Patent ID: 12207444

DETAILED DESCRIPTION

The disclosure provides systems for an electronic package having thermal management and EMI shielding features. The electronic package may include a chassis having a plurality of bent tabs (also referred to as tabs herein) forming a plurality of respective vent openings in the chassis and a circuit board coupled to the chassis. The chassis may be made from a material such as sheet metal for advantages including increasing heat dissipation and providing contact points between the circuit board and the chassis for EMI shielding. Heat dissipation is increased by the bent tabs functioning as mini-fins, vent openings, and contacts for conducting heat from the circuit elements to the chassis. Moreover, the tabs increase heat sinking capacity of the chassis without increasing the overall footprint of the enclosure. The chassis may include a number of additional features such as brackets and dimples for transferring heat from the circuit board to the chassis, and air gaps and fans for enhancing convective cooling. In some examples, the features may work synergistically to increase cooling without increasing package size.

FIG.1shows an example of an electronic package100included in a vehicle system such as an automotive infotainment system. As one example, the electronic package100may provide one or more functionalities associated with the automotive infotainment system, such as one or more of communication, entertainment, driver assistance, guidance, and navigation. An axis system170is shown inFIG.1and the other figures described herein.

The electronic package100may be mounted to a vehicle component. As one example, the electronic package100may be mounted to an instrument panel103, shown schematically. As a few additional, non-limiting examples, electronic package100may be mounted inside a headliner, near a pillar, in a glove compartment, a trunk, or other space of the vehicle system. It may be appreciated that the electronic package100may be mounted to other locations in an automotive vehicle and by other means than the examples given herein.

The electronic package100may include chassis101enclosing and coupled to a circuit board (202inFIG.2). In one example, the chassis101may be substantially box-shaped and flat. The chassis101may be symmetrical along a longitudinal center line156and a lateral center line158. In one example, components of the chassis101described above the longitudinal center line156may be understood to be mirrored below the longitudinal center line156and components described to the right of the lateral center line158may be understood to be mirrored on the left of the lateral center line158. The chassis101may have a length of dimension134that may be slightly longer than a height of dimension136and a first width of dimension138that may be approximately one sixth of the dimension134. In some examples, the relative lengths of dimension134, dimension136, and dimension138may be different. The chassis101housing104comprising five panels joined to form the base and side walls of an open box and cover plate102functioning as a lid to the box. The first panel or back panel (e.g., the base of the box;302inFIG.3A) of the housing104may be arranged in parallel in an xy plane with the cover plate102. The panels or side walls of the housing104include a first wall106arranged in parallel in an xz plane to a third wall (228inFIG.2) and a second wall108arranged in parallel in a zy plane to a fourth wall (230inFIG.2). The first wall106of the housing104may include a first perimeter122and first exterior surface124. The second wall108of the housing104may include a second perimeter142and a second exterior surface144.

The housing104may be shaped to enclose and support the circuit elements contained therein. Each side wall of the housing104may have a similar shape. For example, the first wall106may have a first height of dimension138that is greater than a shorter, second height of dimension140, and an approximate length of dimension134, e.g., similar to the overall length of the chassis101. The first wall106may be the shorter, second height of dimension140at a first corner118of the chassis101. The first wall106may include a first arched portion146where the panel height increases to the first height of dimension138. The first wall106may be the first height of dimension138in a central region148. The first wall106may include a second arched portion150where the panel height decreases down to the shorter, second height of dimension140at a second corner178of the chassis101.

