WO2015150500A1 - Cover lid, housing for electric or electromagnetic applications and method of assembly of a hf housing - Google Patents

Abstract

A cover lid (50) for a housing (1) for electric or electromagnetic applications, such as a housing for a coupler or a filter, and designed to reduce passive intermodulation (PIM) is disclosed. The cover lid comprises a cover lid plate (52) having a bottom plate surface (53), an upper plate surface (54), the upper plate surface being arranged substantially parallel to the bottom plate surface, and a lateral lid surface (55) joining the bottom plate surface and the upper plate surface, wherein the lateral lid surface (55) comprises a bevelled portion (58). A housing (10) comprises a cover lid (50) press fitted into the cover lid reception space (20). The invention also discloses a method of assembly of the housing with a cover lid, which is press fitted into the housing.

Description

Description

Title: Cover lid, housing for electric or electromagnetic applications and method of assembly of a HF housing

Cross reference to related applications

[0001] This application claims priority to British Patent Application No. 1406149.3, filed on 4 April 2014. The entire disclosure of British Patent Application No. 1406149.3 is hereby incorporated herein by reference.

Summary of the invention

[0002] The present invention relates to a housing for electric or electromagnetic applications, in particular for high frequency (HF) requirements. More precisely, the present invention relates to a housing lid, a housing comprising the housing lid, and a method of manufacturing the housing.

Background of the invention

[0003] High frequency components, such as couplers, are subject of strict requirements for robustness and reliability. The high frequency components are packaged in a housing, which is designed to minimize HF or radio frequency (RF)interferences from a signal. [0004] Passive intermodulation (PIM) is a form of intermodulation distortion that can occur even when no active components are present. PIM can occur in a variety of areas ranging from coaxial connectors and cables to rusty bolts or any joint where dissimilar metals occur. Passive intermodulation can produce interference between signals, and this passive intermodulation can sometimes hide a wanted signal. A designer of a circuit will therefore try and reduce the passive intermodulation.

[0005] One element that can lead to reduction in the PIM is the packaging or housing of high frequency components . The housing is designed to reduce the PIM values. Summary of the invention

[0006] The present invention proposes a cover lid for a housing for electric or electromagnetic applications, wherein the cover lid comprises a cover lid plate having a bottom plate surface, an upper plate surface, the upper plate surface being arranged substantially parallel to the bottom plate surface, and a lateral lid surface joining the bottom plate surface and the upper plate surface, wherein the lateral lid surface comprises a bevelled portion. [0007] The bevelled portion helps press-fitting the cover lid into a housing in a homogeneous and regular manner, the cover lid being parallel and remaining parallel to the housing's bottom base during the press-fitting.

[0008] When the cover lid covers a housing, at least a part of the lateral lid surface lies against a lateral wall of the housing, thereby closing and sealing the housing. At least another part of the lateral lid surface does not contact the lateral wall. This geometry of the cover lid, in particular the bevelled portion, therefore helps reducing unwanted cold welding between the housing and the cover lid arising during the assembly process and subsequently in use, which could also lead to passive intermodulation.

[0009] In one aspect of the invention, the lateral lid surface comprises a first lateral lid surface, extending from the upper plate surface and being substantially perpendicular to the upper plate surface, and a second lateral lid surface, extending from the first lateral lid surface to the bottom plate surface, at a bevelled angle with respect to the first lateral lid surface, thereby forming the bevelled portion. Preferably, the bevelled angle lies in the range of 3° to 45°, preferably in the range of 5 to 15°.

[0010] The bevelled portion may comprise a bevelled edge, such that the area or the external dimensions of the bottom plate surface is smaller than the area or the external dimensions of the upper plate surface.

[0011] In an aspect of the invention, the bevelled portion extends along the entire lateral periphery of the cover lid plate. [0012] In yet another aspect of the present invention, a plurality of recesses are spaced apart along the lateral lid surface, across the lateral lid surface. Preferably the plurality of recesses extends along the first lateral lid surface, across the first lateral lid surface, where a contact between the cover lid and the housing peripheral wall is important.

[0013] The plurality of recesses allow reducing the cold welding by allowing material migration when the cover lid is press-fitted within the housing.

