Tyre monitoring device comprising an electronic unit, and tyre comprising such device

Abstract

A monitoring device (200) of a tyre (105) is configured to be applied to an internal surface (115) of the tyre (105) to be monitored and includes: a container (215, 220), an electronic unit (205), housed in said container (215, 220), which includes a printed circuit board assembly comprising a printed circuit board (320) on which electrical and / or electronic components of the electronic unit (205) are mounted. The printed circuit board (320) has a face (835) on which electrical contact pads (805) are provided, perimetral to respective mounting areas (705), provided on said face (835), for mounting said electrical and / or electronic components. At least one of the electrical and / or electronic components mounted on the printed circuit board (320) is packaged in a package (605) having, at a respective lower face (830), perimetral electrical contact pads (610), arranged along perimetral sides of the package, connected through solder joints respectively to the contact pads (805) of the printed circuit board (320) perimetral to the mounting area (705) of the at least one electrical and / or electronic component provided on the face (835) of the printed circuit board. The perimetral electrical contact pads (610) of the package and said solder joints are covered by a filler material (905). A method of manufacturing a tyre monitoring device (200) is also described.

Description

[0001] TYRE MONITORING DEVICE COMPRISING AN ELECTRONIC UNIT, AND

[0002] TYRE COMPRISING SUCH DEVICE

[0003] DESCRIPTION

[0004] Background of the invention

[0005] Technical field

[0006] The present invention relates to the field of tyres for vehicles. More specifically, the invention relates to tyre sensors, and in particular a tyre monitoring device comprising an electronic unit to be associated with a tyre. The present invention further relates to a tyre comprising a tyre monitoring device. The present invention further relates to a manufacturing method for making a tyre monitoring device comprising an electronic unit.

[0007] Overview of the related art

[0008] In the field of vehicle tyres, in particular for some types of tyres such as those for high performance levels, monitoring devices have long been studied which, positioned inside the tyres themselves, are configured and operable to detect physical quantities characteristic of the tyre, in order to allow substantially real-time control of the functioning and conditions of the tyre itself.

[0009] Among the characteristic physical quantities of the tyre that are useful to detect, the air pressure inside the tyre, the internal temperature of the tyre and the deformations undergone by the tyre during rolling are of particular importance.

[0010] Such monitoring devices are configured to periodically communicate with the instrumentation available on board the vehicle on which the tyres are mounted, so that all useful information can be provided to the driver and / or the vehicle control systems, for example to activate o adjust to the best alarm and / or control systems for vehicle dynamics, braking, etc.

[0011] The tyre monitoring devices typically include an electronic unit with an associated source of electrical power (typically comprising a battery), a container for the electronic unit and a device for fixing the container to the tyre.

[0012] The electronic unit includes at least one sensor (typically a pressure sensor and / or a temperature sensor and / or a sensor capable of measuring / identifying the deformations undergone by the tyre during rolling, such as an accelerometer, a strain gauge, etc.) and a transmission system, for sending the data detected by the at least one sensor to a receiving unit external to the monitoring device, for example located on the vehicle. The electronic unit can include a processing unit, for example a microprocessor or a microcontroller, which presides over and governs its operation. The electronic unit typically includes a "PCB Assembly", shortly "PCBA", including the electrical and electronic components and the "Printed Circuit Board", shortly "PCB", on which the electrical and electronic components of the electronic unit are mounted.

[0013] The container of the electronic unit serves to protect the electronic unit (and the associated electrical power source) from the hostile conditions experienced inside a tyre (presence of contaminating agents such as dust, residues of chemical agents used in the tyre production process, stresses resulting from the rolling of the tyre such as for example bending, shear, compression / traction stresses, impacts, etc.).

[0014] The fixing device has the task of keeping the electronic unit attached to the tyre. In particular, it may be convenient to fix the monitoring device on the radially internal surface of the tyre, for example on the portion of the radially internal surface opposite the tread.

[0015] The fixing device and the container of the electronic unit (and the associated electrical power source) can constitute a single assembly, which encloses the electronic unit and the electrical power source and which is then fixed to the radially internal surface of the tyre by gluing with a structural adhesive

[0016] In the present document the terms “radially internal”, “radially external”, “radial” are used with reference to the axis of rotation of the tyre. In particular, by "radial" it is meant a direction substantially perpendicular to the axis of rotation of the tyre.

[0017] The term "tread", or "tread surface", means the radially external surface of the tyre intended for contact with the road surface.

[0018] The term “transverse” is used to refer to the direction transverse to the equatorial plane of the tyre.

[0019] Summary of the invention

[0020] As mentioned previously, the electronic unit of the tyre monitoring device should be protected from the hostile conditions experienced inside a tyre (presence of contaminants such as dust, residues of chemical agents used in the tyre production process, stresses resulting from the rolling of the tyre such as for example bending, shear, compression / traction stresses, impacts, etc.).

[0021] The Applicant observes in particular that the electronic unit of the tyre monitoring devices, particularly the PCB assembly (PCBA) comprising the PCB and the electrical and electronic components mounted on the PCB, should be protected at least against humidity (present both in the manufacturing environment of the electronic unit and inside the tyre on which the monitoring device is mounted), against condensation formation phenomena (consequence of the thermal changes which the monitoring device encounters during its use) and against electromigration phenomena (in particular electrolytic electromigration which, in the presence of water on the surface of the PCB and relatively high current in the electrically conductive traces of the PCB, leads to the formation of dendritic structures).

[0022] The Applicant has observed that the main commercially available electronic components used for the construction of the electronic unit of the tyre monitoring devices, for example the sensor(s), the transmission system and the processing unit, are or comprise integrated circuits or systems on integrated circuits (“System-On- Chip” or “SOC”) encapsulated, packaged in packages of the so-called “Flat No-leads” type, in particular in “Quad-Flat No-leads” packages or, abbreviated, “QFN” packages, or in “Dual-Flat No-leads” packages, abbreviated “DFN” packages.

[0023] The Flat No-leads packages are provided with metallic electrical contact "platforms" ("contact pads" or simply "pads" in jargon) at the perimeter ("perimeter land", in jargon) with exposed surfaces at the bottom side of the package and intended to be soldered to contact pads or islands provided on the PCB, perimetrally to the areas of the PCB surface intended to receive the packages.

[0024] The electronic components packaged in Flat No-leads packages (typically in the form of integrated circuit dies) are electrically connected to the contact pads of the package via connecting metal wires.

