Hermetically sealed printed circuit boards

A method of assembling a hermetically sealed printed circuit board includes: securing a flange of a cap against an electrical contact region on a first side of a substrate, the flange extending across a first end portion of a wall of the cap, the wall extending around the electrical contact region and including a second end portion disposed in an open configuration; and closing the second end portion of the wall to form a hermetically sealed chamber around the electrical contact region.

TECHNICAL FIELD

The present disclosure relates generally to reusable surgical devices. More particularly, the present disclosure relates to powered surgical devices with enhanced durability and increased moisture resistance.

BACKGROUND

Powered surgical devices include electronic components, such as printed circuit boards, switches, sensors, etc., to enhance the control of functions of the surgical devices. The intelligence of such surgical devices result in a higher product cost compared to currently available disposable units. Accordingly, it would be beneficial if such intelligent devices are reusable.

Reusable surgical devices must be cleaned and sterilized prior to subsequent uses. Cleaning and sterilization procedures, however, are aggressive in nature. Cleaning (e.g., washing and/or disinfecting) utilizes alkaline solutions having high pH values (e.g., a pH of 11). Autoclaving (a common method of sterilization) utilizes high pressure superheated steam (e.g., 30 PSI @ 160° C. for 20 minutes). Such environments are known to damage various electronic components. For example, surgical devices may suffer from moisture ingress during cleaning and/or sterilizing procedures which, in turn, may corrode and/or degrade the electronic components.

The electronic components of reusable surgical devices may be protected from high temperatures, steam, and/or moisture by utilizing, for example, conformal coatings, potting, sealed enclosures, and/or overmolding. The electronic components, however, may still suffer from moisture ingress during cleaning and/or sterilizing procedures (e.g., cracking or delamination of conformal coatings), and/or may be damaged during application of the protective materials (e.g., heat damage during sealing of enclosures).

Thus, it would be beneficial if the durability of the electronic components is enhanced to improve the reliability of the electronic components and/or extend the effective cycle life of the surgical devices.

SUMMARY

The surgical devices of the present disclosure include a printed circuit board having electronic components housed within a hermetically sealed chamber. The electronic components are thus protected and configured to withstand environmental stresses associated with high pH cleaning and sterilization (e.g., autowashing and/or autoclaving), thereby rendering the electronic components more durable for re-use. Additionally, methods of the present disclosure include integrating and hermetically sealing the electronic components of the printed circuit board to minimize and/or prevent damage which may occur to the electronic components during the assembly process.

In one aspect of the present disclosure, a method of assembling a hermetically sealed printed circuit board includes: securing a first end portion of a wall of a cap to a substrate around an electrical contact region of the substrate, the wall including a second end portion disposed in an open configuration; mounting an electronic component to the electrical contact region of the substrate; and sealing the second end portion of the wall closed to form a hermetically sealed chamber between the substrate and the cap to encase the electronic component therein.

In embodiments, securing the wall of the cap includes bonding the first end portion of the wall to the substrate. In some embodiments, the first end portion of the wall includes a flange and bonding the first end portion includes welding the flange to the substrate.

The substrate may be a flex cable, and mounting the electronic component may include forming a printed circuit board on the flex cable.

In embodiments, sealing the second end portion of the wall includes heat sealing sections of the wall together. In some embodiments, sealing the second end portion of the wall includes securing a cover of a cap to the wall.

Mounting the electronic component may include positioning the electronic component of the substrate a spaced distance from outer edges of the substrate, and securing the first end portion of the wall of the cap to the substrate may include bonding the first end portion to the outer edges of the substrate. Mounting of the electronic component may be performed prior or subsequent to securing the first end portion of the wall of the cap to the substrate.

In embodiments, the method further includes placing the substrate in an inert gas environment prior to mounting the electronic component and sealing the second end portion of the wall. In some embodiments, the method further includes applying a coating over the electronic component prior to sealing the second end portion of the wall.

In another aspect of the present disclosure, a method of assembling a flex cable and integrating the flex cable into a surgical device includes: assembling electronic components on a first side of a substrate of a flex cable within a perimeter of a wall secured to the substrate, the wall extending transversely from the first side of the substrate and terminating at an open end; and closing the open end of the wall such that the electronic components are disposed within a sealed chamber.