[0014] The recesses further allow absorbing manufacturing tolerances of the cover lid.

[0015] The recesses may be round, rectangular, triangular or have any other form. The recesses may be regularly spaced apart but may also be spaced apart in a non regular disposition. [0016] By providing at least one groove on the upper plate surface, unwanted cold welding between the housing and the cover lid arising during the assembly process and subsequently in use may be further reduced. The groove further allows reducing the press-fitting forces on the cover lid which are applied during the assembly process. [0017] In one aspect of the invention, the cover lid plate comprises at least three corners. At least one of the corners comprises a profile including at least one of a truncation and a curved profile. The profile allows reducing unwanted cold welding.

[0018] In another aspect of the invention, the cover lid plate has a rounded, oval or curved shape.

[0019] The present invention further proposes a housing for electric or electromagnetic applications comprising: a bottom base, a lateral peripheral housing wall, extending from the bottom base, the lateral housing wall having a peripheral internal edge defining a cover lid reception space, and a cover lid as described above, wherein the cover lid is press fitted into the cover lid reception space.

[0020] By providing a cover lid dimensioned to be larger than the cover lid reception space, sealing of the housing may be ensured. [0021] In an aspect of the present invention, the housing comprises a protection cover resting on top of the lateral housing wall, above the cover lid. In another aspect of the present invention, the protection cover is integrally formed with the cover lid. [0022] The present invention further teaches a method of assembling a housing for electric or electromagnetic applications, the housing comprising a bottom base with a peripheral lateral housing wall defining a cover lid reception space, the method comprising press-fitting a cover lid into the cover lid reception space to close the housing, and monitoring at least one electrical parameter to define a final position of the cover lid into the housing.

[0023] The method of assembly allows optimizing electrical parameters values, when the at least one electrical parameter is tuned with the cover lid position during the cover lid assembly. [0024] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

Brief description of the figures [0025] Fig. 1 shows a coupler having a housing with a cover lid according to an embodiment of the present invention;

[0026] Fig.2 shows a cross section view of the coupler of figure 1 ;

[0027] Fig. 3 is an exploded view of the coupler of figure 1 ;

[0028] Fig. 4 shows a cover lid according to an embodiment of the present invention;

[0029] Fig. 5 is a top view of the cover lid of figure 4

[0030] Fig. 6 is a cross sectional view of the cover lid of figure 4;

[0031] Fig. 7 shows a top view of a cover lid according to an embodiment of the present invention;

[0032] Fig.8 shows an exploded view of a filter having a housing with a cover lid according to an embodiment of the present invention;

[0033] Fig. 9 shows an antenna having a housing with a cover lid according to yet another embodiment of the present invention; [0034] Fig. 10 is a block diagram of a method of assembly of a housing with a cover lid according to one embodiment of the present invention.

Detailed description of the invention

[0035] The invention will now be described on the basis of the drawings. It will be understood that the embodiments and aspects of the invention described herein are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will be understood that features of one aspect or embodiment of the invention can be combined with a feature of a different aspect or aspects and/or embodiments of the invention.

[0036] Fig. 1 shows a coupler 1 having a housing 10 according to an aspect of the present invention. Figure 2 is a cross-sectional view of the coupler 1 and figure 3 shows an exploded view of the coupler 1.

[0037] The housing 10 comprises a bottom base 15 and four lateral housing walls forming a peripheral lateral housing wall 17, which extend substantially perpendicularly upwards from the bottom base IS. The lateral housing wall 17 has a peripheral internal edge 19 which define a cover lid reception space 20 for receiving a cover lid 50.

[0038] The housing 10 is closed by the cover lid 50. The cover lid SO is best seen on figures 4 to 6. [0039] The cover lid 50 comprises a cover lid plate 52 with a bottom plate surface 53 and an upper plate surface 54. The upper plate surface 54 is arranged substantially in a plane which is parallel to the plane of the bottom plate surface 53. A lateral lid surface 55 joins the bottom plate surface 53 and the upper plate surface 54. [0040] The lateral lid surface 55 comprises a first lateral lid surface 56, extending substantially perpendicular to the upper plate surface 54, and a second lateral lid surface 57, extending inwards at a bevelled angle from the first lateral lid surface 56. The lateral lid surface 55 therefore comprises a bevelled portion 58. In other words, the area of the bottom plate surface 53 is smaller than the area of the upper plate surface 54. [0041] The bevelled angle is smaller than 10 degrees.

