Housing for a camera and method of manufacture

An electronic device includes a housing, a printed circuit board (PCB) disposed in the housing, and electronic components that are supported on the PCB. The housing is an assembly of a cover and a base. At least one of the cover and the base include a region in which at least a portion of an outer surface of the housing within the region, and a portion of housing material adjoining the portion of the outer surface, have material properties that are different than those in other regions. A method of manufacturing that provides the desired material properties is also described.

BACKGROUND

Electronic devices often include electronics that are disposed in a housing that is configured to support and protect the electronics therein. For example, a vehicle camera is an electronic device that includes a camera housing that is used to support and protect camera electronics that are mounted on a printed circuit board (PCB) and camera lenses that are mounted on the camera housing. The camera housing also supports an electrical connector that is electrically connected to the PCB and permits electrical signals to pass between the PCB including the camera electronics and external circuitry. The housing may include a tray-like base, and a cover that overlies and closes the base. The PCB is supported between the base and the cover. The electronics provided on the PCB and enclosed between the cover and the base generate heat that can negatively affect performance of the camera electronics if not sufficiently dissipated. Moreover, new generation vehicle cameras such as near range cameras are required to be smaller with more functionality. The size and function requirements of the near range camera may result in sufficient heat generation by the camera electronics to cause electrical component failure unless the heat is quickly dissipated to the outside environment. For this reason, it is desirable to provide such housings at a lower cost and having improved passive cooling capabilities relative to some conventional camera housings.

SUMMARY

In some aspects, an electronic device includes a housing that in turn includes a first housing portion. The first housing portion includes a first portion of an outer surface of the housing, a first portion of housing material disposed adjoining the first portion of the outer surface, and a second portion of housing material disposed adjoining the first portion of housing material. The first portion of housing material is disposed between the second portion of housing material and the first portion of the outer surface. The first portion of the outer surface and the first portion of housing material are formed of a first thermally conductive plastic material which comprises a first plastic material and a first filler material. The amount of the first filler material within the first thermally conductive plastic material is a first percentage of the total amount of material that forms the first thermally conductive plastic material. In addition, the second portion of housing material is formed of a second thermally conductive plastic material that comprises the first plastic material and the first filler material, the amount of the first filler material within the second thermally conductive plastic material is a second percentage of the total amount of material that forms the second thermally conductive plastic material, and the second percentage is greater than the first percentage.

The electronic device may include one or more of the following features: The housing includes a sidewall that forms a closed section when viewed in cross-section and an endwall that closes a first end of the sidewall, and the first housing portion is disposed at a second end of the sidewall, where the second end is opposed to the first end. The housing includes a base that is disposed at the second end and closes the second end, the base being joined to the first housing portion via a weld joint, where the weld joint is formed of the first thermally conductive plastic material. The housing includes a sidewall that forms a closed section when viewed in cross-section and an endwall that closes a first end of the sidewall, and the first housing portion is disposed between the first end and a second end of the sidewall, where the second end is opposed to the first end. The housing includes a base, a cover and a sealed interior space that is defined between the base and the cover, the cover includes a cover sidewall that forms a closed section when viewed in cross-section and a cover endwall that closes a first end of the cover sidewall, the base is fixed to a second end of the cover sidewall, the first housing portion is disposed at the second end of the cover sidewall, where the second end is opposed to the first end, the electronic device includes a printed circuit board and a thermal interface device, the printed circuit board is disposed in the interior space, the printed circuit board including a first surface that faces the cover, a second surface that is opposed to the first surface and faces the base, and an electronic element supported on one of the first surface and the second surface, and the thermal interface device is disposed in the interior space, the thermal interface device being formed of a thermal interface material having a thermal conductivity of at least 1 W/mK, and being disposed between the first surface and the housing such that the thermal interface device contacts the printed circuit board and a portion of the cover.

The electronic device may also include one or more of the following features: The portion of the cover is formed of the second thermally conductive plastic material, which has a thermal conductivity of at least 1 W/mK. The base is formed of a laser transparent plastic material, the base is joined to the first housing portion via a weld joint, and the weld joint is formed of the first thermally conductive plastic material. The portion of the cover includes a portion of the cover endwall that is surrounded by, and spaced apart from, a peripheral edge of the cover endwall, and the peripheral edge of the cover endwall is formed of a plastic material that is different than the thermally conductive plastic material. The portion of the cover includes the cover sidewall and a portion of the cover endwall. An outward facing surface of the portion of the cover includes a passive cooling feature that comprise a pair of depressions separated by a land. The base includes a base sidewall having a first end and a second end, a flange disposed at the base sidewall first end, the flange extending outward from the base sidewall in a direction perpendicular to the base sidewall, a base endwall disposed at the base sidewall second end, the base endwall extending inward from the base sidewall in a direction that is parallel to the flange, the base endwall having an opening, and a collar that surrounds the opening and protrudes outward from the base endwall in a direction away from the flange. The electronic device further includes an electrical connector that is supported on the cover, the electrical connector including a connector housing, and electrical conductors that are supported on the connector housing and are electrically connected to the printed circuit board. The connector housing is formed of a material that is different from the thermally conductive plastic material used to form the portion of the cover. The electronic device is a camera and includes a lens assembly disposed in an opening in the base, and the electronic element is an image detector supported on the printed circuit board second surface so as to be aligned with an optical axis of the lens assembly.

