Patent Application
20100043212
The present invention generally relates to bonding a flexible printed circuit board (PCB) to integrated circuits, such as that of a printhead.
The following applications have been filed by the Applicant simultaneously with the present application:
The disclosures of these co-pending applications are incorporated herein by reference. The above applications have been identified by their filing docket number, which will be substituted with the corresponding application number, once assigned.
The following patents or patent applications filed by the applicant or assignee of the present invention are hereby incorporated by cross-reference.
Pagewidth printers that incorporate micro-electromechanical components generally have printhead integrated circuits that include a silicon substrate with a large number of densely arranged micro-electromechanical nozzle arrangements. Each nozzle arrangement is responsible for ejecting a stream of ink drops.
In order for such printers to print accurately and maintain quality, it is important that the printhead integrated circuits be tested. This is particularly important during the design and development of such integrated circuits.
In order to test such integrated circuits, it is necessary to attach some form of data communication arrangement to the integrated circuits. Flexible printed circuit boards are an example of such a data communication arrangement and have been used to communicate data to integrated circuits.
According to a first aspect of the present invention, there is provided a bonding device for bonding a flexible printed circuit board (PCB) to a printhead assembly, the printhead assembly having a printhead carrier and an ink ejection printhead carried by the carrier, the bonding device comprising:
The carrier may be formed from liquid crystal polymer (LCP) material.
The first and second paths may be rectilinear and substantially orthogonal. The heater assemblies may be linearly constrained to move along their respective paths.
The bending mechanism may include a bending member movable along a rectilinear path.
The bonding device may further include at least one clamp configured to clamp the flexible PCB to the printhead assembly.
The support structure assembly may include a cabinet. The heater assemblies and bending mechanisms may be located within an internal space of the cabinet. The cabinet may define an access opening to facilitate access to the heater assemblies and bending mechanism within the internal space.
A carriage may be movably mounted within the cabinet and configured to carry the printhead assembly. The carriage may define a nest in which the printhead assembly can be nested.
The control system may include an operator control panel on the cabinet including a plurality of control actuators configured to control the operation of the bending mechanism and the heater assemblies. The control actuators may include a pair of buttons which are configured to operate exclusively on concurrent depression of the buttons. The pair of buttons may be spaced apart so that they cannot be both concurrently pressed using a single hand. The cabinet may further include an operator display panel including a display for displaying information relating to the operation of the bonding device.
The bonding device may further include:
The bonding device may further include an authentication system for authenticating the printhead assembly. The authentication system may include an optical scanner configured to scan identification indicia borne by either the printhead or the printhead carrier.
The bonding device may further include a stack of beacons mounted to the cabinet wherein the beacons can be illuminated in a plurality of different ways to represent corresponding operational conditions of the bonding device.
According to a second aspect of the present invention, there is provided a bonding device for bonding a flexible printed circuit board (PCB) to a printhead assembly, the bonding device comprising:
The light curtain generator may include:
Thus, the controller may further be configured to cease any heating of said movable bonding part responsive to said breach of the light curtain.
The at least one movable bonding part may include:
The at least one movable bonding part may further include a bending mechanism configured to bend the PCB between bonding the PCB to the printhead and the printhead carrier.
The first and second paths may be rectilinear and substantially orthogonal to each other.
The cabinet may include an operator control panel including a plurality of control actuators configured to control operation of the bonding device.
The cabinet may have an operator display panel including a display for displaying information relating to the operation of the bonding device, the display being a touch screen display operatively connected to the controller to enable an operator to make selections relating to the operation of the bonding device.
According to a third aspect of the present invention, there is provided an attachment apparatus for attaching a flexible printed circuit board (PCB) to a printhead assembly, the attachment apparatus comprising:
The plurality of operational control actuators may further include:
The at least one attachment assembly may include:
The attachment assembly may include at least one clamp configured to clamp the flexible PCB to the printhead assembly.
The attachment assembly may further include a light curtain generator configured to generate a light curtain across an access opening defined by the housing assembly. The control system may be configured to cease operation of said attachment assemblies responsive to a breach of the light curtain.
The housing assembly may further include a light emitting indicator configured to be illuminated in a plurality of different ways to represent corresponding operational conditions of the attachment apparatus.
According to a fourth aspect of the present invention, there is provided a method for connecting a flexible printed circuit board (PCB) to a printhead assembly, the printhead assembly comprising a printhead carrier and an ink ejection printhead carried by the carrier, the method comprising the steps of:
The flexible PCB may be clamped to the printhead assembly.