[0042] In the aspect of the disclosure shown on figures 4 to 6, the bevelled portion 58 extends along the entire lateral periphery of the cover lid plate 52. However, this is not a limiting example and the bevelled portion 58 may extend along part of the lateral periphery, e.g. along two opposite lateral walls, or only along one single lateral wall.

[0043] The bevelled portion 58 may comprise a bevelled edge as in the example of figures 4 to 6. The lateral lid surface 55 with the beveled portion may also comprise a curved profile or a profile such that the area or the external dimensions of the bottom plate surface 53 is smaller than the area or the external dimensions of the upper plate surface 54.

[0044] In the illustrated aspect of the disclosure, the cover lid 50 is in a shape of a rectangular parallelepiped. However, this shape is not limiting the invention, and other forms are conceivable, such as a polygon, a cross, an oval or rounded form.

[0045] At least a part of the first lateral surface 56 lies against the lateral walls 17, thereby closing and sealing the housing 10 when the cover lid 50 covers the housing 10. The second lateral surface 57 does not contact the lateral wall 17. This geometry of the cover lid 50 reduces unwanted cold welding between the housing 10 and the cover lid 50 arising during the assembly process and subsequently in use.

[0046] The first lateral lid surface 56 further comprises a plurality of recesses 66 spaced apart along the bevelled portion 58, on the first lateral lid surface 56. The recesses 66 may be round, rectangular, triangular or have any other form. The recesses 66 may be regularly spaced apart but may also be spaced apart in a non regular disposition. The plurality of recesses 66 further reduces the cold welding by allowing material migration when the cover lid 50 is press-fitted within the housing 10.

[0047] The recesses 66 helps reducing the risk of cold welding between the housing 10 and the cover lid 50 arising during the assembly process and subsequently in use. The recesses 66 further advantageously allows absorbing manufacturing tolerances of the cover lid. [0048] The cover lid plate 52 of this aspect of the disclosure is further designed with four corners 62. At least one of the four corners 62 is truncated. In the aspect shown in figures 4 and S, all of the four corners 62 are truncated. However, this is not a limiting example, and the cover lid plate 52 may have one, two or three truncated corners. The skilled person will understand mat the truncated corners 52 help avoid cold-welding, whilst allow minimizing the forces deployed during the assembly of the cover lid 20 within the housing 10.

[0049] In the aspect shown in figures 4 and 5, the corners are truncated with an angle of about 45°. This is not limiting the present invention. The corners may be truncated with another angle, or the corner may have a shape with a curve.

[0050] The cover lid 50 is pressed in or fitted in the cover lid reception space 20, as will be described with reference to figure 11. The cover lid 50 is slightly larger than the cover lid reception space 20, to ensure a tight closing of the housing whilst helping achieving a regular press fitting during assembly.

[0051] The housing 10 of figures 1 to 3 is a coupler housing, provided with four connectors 80, attached through two opposite sides of the lateral housing wall 17. This is not limiting the invention, and figure 8 gives an example of a filter housing.

[0052] The bottom base 15 of the coupler housing is best seen on Fig. 3. The bottom base 15 is formed by a stack comprising a first substrate 22, a conductor board 24 and a second substrate 26. [0053] The coupler 1 of figures 1 to 3 further comprises a protection cover 60. The protection cover 60 is fastened to the housing 10 by means of screws 61 inserted into screw holes 62 on top of the housing walls 17 (seen on figure 1). This is an example of connection of a protection cover 60 on the housing 10. The protection cover 60 is provided to protect the coupler 1 from its environment.