In some aspects, a method of forming an assembly of a first element formed of a first material and a second element formed of a second material, in which the first element includes a target region. The method includes providing the first element, the first element having an original material structure corresponding to an original set of material properties, the original material structure extending uniformly throughout at least a volume defined by the target region of the first element. The method includes heat treating the target region of the first element such that at least a portion of the outer surface of the target region has a modified material structure corresponding to a modified set of material properties and other portions of the target region retain the material properties corresponding to the original set of material properties, the modified set of material properties being different from the original material properties. The method includes providing the second element, and positioning the first element and the second element so that the portion of the outer surface of the target region of the first element physically contacts the second element while in a predetermined configuration. The method includes forming a bond between the portion of the outer surface of the target region of the first element and the second element, whereby the second element is connected to the first element in the target region and in the predetermined configuration.

The method may include one or more of the following steps and/or features: The bond is formed by performing a laser welding process. The laser welding process includes performing laser welding including passing a laser beam through the second element to the first element. The first element includes a housing that includes a first housing portion. Prior to the heat treating step, the first housing portion includes the original set of material properties extending uniformly throughout at least the volume defined by the target region, and following the heat treating step, the target region includes a portion of an outer surface of the housing, a first portion of housing material disposed adjoining the portion of the outer surface, and a second portion of housing material disposed adjoining the first portion of housing material, the first portion of housing material disposed between the second portion of housing material and the portion of the outer surface. The portion of the outer surface and the first portion of housing material are formed of a first thermally conductive plastic material which comprises a first plastic material and a first filler material, wherein the amount of the first filler material within the first thermally conductive plastic material is a first percentage of the total amount of material that forms the first thermally conductive plastic material, and the second portion of housing material is formed of a second thermally conductive plastic material that comprises the first plastic material and the first filler material, the amount of the first filler material within the second thermally conductive plastic material is a second percentage of the total amount of material that forms the second thermally conductive plastic material, and the second percentage is greater than the first percentage. The bond is formed by a multiple shot injection molding process in which the first element is formed via a first shot of material injection and the second element is formed on the first element in the target region via a second shot of material injection. The first material and the second material are thermally conductive plastic materials having a thermal conductivity of at least 1 W mK. The first material and the second material are formed of the same constituents and differ only in the ratio of amounts of the first plastic material to the first filler material.

A vehicle camera includes a camera housing that is used to support and protect a PCB that in turn supports camera electronics including an image sensor. The camera housing supports a lens assembly so that it is aligned and appropriately spaced apart from the image sensor. In addition, the camera housing supports an electrical connector that is electrically connected to the printed circuit board and permits electrical signals to pass between the camera electronics and external circuitry.

The vehicle camera includes passive cooling features that are configured to conduct heat from the vicinity of the PCT to the camera housing. In addition, the camera housing includes passive cooling features that facilitate efficient transfer of heat from the camera housing to the environment, whereby the failure of the vehicle camera due to excessive heat is avoided. The features include forming the camera housing of two or more types of plastic materials, providing thermal conduction pathways

The housing assembly disclosed herein is advantageously formed of injection-molded plastics. Thus, the housing assembly disclosed herein is much more cost effective to manufacture than some conventional electronic device housings in which the cover is formed of diecast aluminum. In addition to being more expensive to manufacture than plastic housings due to differences in material costs, metal housings also require additional structures that provide sealing and bonding functions that are not required in the plastic housing described herein.

In addition, use of plastic to form the camera housing provides cost reductions since the tooling used to form the disclosed housing has a much greater lifespan than that used to form a conventional electronic device housing. For example, a single injection molding tool may be able to provide approximately a million injection shots, whereas the tool used to diecast the aluminum cover may typically be able to provide approximately a hundred thousand castings.

Further advantages of using plastics to form the camera housing are decreased size and weight relative to the size and weight of some conventional camera housings formed of diecast aluminum. In this case, size reductions may be possible since plastic housing elements can be welded together to provide a dust and moisture seal, and thus require less space within the device that is devoted to performing sealing and securement functions as compared to some camera housing formed of diecast aluminum.