Assembling the electronic components may include forming a printed circuit board on the flex cable. The method may include placing the flex cable in an insert gas environment prior to assembling the electronic components and closing the open end of the wall, and/or applying a conformal coating over the electronic components prior to closing the open end of the wall.

The method may include placing the flex cable into an adapter assembly of the surgical device. In embodiments, the method further includes electrically connecting the flex cable to a sensor disposed within the adapter assembly. In some embodiments, the method further includes electrically connecting the flex cable with a handle assembly and an end effector of the surgical device to enable communication between the handle assembly, the adapter assembly, and the end effector.

According to a further aspect of the present disclosure, a hermetic electronic assembly includes a printed circuit board and a cap. The printed circuit board includes a plurality of electronic components disposed on a first side thereof and offset a distance from outer edges of the printed circuit board. The cap includes a wall having a first end portion and a second end portion. The first end portion is bonded to the printed circuit board entirely around the plurality of electronic components and the second end portion is heat sealed closed a distance spaced from the plurality of electronic components. The bonding of the first end portion to the printed circuit board and the heat sealing of the second portion of the wall together form a hermetic seal encasing the plurality of electronic components therein.

In embodiments, the first end portion of the cap includes a flange, and the flange is bonded to the outer edges of the printed circuit board. The printed circuit board may be a flex cable.

In another aspect of the present disclosure, a method of assembling a hermetically sealed printed circuit board includes: securing a flange of a cap against an electrical contact region on a first side of a substrate, the flange extending across a first end portion of a wall of the cap, the wall extending around the electrical contact region and including a second end portion disposed in an open configuration; and closing the second end portion of the wall to form a hermetically sealed chamber around the electrical contact region.

The method may further include mounting one or more electronic components to the electrical contact region of the substrate. Securing the flange may include aligning one or more openings defined through the flange with the one or more electronic components such that the one or more electronic components extend through the one or more openings.

Securing the flange may include bonding the flange to the substrate. Bonding the flange may include welding the flange to the substrate. Welding the flange may include welding an outer perimeter of the flange to the substrate. Bonding the flange may further include adhering a first side of the flange to the first side of the substrate.

The substrate may be a flex cable, and mounting the one or more electronic components may include forming a printed circuit board on the flex cable.

Closing the second end portion of the wall may include securing a cover of the cap to the wall. Securing the cover may include welding the cover to the wall. In other methods, closing the second end portion of the wall may include heat sealing sections of the wall together.

In yet another aspect of the present disclosure a method of hermetically sealing a printed circuit board and integrating the printed circuit board into a surgical device includes: assembling one or more electronic components onto an electrical contact region on a first side of a substrate; securing a flange of a cap against the electrical contact region, the flange extending across a first end portion of a wall of the cap, the wall extending around the electrical contact region and including a second end portion disposed in an open configuration; and closing the second end portion of the wall to form a hermetically sealed chamber around the electrical contact region.

Assembling the one or more electronic components may include forming a printed circuit board on a flex cable. The method may further include placing the flex cable into the surgical device, electrically connecting the flex cable to a sensor disposed within an adapter assembly of the surgical device; and/or electrically connecting the flex cable with a handle assembly and an end effector of the surgical device to enable communication between the handle assembly, the adapter assembly, and the end effector.

In another aspect of the present disclosure, a hermetically sealed printed circuit board assembly includes a printed circuit board and a cap. The printed circuit board includes one or more electronic components disposed on a first side thereof. The cap includes a wall having a first end portion and a second end portion. The first end portion includes a flange defining one or more openings therein corresponding to the one or more electronic components of the printed circuit board. The flange is bonded to the printed circuit board such that the one or more electronic components extend through the one or more openings of the flange. The wall extends from the flange and forms a continuous perimeter around the one or more electronic components. The second end portion of the wall is sealed to form a hermetic chamber around the one or more electronic components.

The flange may extend inwardly of the wall and across the first end portion of the wall. The cap may include a cover bonded to the second end portion of the wall. The printed circuit board may be a flex cable.

Other aspects, features, and advantages will be apparent from the description, drawings, and the claims.