The first wall106may be perforated with a plurality of bent tabs126, also herein referred to as tabs126. In one example, the bent tabs126may be arranged in rows and columns within the central region148. For example, the bent tabs126may be arranged in a first row180and a second row182. In one example, the first row180may be positioned directly above the second row182and aligned in a plurality of columns184. In some examples, such as depending on a mounting orientation of the chassis101, the first row180may be a top row and the second row182may be a bottom row. In one example, the tabs126may be formed by stamps128or cuts into the first wall106. The stamps128into the first wall106may form bent tabs126having a free fin part or fin130and an attached bend or bend132located opposite from the fin130. The fin130of the tabs126may bend inward in a direction of an interior (seeFIG.2) of the electronic package100. For example, the tabs126may bend inward in the direction of the longitudinal center line156. In one example, the bend132may be oriented to be parallel to the x-axis. In another example the bend132may be oriented to be parallel with the z-axis. The bent tabs126may be shaped to make a vent opening152and to contact the enclosed circuit elements along the fin130, which will be described in more detail below. In one example, the third wall228may similarly include rows and columns of bent tabs126such that the chassis101may include a pair of opposing parallel walls having bent tabs126. When mounted in a system with the first wall106being the top and the third wall228being the bottom, the bent tabs126arranged on opposing parallel walls enables passive or natural convection for increased cooling of the enclosed circuit elements. The direction of the arrow of vent opening152indicates the direction of cooling through the vents provided by the tabs126. In other examples, more than two walls of the housing may include bent tabs126or additional features, such as a fan, for increased cooling.

The cover plate102may be shaped to mate with the housing104. Looking down the z-axis, the cover plate102may be approximately rectangular. The cover plate102has a cover exterior surface110and a cover perimeter112. The cover exterior surface110may be shaped to include a broad planar portion114and a depression116at each corner (e.g., first corner118, second corner178). The broad planar portion114of the cover exterior surface110may occupy a first xy plane174. Each depression116may be planar with respect to a second xy plane176. With respect to surface area, most of the cover exterior surface110occupies the first xy plane174. The cover exterior surface110includes a sloping portion120at each corner (e.g., first corner118, second corner178) connecting the broad planar portion114to each depression116of the cover plate102. The cover perimeter112of the cover plate102may mate with the perimeters of each panel (e.g., first perimeter122of first wall106) along a rim (240inFIG.2) of the housing104. The cover plate102may be affixed to the housing104over the rim240by fasteners154, such as bolts, screws, and so on. As one example, fasteners154may be inserted through the cover exterior surface110in the depression116of the first corner118and into each of the other three corners.

The chassis101may be formed of metallic materials to prevent EMI interference between other electrical components of a vehicle and the enclosed circuit board. The chassis101may provide EMI shielding of circuit elements, such as circuit board202. For example, the chassis101of package100may provide a Faraday cage for enclosed circuit elements. The chassis101may shield circuit boards from interference from automotive elements such as motors, vehicle actuator, and so on. The chassis101may allow for external connections. Plug elements of the circuit board, such as cable162shown exiting via a through hole160in second wall108, may extend beyond the chassis101to allow for connection to one or more other devices or components. The through hole160may be defined by an opening on the second exterior surface144and an opening on an interior surface (not shown) of the second wall108. According to one example, chassis101may be formed of one or more electrically conductive and magnetically permeable materials to provide EMI shielding, including but not limited to aluminum (e.g., die-cast, extruded, forged, etc.) and steel (e.g., cold-rolled sheet metal, etc.). An advantage of the disclosure described herein is by forming the chassis101from sheet metal, bent tabs126may be stamped (e.g., cut) into metal and bent inward in the direction of an interior of the chassis. Rather than discarding as waste perforated material to make a ventilation hole, the bent tabs126remain attached, thus increasing the heat sinking capacity of the chassis without increasing the package size. The heat sinking capacity is increased by retaining the bent tabs126due to the increased total surface area and increased total volume of heat sinking material of the chassis101.

As one example, electronic package100is shown mounted to the instrument panel103via a pair of brackets164. As one example, a first bracket of the pair of brackets164is shown affixed to the second wall108of the housing104and a second bracket of the pair of brackets164may be arranged in parallel on the fourth wall230. In other examples, a pair or more of brackets may be affixed to the cover plate102or to the housing104and the cover plate102. The pair of brackets164may be affixed to the chassis101via brazing or welding. As another example, the pair of brackets164may be fastened to the chassis101using screws or bolts. The brackets164may include through holes172for mounting the electronic package100to the instrument panel103via fasteners such as bolts or screws.