In some embodiments, selected portions of the camera housing are formed of a thermally conductive plastic (TCP). By doing so, the camera housing has some material properties similar to those of a metal enclosure and while providing the cost and design benefits of a plastic enclosure. For example, some TCP materials have polyamide 66 (PA66) or polybutylene terephthalate (PBT) as base materials, and have additives or fillers that increase the thermal conductivity from 0.25 W/m·K of traditional thermoplastics to approximately 6-10 W/m·K or more. They are available in electrically insulative and electrically conductive grades, and may be up to 50 percent lighter than aluminum, which may have a thermal conductivity of about 130 Watts/meter/Kelvin. In addition, the electrically conductive form of the TCP material may provide some level of electromagnetic compatibility (EMC) shielding for the electronics disposed within the housing.

In some embodiments, the TCP is manufactured so as to provide a housing having an optimized surface for laser welding, bonding with adhesive and/or bonding with a second material. This is achieved using a process that provides a housing surface in a target region that has a relatively higher percentage of base material relative to filler material than portions of the housing adjacent the surface. By providing a relatively higher percentage of base material at the housing surface, joining processes such as laser welding, bonding with adhesive and/or bonding with a second material at that location can be achieved more easily and reliably than with some conventionally formed TCP housings having a uniform distribution of base and filler materials.

In some embodiments, the TCP is black in color, which further improves its radiation properties when compared to some conventional electronic device housings in which the cover is formed of diecast aluminum and thus has a silver color.

DETAILED DESCRIPTION

Referring toFIGS. 1, 2 and 4, an electronic device, such as a vehicle camera1, includes electronic components64that are disposed in a camera housing4that is configured to support and protect the electronic components64therein. The electronic components64, including an image detector67, are mounted on a PCB60. The vehicle camera1also includes a camera lens assembly80that is mounted on the camera housing4. The camera housing4also supports an electrical connector50that is electrically connected to the PCB60and permits electrical signals to pass between the electronic components64of the PCB60and external circuitry (not shown). The camera housing4may include a tray-like base30and a cover10that overlies and closes the base30, and the PCB60is supported between the base30and the cover10. The camera housing4protects the PCB60and the associated electronic components64from moisture and debris, and includes passive cooling features that permit reliable operation of the vehicle camera1, as discussed in detail below.

The base30of the camera housing4is a shallow container that includes a base sidewall34having a first end35and a second end36that is opposed to the first end35. The base sidewall34forms a closed section having a rectangular shape when viewed along a housing centerline8that is parallel to the base sidewall34. A flange32is disposed at the base sidewall first end35. The flange32protrudes outwardly from the base sidewall34in a direction perpendicular to the base sidewall34and surrounds a periphery of the base sidewall34.

The base30includes a base endwall37disposed at the base sidewall second end36. The base endwall37closes the base sidewall second end36, and is offset from, and parallel to, the flange32. Bosses40are disposed in a pair of diagonally opposed corners of the base30and protrude from the base endwall37toward the cover10. The bosses40include blind openings that are configured to receive screws46used to secure the PCB60to the base endwall37. The bosses40also serve as stand-offs that support the PCB60in a spaced relationship relative to the base endwall37. The base30may also include alignment pins42that protrude from the base endwall37toward the cover10, and are received in corresponding openings formed in the PCB60. The alignment pins42serve to position the PCB60relative to the base30and lens assembly80prior to insertion of the screws46into the bosses40.

The base endwall37includes an opening38through which the lens assembly80extends. A cylindrical collar39surrounds the opening38and protrudes outward from an outer surface of the base endwall37. The collar39supports the lens assembly80and facilitates alignment of the lens assembly80with the image detector67. A seal83, for example a bead of adhesive, is disposed between the collar39and the lens assembly80to retain the lens assembly80within the collar39and to prevent moisture from entering the camera housing4.

The cover10is a cup-like container that when assembled with the base30cooperates with the base30to define a housing interior space6. The cover10includes a cover sidewall12having a first end13and a second end14that is opposed to the first end13. The cover sidewall12is long relative to a length of the base sidewall34. For example, in the illustrated embodiment, the distance between the cover sidewall first and second ends13,14is at least twice the distance between the base sidewall first and second ends35,36. The cover sidewall12forms a closed section having a shape when viewed along the housing centerline8that corresponds to the shape of the base sidewall34. In the illustrated embodiment, the cover sidewall12is rectangular in shape.

The cover10includes a cover end wall20disposed at the cover sidewall first end13. A peripheral edge23of the cover endwall20is joined to the cover sidewall first end13, and the cover endwall20closes the cover sidewall first end13. The electrical connector50is supported on the cover endwall20adjacent to a first portion12(1) of the cover sidewall12. In addition, a passive cooling feature26is formed in the cover end wall20at a location between the electrical connector50and a second portion12(2) of the cover sidewall12. The second portion12(2) is on an opposed side of the cover endwall20relative to the first portion12(1). The passive cooling feature26includes a pair of depressions27,28separated by a land29. In effect, the passive cooling feature26provides a region of relatively high surface area along the cover end wall20, facilitating efficient thermal convection from the cover end wall20to the atmosphere.

