metal patterns disposed between the substrate and the insulation layer and respectively corresponding to the strain gauges, and first and second electrode lines respectively connected to both ends of the strain gauges and extending to a surface of the insulation layer through the insulation layer; attaching a support part to the insulation layer, the support part including first openings through which regions respectively including the strain gauges are exposed, and second openings through which ends of the first and second electrode lines are exposed; separating the substrate from the insulation layer of the structure to expose the metal patterns; applying an adhesive to top sides of the exposed metal patterns by printing; placing a shadow mask above the insulation layer, the shadow mask including a plurality of openings; inserting beads through the openings of the shadow mask to bring the beads into contact with the metal patterns, respectively; and after removing the shadow mask, hardening the beads onto the metal patterns, respectively.

Advantageous Effects

[15] According to the present disclosure, in the flexible tactile sensor module, a terminal having a flat cable shape and connected to an electrode line of a tactile sensor is formed together with the tactile sensor, so that the flexible tactile sensor module can be conveniently used by inserting the flexible tactile sensor module into a connector socket connected to a control unit.

[16] Furthermore, according to the present disclosure, an additional packaging process is not necessary for connecting the tactile sensor module to the control unit for signal processing.

[17] Moreover, according to the present disclosure, a flexible tactile sensor module including a signal processing connection part having a flexible flat cable (FFC) shape can be provided. The flexible tactile sensor module can be attached to various support structures for sensing a contact pressure applied from an object contacting the flexible tactile sensor module. Brief Description of Drawings

[18] FIG. 1 is a schematic cross-sectional view illustrating a silicon tactile sensor of the related art.

[19] FIG. 2 is a schematic cross-sectional view illustrating a silicon tactile sensor array of the related art.

[20] FIG. 3 is a schematic cross-sectional view illustrating a flexible tactile sensor module according to an exemplary embodiment.

[21] FIGS. 4 to 13 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to an exemplary embodiment.

[22] FIG. 14 is an image of a flexible tactile sensor module captured after a plating process is performed according to an exemplary embodiment. [23] FIG. 15 is another cross-sectional view for explaining a process illustrated in FIG.

12.

[24] FIG. 16 is a schematic plan view illustrating a flexible tactile sensor module according another exemplary embodiment.

[25] FIGS. 17 and 18 are schematic cross-sectional views illustrating a flexible tactile sensor module according to another exemplary embodiment.

[26] FIG. 19 is a schematic plan view illustrating a flexible tactile sensor module according to another exemplary embodiment.

[27] FIGS. 20 to 24 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to another exemplary embodiment.

[28] FIG. 25 is a cross-sectional view for illustrating another load block of the flexible tactile sensor module according to an exemplary embodiment.

[29] FIGS. 26 to 32 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to another exemplary embodiment.

[30] FIGS. 33 and 34 are cross-sectional views for explaining a process of forming a support part according to an exemplary embodiment.

[31] FIGS. 35 to 39 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to another exemplary embodiment.

[32] FIG. 40 is a schematic plan view illustrating a flexible tactile sensor module according to an exemplary embodiment.

[33] FIGS. 41 and 42 are images illustrating flexible tactile sensor modules inserted in connector sockets according to exemplary embodiments.

[34] FIGS. 43 to 46 are images for explaining test results of a flexible tactile sensor module according to an exemplary embodiment. Mode for the Invention

[35] Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings.

[36] FIG. 3 is a schematic cross-sectional view illustrating a flexible tactile sensor module according to an exemplary embodiment. The flexible tactile sensor module includes: a strain gauge 120; an insulation layer 110 enclosing the strain gauge 120; a first electrode line 125 connected to an end of the strain gauge 120 and extending to a surface of the insulation layer 110 through the insulation layer 110; a second electrode line 130 connected to the other end of the strain gauge 120 and extending to the surface of the insulation layer 110 through the insulation layer 110; a first opening 151 on which a portion of the strain gauge 120 floats; second openings 152 through which the first electrode line 125 and the second electrode line 130 are exposed; and a support part 150 formed on the bottom side of the insulation layer 110.

[37] The insulation layer 110 includes a first insulation layer 111 and a second insulation layer 112, and the strain gauge 120 is formed between the first and second insulation layers 111 and 112. The first electrode line 125 is connected to the end of the strain gauge 120 at a position disposed inside the first insulation layer 111, and then the first electrode line 125 extends from the position between the first and second insulation layers 111 and 112. The second electrode line 130 is connected to the other end of the strain gauge 120 at a position inside the first insulation layer 111 and extends along the surface of the first insulation layer 111.