FIG.2shows the chassis101for the electronic package100with the cover plate102removed to show an interior including enclosed circuit elements such as circuit board202. In one example, circuit board202may be a printable circuit board having a plurality of integrated circuits (e.g., first integrated circuit352inFIG.3B, second integrated circuit402inFIG.4A). Looking down the z-axis, the circuit board202may be shaped to mate with the housing104. The circuit board202may have a board perimeter204, a first external surface or board first surface206, and a second external surface or board second surface (354inFIG.3B). In one example, the general shape of the circuit board202may be symmetrical along the longitudinal center line156and the lateral center line158. The circuit board202may be approximately rectangular, having a length of dimension216and a height of dimension218. In one example, dimension216may be longer than dimension218. In other examples, the relative lengths of dimensions216,218may be similar and in other examples, dimension218may be longer than dimension216. The circuit board202may have a first pair of straight, parallel sides, or a board first side208and a board second side210, and a second pair straight, parallel sides, or a board third side212and a board fourth side214. The board perimeter204may be flush with (e.g., abut) the second wall108along the board first side208, the fourth wall230along the board second side210, the first wall106along the board third side212, and the third wall228along the board fourth side214. The circuit board202may make contact with at least some of the plurality of bent tabs126of first wall106and the third wall228.

FIG.3AandFIG.3Bshow further views of the electronic package100.FIG.3Ais a view looking at the back panel302of the housing104of the chassis101.FIG.3Bis a view of the circuit board202affixed the cover plate102. The housing104of the chassis101is removed to show a board second surface354of the circuit board202and a first integrated circuit352. Together,FIG.3AandFIG.3Billustrate an example surface modification of the housing104designed to increase thermal transfer from the circuit board202to the chassis101.

The back panel302of the housing104includes an exterior surface304. The exterior surface304may be shaped to include a planar portion306and one or more depression features, shown as dimple feature308. The planar portion306of the exterior surface304may occupy a third xy plane310. In one example, the dimple feature308may be an approximately square depression having sloped sides312and a square base314. The square base314may be planar with respect to a fourth xy plane318. The sloped sides312may have a depth of dimension316.

The one or more depression features may be formed into the back panel302to increase contact with the one or more integrated circuits. For example, the dimple feature308may be the depth of dimension316so as to make contact with a face356of the first integrated circuit352. Dimension316may be relatively deeper or shallower based on a position of the face356of the integrated circuit352. In one example, the dimple feature308may make contact with the face356of the first integrated circuit352through a thermal pad or gap filler. The heat may transfer from the first integrated circuit352, to the housing104, and dissipate though the side panels and bent tabs126of the chassis101to the surrounding air via natural convection or fan-driven convection.

FIG.3B, further illustrates the cover plate102joined with the circuit board202. As one example, each of the fasteners154may be inserted via through holes (not shown) in the cover plate102aligned with through holes358in the circuit board202. The fasteners154, when affixed over the cover plate102, may apply pressure evenly to increase contact between the circuit board202and the chassis101for improved thermal transfer and EMI shielding.

FIG.4AandFIG.4Bshow interior views of the electronic package100. The back panel302of the chassis101is removed to show the integrated circuits of the circuit board202and chassis components for increasing thermal management capability and EMI shielding.

In one example, the fin130of the bent tabs126may be D-shaped and relatively flat, having a first face418, a parallel, second face (502inFIG.5A), and a small side surface420. A first tab orientation is shown inFIGS.4A and4B. As one example, the bend132of the tabs126may be oriented parallel to the x axis. The tab126may be bent along the bend132such that the first face418and the second face502may be arranged approximately perpendicular to the wall. In other words, the first face418and second face502may be planar with respect to an xy plane that may be parallel with the board first surface206and the board second surface354. Oriented in this way, the chassis101may make contact with solder bumps on an external surface of the circuit board. For example, the chassis101may make contact with the board second surface354at or near the board perimeter204along the second face502of the tabs126. A second tab orientation is shown inFIG.7, where the bend132of the tabs126may be oriented parallel to the z axis. Oriented in this way, the small side surface420of the tabs126may make contact with solder bumps on the external surface of the circuit board.