DETAILED DESCRIPTION

Surgical devices in accordance with embodiments of the present disclosure include a printed circuit board having electronic components disposed within a hermetically sealed chamber to protect the electronic components from exposure to moisture during, for example, cleaning and/or sterilizing procedures where the surgical devices may be subjected to high temperatures, steam, chemicals, and/or moisture. The electronic components of the surgical devices of the present disclosure are protected to prevent and/or resist breakdown over multiple/repeated cleaning and sterilizing cycles.

While the present disclosure is directed to printed circuit boards integrated on a flexible or flex cable of a surgical device, it is envisioned that the principles of the present disclosure are equally applicable to a range of printed circuit boards (e.g., rigid printed circuit boards, such as FR4 circuit boards) and electronic components (e.g., sensors) housed within reusable surgical devices.

Embodiments of the present disclosure are now described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. Throughout this description, the term “proximal” refers to a portion of a device, or component thereof, that is closer to a user, and the term “distal” refers to a portion of the device, or component thereof, that is farther from the user.

Turning now toFIG. 1, a surgical device1in accordance with an embodiment of the present disclosure is shown. The surgical device1is in the form of a powered handheld electromechanical surgical instrument, and includes a powered handle assembly10, an adapter assembly20, and a tool assembly or end effector30. The powered handle assembly10is configured for selective connection with the adapter assembly20and, in turn, the adapter assembly20is configured for selective connection with the end effector30.

The surgical device1will only further be described to the extent necessary to disclose aspects of the present disclosure. For a detailed description of the structure and function of exemplary surgical devices, reference may be made to commonly owned U.S. Patent Publication Nos. 2016/0296234, (“the '234 Publication”), and 2016/0310134 (“the '134 Publication”), the entire contents of each of which are incorporated herein by reference.

With continued reference toFIG. 1, the handle assembly10includes a handle housing12housing a power-pack (not shown) configured to power and control various operations of the surgical device1, and a plurality of actuators14(e.g., finger-actuated control buttons, knobs, toggles, slides, interfaces, and the like) for activating various functions of the surgical device1. The adapter assembly20includes a proximal portion20aconfigured for operable connection to the handle assembly10and a distal portion20bconfigured for operable connection to the end effector30. The end effector30including a loading unit32having a plurality of staples (not shown) disposed therein and an anvil assembly34including an anvil head34aand an anvil rod34b.

For a detailed description of exemplary handle assemblies, adapter assemblies, and end effectors which may be utilized in a surgical device of the present disclosure, reference may be made to the '234 and '134 Publications, the entire contents of each of which were previously incorporated herein by reference.

With reference now toFIG. 2, in conjunction withFIG. 1, the adapter assembly20includes a wiring harness22having at least one flex cable100electronically interconnecting the handle assembly10and the end effector30of the surgical device1. The wiring harness22of the adapter assembly20is configured to enable communication between the handle assembly10and the end effector30, and to relay power from the handle assembly10to the end effector30. For example, this communication allows for calibration and communication of data and control signals between the end effector30and the adapter assembly20, as well as between the adapter assembly20and the handle assembly10, thereby transferring data pertaining to the end effector30to the handle assembly10and signals from the handle assembly10to the end effector30.

The flex cable100includes a body or substrate110suitable for supporting and/or electrically connecting electronic components120thereto. The substrate110is formed from one or more layers or sheets of dielectric material, such as a polymer or a ceramic, and one or more layers of conductive material, such as copper foil, that form conductive traces (not explicitly shown) in the substrate110.

In embodiments, the substrate110of the flex cable100is formed from copper-clade polyimides, such as PYRALUX® or NIKAFLEX®, which are registered trademarks owned by DuPont. In some embodiments, the substrate110is formed from high temperature materials, such as PYRALUX® HT, also a registered trademark owned by DuPont. It should be understood that the substrate110is configured to allow for the fabrication of single or double sided flex circuits, multilayer flex circuits, and rigid flex circuits. The layers of the substrate110may be joined to one another by, for example, laminating, welding, and/or using adhesives, among other methods and materials within the purview of those skilled in the art.