[38] Plating layers may be further formed in the second openings 152 for plating the first and second electrode lines 125 and 130.

[39] The insulation layer 110 may be formed of a flexible polymer.

[40] FIGS. 4 to 13 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to an exemplary embodiment. First, a first insulation layer 210 is formed on the top surface of a substrate 200 (FIG.

4). [41] If the substrate 200 is a silicon wafer, the first insulation layer 210 is a thermal oxide layer and is also formed on the bottom surface of the silicon wafer as indicated by reference numeral 212 in FIG. 4. [42] Thereafter, a metal pattern 230 is formed on the top surface of the first insulation layer 210 to mark a position at which a load block will be formed in a later process

(FIG. 5). [43] At this time, a Cr layer may be formed on the top surface of the first insulation layer

210 as an adhesion layer 220, and then an Au layer may be formed on the top surface of the adhesion layer 220 as the metal pattern 230. [44] Next, a second insulation layer 240 is formed on the top surface of the first insulation layer 210 to cover the metal pattern 230 (FIG. 6).

[45] The second insulation layer 240 may be formed of a polymer such as polyimide.

[46] In the case where the adhesion layer 220 is formed on the top surface of the first insulation layer 210, a polyimide layer may be formed on the adhesion layer 220 by spin coating, and then the polyimide layer may be hardened at about 35O⁰C. [47] To form the polyimide layer to a desired thickness, the volume of the polyimide layer may be calculated according to mass variation, and test coating may be performed. [48] Next, a metal pattern 250 for a strain gauge and a metal pattern 260 for a first electrode line are sequentially formed on the top surface of the second insulation layer

240 (FIG. 7). [49] The strain gauge metal pattern 250 and the first electrode line metal pattern 260 are formed by depositing a strain gauge metal layer and a first electrode by sputtering or vacuum deposition and patterning the strain gauge metal layer and the first electrode line metal layer through a lift process.

[50] Thereafter, a portion of the first electrode line metal pattern 260 is etched away so as to form a strain gauge 251, a first electrode line 261 connected to an end of the strain gauge 251, and an electrode pad 262 connected to the other end of the strain gauge 251 (FIG. 8).

[51] As illustrated in FIG. 8, if an electrode line is formed after a strain gauge is formed, oxidation of the strain gauge can be prevented when moisture and organic substances generated from the electrode line are removed using oxygen plasma, and the process of forming the strain gauge and the electrode line can be simplified.

[52] Thereafter, a third insulation layer 270 is formed on the top surface of the second insulation layer 240 in a manner such that the electrode pad 262 connected to the other end of the strain gauge 251, an end of the first electrode line 261, and a top surface portion of the second insulation layer 240 are exposed (FIG. 9).

[53] Next, a second electrode line 280 is formed from the exposed electrode pad 262 to the exposed top surface portion of the second insulation layer 240 (FIG 10).

[54] After that, a support part 290 is formed on the top surface of the third insulation layer

270. The support part 290 includes a first opening 291 through which a region of the third insulation layer 270 including an top side of the strain gauge 251 is exposed, and second openings 292 through which ends of the first and second electrode lines 261 and 280 are exposed (FIG. 11).

[55] The support part 290 is formed in a cavity shape to facilitate deflection of a membrane. The support part 290 may be formed of photosensitive polyimide through a photolithography process.

[56] That is, a photosensitive polyimide may be formed on the third insulation layer 270, and the first and second openings 291 and 292 may be formed by etching.

[57] Alternatively, the support part 290 may be formed by forming first and second openings 291 and 292 through a polyimide film having an adhesion layer by using a punching device, and attaching the polyimide film to the top surface of the third insulat ion layer 270 by hot pressing.

[58] Next, plating layers 293 are formed in the second openings 292 through which the first and second electrode lines 261 and 280 are exposed (FIG. 12).

[59] The plating layers 293 may be formed by electro-plating. The plating layers 293 may be formed of Cu (293a)/Ni (293b)/Au (293c).

[60] The plating layers 293 function as terminals connected to the first and second electrode lines 261 and 280 so that the flexible tactile sensor module of the current embodiment can be connected to an external device more easily.