The PCB60is disposed in the interior space6between the base30and the cover10in such a way that the PCB60is fixed within the camera housing4. In the illustrated embodiment, the PCB60is fixed to the base30and is used to support and provide electrical connections between the electrical connector50and the external circuitry which may include an electronic control unit (not shown).

The PCB60is a rigid, multi-layer sheet of insulative material that includes electrically conductive tracks (not shown) used to electrically connect electronic components64to each other and/or to the electrical connector50. The electrical connector50is electrical connected to the PCB60via a plug52disposed on a first, cover-facing surface61of the PCB60. The electrical connector50may, for example, be of the type used to engage a wiring harness connector (not shown). The PCB60supports the electronic components64, a controller, electrolytic capacitors, power components, etcetera, on both the first surface61, and on the opposed, second surface62that faces the base30. In the vehicle camera1, the image detector67is disposed on the PCB second surface62at a location that is in alignment with the lens assembly80. In addition, the PCB60may include thermally conductive vias (not shown) that extend between the first and second sides61,62. In some embodiments, the vias are dedicated to thermal conduction, while in other embodiments, the vias function as both electrical and thermal conduction pathways.

The vehicle camera1includes a thermal interface device90that is disposed between the PCB first surface61and the camera housing4such that the thermal interface device90physically contacts both the PCB60and a portion of the cover10. In particular, the thermal interface device90physically contacts the PCB60and the portion of the cover10that includes the passive cooling feature26. The relatively large surface area provided by the inner surface of the cover end wall20in the portion including the passive cooling feature26facilitates good thermal conduction between the thermal interface device90and the cover10. In addition, the relatively large surface area provided by the outer surface of the cover end wall20in the portion including the passive cooling feature26facilitates good thermal convection between the cover10and the atmosphere.

The thermal interface device90is a thermal interface material (TIM). The term TIM is used herein to refer to a thermally conductive material that is relatively soft and compliant prior to curing, and becomes substantially rigid after curing. Alternatively the TIM may be in the form of a grease, a paste, a gel, a tape, a pad, etc. as appropriate. In the illustrated embodiment, the TIM has a thermal conductivity of at least 1 W/mK.

Since the TIM is disposed between the PCB first surface61and the cover10, cooling of the PCB60and its associated electronics is achieved via thermal conduction between the PCB60and the cover10via the TIM. In addition, conductive cooling of the electronic components64including the image detector67that are supported on the second surface62of the PCB60may be facilitated by way of the thermally conductive vias that extend between the first surface61and the second surface62of the PCB60.

The cover10is formed of a TCP material. As used herein, the term TCP refers to a plastic material having a higher thermal conductivity than some conventional plastic materials. In the illustrated embodiment, the TCP has a thermal conductivity of at least 1 W/mK. In other embodiments, the TCP has a thermal conductivity of at least 2 W/mK. In still other embodiments, the TCP has a thermal conductivity of at least 5 W/mK. In some embodiments, the TCP may include a conventional plastic base material such as PA66 or PBT that includes filler material that increases the thermal conductivity of the plastic base material. For example, the filler material may be graphite, glass or ceramic particles. In some embodiments, the TCP may be electrically conductive. In embodiments in which the TCP is electrically conductive, the cover10may provide EMC shielding of the PCB60and the electronic components67.

Use of the TCP material to form portions of the camera housing4is advantageous since a metal enclosure can be avoided while known cost and design benefits of a plastic enclosure are provided.

Referring toFIGS. 2 and 3, the cover10may include features that facilitate bonding of the cover10with a second element (e.g., the base) for example via a laser welding process. The features include providing a housing surface that is optimized for bonding by having a relatively higher percentage of base material relative to filler material than portions of the housing adjacent the surface. This is achieved, for example, using a manufacturing process described in detail below. The optimized housing surface includes a housing portion (e.g., a target portion)91corresponding to a location at which it is desired to form a weld joint with the base30. Thus, in the illustrated embodiment, the housing portion91corresponds to the cover sidewall second end14, which is laser welded to the base flange32. The housing portion91includes a surface portion92corresponding to an outer surface of the cover sidewall second end14, a first portion of housing material93disposed adjoining the surface portion92, and a second portion of housing material94disposed adjoining the first portion of housing material93. The first portion of housing material93is disposed between the second portion of housing material94and the surface portion92.