As one example, solder bumps on the circuit board202may sit on the tabs126while the circuit board202is secured to the chassis101by fasteners154, such as screws, at each corner (e.g., first corner118). Due to the compressive forces from the fasteners154, the bent tabs126may make robust contact with the circuit board202for improved EMI shielding and increased resiliency to vibration. Additionally, the face of the tabs126making face sharing contact with the circuit board202may provide a greater surface area of contact for increased heat transfer from heat producing circuit elements to the chassis101.

The chassis101may include a plurality of brackets for coupling the circuit board202to the housing104. In one example, brackets may be formed from sheet metal, such as copper or aluminum, and may act as heat sinks that may be mounted over integrated circuits, such as first integrated circuit352and second integrated circuit402, for improved thermal transfer. As one example, corner brackets406may be positioned at each corner (e.g., first corner118, second corner178, and so on) of the chassis101. As one example, corner brackets406may be L-shaped, including a first part408in contact with the circuit board202and a second part410in contact with a panel of the housing104. Long brackets452may similarly be mounted over circuit elements, such as over the second integrated circuit402. Long brackets452may include a third part454in contact with the circuit board and a fourth part456in contact with a panel of the housing104. In some examples, brackets may be mounted over an integrated circuit with a layer of thermal interface material applied therebetween. Example thermal interface materials may include thermal paste, gap fillers, or gap pads. Corner brackets406may include a through hole (e.g.,412) aligned with the through hole (e.g.,358inFIG.3B) of the circuit board202through which fasteners154may be inserted. Similarly, long brackets452may include a through hole (e.g.,458) that aligns with a through holes of the circuit board. The plurality of brackets increase the surface area of heat sinking material from which the chassis101is formed without increasing the footprint of the electronic package100. Brackets may also provide secure attachment points for coupling the circuit board202to the chassis101to increase stability and robustness of EMI shielding.

The electronic package100as configured inFIG.4AandFIG.4Bmay include a plurality of bent tabs126stamped into the first wall106, the third wall228, and the fourth wall230. By functioning as vents, the bent tabs126draw airflow through the interior of the chassis101for cooling the enclosed electronics via convection. In one example, the housing may include a fan for forced convection. In one example, the fan may be positioned in a wall on an opposite side of the housing from a wall having bent tabs. For example, a fan414may be positioned in a cutout422in the second wall108. The cutout422may be fully punched out of (e.g., cut free from or stamped into) a wall of the housing104. As one example, a method for cooling the electronic package100may include operating the fan414to blow air from inside the enclosure to outside the enclosure. As one example, the fan414may be used optionally to increase airflow in the direction indicated by arrow416. The fan414may be turned on when increased airflow is desired. When the fan414is off, air flow directed upwards by buoyancy effect may be predominant such as in the direction indicated by the arrow of vent opening152.

FIG.5Ashows a cross section view of the chassis101that may be included in the electronic package100for a vehicle system. The interior of the chassis101may include a first air gap504defined by a three-dimensional void between the circuit board202and the cover plate102and a second air gap506defined similarly between the circuit board202and the back panel302of the housing104. The first air gap504may have an approximate width of dimension508that may be the difference in dimension between the internal surface512of the cover plate102and the board first surface206of circuit board202. The second air gap506may have an approximate width of dimension510that may be the difference in dimension between the board second surface354of the circuit board202and an internal surface514of the back panel302. The air gaps may increase thermal convection (e.g., natural or fan-driven) through the chassis101.