[61] Next, the substrate 200 and the first insulation layer 210 are separated from the bottom surface of the second insulation layer 240 (FIG. 13).

[62] In the case where the adhesion layer 220 exists, the adhesion layer 220 is also removed to expose the metal pattern 230 that indicates a position where a load block will be formed.

[63] FIG. 14 is an image of a flexible tactile sensor module captured after a plating process is performed according to an exemplary embodiment. Ends of electrode lines of a plurality of arrayed tactile sensors 300 are exposed through openings of a support part, and terminals 320 are formed on the exposed regions 310 of the electrodes through a plating process.

[64] According to exemplary embodiments, a tactile sensor including a strain gauge can be provided, and a plurality of arrayed tactile sensors can also be provided.

[65] FIG. 15 is another cross-sectional view for explaining a process illustrated in FIG.

12. FIG. 15 illustrates the plating layer 293 formed in the second opening 292 through which an end of the first electrode line 261 is exposed.

[66] That is, in the flexible tactile sensor module of the current embodiment, the plating layers 293 are formed in the openings 292 through which ends of the first and second electrode lines 261 and 280 are exposed. Therefore, the strain gauge 251 used to detect a contact force can be connected to the first and second electrode lines 261 and 280, and terminals can be formed to connect the first and second electrode lines 261 and 280 to an external device.

[67] In other words, since the terminals connected to the first and second electrode lines

261 and 280 are formed in a flat cable shape together with the tactile sensor module, the tactile sensor module can be easily used by inserting the tactile sensor module in a connector socket connected to a control unit.

[68] Therefore, according to the current embodiment, an additional packaging process is not necessary for connecting the tactile sensor module to the control unit for signal processing.

[69] FIG. 16 is a schematic plan view illustrating a flexible tactile sensor module according to another exemplary embodiment. A strain gage 351 is disposed in a membrane region 350. An end of a first electrode line 361 is connected to an end of the strain gage 351, and an end of a second electrode line 362 is connected to the other end of the strain gage 351. Plated terminals 361a and 362a are formed on the other ends of the first and second electrode lines 361 and 362.

[70] FIGS. 17 and 18 are schematic cross-sectional views illustrating a flexible tactile sensor module according to another exemplary embodiment. In the flexible tactile sensor module of the current embodiment, a load block is formed in a membrane region for transmitting a force. [71] That is, after a substrate separating process is finished, a load block configured to transmit a force is formed in a membrane region of the second insulation layer 240 of the flexible tactile sensor module of FIG. 13. [72] When the flexible tactile sensor module receives a contact force from an object, a membrane of the flexible tactile sensor module can be deflected more largely owing to the load block. [73] As shown in FIG. 17, the load block may be formed by dispensing a polymer drop

400 in the membrane region of the flexible tactile sensor module and hardening the polymer drop 400. [74] The polymer drop 400 may be dispensed to a metal pattern formed as a mark for forming the load block 400. [75] The polymer drop 400 may be an ultraviolet epoxy drop, a thermosetting epoxy drop, a polyurethane drop, or the like. [76] As shown in FIG. 18, the load block may further include a polymer elastic part 410 formed on the top surface of a second insulation layer 240 to cover the polymer drop

400. [77] FIG. 19 is a schematic plan view illustrating a flexible tactile sensor module according to another exemplary embodiment. A polymer drop 400 is formed in a membrane region 350 of a flexible tactile sensor module as a load block. [78] When an object makes contact with the polymer drop 400, a load is transmitted to the membrane region 350 through the polymer drop 400 so that the membrane region 350 is deflected and the resistance of a strain gauge 351 is changed. [79] Therefore, a contact force exerted by the object can be measured by sensing the resistance variation of the strain gage 351. [80] In FIG. 19, reference numeral 361 denotes a first electrode line, reference numeral

361a denotes a terminal connected to the first electrode line 361, reference numeral

362 denotes a second electrode line, and reference numeral 362a denotes a terminal connected to the second electrode line 362.