The surface portion92and the first portion of housing material93are formed of a first thermally conductive plastic material which comprises a first base material and a first filler material. For example, in the illustrated embodiment, the first base material is a conventional plastic such as PA66 and the first filler material is a thermally conductive material such as graphite, but other appropriate materials can be substituted. The amount of the first filler material (e.g., graphite) within the first thermally conductive plastic material is a first percentage of the total amount of material that forms the first thermally conductive plastic material. In addition, the second portion of housing material94is formed of a second thermally conductive plastic material that comprises the first base material (e.g., PA66) and the first filler material (e.g., graphite). The amount of the first filler material (e.g., graphite) within the second thermally conductive plastic material is a second percentage of the total amount of material that forms the second thermally conductive plastic material, and the second percentage is greater than the first percentage. That is, the first thermally conductive plastic material and the second thermally conductive plastic material have substantially the same components, but have different proportions of base material and filler material.

As a result, the surface portion92and the first portion of housing material93have more base material than does the second portion of housing material94, which is disposed at a location spaced apart from the surface portion92. Since the surface portion92and the first portion of housing material93have a relatively high proportion of base material, forming a reliable weld joint with the base30becomes easy and reliable.

The base30is formed separately from the cover10and is formed of a different plastic material. In some embodiments, the base30is formed of a laser transparent plastic (LTP) material. Use of a LTP material to form the base30is advantageous since it allows use of a laser welding process to join the cover10to the base30, as discussed in detail below. An additional advantage in forming the base30of a different plastic material includes an overall reduction in material costs, since TCP materials are relatively higher in cost of as compared to some conventional plastic materials. In further addition, some TCP materials may be relatively brittle as compared to some other plastic materials. By forming the base30of a non-TCP material, the base30may have a higher strength than the portions of the camera housing4formed of TCP material, whereby the structural integrity of the camera housing4is improved relative to a camera housing formed entirely of TCP materials.

The camera housing4securely supports the PCB60and its associated electronic components64while providing improved cooling properties and lower manufacturing costs. This is achieved by forming the cover10of a TCP material, providing the thermal interface device90formed of a TIM between the PCB60and the cover10, and by providing the passive cooling features26formed of a TCP on an outer surface of the cover10. By strategic selection and placement of the materials used to form the camera housing4, cooling of the vehicle camera1can be improved relative to some conventional plastic housings.

As a result, the advantages of using a light weight material such as plastic can be realized while providing a camera housing4configured to safely and securely house the PCB60including the image sensor67. By forming the cover10as an assembly that includes a TCP plastic cover10having passive cooling features and a base30having relatively high strength and a plastic heat sink portion60having optimized thermal conduction properties, a light weight, low cost housing assembly is provided.

Referring toFIGS. 5-7, an alternative embodiment vehicle camera100is similar to the vehicle camera1described above with respect toFIGS. 1-4, and common reference numbers are used to refer to common elements. The vehicle camera100illustrated inFIGS. 5-7differs from the vehicle camera1described above with respect toFIGS. 1-4in that it includes an alternative embodiment camera housing104. The camera housing104includes the base30and a cover110that overlies and closes the base30. Like the earlier-described embodiment, the PCB60is supported between the base30and the cover110. In addition, the camera housing104protects the PCB60and the associated electronic components64from moisture and debris, and includes passive cooling features that permit reliable operation of the vehicle camera100.

The cover110illustrated inFIGS. 5-7differs from the cover10illustrated inFIGS. 1-4in that only a portion of the cover110is formed of a TCP material. In particular, a portion25of the cover endwall20is formed of TCP. The remainder of the cover10, including the connector50, the peripheral edge23of the cover endwall20and the cover sidewall12, is formed of a plastic material that is different than the thermally conductive plastic material. For example, in some embodiments, the connector50, the peripheral edge23of the cover endwall20and the cover sidewall12may be formed of a conventional plastic such as carbon black plastic (CBP).

The portion25of the cover endwall20that is formed of a TCP material is surrounded by, and spaced apart from, a peripheral edge23of the cover endwall20. The portion25of the cover endwall20is strategically placed to facilitate cooling of the vehicle camera1. In particular, The portion25of the cover endwall20includes the passive cooling feature26and portions of the cover endwall20immediately adjacent to the passive cooling feature26. As a result, the portion25of the cover endwall20contacts the thermal interface device90, and the camera housing104provides passive conducive and convective cooling benefits, while minimizing material costs associated with use of TCP.

Referring toFIGS. 8-10, another alternative embodiment vehicle camera200is similar to the vehicle camera1described above with respect toFIGS. 1-4, and common reference numbers are used to refer to common elements. The vehicle camera200illustrated inFIGS. 8-10differs from the vehicle camera1described above with respect toFIGS. 1-4in that it includes an alternative embodiment camera housing204. The camera housing204includes a base230and a cover210that overlies and closes the base230. Like the earlier-described embodiment, the PCB60is supported between the base230and the cover210. In addition, the camera housing204protects the PCB60and the associated electronic components64from moisture and debris, and includes passive cooling features that permit reliable operation of the vehicle camera200.