[0025] Both QFN packages and DFN packages have a generically quadrangular shape; the main difference between QFN packages and DFN packages lies in the fact that the former generally have perimetral pads along all four sides of the package, while the latter have perimetral pads only on two opposite sides of the four sides of the package.

[0026] Flat No-leads packages, for example QFN packages and DFN packages, have the advantage of being light, having limited physical dimensions, smaller than traditional packages with "pins", being easily manipulated, requiring short metal connection wires between the integrated circuit dies and the contact pads, being relatively economical and being able to be mounted on the PCBs using so-called "surface" mounting technologies ("Surface Mount Technology" or "SMT", in jargon) without the need of providing holes on the PCB for inserting the pins of the packaged components, as is instead necessary when using components packaged in packages with pins. Another advantage of the Flat No-leads packages is that checking the quality of the soldering of the pads to the contact pads on the PCB is relatively easy and can be made by visual inspection.

[0027] The Applicant has however observed that, since the pads are perimetral pads, the pads and their soldering to the contact pads on the PCB of the electronic unit are exposed to humidity, to the possible formation of condensation and to electromigration, in particular electrolytic electromigration.

[0028] The Applicant has faced the problem of providing adequate protection of the electronic unit of a tyre monitoring device, in particular a protection of the PCB assembly of the electronic unit itself against humidity, against condensation formation phenomena and against phenomena of electromigration.

[0029] According to an aspect of the present invention, there is provided a tyre monitoring device configured for being applied to a radially internal surface of said tyre to be monitored.

[0030] The monitoring device comprises:

[0031] - a container, and

[0032] - an electronic unit housed in said container.

[0033] The electronic unit comprises a printed circuit board assembly comprising a printed circuit board on which electrical and / or electronic components of the electronic unit are mounted.

[0034] The printed circuit board has a face on which electrical contact pads are provided, perimetral to respective mounting areas, provided on said face, for mounting said electrical and / or electronic components.

[0035] At least one electrical and / or electronic component of said electrical and / or electronic components mounted on said printed circuit board is packaged in a package having, at a respective lower face, perimetral electrical contact pads, arranged along perimetral sides of the package, connected, through solder joints, respectively to said contact pads of the printed circuit board perimetral to the mounting area of the at least one electrical and / or electronic component provided on said face of the printed circuit board.

[0036] Said perimetral electrical contact pads of the package and said solder joints are covered by a filler material.

[0037] Advantageously, thanks to the present invention, the electronic unit of a tyre monitoring device, in particular the PCB assembly of the electronic unit itself, even more particularly the perimetral electrical contact pads of the package(s) in which one or more electrical and / or electronic components of the electronic unit is (are) packaged, and the solder joints of the electrical contact pads to the contact pads provided for this purpose on the PCB of the electronic unit, are protected against hostile conditions that are experienced inside a tyre, in particular they are protected against humidity, against condensation formation phenomena and against electromigration phenomena, particularly electrolytic electromigration.

[0038] According to another aspect of the present invention, there is provided a tyre equipped with a tyre monitoring device. The tyre comprises a radially internal surface and the tyre monitoring device is applied to the radially internal surface of the tyre. The tyre monitoring device is in accordance with the previous aspect of the invention.

[0039] According to a further aspect of the present invention, there is provided a method of manufacturing a tyre monitoring device comprising an electronic unit that comprises electrical and / or electronic components, at least one electrical and / or electronic component of said electrical and / or electronic components being packaged in a package having, at a respective lower face, perimetral electrical contact pads, arranged along perimetral sides of the package.

[0040] The manufacturing method comprises:

[0041] - providing a printed circuit board having:

[0042] - a mounting area for the at least one electrical and / or electronic component, said mounting area being formed on a face of the printed circuit board, and

[0043] - electrical contact pads of the printed circuit board perimetral to said mounting area;

[0044] - mounting said at least one electrical and / or electronic component to the printed circuit board at said mounting area, said mounting comprising:

[0045] - forming solder joints of said electrical contact pads of said package to said electrical contact pads perimetral to the mounting area of the printed circuit board;

[0046] - applying a liquid filler material along at least one of said perimetral sides, preferably along two contiguous perimetral sides of the package, such that the liquid filler material diffuses and by capillarity covers said perimetral electrical contact pads and said solder joints, and

[0047] - performing a thermal treatment to cause the hardening of the filler material to form a protection on said perimetral electrical contact pads and said solder joints.

[0048] The present invention, in one or more of its aspects previously set forth, may comprise one or more of the following optional features.

[0049] Preferably, said filler material is further arranged in such a way as to at least partially fill a gap, below said package, between said lower face of the package and said face of the printed circuit board. In this way, also the region of the mounting area(s) of the printed circuit board provided for mounting the electrical and / or electronic component(s) is protected by said filler material against humidity, against phenomena of formation of condensation and against electromigration phenomena, particularly electrolytic electromigration.

[0050] Correspondingly, in the method of manufacturing of the tyre monitoring device, said applying the liquid filler material comprises causing the liquid filler material to diffuse in a gap between the lower face of the package and said face of the printed circuit board.

[0051] Preferably, said filler material is a low-viscosity monocomponent filler material, having a nominal viscosity comprised between 100 mPa / s and 1000 mPa / s, preferably having a nominal viscosity between about 100 mPa / s and about 500 mPa / s and preferably between about 300 mPa / s and about 400 mPa / s.

[0052] Preferably, for an even better protection against the hostile conditions experienced inside a tyre, said printed circuit board assembly, particularly said face of the printed circuit board and the electrical and / or electronic components mounted on said face, are covered by a conformal coating adapted to protect the printed circuit board assembly against humidity, chemical agents, high temperatures and other harsh conditions. For example, said conformal coating may have a thickness from about 1 pm to about 250 pm.

[0053] In embodiments of the present invention, said printed circuit board comprises: at least two layers of electrically conductive material, electrically conductive traces, formed in said at least two electrically conductive layers, for the electrical interconnection between the electrical and electronic components of the electronic unit, and electrical interconnection vias between the electrically conductive traces of different electrically conductive layers.

[0054] Preferably, still in order to ensure a protection of the electronic unit against the harsh conditions experienced inside a tyre, said electrical interconnection vias are filled and capped with copper.

[0055] Preferably, the finishing of said electrical interconnection vias is compliant with the prescriptions of Standard IPC 4761 Type VII.