The printhead assembly may be authenticated by scanning a barcode borne by the printhead assembly. The PCB may also be authenticated scanning a barcode borne by the PCB.
The step of connecting the flexible PCB to the printhead may involve mechanically connecting the PCB to the printhead with adhesive.
The step of connecting the bent PCB to the printhead carrier may involve mechanically connecting the PCB to the printhead carrier with an adhesive.
The connectors may be linearly constrained to move along the first and second paths, which are rectilinear and substantially orthogonal to each other.
According to a fifth aspect of the present invention, there is provided a fastening apparatus for fastening a flexible printed circuit board (PCB) to a printhead assembly, the printhead assembly having a printhead carrier and an ink ejection printhead carried by the carrier, the fastening apparatus comprising:
The authentication system may include an optical scanner configured to scan identification indicia borne by either the printhead or the printhead carrier. The identification indicia may be a barcode.
The authentication system may be configured to further authenticate the PCB, and the controller may be configured to control the bonding assembly to bond the PCB to the printhead assembly subsequent to the further authentication of the PCB.
The bonding assembly may further include a bending mechanism configured to bend the PCB subsequent to bonding the PCB to the printhead of the printhead assembly.
The support assembly may include a visible indicator operatively connected to the controller, which may be configured to control the visible indicator in a plurality of different ways to represent corresponding operational conditions of the fastening apparatus.
According to a sixth aspect of the present invention, there is provided a bonding device for bonding a flexible printed circuit board (PCB) to an ink ejection printhead, the bonding device comprising:
Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:
According to an embodiment of the present invention, there is provided a bonding, attachment or fastening device or apparatus 10 shown in
The film defines a plurality of openings (not shown) which correspond with openings in the printhead 18 and in part of the carrier 16 so that the printhead 18 can be fed with fluid for testing purposes.
The underside of the PCB 12 is coated with an adhesive and the carrier 16 is formed from liquid crystal polymer (LCP) material which is inherently resistant to heat deformation. In use, one or more bonding assemblies, fasteners or connectors or platen assemblies of the bonding device 10 mechanically bond the flexible PCB 12 to the printhead assembly 14 with the adhesive. A detailed description of the bonding device 10 is provided below.
Turning to
The bonding device 10 further includes a control system or controller which is configured to cease the operation of the movable bonding parts 21, including the bonding or heater assemblies, responsive to a breach of the light curtain. That is, any movement and heating of the parts 21 is immediately ceased in the event that the operator reaches a hand into the internal space 22, thereby reducing the possibility of injury to the operator.
The cabinet 20 includes an operator control panel 28 located at its base. The control panel 28 includes a row of control press-buttons 30 (i.e. actuators) configured to control the operation of the bonding device 10. The outer press buttons 30a, 30e are START buttons which must be concurrently pressed before the PCB 12 can be bonded to the printhead assembly 14. The controller is configured to control the heater assemblies to bond the PCB 12 to the printhead assembly 14 responsive to the buttons 30a, 30e being concurrently pressed. The START buttons 30a, 30e are spaced apart so that the operator cannot concurrently press both of them using a single hand. In this manner, the operator must have both hands located external to the cabinet 20 when initiating operation of the bonding device 10, thereby ensuring that one hand cannot be located within the cabinet 20.
The bonding device 10 further includes an authentication system for authenticating the printhead assembly 14. The authentication system includes an optical barcode scanner 15 configured to scan barcodes borne by either the printhead 18 or the printhead carrier 16. The scanner 15 is fastened to the cabinet 20, either in the space 22 or on a front panel, and reading of the barcodes is initiated when the operator presses a SCAN press button 30b of the operator control panel 28. The controller is configured to control the heater assemblies to bond the PCB 12 to the printhead assembly 14, only subsequent to the authentication of the printhead assembly 14.
The operator control panel 28 further includes an EMERGENCY STOP button 30c which can be pressed by the operator to cease operation of the bonding device 10 at any time and, in particular, in the event of an emergency. Pressing the EMERGENCY STOP button 30c causes the controller to cease any movement and heating of the heater assemblies. Once the emergency has been addressed, a RESET button 30d of the operator control panel 28 can be pressed to cause the controller to reset the operation of the bonding device 10.