The cover210illustrated inFIGS. 8-10differs from the cover10illustrated inFIGS. 1-4in that the cover210is formed of two different plastic materials. In particular, a portion225of the cover sidewall212is formed of a conventional plastic material such as CBP. More particularly, the cover sidewall second end214is formed of CBP. The remainder of the cover210including the cover sidewall first end213, the cover endwall220including the connector and the passive cooling feature26, are formed of TCP.

The portion225of the cover sidewall212that is formed of a CBP material is provides the terminal or free end of the cover sidewall212that is joined to the base by laser welding. By forming the portion225of the cover sidewall of CBP, a secure weld joint is easily and reliably formed between the cover210and the base230. In some embodiments, the portion225of the cover sidewall212is formed on the remainder of the cover210in a second shot injection molding process.

Since a portion of the cover sidewall212and the cover endwall220including the passive cooling feature26are formed of TCP, the camera housing204provides passive conducive and convective cooling benefits, while minimizing material costs associated with use of TCP.

The vehicle camera200illustrated inFIGS. 8-10further differs from the vehicle camera1described above with respect toFIGS. 1-4in that it includes an alternative mechanism for fastening the PCB60to the base230. The base230is similar to the base30described above with respect toFIGS. 1-4except that the bosses40ofFIGS. 1-4are replaced by standoffs240. A standoff240is disposed in each corner of the base30and protrudes from the base endwall37toward the cover210. The standoffs240are cylindrical, and each has a planer terminal end surface241. The standoffs240support the PCB60in a spaced relationship relative to the base endwall37. In the illustrated embodiment, the second side62of the PCB60is secured to the standoff terminal end surface241using adhesive243.

Referring toFIGS. 11-14, another alternative embodiment vehicle camera300is similar to the vehicle camera1described above with respect toFIGS. 1-4, and common reference numbers are used to refer to common elements. The vehicle camera300illustrated inFIGS. 11-14differs from the vehicle camera1described above with respect toFIGS. 1-4in that it includes an alternative embodiment camera housing304. The camera housing304includes a base330and a cover310that overlies and closes the base330. Like the earlier-described embodiment, the PCB60is supported between the base330and the cover310. In addition, the camera housing304protects the PCB60and the associated electronic components64from moisture and debris, and includes passive cooling features that permit reliable operation of the vehicle camera300.

The cover310illustrated inFIGS. 11-14differs from the cover10illustrated inFIGS. 1-4in that the cover310is sidewall-free. In particular, the cover310is a generally plate-like element that, when assembled with the base330, cooperates with the base330to define the housing interior space6. The cover310includes an outward-facing surface321, and an opposed, PCB-facing surface322. A peripheral edge323of the cover310has a rectangular profile when viewed along the housing centerline8. In addition, openings324are provided in each corner of the cover310. The openings324receive posts333that are provided on the base330and used to secure the cover310to the base330as discussed in detail below.

Similar to the cover30illustrated inFIGS. 11-14, the cover310includes the connector50and the passive cooling features26as described above. In addition, the cover310is formed of TCP.

The base330illustrated inFIGS. 11-14differs from the base30illustrated inFIGS. 1-4in that the base30includes a secondary sidewall340that protrudes from a cover-facing surface of the flange32. The secondary sidewall340includes a first end313and a second end314. The secondary wall second end314is opposed to the first end313. The secondary sidewall340is long relative to the length of the base sidewall34. For example, in the illustrated embodiment, the distance between the secondary sidewall first and second ends313,314is at least twice the distance between the base sidewall first and second ends35,36. The secondary sidewall340forms a closed section having a shape when viewed along the housing centerline8that corresponds to the shape of the base sidewall34. In the illustrated embodiment, the secondary sidewall340is rectangular in shape.

The secondary wall second end314is joined to, or integral with, the flange32. The secondary wall first end313includes a free edge315. The posts333protrude from the free edge315in a direction parallel to the housing centerline8. In the illustrated embodiment, the secondary sidewall340includes four posts333, and a post333is disposed in each corner of the secondary sidewall340. The posts333are shaped and dimensioned to be received within the cover openings324in a press-fit manner, and terminal ends335of the posts333are generally flush with the cover outward-facing surface321. In some embodiments, following assembly of the cover310with the secondary sidewall first end313, each of the terminals ends335of the posts333are deformed via for example a punching process. The deformed terminal ends335engage the cover310, thereby retaining the cover310on the secondary sidewall first end313.

In some embodiments, the base330, including the secondary sidewall340, the flange32, the base sidewall34, the base endwall37and the collar39, are formed of TCP.

The camera housing304includes an annular seal398that is disposed on the cover inward facing surface322at a location that is slightly inboard relative to the cover peripheral edge323. The seal398abuts the secondary sidewall first end313. The seal398prevents moisture and debris from entering the camera housing304along the interface between the cover310and the base330.