[81] FIGS. 20 to 24 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to another exemplary embodiment. After the process illustrated in FIG. 5, the metal pattern 230, formed to mark a position at which a load block will be formed in a later process, is exposed, and a polyimide layer 231 is formed on the top surface of the first insulation layer 210

(FIG. 20). [82] Next, a thin metal layer 232 is formed on the top surface of the polyimide layer 231 to cover the metal pattern 230 (FIG. 21). [83] Then, a second insulation layer 240 is formed on the top surface of the polyimide layer 231 to cover the thin metal layer 232 (FIG. 22). [84] When a load block is formed in a later plating process, the thin metal layer 232 is connected to a negative electrode. [85] After the process illustrated in FIG. 22, the same processes as illustrated in FIGS. 7 to 12 are performed. [86] After the plating process illustrated in FIG. 12, the substrate 200 and the first insulation layer 210 are separated from the bottom surface of the polyimide layer 231 to expose the metal pattern 230 as shown in FIG. 23. [87] In the case where the adhesion layer 220 exists, the adhesion layer 220 is also removed to expose the metal pattern 230 that indicates a position where a load block will be formed. [88] Next, a plating structure 450 is formed on the exposed metal pattern 230 as a load block (FIG. 24). [89] FIG. 25 is a cross-sectional view for illustrating another load block of the flexible tactile sensor module according to an exemplary embodiment. A polymer elastic part

451 is formed on the top surface of a polyimide layer 231 to cover a plating structure

450 formed as shown in FIG. 24. [90] In the flexible tactile sensor module of the current embodiment, a load block is formed by the plating structure 450 formed on an exposed metal pattern 230 and the polymer elastic part 451 formed on the top surface of the polyimide layer 231 to cover the plating structure 450.

[91] FIGS. 26 to 32 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to another exemplary embodiment. As shown in FIG. 26, a plurality of arrayed strain gauges, and first and second electrode lines connected to the strain gauges are formed through the processes illustrated in FIGS. 4 to 10. [92] In detail, an insulation layer is formed on a substrate, and a plurality of strain gauges are arrayed in the insulation layer. Metal patterns corresponding to the strain gauges are formed between the substrate and the insulation layer. First and second electrode lines are connected to both ends of the strain gauges and extend to a surface of the insulation layer through the insulation layer. [93] Referring to FIG. 26 and the description of FIG. 10, a third insulation layer 270 is formed on a side opposite to a substrate 200. [94] Referring to FIG. 27, a support part 500 having a plurality of penetration openings

501 is bonded to the third insulation layer 270. [95] The penetration openings 501 include first openings through which regions including the strain gauges are exposed, and first openings through which ends of the first and second electrode lines are exposed. [96] The support part 500 may be bonded to the third insulation layer 270 by applying pressure and heat after disposing an adhesion layer 510 between the support part 500 and the third insulation layer 270.

[97] Membrane regions are defined by the penetration openings 501.

[98] The strain gauges are located in the membrane regions, respectively.

[99] Thereafter, the substrate and a first insulation layer 210 are separated from a second insulation layer 240 so as to expose metal patterns 230 (FIG. 28).

[100] That is, the metal patterns 230 are exposed by separating the substrate 200 from the second insulation layer 240 of the above-described described structure.

[101] The metal patterns 230 are disposed at positions corresponding to the strain gauges, respectively. That is, the metal patterns 230 exist in the membrane regions, respectively.

[102] Thereafter, solder paste 550 is applied to the top surfaces of the metal patterns 230 by printing (FIG 29).

[103] Next, a shadow mask 570 is placed above the second insulation layer 240 (FIG. 30). The shadow mask 570 includes a plurality of openings 571 so that solder balls can be inserted through the shadow mask 570.

[104] At this time, the openings 571 of the shadow mask 570 are aligned with the metal patterns 230, respectively.

[105] Next, solder balls 580 are inserted through the openings 571 of the shadow mask 570 to bring the solder balls 580 into contact with the solder paste 550 (FIG. 31).

[106] Thereafter, a reflow process is performed so as to fuse the solder balls 580 onto the metal patterns 230, respectively (FIG. 32).

[107] The reflow process is performed at about 25O⁰C.

[108] In the current embodiment, solder balls are formed in the flexible tactile sensor module as load blocks.

[109] FIGS. 33 and 34 are cross-sectional views for explaining a process of forming a support part according to an exemplary embodiment. In the current embodiment, as shown in FIG. 33, first, a polyimide film 500 is prepared to form a support part. An adhesion layer is formed on the top surface of the polyimide film 500.

[110] Next, as shown in FIG. 34, penetration openings 501 having a size corresponding to a membrane are formed through the polyimide film 500 using a punching device.