The cabinet 20 also has an upper operator display panel 32. The display panel 32 includes a “touch screen” liquid crystal display (LCD) 34 displaying information relating to the operation of the bonding device 10. The operator can modify operating parameters of the bonding device 10 with a finger, by selecting various options displayed on the LCD 34. The operator display panel 32 further includes a quartet of binary coded decimal (BCD) displays 36 for each displaying the set clamping pressure of a respective clamp or heater assembly of the bonding device 10. A quartet of adjustment knobs 38 are provided on the roof of the cabinet 20 in register with respective BCD displays 36. The set clamping pressure of the internal clamps and heater assemblies can be adjusted by adjusting corresponding adjustment knobs 38.
The bonding device 10 further includes a visible indicator in the form of a light emitting indicator such as a stack of three beacons 40 mounted to the roof of the cabinet 20. The uppermost beacon includes a green light, the intermediate beacon includes an amber light and the bottommost beacon includes a red light. The beacons can be illuminated in a plurality of different ways to represent corresponding operational conditions of the bonding device, the operational conditions including: an occurrence of an operational error with the bonding device 10; a warm up period when the heater assemblies are being warmed up to a threshold operational temperature; a standby mode where the bonding device 10 is ready to initiate operation; and an operational mode where the bonding device 10 is operating.
The movable bonding parts 21 include a pneumatic carriage 42 which is movably mounted within the cabinet 20 and is configured to carry the printhead assembly 14. The carriage 42 defines a raised nest 44 in which the printhead assembly 14 can be nested. In use, the nest 44 carrying the printhead assembly 14 and PCB 12 can be rectilinearly moved from outside the cabinet 20, to within the space 22 of the cabinet 20 via the front opening (before the light curtain 46 is generated) so that various bonding parts 21 can perform suitable operations to fasten the printhead assembly 14 and PCB 12 together.
Furthermore, a pair of locating pins 56a,b extend upwardly from the base of the nest 44 and are spaced apart to correspond to: complementary guide holes 52a,b defined in the printhead assembly 14; and complementary guide holes 54a,b defined in the PCB 12 (see
Returning to
The vertical clamping assembly 60 and forming bar assembly 62 are of like construction. The vertical clamping assembly 60 includes a pneumatic actuator 65 which is fixed within the cabinet 20, and a movable clamp 66 which is constrained to reciprocate rectilinearly upon actuation of the actuator 65. Similarly, the forming bar assembly 62 includes a pneumatic actuator 68 which is fixed within the cabinet 20, and a movable bar 70 (or member) which is constrained to reciprocate rectilinearly upon actuation of the actuator 68. In use, the forming bar assembly 62 forms a bending mechanism for bending the flexible PCB 12.
The heater assembly 74 includes a steel platen 76, a thermal insulation sheet 78 mounted to the steel platen 76, and a thermally conductive brass platen 80 mounted to the insulation sheet 78. The brass platen 80 tapers to an apex at its base for engagement with the PCB 12. The brass platen defines an internal chamber in which a replaceable heater cartridge 82 is located.
The heater assembly 86 includes a steel platen 88, a silicone sheet 89 mounted to the steel platen 88, a thermal insulation sheet 90 mounted to the silicone sheet 89, and a thermally conductive brass platen 92 mounted to the insulation sheet 90. The brass platen 92 defines a substantially flat engagement surface. The brass platen 92 further defines an internal chamber in which a replaceable heater cartridge 94 is located.
The controller 100 controls the operation of the pneumatic movable bonding parts 21, as described in detail below, and receives feedback from each of those parts. The controller 100 further receives inputs from the operator control panel 28 as previously described, and displays information using the operator display panel 32 and the beacon stack 40. The controller 100 further controls a light curtain generator 102 to generate the light curtain 46 (
Software is typically provided on a media, such as a magnetic or optical disk or solid state memory, which contains computer readable instructions for execution by the controller 100 to thereby perform the automated steps of the proceeding method 110.
A method 110 for bonding the flexible PCB 12 to the printhead assembly 14 is now described in detail below with reference to
At step 112, the operator removes the printhead assembly 14 from a clean storage facility.
At step 114, the operator holds a printhead barcode borne by the printhead assembly 14 in register with the barcode scanner 15 of the authentication system 104. The operator then presses the SCAN press button 30b of the operator control panel 28 to scan the printhead barcode. The controller 100 compares the identity of the scanned printhead barcode with a list of valid printhead barcodes stored in memory and authenticates the printhead assembly 14 upon detecting a match.
At step 116, the operator loads the authenticated printhead assembly 14 into the nest 44 of the carriage 42. The carriage 42 is located external to the internal space 22 of the cabinet 20 as shown in
At step 118, the operator manually removes the flexible PCB 12 from an anti-static storage cabinet.