[0056] Brief description of the figures

[0057] Features and advantages of the present invention, both those discussed in the previous section and other, further advantages and features, will appear more clearly by reading the following detailed description of exemplary and non-limitative embodiments of the present invention; for a better intelligibility, the following description should be read making reference to the annexed figures, wherein:

[0058] - Fig. 1 schematically shows a portion of a tyre equipped with a tyre monitoring device according to an embodiment of the present invention;

[0059] - Fig- 2 is a schematic exploded view of a tyre monitoring device according to an embodiment of the present invention, for example the monitoring device that equips the tyre of Fig. 1;

[0060] - Fig. 3 is a schematic sectional view of the exploded view of Fig. 2, according to sectional plane III - III of Fig. 2;

[0061] - Fig. 4 is a sectional view along a vertical plane of the tyre monitoring device applied to a tyre;

[0062] - Fig. 5 schematically shows the main functional blocks of a tyre monitoring device in accordance with the present invention;

[0063] - Fig. 6A and Fig. 6B show, respectively in view from above and in view from below, a generic package enclosing electronic components of an electronic unit of the tyre monitoring device in accordance with the present invention;

[0064] - Fig. 6C is a schematic sectional view of the package along the sectional plane VI-C-VI-C indicated in Fig. 6A;

[0065] - Fig. 7 schematically shows the package of Fig. 6A and Fig. 6B in its mounting to a printed circuit board, PCB, of the electronic unit of the tyre monitoring device;

[0066] - Fig. 8A - Fig. 8E schematically show some phases of a manufacturing process of the tyre monitoring device in accordance with the present invention, in particular phases of mounting of the package of Fig. 6A and Fig. 6B to the PCB of the electronic unit, and

[0067] - Fig. 9 shows, in a section similar to that of Fig. 6C, a subsequent phase of the manufacturing process.

[0068] Detailed description of exemplary embodiments

[0069] In the following description, use may be made of terms such as "lower", "higher" and similar: these terms, where adopted, must not be understood in a restrictive sense, having only a descriptive function to distinguish different parts or portions of the objects to which they refer.

[0070] Referring to the figures, Fig. 1 schematically shows a portion of a tyre 105 equipped with a tyre monitoring device 200 according to an embodiment of the present invention.

[0071] In particular, the tyre monitoring device 200 is conveniently fixed to the radially internal surface 115 of the tyre 105, opposite the tread 120 of the tyre 105.

[0072] Only by way of example, but not by way of limitation, for example the tyre monitoring device 200 can be conveniently fixed to a portion of the radially internal surface 115 of the tyre located in correspondence with the equatorial plane 125 of the tyre, i.e., the centerline plane perpendicular to the rotation axis of the tyre, for example transversely to the equatorial plane 125.

[0073] For example, the tyre monitoring device 200 can be of the type described in one of the following documents in the name of the same Applicant: WO 2018 / 065846 Al, WO 2019 / 123118 Al and WO 2020 / 026282 Al.

[0074] Shown in Fig. 2 is a schematic exploded view of the tyre monitoring device 200 of Fig. 1 according to an embodiment of the present invention. Fig. 3 is a schematic sectional view of the exploded view of Fig. 2, according to the sectional plane III - III of Fig. 2

[0075] Advantageously, the tyre monitoring device 200 comprises an electronic unit 205. The aforementioned electronic unit 205 is associated with an electrical power supply device for the electrical power supply of the electrical and electronic components of the electronic unit 205. In preferred embodiments of the invention, such an electrical power supply device is an electrical power supply battery 210.

[0076] With reference to Fig. 5, the main functional blocks of the electronic unit 205 are shown schematically. The electronic unit 205 is configured so as to be able to detect at least one characteristic quantity of the tyre 105, for example the inflation pressure of the tyre 105 and / or the temperature of the tyre and / or a deformation experienced by the tyre when rolling on a surface (road), such as a strain gauge or an accelerometer or an optical sensor or a magnetoresistive sensor or an inertial sensor or a gyroscope, etc., and to transmit at least one corresponding parameter representative of said detected quantity to an external receiver or device, for example a smartphone or the instrumentation available on board the vehicle on which the tyre 105 is mounted. For this purpose, the electronic unit 205 is provided with at least one sensor 505 suitable for detecting said at least one characteristic physical quantity, for example a pressure sensor suitable for detecting the inflation pressure of the tyre 105, and / or a temperature sensor and / or a sensor capable of measuring / identifying the deformations undergone by the tyre during rolling on the road.

[0077] Still with reference to Fig. 5, by way of example only, the at least one sensor 505 is operationally associated with a processing and transmission system 510 of said at least one parameter representative of said detected physical quantity; for example, the processing and transmission system 510 is configured for transmission to an instrumentation available on board the vehicle on which the tyre 105 is mounted. The processing and transmission system 510 can for example include a microprocessor or microcontroller 515, a transmitter 520, an antenna and other circuitry necessary to carry out processing and / or analysis of the signals coming from the at least one sensor 505, to make them suitable for data transmission from the monitoring device 200 to a receiver external to the tyre, for example placed on board the vehicle on which the tyre 105 is mounted. The data made available by the at least one sensor 505 can be at least partially processed directly by the processing and transmission system 510, for example from the microprocessor or microcontroller 515 or other dedicated integrated circuit (for example of the ASIC - “Application Specific Integrated Circuit” - type). The processing and transmission system 510 therefore allows communication with an external receiver or device, for example with a smartphone or with the instrumentation available on board the vehicle on which the tyre is mounted. The communication can be carried out, for example, periodically, so that all relevant information can be provided to the driver and / or a vehicle control system, and / or to activate or adjust to the best the alarm and / or the vehicle alarm, dynamic control, braking, etc. This communication can be unidirectional (from the electronic unit 205 to the external receiver), or bidirectional.

[0078] As visible in Fig. 2 and Fig. 3, advantageously, the electrical power supply device or battery 210 is configured and connected to the electronic unit 205 so as to be suitable for powering the electrical and electronic components of the electronic unit 205 itself.

[0079] Preferably, the monitoring device 200 includes a container 215, 220 configured to contain, at least partially, the electronic unit 205 and the associated battery 210.

[0080] In the embodiment under consideration, and shown in the figures, the container 215, 220 includes a first casing portion 215, or lower casing portion, and a second casing portion 220, or upper casing portion. Preferably, the first 215 and second 220 casing portions are configured to be coupled to each other to enclose within them the electronic unit 205 and the associated battery 210.