[I l l] FIGS. 35 to 39 are schematic cross-sectional views for explaining a method for manufacturing a flexible tactile sensor module according to another exemplary embodiment. Through the processes illustrated in FIGS. 4 to 10 and FIGS. 26 and 27, the structure shown in FIG. 35 is formed. In detail, a plurality of arrayed strain gauges and first and second electrode lines connected to the strain gauges are formed, a support part 500 including a plurality of penetration openings 501 is attached to a third insulation layer 270, and a substrate 200 and a first insulation layer 210 are separated from a second insulation layer 240 to expose metal patterns 230. [112] That is, the structure shown in FIG. 35 is substantially the same as that shown in

FIG. 28. [113] Thereafter, an adhesive 610 is applied to the top surfaces of the exposed metal patterns 230 by printing (FIG. 36). [114] The adhesive 610 is a polymer adhesive such as ultraviolet epoxy and thermosetting epoxy and is applied by a screen printing method. [115] Next, a shadow mask 570 including a plurality of openings 571 for receiving beads is placed above the second insulation layer 240 (FIG. 37). [116] At this time, the openings 571 of the shadow mask 570 are aligned with the metal patterns 230. [117] Next, beads 650 are inserted through the openings 571 of the shadow mask 570 to bring the beads 650 into contact with the metal patterns 230 (FIG. 38). [118] The shadow mask 570 may be formed of stainless steel. The shadow mask 570 is placed at a height to receive the beads 650 without making contact with the adhesive

610. [119] The beads 650 may be formed of at least one of acrylic, ceramic, and metallic materials. [120] After removing the shadow mask 570, the beads 650 are respectively fixed to the metal patterns 230 by hardening (FIG 39). [121] As described above, the flexible tactile sensor module of the current embodiment use beads as load blocks. [122] FIG. 40 is a schematic plan view illustrating a flexible tactile sensor module according to an exemplary embodiment. The flexible tactile sensor module of the current embodiment includes a plurality of arrayed tactile sensors 710 (or a single tactile sensor). The arrayed tactile sensors 710 are connected to terminals 730 via electrode lines 720. [123] The terminals 730 are signal processing connection part for connecting the arrayed tactile sensors 710 to an external device such as a control unit. A region where the terminals 730 are disposed is protruded from a region where the arrayed tactile sensors

710 are disposed. [124] That is, as shown in FIG. 40, the region where the terminals 730 are disposed is protruded by about a thickness T so that the flexible tactile sensor module can be easily inserted into a connector socket connected to an external device. Therefore, the flexible tactile sensor module can be conveniently used. [125] FIGS. 41 and 42 are images illustrating flexible tactile sensor modules inserted in connector sockets according to exemplary embodiments. Referring to FIG. 41 from let to right, 4x4, 8x8, and 16x16 array tactile sensor modules are inserted into connector sockets, respectively.

[126] Referring to FIG. 42, a 32x32 array tactile sensor module is inserted into a connector socket.

[127] The above-described embodiments provide flexible tactile sensor modules including signal processing connection parts similar to flexible flat cables (FFC). Therefore, the tactile sensor modules can be easily connected to various support structures for sensing a contact pressure applied from an object contacting the tactile sensor module.

[128] FIGS. 43 to 46 are images for explaining test results of a flexible tactile sensor module according to an exemplary embodiment. Referring to FIG. 43, a metal rod was brought into contact with the flexible tactile sensor module, and referring to FIG. 45, a finger was brought into contact with the flexible tactile sensor module. A force (refer to FIG. 44) applied to the flexible tactile sensor module by the metal rod was larger than a force (refer to FIG. 46) applied to the flexible tactile sensor module by the finger.

[129] That is, it can be understood from the test results that the flexible tactile sensor module has a good sensing ability for sensing the magnitude of a force applied to the flexible tactile sensor module.

[130] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

[1] A flexible tactile sensor module comprising: a strain gauge; an insulation layer enclosing the strain gauge; a first electrode line connected to an end of the strain gauge and extending to a surface of the strain gauge through the strain gauge; a second electrode line connected to the other end of the strain gauge and extending to the surface of the strain gauge through the strain gauge; and a support part comprising a first opening on which a portion of the strain gauge floats and second openings through which the first and second electrode lines are exposed, the support part disposed at a lower side of the insulation layer.