The cross section view further illustrates contact surfaces between the chassis101and the circuit board202for heat transfer and EMI shielding. For example, contact may occur between the chassis101and the circuit board202along the first face418of the tabs126and the board second surface354of the circuit board202. In one example, one or more long brackets452may transfer heat from the circuit board202to one or more of the corner brackets406of the chassis101. Heat may be transferred to the chassis101from the first integrated circuit352being in face-sharing contact with the internal surface514of the dimple feature308.

FIG.5Billustrates a side view of the electronic package100with the cover plate102removed. The side view shows the approximately D-shaped stamp128into the first wall106from which tabs126are formed. A portion of a housing exterior surface552forms the first face418of the fin130. In one example, the first row180of the tabs may bend in an opposite direction from the second row182of tabs126. For example, the first row180of tabs126may bend down such that portion of the housing exterior surface552forming the first face418touches the circuit board202. As another example, the second row182of tabs126may bend up such that the portion of the housing exterior surface552forming the first face418faces the internal surface of the back panel302. Configured in this way, the first row180of tabs126may contact the circuit board202and the second row182of tabs126may be spaced away from the other set by dimension554.

FIG.6shows a perspective view of the chassis101that may be included in the electronic package100for a vehicle system. The view includes the cover plate102affixed to housing104via the plurality of fasteners154. The view shows the plurality of bent tabs126stamped into the third wall228and a fan414installed in the second wall108. When the cover plate102is joined to the housing104, evenly distributed compression across the housing securely presses the tabs126against the enclosed electronics for robust EMI shielding and thermal management. The tabs126dually functioning as vents and in combination with the fan414may further increase airflow for faster cooling of enclosed electronics.

FIG.7shows an interior view of the electronic package100including a second example for bent tabs702. The back panel302of the chassis101is removed to show the circuit board202and chassis components for increasing thermal management capability and EMI shielding.

Similar to the above examples, the bent tabs702may be formed by a stamp704or cut into one or more panels of the chassis. The tabs702may have an attached bend or bend708and a free fin part or fin706. In one example, the fin706may be D-shaped and flat, having a first face710, a parallel, second face712, and a small side surface714. As one example, the bend708of the tabs702may be oriented parallel to the z axis. The fin706of the tabs702may bend inward, in the direction of the interior of the electronic package100, along the bend708. For example, the tabs702may bend inward in the direction of the longitudinal center line156. Similar to the above examples, the bent tabs702may be shaped to make a vent opening152and a contact surface for heat transfer from the circuit board202to the chassis101. In one example, the first face710and the second face712of the tabs702may be arranged approximately perpendicular to the surface of the panel. Oriented in this way, the small side surface714of the tabs702may make contact with solder bumps on the board second surface354at or near the board perimeter204.

In one example, the electronic package100, as configured inFIG.7, may include the plurality of bent tabs702stamped into the first wall106, the third wall228, and the fourth wall230. The chassis101may include the fan414positioned in the second wall108for increased convection as well as a plurality of brackets such as corner brackets406and long brackets452for increased heat conduction from the circuit board202to the heat sinking chassis. Similar to the above examples, the tabs702, the long brackets452, corner brackets406, and fasteners154may securely position the circuit board202within the chassis101.

In this way, an electronic package for a vehicle system including a chassis having a plurality of bent tabs coupled to a circuit board may improve thermal management and EMI shielding for high performance automotive infotainment systems. Such improvements are enabled by retaining chassis material as bent tabs that function as vents, contact surfaces, and mini-fins. The chassis may be affixed to a vehicle component such as an instrument panel. By positioning bent tabs on an upper wall and lower wall of the chassis, the electronic package may take advantage of cooling via natural convection directed upwards by buoyancy effect. Additionally or alternatively, by including a fan positioned in a wall arranged opposite from a wall having bent tabs, the electronic package may increase cooling via forced convection. The technical effect of the electronic package for a vehicle system is increased cooling of enclosed electronics and EMI shielding without enlarging the overall footprint of the package.