[0081] As visible in Fig. 3, the first casing portion 215 is shaped so as to define thereinside a housing 305 for the battery 210. In embodiments of the present invention, the battery 210, housed in the housing 305, is incorporated in the material constituting the first casing portion 215, as will be better described below.

[0082] Preferably, the housing 305 for the battery 210 is closed at the top by a wall 310, for example in one piece with the rest of the first casing portion 215. The electrical terminals 213 of the battery 210 extend through the wall 310 until they protrude above it, for the mechanical and electrical connection to the electronic unit.

[0083] Advantageously, inside the container 215, 220, particularly in the upper casing portion 220, the electronic unit 205 rests on the wall 310. In preferred embodiments, the second casing portion 220 is shaped like a lid or hood, open at one of its first ends and which can be coupled to the first casing portion 215

[0084] In further embodiments, not shown in the figures, the container of the electronic unit 205 (and the associated battery 210) is constituted by the first casing portion 215 configured to contain the second casing portion 220 in a specific housing inside it and to constrain it to the radially internal surface of the tyre 105, when said monitoring device 200 is mounted in said tyre 105.

[0085] Advantageously, the second casing portion 220 is configured to completely enclose within it the electronic unit 205 and the associated battery 210.

[0086] In other words, advantageously, in the embodiment under consideration, the first casing portion 215 is a separate element with respect to the second casing portion 220 and is shaped so as to define a housing inside itself to contain the aforementioned second casing portion 220 containing the electronic unit 205 and the battery 210. More in detail, the first casing portion 215, in addition to being configured to have a containing function for the electronic unit 205 and the associated battery 210, is capable of binding them to the radially internal surface of the tyre, when said monitoring device 200 is mounted in said tyre.

[0087] Preferably, in this embodiment, the first casing portion 215 is a rubber housing body adapted to be attached (for example by gluing) to the radially internal surface of the tyre, said rubber housing body having a seat to accommodate the assembly of tyre monitoring device electronic unit and battery. Preferably, such housing body is a "Rubber house".

[0088] Advantageously, walls, preferably external, of the second casing portion 220 delimit, internally to the second casing portion 220, a first hollow space or first cavity 315, configured to accommodate (at least in part) the electronic unit 205. In particular, the first cavity 315 is preferably configured to accommodate a printed circuit board assembly ("PCBA") of the electronic unit 205 comprising a printed circuit board 320 (PCB) on which the electrical and electronic components of the electronic unit 205 are mounted and electrically conductive traces are defined for electrical interconnection between the various electrical and electronic components of the electronic unit 205.

[0089] Preferably, above the first cavity 315, a second hollow space or second cavity 325 is defined in the second casing portion 220. At least some electrical and electronic components of the electronic unit 205 protrude from an upper face of the PCB 320 inside the second cavity 325, in particular a pressure sensor 330 (being part of the at least one sensor 505 previously described in relation to Fig. 5). The upper face of the PCB 320 and the electrical and electronic components mounted on it, in particular the pressure sensor 330, even more particularly the sensitive surface of the pressure sensor 330, are exposed to the second cavity 325.

[0090] Preferably, the second casing portion 220 includes an upper closing wall 225, which closes the second cavity 325 at the top.

[0091] In case the electronic unit 205 of the tyre monitoring device 200 includes a pressure sensor (such as the pressure sensor 330 in the example considered here), in order to be able to detect the pressure inside the tyre by means of the pressure sensor it is necessary to provide a communication of gaseous fluids between the pressure sensor and the environment inside the tyre.

[0092] For this purpose, as visible in Fig. 2 and Fig. 3, the upper wall 225 of the second casing portion 220 is provided with at least one opening or through hole 230 which passes through the entire thickness of the upper wall 225. Advantageously, the opening or through hole 230 can be made in any position of the upper wall 225, substantially without positioning constraints (without prejudice to the constraints deriving from the tolerances construction). When the second casing portion 220 is mounted on the first casing portion 215 with the electronic unit 205 housed in the external casing 215, 220, the at least one opening or through hole 230 is suitable for placing the second cavity 325 in communication of gaseous fluids with the external environment in which the monitoring device 200 is located, and therefore, in use, the environment or space internal to tyre 105.

[0093] Advantageously, a sealing element or gasket 235 is provided which is associated or can be associated with at least one opening or through hole 230.

[0094] Advantageously, the sealing element or gasket 235 is an element capable of substantially preventing the penetration, from the environment external to the monitoring device into the second cavity 325, of dust particles, impurities, dirt, solid foreign bodies, liquids, in general non-gaseous bodies, while allowing the passage of air. The sealing element or gasket 235 is permeable to gaseous fluids but impermeable to non-gaseous bodies.

[0095] With the term “permeable” referring to a body it is meant that this body allows itself to be penetrated and passed through by another body. With the term “non- gaseous bodies” it is meant bodies that are in the solid state and therefore not in the airy state or in the gaseous state. With the term “gaseous fluids” it is meant substances in the gaseous state that have no volume of their own, assuming the volume of the container that contains them and which are compressible.

[0096] Such non-gaseous bodies, if they penetrated the second cavity passing through the opening or through hole 230, could make the communication of gaseous fluids between the pressure sensor and the environment inside the tyre ineffective, with the consequence that the detection of the tyre pressure by the tyre pressure sensor might be incorrect.

[0097] In embodiments of the present invention, the sealing element or gasket 325 is made in the form of a membrane, for example of a circular shape. In embodiments of the present invention, the sealing element or gasket 235 is made of Polytetrafluoroethylene (PTFE).

[0098] Preferably, the upper wall 225 of the second casing portion 220 is formed so as to include, on its internal face 333 and in correspondence with the at least one opening or through hole 230, a seat 335 to accommodate the sealing element or gasket 235. In embodiments of the present invention, the sealing element or gasket 235 can be applied in the seat 335 on the internal face of the upper wall 225 of the second casing portion 220 by means of an adhesive, prior to the assembly of the monitoring device 200. The sealing element or gasket 235 can have a discoidal shape and the seat 335 has a corresponding shape.