A plurality of electrical contact regions112(referred to herein as first, second, third, and fourth electrical contact regions112a-d) are disposed at terminal ends of the conductive traces (not shown) defined through the substrate110on a first side114of the flex cable100. Each of the plurality of electrical contact regions112includes one or more pads (e.g., solder pads) to which electronic components120are joined (e.g., soldered). The electronic components120may be, for example, surface mount technology and/or through-hole technology, including, for example, integrated circuits (e.g., microchips, microcontrollers, microprocessors), resistors, amplifiers, inductors, capacitors, sensing elements (e.g., optical sensors, pressure sensors, capacitive sensors), buttons, switches, circuit boards, electrical connectors, cables, and/or wires, among other elements or circuitry within the purview of those skilled in the art.

The first electrical contact regions112aincludes electronic components120(see e.g.,FIG. 4) disposed thereon. A cap130is disposed over the first electrical contact region112ato hermetically seal the electronic components120therein, as described in further detail below. The second electrical contact region112bis in the form of solder pads which are aligned and soldered to solder pads24of an adapter flex cable26which, in turn, is electrically coupled to a force sensor28disposed within the adapter assembly20(FIG. 1) for measuring forces of the end effector30(e.g., as shown inFIG. 1, the pressure applied by the anvil head34ain the direction of arrow “A” against the distal portion20bof the adapter assembly20, the pressure applied by tissue acting on the anvil head34ain a direction opposite of arrow “A” as the anvil head34ais closed onto tissue, etc.).

With continued reference toFIG. 2, a proximal portion110aof the substrate110includes the third electrical contact region112cconfigured for electrical connection with the handle assembly10(FIG. 1). A distal portion110bof the substrate110includes the fourth electrical contact region112d(shown in phantom) coupled to an electronic component120in the form of an electrical connector “C” for electrical connection with the end effector30(FIG. 1).

It should be understood that while the flex cable100is shown including four electrical contact regions112, the flex cable100may have any number of electrical contact regions depending upon the desired configuration and functionality of the flex cable100, as is within the purview of those skilled in the art.

Referring now toFIGS. 3A-5B, a method of integrating and hermetically sealing a printed circuit board122to the substrate110of the flex cable100in accordance with an embodiment of the present disclosure is shown. As shown initially inFIGS. 3A and 3B, a cap130, in an initial open-ended configuration, is joined to the substrate110of the flex cable100such that a wall132of the cap130extends transversely from the first side114of the substrate110and defines a closed perimeter around the first electrical contact region112aof the substrate110. The wall132may be sized to be complementary in shape with the first electrical contact region112aof the substrate110. The wall132may be formed from the same material or a different material from that of the substrate110(e.g., the same or a different polymeric material).

A first end portion132aof the wall132includes a flange134that provides a flat surface or increased surface area for bonding of the wall132to the substrate110. The first end portion132aof the wall132may be secured to the substrate110by, for example, laminating or welding the flange134around an entire perimeter thereof to the substrate110to seal and form a leak-proof barrier at the junction of the substrate110and the cap130. The flange134is positioned adjacent to and is aligned with outer edges116of the substrate110, and extends along the outer edges116as well as across the substrate110. A second end portion132bof the wall132is open to provide access to the first electrical contact region112aof the substrate110. Accordingly, the cap130is open-ended during the initial stages of assembling the flex cable100.

As shown inFIG. 4, electronic components120are assembled onto the substrate110at the first electrical contract region112adisposed within the wall132of the cap130to form a printed circuit board122. The electronic components120are disposed on the substrate110in spaced relation relative to the wall132of the cap130such that the electronic components120are offset a distance from the outer edge116of the substrate110to which the flange134of the cap130is bonded, as well as the portions of the flange134extending across the substrate110. Placement of the electronic components120onto the substrate110in spaced relation relative to the flange134of the cap130and/or placement of the electronic components120onto the substrate110after securing the wall132to the substrate110prevents damage to the electronic components120that may have occurred due to heat transfer during bonding of the flange134to the substrate110.

Bonding processes may require high temperatures and/or high pressure which may transfer to the substrate110. For example, in embodiments in which the substrate110and the wall132are formed from high temperature materials, high temperatures and/or long bonding times may be required to secure the wall132to the substrate110. Accordingly, assembling the electronic components120onto the substrate110a spaced distance from the flange134of the cap130either prior to or after securing the wall132to the substrate110minimizes potential damage to the electronic components120. Further, assembling the electronic components120onto the substrate110after securing the wall132to the substrate110mitigates potential damage to the electronic components120.