Referring toFIGS. 12 and 13, in some embodiments, the cover310may include features that facilitate bonding of the seal398with the cover inward facing surface322. The features include providing a housing surface that is optimized for bonding by having a relatively higher percentage of base material relative to filler material than portions of the housing adjacent the surface. This is achieved, for example, using the manufacturing process described in detail below. The optimized housing surface includes a housing portion391corresponding to a location at which it is desired to form an adhesive joint with the base330. Thus, in the illustrated embodiment, the housing portion391corresponds to cover inward facing surface322, which is joined to the seal398during manufacturing. The housing portion391includes a surface portion392corresponding to the cover inward facing surface322for example at a location adjacent the cover peripheral edge323, a first portion of housing material393disposed adjoining the surface portion392, and a second portion of housing material394disposed adjoining the first portion of housing material393. The first portion of housing material393is disposed between the second portion of housing material394and the surface portion392.

The surface portion392and the first portion of housing material393are formed of a first thermally conductive plastic material which includes a first base material and a first filler material. For example, in the illustrated embodiment, the first base material is a conventional plastic such as PA66 and the first filler material is a thermally conductive material such as graphite, but other appropriate materials can be substituted. The amount of the first filler material (e.g., graphite) within the first thermally conductive plastic material is a first percentage of the total amount of material that forms the first thermally conductive plastic material. In addition, the second portion of housing material394is formed of a second thermally conductive plastic material that comprises the first base material (e.g., PA66) and the first filler material (e.g., graphite). The amount of the first filler material (e.g., graphite) within the second thermally conductive plastic material is a second percentage of the total amount of material that forms the second thermally conductive plastic material, and the second percentage is greater than the first percentage. That is, the first thermally conductive plastic material and the second thermally conductive plastic material have substantially the same components, but have different proportions of base material and filler material.

As a result, the surface portion392and the first portion of housing material393have more base material than does the second portion of housing material394, which is disposed at a location spaced apart from the surface portion392. In some embodiments, the seal398is formed as a second shot of an injection molding process, in which the base330is formed as the first shot. Since the surface portion392and the first portion of housing material393have a relatively high proportion of base material, forming a reliable bond between the seal398and the surface portion392becomes easy and reliable.

In other embodiments, the base330, including the secondary sidewall340, the flange32, the base sidewall34, the base endwall37and the collar39, are formed of metal such as aluminum. When the base330is formed of a metal, the seal398may be secured to the inner surface using adhesive or by other appropriate methods.

Referring toFIGS. 15-17, another alternative embodiment vehicle camera400is similar to the vehicle camera1described above with respect toFIGS. 1-4, and common reference numbers are used to refer to common elements. The vehicle camera400illustrated inFIGS. 15-17differs from the vehicle camera1described above with respect toFIGS. 1-4in that it includes an alternative embodiment camera housing404. The camera housing404includes an alternative base430and the cover10that overlies and closes the base430. Like the earlier-described embodiment, the PCB60is supported between the base430and the cover10. In addition, the camera housing404protects the PCB60and the associated electronic components64from moisture and debris, and includes passive cooling features that permit reliable operation of the vehicle camera400.

The base430illustrated inFIGS. 15-17differs from the base30illustrated inFIGS. 1-4in that the base430includes connection pins446that are supported in the blind openings provided in the bosses40and are used to secure the PCB60to the base endwall37. In particular, the connection pins446are fixed within the bosses40, and protrude toward the cover10. The connection pins446are press-fit into openings468provided in the PCB60, whereby the PCB is secured to the base430.

The base430illustrated inFIGS. 15-17further differs from the base30illustrated inFIGS. 1-4in that the second end14of the cover sidewall12is secured to the base flange32via adhesive. As previously described, the cover10may include features that facilitate bonding of the cover10with the base30using an adhesive447. The features include providing a housing surface that is optimized for bonding by having a relatively higher percentage of base material relative to filler material than portions of the housing adjacent the surface as shown inFIG. 3.

Referring toFIGS. 18-21, a method of manufacturing an electronics device housing includes method steps that provide structural elements of the device housing that have surfaces that are optimized for bonding to each other. In particular, the structural elements of the device housing may have a housing surface that has a relatively higher percentage of base material relative to filler material than portions of the housing adjacent the surface. In some embodiments, the method facilitates forming an assembly of a first element that is formed of one material and a second element that is formed of another material, in which the first element is connected to the second element in a predetermined configuration. The method will be described with respect to forming the vehicle camera housing4discussed above with respect toFIGS. 1-4.

The method includes providing the first element (step500). In the illustrated embodiment, the first element corresponds to the cover10. The first element is formed of TCP and has an original material structure (e.g., a material structure prior to heat treatment) corresponding to an original set of material properties.

In some embodiments, the first element is provided in an injection molding process. The first element is formed by injecting a first plastic material into a mold600having the shape of the cover10.