[0099] In embodiments of the present invention, the first casing portion 215 can be made by molding of a plastic material, for example polyurethane, which is poured into a mold in which the battery 210 has previously been placed; in this way, the battery 210 is encapsulated in the injected material which constitutes the first casing portion 215

[0100] In embodiments of the present invention, the mold used for molding the plastic material can be configured to also accommodate the electronic unit 205, or at least part thereof, in particular the lower part, for example the PCB 320. In this way, following the injection of the plastic material into the mould, not only is the battery 210 encapsulated in the injected material which constitutes the first casing portion 215: the electronic unit 205 is also partially incorporated, and therefore firmly retained, in the material of the first casing portion.

[0101] In alternative embodiments of the present invention, the PCB 320 may be glued to the wall 310 of the first casing portion 215.

[0102] In embodiments of the present invention the second casing portion 220 can be made of plastic material, and / or using resins (for example epoxy or polyurethane resins), and / or of sufficiently rigid elastomeric material.

[0103] Preferably, the width wl of the first cavity 315 inside the second casing portion 220 is substantially equal to the width of the PCB 320 of the electronic unit 205.

[0104] Preferably, the width of the second cavity 325 internal to the second casing portion 220 is reduced compared to the width wl of the first cavity 315; in this way, a shoulder 345 is formed which, when the tyre monitoring device 200 is assembled and the second casing portion 220 is mounted to the first casing portion 215, abuts against the upper face of the PCB 320 of the electronic unit 205, keeping it pressed against the wall 310 of the first casing portion 215.

[0105] Preferably, the wall 310 of the first casing portion 215 has a width substantially equal to the width wl of the first cavity 315 formed internally to the second casing portion 220, and the width of the wall 310 is reduced compared to the external width of the upper part 347 of the first casing portion 215 in which the housing 305 of the battery 210 is defined. In this way, when the tyre monitoring device 200 is assembled and the second casing portion 220 is mounted to the first casing portion 215, a perimetral edge of the second casing portion 220 abuts against a perimeter frame 350 of the first casing portion 215 which surrounds the wall 310.

[0106] In the assembling of the tyre monitoring device 200, the second casing portion 220 can be fixed to the first casing portion 215. In the further embodiment, as described in the foregoing, the second casing portion 220 can be inserted into the first casing portion 215 or container which is bound to or is already an integral part of the radially internal surface of the tyre 105.

[0107] Preferably, the first casing portion 215 is shaped so as to include a base 240 of a wider width than the remaining parts of the first casing portion 215, in particular the part 347 of the first casing portion 215 in which the battery 210, or the entire container as in the further embodiment, is housed.

[0108] The base 240 of the first casing portion 215 is intended, in use, to be applied to the internal surface 115 of the tyre 105. To make the base 240 of the first casing portion 215 adhere to the internal surface 115 of the tyre it is possible to use, preferably, a film of double-sided adhesive material 245, for example of a Pressure Sensitive Adhesive (PSA), one side of which is applied to the face of the base 240 which, in use, has to be applied to the internal surface 115 of the tyre. The opposite face of the double-sided adhesive film 245 is preferably protected by a removable coating film 250, adapted to be removed when the monitoring device 200 has to be applied to the internal surface 115 of the tyre 105.

[0109] The use of a pressure sensitive adhesive (PSA) advantageously allows the tyre monitoring device 200 to be fixed to the internal surface 115 of the tyre 105 with an extremely simplified procedure. The PSA in fact allows gluing to the internal surface 115 of the tyre 105 through the action of a pressure exerted on the base of the device which does not require particularly long times or particular attention in the application of the pressure itself, i.e., it does not require particular environmental conditions during the gluing.

[0110] At the same time, the enlarged surface of the base 240 compared to the rest of the external casing 215, 220 allows for a solid and effective bonding to be obtained against the stresses imposed by the rolling of the tyre.

[0111] In embodiments of the present invention, the PSA may be an acrylic adhesive, a silicone adhesive, a butyl adhesive, a natural rubber-based adhesive, a block copolymer-based adhesive. The PSA should be selected such that it is compatible with the compound of the inner surface 115 of the tyre 105 (i.e., the liner or inner liner of the tyre 105). This characteristic does not appear to be particularly critical in itself, as substantially all self-adhesives have a formulation based on elastomeric polymers. Furthermore, PSA should be able to ensure strong adhesion at room temperature (i.e., around 25°C) and not degrade at high temperatures (i.e., up to around 100-160°C), and / or ensure high strength to shear stresses, in particular to cyclic shear stresses. The Applicant has verified that acrylic adhesives in particular can be suitable for these purposes. For example, it is possible to use double-sided adhesives supported by PSA (consisting of several layers, including two layers of PSA on two external faces and a central layer of plastic and / or elastomeric and / or expanded material), transfer adhesives (i.e., layers or films made up of loose acrylic adhesive) and acrylic foams double-sided adhesives (i.e., layers or films made up of a mass of acrylic adhesive, expanded at least in the central part of the layer or film itself).

[0112] Advantageously, in the tyre monitoring device 200 a communication channel or pressure channel is not provided for the communication of gaseous fluids, for example air, between the pressure sensor 330 and the environment external to the tyre monitoring device 200, which in use (when the monitoring device 200 is mounted to the radially internal surface of the tyre 105) is the environment inside the tyre 105. The pressure sensor 330 can be positioned anywhere on the PCB 320, without any mutual positioning constraints between the pressure sensor 320 and the opening or through hole 230. The provision of the sealing element or gasket 235, for example the PTFE membrane, associated with the opening or through hole 230, prevents the penetration into the monitoring device 200 of foreign bodies, such as for example dust particles, dirt, residues from tyre 105 manufacturing or other, in general non-gaseous bodies, which could have the consequence that the detection of the tyre pressure by the pressure sensor 330 is incorrect. The entire second cavity 325 is in communication of gaseous fluids with the environment inside the tyre 105, therefore wherever the pressure sensor 330 is positioned with respect to the opening or through hole 230, the pressure sensor 330 is able to detect the tyre inflation pressure. In other words, the (position of) pressure sensor 330 is decoupled from the position of the opening or through hole 230.

[0113] Advantageously, even if it is desired or necessary to modify the layout of the electronic unit, with consequent re-arrangement of the electrical and electronic components of the electronic unit itself, and in particular of the pressure sensor, it is not necessary to also modify the design of the external casing, i.e., the container, of the tyre monitoring device to adapt it by moving, as in previously known solutions, the pressure channel so that it corresponds to the new position of the pressure sensor.