As shown inFIGS. 5A and 5B, after the electronic components120are assembled onto the substrate110of the flex cable100, the cap130is sealed to a closed configuration by joining together the second end portion132bof the wall132. The second end portion132bof the wall132is gathered and secured together in a fluid tight manner to define a hermetically sealed chamber135housing the electronic components120therein. As specifically shown inFIG. 5A, for example, the second end portion132bof first and second sections133a,133bof the wall132are moved from an open position (see e.g., first section133a) to a closed position (see e.g., second section133b) so that, as shown inFIG. 5B, the second end portion132bof the first and second sections133a,133bcan be secured together along the entire length of the junction thereof. The second end portion132bof the wall132may be secured together by, for example, laminating or welding the second end portion132bof the wall132together to seal and form a leak-proof barrier at the second end portion132of the wall132. Accordingly, the cap130is close-ended at the end stages of assembling the flex cable100.

The space provided by the wall132around the electronic components120minimizes damage which may occur during the process of closing the second end portion132bof the wall132(e.g., by spacing the second end portion132of the wall132a distance from the electronic components120so that heat from the bonding process does not reach the electronic components120). The height of the wall132may vary depending, for example, on the space and/or distance needed to optimize protection of the electronic components120from the settings (e.g., heat) of the bonding process utilized. The second end portion132bof the wall132may be shaped (e.g., have a domed shape) to provide additional space within the cap130for the electronic components120.

While the wall132is shown as a single piece that is secured to the substrate110and to itself at the second end portion132bthereof to form the hermetically sealed chamber135, other configurations of the cap130are envisioned. For example, as shown inFIG. 6, a flex cable200includes a substrate110, electronic components120(see e.g.,FIG. 4) assembled onto the substrate110, and a cap230including a wall232secured to the substrate110at a first end portion232athereof around the electronic components120, and a cover236positioned over and secured to a second end portion232bof the wall232in a fluid tight manner to define a hermetically sealed chamber235(shown in phantom) housing the electronic components120(see e.g.,FIG. 4) therein. The cover236may be secured to the wall232by, for example, laminating or welding the entire outer perimeter of the cover236to the second end portion232bof the wall232to seal and form a leak-proof barrier between the wall232and the cover236. The cover236may be formed from the same material or a different material from that of the wall232.

Turning now toFIGS. 7A-9B, a method of integrating and hermetically sealing a printed circuit board122to a substrate110of a flex cable300in accordance with another aspect of the present disclosure is shown. As shown initially inFIGS. 7A and 7B, the flex cable300includes electronic components120assembled (e.g., soldered) onto a first electrical contact region112aon a first side114of the substrate110. A cap330, shown in an initial open configuration, is configured and dimensioned for bonding to the first electrical contact region112aof the substrate110. The cap330includes a wall332having first and second end portions332a,332b, and defines a void331therein. A flange334is disposed at the first end portion332aof the wall332and includes openings333defined therethrough. The flange334extends inwardly of the wall332and across the first end portion332asuch that the first end portion332ais closed by the flange334. The second end portion332bof the wall332is open.

As shown inFIGS. 8A-8C, the cap330is joined to the substrate110of the flex cable300by positioning the flange334directly against the first electrical contact region112aon the first side114of the substrate110such that the wall332of the cap330extends transversely from the first side114of the substrate110and defines a closed (e.g., continuous) perimeter around the first electrical contact region112aof the substrate110. The wall332and/or flange334may be sized to be complementary in shape with the first electrical contact region112aof the substrate110. The wall332and/or the flange334may be formed from the same material or a different material from that of the substrate110(e.g., the same or a different polymeric material).

The cap330is bonded to the substrate110at the flange334. The flange334closes the first end portion332aof the wall332, except for the openings333extending through the flange334. The openings333are sized and positioned to correspond with the electronic components120disposed on the substrate110such that the electronic components120are in communication with the void331defined within the wall332of the cap330when the flange334is bonded to the substrate110. A first side334aof the flange334is positioned adjacent to the first side114of the flex cable300with the openings333aligned with the electronic components120of the printed circuit board122. The flange334is also aligned with outer edges116of the substrate110, and extends along the outer edges116as well as across the substrate110(e.g., the flange334is coterminous with the first electrical contact region112aof the substrate110). The flange334provides a flat surface or increased surface area for bonding of the cap330to the substrate110. The first side334aof the flange334may be secured to the first side114of the substrate110by, for example, adhering, laminating, or otherwise bonding the flange334to the substrate110, and/or welding the flange334around an entire outer perimeter thereof to the substrate110to seal and form a leak-proof barrier at the junction of the substrate110and the cap330.