The original material used to form the first element is a TCP that includes a base material and a filler material. For example, the base material is a conventional plastic such as PA66 and the filler material is a thermally conductive material such as graphite particles. In some embodiments, the filler material of the original material is uniformly distributed within the base material. Thus, the original material structure extends uniformly throughout a volume of a target portion of the first element, where the target portion is the portion of the first element that is to be bonded with a second element.

The amount of the filler material (e.g., graphite) within the original material is a first percentage of the total amount of material that forms the original material. In some embodiments, the first material structure results in a TCP that has a thermal conductivity of at least 1 W/mK. In other embodiments, the TCP has a thermal conductivity of at least 2 W/mK. In still other embodiments, the TCP has a thermal conductivity of at least 5 W/mK.

In a second step, the target portion of the first element is heat treated such that at least a portion of the outer surface of the target portion has a modified material structure corresponding to a modified set of material properties. In addition, other portions of the target portion retain the material structure and properties of the original material (step502). Heat treatment of the target portion is achieved by providing heating elements602within the mold (injection tool)600at a location corresponding to the target area (FIG. 19). As a result, specific areas of the mold600have localized heating elements602near the surface of the target portion (FIG. 19). During heat treatment, the heating elements602are activated, which has the effect of pulling the base material (e.g., PA66) to the surface and reducing the amount of filler material (e.g., graphite) at the surface. Following heat treatment, the first element is allowed to cool, following which the resin rich surface is maintained.

In the cover10, the target portion corresponds to the cover sidewall second end14that is to be laser welded to the base flange32, which is also referred to as the housing portion91(see discussion above with respect toFIG. 3). Following heat treatment of the target portion, the housing portion91includes the surface portion92corresponding to an outer surface of the cover sidewall second end14, the first portion of housing material93disposed adjoining the outer surface of the cover sidewall second end14, and the second portion of housing material94disposed adjoining the first portion of housing material93(FIG. 20).

The surface portion92and the first portion of housing material93are formed of the modified material and have the modified set of material properties, whereas, the second portion of housing material94is formed of the original material having the original set of material properties. The amount of the filler material within the modified material is a second percentage of the total amount of material that forms the modified material. That is, the original thermally conductive plastic material and the modified thermally conductive plastic material have substantially the same components, but have different proportions of base material and filler material. In particular, the second percentage is less than the first percentage.

As a result, the original material retains the first set of material properties, whereas the modified material has a second set of material properties that are different from the those of the original set and correspond to the relatively lower amount of filler material disposed therein. Although the modified material is less thermally conductive than the original material due to its relatively lower amount of filler material, the relatively higher amount of base material within the modified material facilitates bonding with other types of plastic materials. Thus, bonding between two structural elements can be achieved more easily and reliably when compared to some conventionally formed TCP housings having a uniform distribution of base and filler materials.

Following the heat treating step, the method includes providing the second element (step504). In this example, the second element is the base30. The base30is formed of a conventional plastic material such as CBP. The base30is formed in an injection molding process or by other suitable techniques.

Next, the cover10and the base30are positioned so that the surface portion92of the cover10physically contacts the flange32of the base30(step506). In particular, the cover second end14contacts the flange32, whereby the cover10closes the open end of the base30, forming the interior space60.

Once the cover10and base30have been positioned, a bond is formed between the surface portion92of the cover10and the flange32of the base30using a laser welding process (step508). In the illustrated embodiment, the laser welding process is performed in such a way that a laser beam passes through the flange32to the surface portion92of the cover10(FIG. 21). By this procedure, the cover is joined to the flange32of the base30via the laser weld joint18.

In the method described above, the cover10and the base30illustrated inFIGS. 1-4 and 18-20are formed as separate elements and then joined via the laser welding process. For example, both the cover and the base may be formed in separate, single-shot injection molding processes, each having its own injection tool. In other embodiments, for example the embodiment illustrated inFIGS. 11-14, the bond between the seal398and the base330is formed by a multiple shot injection molding process in which the first element (e.g., the base330) is formed via a first shot of material injection and the second element (e.g., the seal398) is formed on the target region of the first element via a second shot of material injection.

Although the camera housing4, including the base30, the PCB60and the cover10are illustrated as having a rectangular shape when viewed in plan view, the base30, the PCB60and the cover10are not limited to having a rectangular shape. For example, the base30, the PCB60and the cover10may have another polygonal shape, an irregular shape including cut outs, or other shape as determined by the requirements of the application.

Selective illustrative embodiments of the system and device are described above in some detail. It should be understood that only structures considered necessary for clarifying the system and device have been described herein. Other conventional structures, and those of ancillary and auxiliary components of the system and device, are assumed to be known and understood by those skilled in the art. Moreover, while a working example of the system and device have been described above, the system and device are not limited to the working examples described above, but various design alterations may be carried out without departing from the system and device as set forth in the claims.