[0114] The redesign of the container of the electronic unit of the monitoring device, which represents an additional burden in terms of time and costs of development and engineering of the monitoring device, is not essential and can be avoided. Returning to the electronic unit 205, the main commercially available electronic components used for the construction of the electronic unit 205 of the tyre monitoring device 200, in particular the sensor(s) 505, the microprocessor or microcontroller (or ASIC) 515, the transmitter 525, are or include integrated circuits or systems on integrated circuits (“System-On-Chip” or “SOC”) encapsulated in packages of the so-called “Flat No-leads” type. In particular, the sensor or sensors 505, the microprocessor or microcontroller (or ASIC) 515, the transmitter 525 are encapsulated in “Quad-Flat No-leads” or, abbreviated, “QFN” packages, or in “DualFlat No-leads” packages, abbreviated “DFN”, which are soldered onto the PCB 320.

[0115] The “Flat No-leads” packages, in particular the QFN and DFN capsules, are mounted on PCBs, such as PCB 320, using so-called “surface” mounting technologies (“Surface Mount Technology” or “SMT”, in jargon) without the need to provide holes on the PCB for mounting the packaged components (as is instead necessary when using components encapsulated in capsules with "pins").

[0116] Fig. 6A and Fig. 6B schematically show a QFN package 605, for example of the microprocessor 515. Fig. 6C is a schematic sectional view of the package, along the sectional plane VI-C - VI-C indicated in Fig. 6A.

[0117] The Flat No-lead packages are equipped with a planar frame of conductors ("lead frame" in jargon), with perimetral electrical contact pads 610 ("perimeter land", in jargon) exposed at the bottom face (830) of the package 605 to form the electrical connections to the PCB 320. An exposed thermally conductive pad 615 is also often provided ("exposed thermally conductive pad", in jargon), exposed in a substantially central position on the underside of the package, to improve the dissipation of the heat generated inside the package to the PCB 320.

[0118] The electronic component packaged in the Flat No-leads package, typically in the form of an integrated circuit die 620, is electrically connected to the contact pads 810 of the package 605 by means of electrical connection metal wires 625. The whole is incorporated in a plastic material 630.

[0119] Although the example shown in Fig. 6 A - Fig. 6C is a QFN package, this is purely illustrative and not limiting, and completely similar considerations also apply directly to other types of Flat No-leads packages, such as DFN, and more generally to components packaged in packages having, in correspondence with a respective lower face (such as the lower face indicated with 830 in Fig. 6C), perimetral electrical contact pads (such as the electrical contact pads 610 of the QFN package 605 of the example considered), arranged along the perimetral sides of the package, intended to be connected via soldering to respective contact pads of a printed circuit board perimetral to a mounting area of the at least one electrical and / or electronic component provided on one face of the printed circuit board itself.

[0120] Flat No-leads packages, such as QFN packages and DFN packages, have a generically quadrangular shape; the main difference between QFN packages and DFN packages lies in the fact that the former generally have perimetral electrical contact pads (or, simply, "pads" in jargon) along all four perimetral sides of the package, while the latter have perimetral pads only on two opposite perimetral sides of the four sides of the package.

[0121] The QFN package 605 of Fig. 6 A - Fig. 6C is mounted to the PCB 320, to physically and electrically connect the integrated circuit(s) packaged therein to the PCB 320, via SMT, which does not require the provision of through holes on the PCB for mounting the QFN package 605. When mounting to the PCB 320, the contact pads or pads 610 of the package 605, located around the perimeter of the package itself, are soldered to respective contact pads, or contact islands, provided on the PCB 320 perimetrically to an area of the PCB 320 intended for mounting the package 605.

[0122] With reference to Fig. 7 and Fig. 8A - Fig. 8E, some phases of a manufacturing process of the electronic unit 205 in accordance with an embodiment of the present invention are schematically illustrated, in particular some phases of an assembly process of the generic QFN package 605 of Fig. 6A - Fig. 6C to the PCB 320 of the electronic unit.

[0123] First, Fig. 8A, the QFN package 605 is positioned on the PCB 320 so that the contact pads 610 of the QFN package 605 are located in correspondence with respective contact islands 805, made of electrically conductive material, provided on the PCB 320 perimetrally to an area 705 of the surface of the upper face 835 of the PCB 320 intended for mounting the QFN package 605.

[0124] The contact pads 610 of the QFN package 605 are then soldered, 810 in Fig. 8B, to the respective contact islands 805 of the PCB 320.

[0125] The positioning on the PCB 320 of the QFN package(s) 605 and the soldering of its / their contact pads 610 to the contact islands 805 are carried out, for example, according to methods known to those skilled in the art, using "Pick&Place" machines configured to select the correct electronic components and place them on the PCB and, subsequently, to solder the components to the PCB, reflow ovens can be used, which return to the liquid state a soldering alloy, previously deposited on the contact islands of the PCB in the form of soldering paste, for soldering the joint upon solidification.

[0126] Subsequently, as schematized in Fig. 8C - Fig. 8D, the PCB 320 with the QFN package 605 soldered thereto is subjected to an "underfill" process.

[0127] As known to those skilled in the art, the underfill process involves the application of a filler material, consisting of a liquid polymer, to a PCB after the reflow phase. The liquid filler material seeps into the gaps between the (bottom faces of) the electronic component packages and the surface of the PCB on which the packages are soldered. The filling material is then subjected to a hardening process (“curing”).

[0128] It is known to use the underfill process for assembling certain types of packages to PCBs, other than Flat No-leads packages, typically "Ball Grid Array" ("BGA") type packages, a particular format of package for integrated circuits which does not have pins / contact pads / pads on the perimeter, but rather a grid of metal electrical contact spherules positioned underneath the package and directly soldered onto the printed circuit board by means of "balls" of tin): the filler material serves in this case to protect the fragile solder balls of the contact spherules of the BGA package to the contact islands on the PCB, providing a strong mechanical bond between the BGA package and the PCB.

[0129] In the art, the underfill process is not used with Flat No-leads packages such as QFN packages and DFN packages, since this type of package does not present the problem of the fragility of the soldering of the contact spherules to the contact islands on the PCB, which occurs in the case of BGA packages.

[0130] However, in accordance with the present invention, the Applicant has observed that, for applications in the field of tyre sensors, and in particular for the manufacturing of tyre monitoring devices such as the tyre monitoring device 200, the use of the underfill technique in connection with Flat No-leads type packages, and more generally with packages having, in correspondence with a respective lower face, perimetral electrical contact pads, arranged along the perimeter sides of the package, allows to solve various problems and provides particular advantages.