The disclosure also provides support for an electronic package for a vehicle comprising: a chassis having a plurality of bent tabs forming a plurality of respective vent openings in the chassis, and a circuit board coupled to the chassis, wherein the bent tabs directly contact the circuit board. In a first example of the system, the bent tabs bend inward in a direction of an interior of the chassis. In a second example of the system, optionally including the first example, the bent tabs comprise a bend and a fin having a first face, a second face, and a small side surface. In a third example of the system, optionally including one or both of the first and second examples, the small side surface of the fin directly contacts an external surface of the circuit board. In a fourth example of the system, optionally including one or more or each of the first through third examples, a face of the fin directly contacts an external surface of the circuit board. In a fifth example of the system, optionally including one or more or each of the first through fourth examples, the first face, and the second face of the fin are oriented perpendicular to a surface of the circuit board. In a sixth example of the system, optionally including one or more or each of the first through fifth examples, the first face and the second face of the fin are oriented parallel to a surface of the circuit board. In a seventh example of the system, optionally including one or more or each of the first through sixth examples, the bend is located opposite the fin of the bent tabs. In an eighth example of the system, optionally including one or more or each of the first through seventh examples, a face of the bent tabs makes face-sharing contact with an external surface of the circuit board. In a ninth example of the system, optionally including one or more or each of the first through eighth examples, the circuit board is joined to the chassis via fasteners inserted through a plurality of aligned through holes. In a tenth example of the system, optionally including one or more or each of the first through ninth examples, the bent tabs are arranged in a top row and a bottom row, and the top row of bent tabs bend in an opposite direction than the bottom row of bent tabs. In a eleventh example of the system, optionally including one or more or each of the first through tenth examples the chassis further comprising a back panel having a depression, wherein an internal surface of the depression makes face-sharing contact with an external surface of the circuit board. In a twelfth example of the system, optionally including one or more or each of the first through eleventh examples the chassis further comprising a first pair of opposing parallel walls and a second pair of opposing parallel walls. In a thirteenth example of the system, optionally including one or more or each of the first through twelfth examples, the bent tabs are located on the first pair of opposing parallel walls. In a fourteenth example of the system, optionally including one or more or each of the first through thirteenth examples, the system further comprises: a fan, and wherein the bent tabs are located on a first wall of the second pair of opposing parallel walls and the fan is located in a second wall of the second pair of opposing parallel walls.

The disclosure also provides support for a method for cooling an electronic package, comprising: operating a fan where the fan blows air from inside an enclosure to outside the enclosure, the enclosure comprised of a chassis having the fan, a plurality of bent tabs forming a plurality of respective vent openings in the chassis, and a circuit board coupled to the chassis, wherein the bent tabs directly contact the circuit board.

The disclosure also provides support for a system for a vehicle, comprising: a vehicle component, a chassis having a plurality of bent tabs forming a plurality of respective vent openings in the chassis mounted to the vehicle component, and a circuit board coupled to the chassis wherein the bent tabs directly contact the circuit board. In a first example of the system, the vehicle component is an instrument panel. In a second example of the system, optionally including the first example the chassis further comprising a housing, a cover plate fastened over the circuit board to the housing, and a pair of brackets coupled to at least one of the housing and the cover plate, wherein the chassis is coupled to the vehicle component by fasteners inserted through the pair of brackets. In a third example of the system, optionally including one or both of the first and second examples, the chassis is made from sheet metal.

The description of embodiments has been presented for purposes of illustration and description. The described systems are exemplary in nature, and may include additional elements and/or omit elements. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed. As used herein, the term “approximately” is construed to mean plus or minus five percent of the range unless otherwise specified.

As used in this application, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is stated. Furthermore, references to “one embodiment” or “one example” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. The terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements or a particular positional order on their objects. The following claims particularly point out subject matter from the above disclosure that is regarded as novel and non-obvious.