The second end portion332bof the wall332is open to provide access to the electronic components120on the substrate110and to allow for bonding of the flange334to the substrate110. Accordingly, the cap330is open-ended during the initial stages of assembling the flex cable300. The electronic components120may be assembled onto the substrate110at the first electrical contact region112ato form the printed circuit board122prior to or after the flange334of the cap330is secured to the substrate110.

As shown inFIGS. 9A and 9B, after the electronic components120are assembled onto the substrate110of the flex cable300and the cap330is bonded to the substrate110, the cap330is sealed to a closed configuration by closing the second end portion332bof the wall332. The cap330is sealed by positioning and securing a cover336to the second end portion332bof the wall332in a fluid tight manner to define a hermetically sealed chamber335housing the electronic components120(see e.g.,FIG. 8C) therein. The cover336may be secured to the wall332by, for example, laminating or welding the entire outer perimeter of the cover336to the second end portion332bof the wall332to seal and form a leak-proof barrier between the wall332and the cover336. The cover336may be formed from the same material or a different material from that of the wall332. Alternatively, the second end portion332bof the wall332may be gathered and secured together in a flight tight manner to define the hermetically sealed chamber335as described and shown above with regard to the cap130ofFIGS. 5A and 5B.

Assembly of the flex cable100,200,300may be performed using vacuum or in the presence of an inert gas (i.e., argon, nitrogen, etc.), as is within the purview of those skilled in the art. In embodiments, the electronic components120are assembled onto the substrate110and sealed with the cap130,230,330by fully drying, assembling, and sealing the electronic components120in an inert gas environment, such as an inert glove box (e.g., a nitrogen-filled atmosphere), to ensure zero moisture content within the electronic components120and the hermetically sealed chamber135,235,335.

In embodiments, a coating may be disposed over the electronic components120prior to sealing with the cap130,230,330. The coating may be a conformal coating that protects the electronic components120against moisture and/or heat. Accordingly, the coating may act as an additional layer of protection from any heat that may be produced while sealing the cap130,230,330and/or in the event that the seal should fail and moisture should permeate or ingress through the cap130,230,330the coating may provide a layer of protection from the moisture that may otherwise attack the substrate110and/or electronic components120.

In an embodiment, it is further contemplated that a moisture collection agent, e.g., a desiccant, may be provided within the void of the cap130,230,330prior to the sealing of the cap130,230,330to the closed configuration. For a detailed description of moisture collection agents, for use in flex circuits and the like, reference may be made to U.S. Provisional Patent Application Ser. No. 62/464,584, filed on Feb. 28, 2017, now U.S. Patent Appl. Pub. No. 2018/0242970, the entire content of which is incorporated herein by reference.

It should be understood that while the flex cable is shown and described above as being disposed within an adapter assembly of the surgical device, the flex cable may be utilized in other components of the surgical device, or other surgical devices. It should also be understood that while the flex cable is described and shown disposed within a powered surgical device, the flex cable may be utilized in non-motor driven yet powered surgical devices (e.g., reusable surgical devices subject to washing and/or sterilization procedures).

Persons skilled in the art will understand that the structures specifically described herein and shown in the accompanying figures are non-limiting exemplary embodiments, and that the description, disclosure, and figures should be construed merely as exemplary of particular embodiments. It is to be understood, therefore, that the present disclosure is not limited to the precise embodiments described, and that various other changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the disclosure. For example, the flexible cables of the present disclosure may be utilized in other surgical devices, such as robotic or powered surgical devices/instruments that are subject to sterilization procedures (e.g., autoclaving and/or autowashing). Additionally, the elements and features shown or described in connection with certain embodiments may be combined with the elements and features of certain other embodiments without departing from the scope of the present disclosure, and that such modifications and variations are also included within the scope of the present disclosure. Accordingly, the subject matter of the present disclosure is not limited by what has been particularly shown and described.