[0131] As schematized in Fig. 8C, the liquid filler material 815, or filler liquid, is applied by deposition 820 to the PCB 320 at the QFN package(s) 605.

[0132] The filler liquid 815 is deposited along at least one lateral edge 825 of the QFN package 605 (the deposition pattern along one side of the package is also called “I” deposition pattern), preferably along two contiguous edges (the deposition pattern along two contiguous sides of the package is also called “L” deposition pattern, as schematized in Fig. 7) of the QFN package 605.

[0133] The filler liquid 815 spreads and by capillarity rises up to cover the contact pads 610 and the respective solder joints to the contact islands 805.

[0134] In preferred but non-limiting embodiments of the present invention, the filler liquid 815 flows and diffuses through the gap between the lower face 830 of the QFN package 605 and the upper face 835 of the PCB 320 (where by "lower face of the QFN package” it is meant the face of the QFN package that has the electrical terminals soldered to the contact islands of the PCB, and by “upper face of the PCB” it is meant the face of the PCB on which there are contact islands soldered to the electrical terminals of the QFN package), until it reaches all the lateral edges of the package 605 and, by capillarity, rises up till covering the contact pads 610 and the respective solder joints to the contact islands 805. The filler liquid 815 can spread until it substantially occupies the entire gap (Fig. 8D).

[0135] The deposition of the filler liquid 815 is preferably carried out in two or more stages, to ensure that, at each stage of the deposition, the amount of filler liquid deposited is not such as to exceed the height of the QFN package 605. Although the deposition of the filler liquid along only one side of the QFN package 605 (“I” deposition pattern) can cause the filler liquid 815 to spread under the entire QFN package 605, a deposition according to the “L” pattern, i.e., along two contiguous edges of the QFN package 605, offers a greater guarantee that this will happen.

[0136] The choice of the filler material determines the characteristics of the final result, which depend on the particular application.

[0137] The Applicant has found that a suitable filler material is the material commercially known as IQ-BOND 2473 -LV by RO ARTIS bvba, a single-component underfill material which is defined by the manufacturer itself as having very low viscosity.

[0138] In general, for the purposes of the present invention, there are two main parameters to be taken into consideration when choosing the filler material to be used in the underfill process: its nominal viscosity (which is conventionally defined at 25 °C, as the viscosity changes with the temperature) and the Coefficient of Thermal Expansion or “CTE”.

[0139] Since, for the purposes of the present invention, the filler material should not only diffuse by capillarity underneath the QFN package(s) (such as the QFN package 605) but also remain adhered to the edges of the QFN package, so as to encapsulate and protect the pads of the package itself which are soldered to the contact islands on the PCB, the (nominal) viscosity of the chosen filler material should be low, in the order of hundreds of mPa / s. The Applicant has experimentally verified that underfill materials with (nominal) viscosity of the order of thousands of mPa / s are not suitable for achieving the desired result. The aforementioned IQ-BOND 2473 -LV material has a nominal viscosity of 375 mPa / s. Suitable materials should have nominal viscosities in the range from about 100 mPa / s to about 1000 mPa / s, preferably from about 100 mPa / s to about 500 mPa / s, even more preferably from about 300 mPa / s to about 400 mPa / s.

[0140] As for the CTE, materials characterized by too high values of this parameter would be subject, both during the manufacturing of the PCB A and in use, to thermal expansions such as to generate excessive mechanical stresses on the QFN packages, on the PCB, on the solder joints between the pads of the QFN packages and the contact islands on the PCB. Materials with CTE values no higher than approximately 100 ppm (parts per million) may be suitable.

[0141] The amount of encapsulation material to be deposited can be estimated by calculating the volume of the gap between the QFN package 605 and the PCB 320.

[0142] The filler material in the liquid state is deposited outside the QFN package, and spreads by capillarity; the filler material therefore remains substantially where desired (on the solder joints) and in the desired quantity (without excess) and there is no risk of it spreading onto the surface of the PCB outside the mounting area 705 of the electronic component.

[0143] After the deposition of the encapsulation liquid 815, it is subjected to hardening (“curing”) by means of a heat treatment. In particular, the IQ-BOND 2473 -LV material can be cured by a rapid process at high temperature.

[0144] Subsequently, an additional deposition of encapsulating material (for example the same material already used) can be carried out all around the QFN package 605.

[0145] Once the underfill phase has been completed, as schematized in Fig. 8E, the PCBA assembly of the electronic unit 205, in particular the upper face of the PCB 320 and the electrical and electronic components mounted on it, are covered with a conformal coating 340, a thin polymer film protective coating normally applied to printed circuit boards and providing protection against moisture, dust, chemicals, high temperatures, and other conditions hostile.

[0146] This coating 340 is “conformal” because it conforms to the profile of the PCBA assembly.

[0147] The conformal coating can have a thickness ranging from about 1 pm to about 250 pm.

[0148] The Applicant has found that, for example, a suitable conformal coating is the one commercially known as NOVEC 1700, marketed by 3M; however, other suitable materials can be used. 340 conformal coating can be applied to the PCBA assembly using a dipping process.

[0149] Advantageously, as shown schematically in Fig. 3, the conformal coating 340 is not formed over the pressure sensor 330, in particular the conformal coating 340 is not formed on the active, sensitive surface of the pressure sensor 330, so as not to affect its operation .

[0150] Fig- 9 schematizes the result of the underfill process: the filler material, rising by capillarity along the lateral edges of the QFN package 605, forms a protective cover 905 on the contact pads 610 and the respective solder joints to the contact islands 805.

[0151] It is emphasized that the fact that the sealing element or gasket 235, particularly the PTFE membrane, permeable to gaseous fluids, and therefore permeable to air, can allow humidity to penetrate into the second cavity 325, through the opening or through hole 230 present in the air contained in the tyre 105 does not constitute a problem for the electronic unit 205 and for its components which are exposed to the air coming from the tyre 105, as the upper face of the PCB 320 and the electrical and electronic components of the electronic unit 205 mounted on it are covered by the conformal coating 340.

[0152] To satisfy dimensional compactness requirements, the PCB 320 of the electronic unit 205 is preferably a "double-sided" PCB, having two layers of electrically conductive material on the two opposite faces of prevailing dimensions. This allows the electrical and electronic components of the electronic unit 205 to be mounted and electrically interconnected on both faces of the PCB 320. Even greater dimensional compactness can be achieved by using multilayer PCBs, including further layers of electrically conductive material enclosed in the PCB material. For the electrical connection between the different layers of electrically conductive material, electrical interconnection "tunnels" ("vias" in jargon) are provided.