[2] The flexible tactile sensor module of claim 1, wherein the insulation layer comprises a first insulation layer and a second insulation layer; the strain gauge is disposed between the first and second insulation layers; the first electrode line is connected to the end of the strain gauge at an inner region of the first insulation layer and extends between the first and second insulation layers; and the second electrode line is connected to the other end of the strain gauge at an inner region of the second insulation layer and extends along a surface of the first insulation layer.

[3] The flexible tactile sensor module of claim 1, wherein the strain gauge, the first electrode line, the second electrode line, and the first opening are provided in plurality; the strain gauges are connected to the first electrode lines, respectively, and to the second electrode lines, respectively; and portions of the strain gauges float on the first openings, respectively.

[4] The flexible tactile sensor module of any one of claims 1 to 3, further comprising plating layers formed in the second openings for plating potions of the first and second electrode lines exposed through the second openings.

[5] The flexible tactile sensor module of claim 1 or 3, wherein an exposed metal pattern is formed on a portion of the insulation layer disposed above the second opening, and a load block is disposed at the exposed metal pattern.

[6] The flexible tactile sensor module of claim 5, wherein the load block is one of a solder ball and a bead.

[7] The flexible tactile sensor module of claim 5, wherein the load block is formed by a plating structure deposited on the metal pattern or a polymer drop hardened on the metal pattern.

[8] The flexible tactile sensor module of claim 5, wherein the load block is a plating structure deposited on the metal pattern, a thin metal layer is disposed between the metal pattern and the insulation layer, and a polyimide layer is formed on the thin metal layer and the insulation layer and exposes the metal pattern.

[9] The flexible tactile sensor module of any one of claims 1 to 3, wherein a region in which the second openings are disposed is protruded from a region in which the strain gauge is disposed.

[10] The flexible tactile sensor module of claim 4, further comprising a connector socket into which the region where the second openings are disposed is inserted, wherein the plating layers formed in the second openings are electrically connected to the connection socket.

[11] The flexible tactile sensor module of claim 1, wherein the insulation layer is formed of a polymer.

[12] A method for manufacturing a flexible tactile sensor module, the method comprising: forming a first insulation layer on a top side of a substrate; forming a metal pattern on a top side of the first insulation layer; forming a second insulation layer on the top side of the first insulation layer to enclose the metal pattern; forming a strain gauge metal pattern and a first electrode line metal pattern sequentially on a top side of the second insulation layer; etching a portion of the first electrode line metal pattern to form a strain gauge, a first electrode line connected to an end of the strain gauge, and a electrode pad connected to the other end of the strain gauge; forming a third insulation layer on the top side of the second insulation layer, the third insulation layer exposing the electrode pad connected to the other end of the strain gauge, an end of the first electrode line, and a portion of the top side of the second insulation layer; forming a second electrode line extending from the exposed electrode pad to the exposed portion of the top side of the second insulation layer; forming a support part on a top side of the third insulation layer, the support part comprising a first opening through which a region including a top side of the strain gauge is exposed, and second openings through which ends of the first and second electrode lines are exposed; forming plating layers in the second openings through which the ends of the first and second electrode lines are exposed; and separating the substrate and the first insulation layer from a bottom side of the second insulation layer.

[13] The method of claim 12, wherein the forming of the support part is performed by forming a photosensitive polyimide film on the top side of the third insulation layer and etching the polyimide film to form the first and second openings, or the forming of the support part is performed by forming the first and second openings in a polyimide film to which an adhesive is applied by using a punching device, and attaching the polyimide film to the top side of the third insulation layer by hot pressing.

[14] The method of claim 12, wherein the metal pattern and the second insulation layer are exposed after the separating of the substrate and the first insulation layer, and the method further comprises forming a load block on the exposed metal pattern after the separating of the substrate and the first insulation layer.

[15] The method of claim 14, wherein the forming of the load block comprises: dispensing a polymer drop onto the metal pattern; and hardening the polymer drop.

[16] The method of claim 15, further comprising forming a polymer elastic part on the second insulation layer to enclose the hardened polymer drop.