At step 120, the operator holds a PCB barcode borne by the PCB 12 in register with the barcode scanner 15 of the authentication system 104. The operator then presses the SCAN press button 30b of the operator control panel 28 to scan the PCB barcode. The controller 100 compares the identity of the scanned PCB barcode with a list of valid PCB barcodes stored in memory and authenticates the PCB 12 upon detecting a match.
At step 122, the operator peels a protective backing strip from the authentic PCB 12 to reveal an exposed adhesive on the underside of the PCB 12.
At step 124, the operator loads the authentic PCB 12 onto the carriage 42 with the adhesive facing downwards toward the previously loaded printhead assembly 14. As previously described, the locating pins 56a, b extending from the nest 44 (
At step 126, the operator initiates bonding of the PCB 12 to the printhead assembly 14 with the bonding device 10. The operator concurrently presses the START buttons 30a, 30e with respective hands and the controller 100 moves the nest into the internal space 22 of the cabinet 20 as shown in
The controller 100 controls the heater cartridge 82 at the tip of the vertical heater assembly 74 to be heated. As shown in
At step 128 of
At step 130 of
At step 132 of
At step 134 of
At step 136 of
At step 138 of
Broadly, a 24 Volt power supply is indicated at 140. A 5 Volt power supply is indicated at 142. The power supplies 140, 142 are connected to a fuse arrangement 144.
In this diagram, the light curtain emitter and receiver or light curtain is indicated at 146. The light curtain 146 is connected to a light curtain safety relay 148 that acts to cut the 24 Volt power supply 140 with a switch 150.
A safety mute relay is indicated at 152. The relay 152 is configured to receive a signal from a PLC (described below) to cut off the 24 Volt power supply 142 to the heating arrangement (described below) and to the various pneumatic actuators (also described below).
The emergency stop buttons 30c are indicated at 154 in
The PLC 160 communicates with solenoid valves (described with reference to
At 164, the PLC 160 communicates with solenoid valves to operate the horizontal bar 70, the clamp 66 and the carriage 42.
At 166, the PLC 160 communicates with the mute relay 152, a start lamp 168, a carriage in signal and a scan lamp 170.
At 172, the PLC 160 communicates with the beacon stack 40.
The PLC 160 also communicates with solid state switches (
The PLC 160 communicates with the optical barcode scanner 15 at 163.3 and with an Ethernet connection at 163.4.
At 165, the PLC 160 communicates with start buttons 167.
At 169, the PLC 160 communicates with a scan console 171 of the scanner 15.
A circuit for the vertical heated platen assembly 58 includes an “up” solid state limit switch 182.1 and a “down” solid state limit switch. A solenoid valve 186.1 actuates the assembly 58.
A circuit for the vertical clamping assembly 60 includes an “up” solid state limit switch 182.2 and a “down” solid state limit switch 184.2. A solenoid valve 186.2 actuates the assembly 60.
A circuit for the forming bar assembly 62 includes an “up” solid state limit switch 182.3 and a “down” solid state limit switch 184.3. A solenoid valve 186.3 actuates the forming bar assembly 62.
A circuit for the horizontal heated platen assembly 64 includes a pair of limit switches 185. A solenoid valve 186.4 actuates the platen assembly 64.
A circuit for the heater assembly 86 including the brass platen 92 includes a solenoid valve 186.5 to actuate the heater assembly 86.
A circuit for retracting the horizontal heated platen assembly 64 includes a pair of limit switches 184.5. A solenoid valve 186.6 actuates the platen assembly 64.
A circuit for a carriage actuator includes a mid-limit switch 189.1, an “in” limit switch 189.2 and an “out” limit switch 189.3. A pair of solenoid valves 193 provides the necessary actuation.
A circuit for the carriage 42 includes an “in” limit switch 191.1 and an “out” limit switch 191.2. A solenoid valve 195 is provided for displacement of the carriage 42.
As described above, the switches and the solenoid valves are connected to the PLC 160 to facilitate control of the electrical components and thus the pneumatic circuit described below.
The circuit receives a pressurized air supply via, in series, a pressure regulator 206, a manual valve 208 and the safety valve 158.
The pressurized air supply is then delivered to via pressure regulators 216 to the various components described above.
A person skilled in the art will appreciate that many embodiments and variations can be made without departing from the ambit of the present invention.
In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.