[0153] The electrical interconnection vias formed on the PCBs can have different types of finishing, which are regulated by the IPC 4761 standard, “Design Guide for Protection of Printed Board Via Structures” of the IPC - Association Connecting Electronics Industries. According to this standard, electrical interconnection vias can be left open or closed, covered or uncovered, etc.

[0154] The Applicant has observed that the type of finishing of the electrical interconnection tunnels has an impact on the reliability of the PCBA assembly over time, especially when the PCBA assembly is exposed to environments in which humidity and condensation is present.

[0155] Advantageously, in order to provide adequate protection of the electronic unit 205 of the tyre monitoring device 200 in accordance with the present invention, the electrical interconnection vias of the PCB 320 of the electronic unit 205 are filled and capped with copper and their finishing is in accordance with the requirements of the IPC 4761 Type VII standard.

[0156] The Applicant has found that the use of the underfill technique for the Flat Noleads package(s), thanks to which the contact pads of the package(s) of the electronic components of the electronic unit 205 and the respective solder joints to the contact islands on the PCB are protected by the filler material, allows to effectively prevent electromigration phenomena on the PCB 320 underneath the QFN package(s). Furthermore, the use of the underfill technique improves the mechanical robustness of the soldering to the PCB of the electronic components packaged in the QFN package(s), in particular against shocks, vibrations and strong accelerations. Thanks to the fact that, with the use of the underfill technique, the soldering to the PCB of the electronic components packaged in the QFN package(s) are covered by the filler material, oxidation of the contact islands 805 of the PCB 320 and of the electrical terminals 610 of the QFN package(s) mounted on the PCB, in particular any electrical terminals present along the sides of the QFN package(s), is avoided.

Claims

CLAIMS1. A monitoring device (200) of a tyre (105) configured for being applied to a radially internal surface (115) of said tyre (105) to be monitored, the monitoring device comprising:- a container (215, 220),- an electronic unit (205) housed in said container (215, 220), said electronic unit comprising a printed circuit board assembly comprising a printed circuit board (320) on which electrical and / or electronic components of the electronic unit (205) are mounted, said printed circuit board (320) having a face (835) on which electrical contact pads (805) are provided, perimetral to respective mounting areas (705), provided on said face (835), for mounting said electrical and / or electronic components, wherein at least one electrical and / or electronic component of said electrical and / or electronic components mounted on said printed circuit board (320) is packaged in a package (605) having, at a respective lower face (830), perimetral electrical contact pads (610), arranged along perimetral sides of the package, said perimetral electrical contact pads being connected, through solder joints, respectively to said contact pads (805) of the printed circuit board (320) perimetral to the mounting area (705) of the at least one electrical and / or electronic component provided on said face (835) of the printed circuit board, characterized in that said perimetral electrical contact pads (610) of the package and said solder joints are covered by a filler material (905).

2. The tyre monitoring device (200) according to claim 1, wherein said filler material is further arranged in such a way as to at least partially fill a gap, below said package (605), between said lower face (830) of the package (605) and said face (835) of the printed circuit board (320).

3. The tyre monitoring device (200) according to claim 1 or 2, wherein said filler material is a low-viscosity monocomponent filler material, having a nominal viscosity comprised between 100 mPa / s and 1000 mPa / s, preferably having a nominalviscosity between about 100 mPa / s and about 500 mPa / s and preferably between about 300 mPa / s and about 400 mPa / s.

4. The tyre monitoring device (200) according to any one of the preceding claims, wherein said printed circuit board assembly, particularly said face (835) of the printed circuit board (320) and the electrical and / or electronic components mounted on said face (835), are covered by a conformal coating (340) adapted to protect the printed circuit board assembly against humidity, chemical agents, high temperatures and other harsh conditions.

5. The tyre monitoring device (200) according to claim 4, wherein said conformal coating (340) has a thickness from about 1 pm to about 250 pm.

6. The tyre monitoring device (200) according to any one of the preceding claims, wherein said printed circuit board (320) comprises: at least two layers of electrically conductive material, electrically conductive traces, formed in said at least two electrically conductive layers, for the electrical interconnection between the electrical and electronic components of the electronic unit (205) and electrical interconnection vias between the electrically conductive traces of different electrically conductive layers, wherein said electrical interconnection vias are filled and capped with copper.

7. The tyre monitoring device (200) according to any one of the preceding claims, wherein a finishing of said electrical interconnection vias is compliant with the prescriptions of Standard IPC 4761 Type VII.

8. A tyre (105) comprising a radially internal surface (115) and a tyre monitoring device (200) applied to the radially internal surface of the tyre, the tyre monitoring device (200) being in accordance with any one of the preceding claims.

9. A method of manufacturing a tyre monitoring device (200) comprising anelectronic unit (205) that comprises electrical and / or electronic components, at least one electrical and / or electronic component of said electrical and / or electronic components mounted on said printed circuit board (320) being packaged in a package (605) having, at a respective lower face (830), perimetral electrical contact pads (610), arranged along perimetral sides (825) of the package, the method comprising:- providing a printed circuit board (320) having:- a mounting area (705) for the at least one electrical and / or electronic component, said mounting area (705) being formed on a face (835) of the printed circuit board, and- electrical contact pads (805) of the printed circuit board (320) perimetral to said mounting area (705);- mounting said at least one electrical and / or electronic component to the printed circuit board (320) at said mounting area (705), said mounting comprising:- forming solder joints of said electrical contact pads (610) of said package (605) to said electrical contact pads (805) perimetral to the mounting area (705) of the printed circuit board (320);- applying a liquid filler material (815) along at least one of said perimetral sides (825), preferably along two contiguous perimetral sides (825) of the package (605), such that the liquid filler material (815) diffuses and by capillarity covers said perimetral electrical contact pads (610) and said solder joints, and- performing a thermal treatment to cause the hardening of the filler material to form protections (905) on said perimetral electrical contact pads (610) and said solder joints.

10. The manufacturing method according to claim 9, wherein said applying the liquid filler material (815) comprises causing the liquid filler material (815) to diffuse in a gap between the lower face (830) of the package (605) and said face (835) of the printed circuit board (320).

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