[17] A method for manufacturing a flexible tactile sensor module, the method comprising: forming a first insulation layer on a top side of a substrate; forming a metal pattern on a top side of the first insulation layer; forming a polyimide layer on a top side of the first insulation layer, the polyimide layer exposing the metal pattern; forming a thin metal layer on a top side of the polyimide layer to enclose the exposed metal pattern; forming a second insulation layer on the side of the polyimide layer to enclose the thin metal layer; forming a strain gauge metal pattern and a first electrode line metal pattern sequentially on a top side of the second insulation layer; etching a portion of the first electrode line metal pattern to form a strain gauge, a first electrode line connected to an end of the strain gauge, and a electrode pad connected to the other end of the strain gauge; forming a third insulation layer on the top side of the second insulation layer, the third insulation layer exposing the electrode pad connected to the other end of the strain gauge, an end of the first electrode line, and a portion of the top side of the second insulation layer; forming a second electrode line extending from the exposed electrode pad to the exposed portion of the top side of the second insulation layer; forming a support part on a top side of the third insulation layer, the support part comprising a first opening through which a region including a top side of the strain gauge is exposed, and second openings through which ends of the first and second electrode lines are exposed; forming plating layers in the second openings through which the ends of the first and second electrode lines are exposed; separating the substrate and the first insulation layer from a bottom side of the second insulation layer to expose the metal pattern; and forming a plating structure on the exposed metal pattern for forming a load block.

[18] The method of claim 17, wherein after the forming of the plating structure, the method further comprises forming a polymer elastic part on a side of the polyimide layer to enclose the plating structure.

[19] A method for manufacturing a flexible tactile sensor module, the method comprising: preparing a structure comprising an insulation layer formed on a substrate, a plurality of strain gauges arrayed in the insulation layer, metal patterns disposed between the substrate and the insulation layer and respectively corresponding to the strain gauges, and first and second electrode lines respectively connected to both ends of the strain gauges and extending to a surface of the insulation layer through the insulation layer; attaching a support part to the insulation layer, the support part comprising first openings through which regions respectively including the strain gauges are exposed, and second openings through which ends of the first and second electrode lines are exposed; separating the substrate from the insulation layer of the structure to expose the metal patterns; applying solder paste to top sides of the exposed metal patterns by printing; placing a shadow mask above the insulation layer, the shadow mask comprising a plurality of openings; inserting solder balls through the openings of the shadow mask to bring the solder balls into contact with the metal patterns, respectively; and fusing the solder balls onto the metal patterns by a reflow process.

[20] A method for manufacturing a flexible tactile sensor module, the method comprising: preparing a structure comprising an insulation layer formed on a substrate, a plurality of strain gauges arrayed in the insulation layer, metal patterns disposed between the substrate and the insulation layer and respectively corresponding to the strain gauges, and first and second electrode lines respectively connected to both ends of the strain gauges and extending to a surface of the insulation layer through the insulation layer; attaching a support part to the insulation layer, the support part comprising first openings through which regions respectively including the strain gauges are exposed, and second openings through which ends of the first and second electrode lines are exposed; separating the substrate from the insulation layer of the structure to expose the metal patterns; applying an adhesive to top sides of the exposed metal patterns by printing; placing a shadow mask above the insulation layer, the shadow mask comprising a plurality of openings; inserting beads through the openings of the shadow mask to bring the beads into contact with the metal patterns, respectively; and after removing the shadow mask, hardening the beads onto the metal patterns, respectively.

[21] The method of claim 19 or 20, wherein the preparing of the structure comprises: forming a first insulation layer on a top side of a substrate; forming a metal pattern on a top side of the first insulation layer; forming a second insulation layer on the top side of the first insulation layer to enclose the metal pattern; forming a strain gauge metal pattern and a first electrode line metal pattern sequentially on a top side of the second insulation layer; etching a portion of the first electrode line metal pattern to form a strain gauge, a first electrode line connected to an end of the strain gauge, and a electrode pad connected to the other end of the strain gauge; forming a third insulation layer on the top side of the second insulation layer, the third insulation layer exposing the electrode pad connected to the other end of the strain gauge, an end of the first electrode line, and a portion of the top side of the second insulation layer; and forming a second electrode line extending from the exposed electrode pad to the exposed portion of the top side of the second insulation layer.

[22] The method of claim 19 or 20, wherein the attaching of the support part comprises: preparing a polyimide film comprising an adhesion layer on a top side; and forming the first and second openings through the polyimide film using a punching device. [23] The method of claim 20, wherein the beads are formed of one of acrylic, ceramic, and metallic materials.