[0054] Fig. 7 shows another example of cover lid 450, which comprises a cover lid plate 452 with a bottom plate surface 453 and an upper plate surface 454. The upper plate surface 454 is arranged substantially in a plane which is parallel to the plane of the bottom plate surface 453. A lateral lid surface 455 joins the bottom plate surface 453 and the upper plate surface 454. [0055] The lateral lid surface 455 comprises a first lateral lid surface 456, extending substantially perpendicular to the upper plate surface 454, and a second lateral lid surface 457, extending inwards at a bevelled angle from the first lateral lid surface 456. The lateral lid surface 455 therefore comprises a bevelled portion 458. A plurality of recesses 466 are provided on the lateral lid surface 455.

[0056] The cover lid plate 452 of figure 7 differs from the cover lid plate 52 in that the cover lid plate 452 comprises at least one groove 76 on the bottom lid surface 453. The groove 76 is peripheral but this is not limiting the invention.

[0057] The groove 476 helps reducing unwanted cold welding between the housing and the cover lid arising during the assembly process and subsequently in use. The groove 476 further allows reducing the press-fitting forces on the cover lid which are needed during the assembly process.

[0058] Fig.8 shows an exploded view of a filter 201 having a housing 210 closed by a cover lid 250 according to another aspect of the present disclosure.

[0059] The housing 210 comprises a bottom base 215 and a lateral housing peripheral wall 217 extending substantially perpendicular to the bottom base 215. The lateral housing wall 217 with a peripheral internal edge 219 defines a cover lid reception space 220 for receiving the cover lid 250.

[0060] The cover lid 250 comprises a cover lid plate 252 in a shape of a rectangular parallelepiped with a bottom plate surface 253, an upper plate surface 254, mainly parallel to the bottom plate surface 253, and a lateral lid surface 255 joining the bottom plate surfaces 253 and the upper plate surfaces 254.

[0061] The lateral lid surface 255 comprises a first lateral lid surface 256, extending substantially perpendicular to the upper plate surface 254, and a second lateral lid surface 257, extending inwards at a bevelled angle from the first lateral lid surface 256. The lateral lid surface 255 therefore comprises a bevelled portion 258.

[0062] The bevelled angle lies in the range of 0 to 10 degrees. [0063] In the aspect shown on figure 8, the bevelled portion 258 extends along the entire lateral periphery of the cover lid plate 252. However, this is not a limiting example and the bevelled portion 282 may extend along part of the lateral periphery, e.g. along two opposite lateral walls, or only one lateral wall.

[0064] The first lateral lid surface 256 comprises a plurality of recesses 266 regularly spaced apart along the first lateral lid surface 256.

[0065] The cover lid plate 252 has four corners 262. At least one of the corners 262 is truncated. However, this is not a limiting example, and the cover lid plate may have one, two or three truncated corners.

[0066] As can be seen on figure 8, the filter 201 comprises a plurality of coaxial resonators 282. An isolator 284 is provided to prevent electrical contact between the cover lid 210 and the peripheral internal edge 219.

[0067] Fig. 9 shows a side view of an antenna 301 having a housing 310 with a cover lid 350 according to yet another aspect of the disclosure of the present invention. [0068] The housing 310 comprises a bottom base 315 and a lateral peripheral housing wall 317 extending substantially perpendicular to the bottom base 315 and defining with a peripheral internal edge 319 a cover lid reception space 320 for receiving the cover lid 350.

[0069] The cover lid 350 comprises a cover lid plate 352 in a shape of a rectangular parallelepiped with a bottom plate surface 353, an upper plate surface 354, which is formed substantially parallel to the bottom plate surface 353, and a lateral lid surface 355 joining the bottom plate surfaces 353 and the upper plate surfaces 354.

[0070] The lateral lid surface 355 comprises a first lateral lid surface 356, extending substantially perpendicular to the upper plate surface 354, and a second lateral lid surface 357, extending inwards at a bevelled angle from the first lateral lid surface 356. The lateral lid surface 355 therefore comprises a bevelled portion 358. In other words, the area or the external dimensions of the bottom plate surface 353 is smaller than the area or the external dimensions of the upper plate surface 354. [0071] The first lateral lid surface 356 in the aspect shown on figure 9 extends substantially perpendicular to the upper plate surface 354. However, this is not limiting the invention and the first lateral lid surface 356 may also extends at a first angle different from 90° from the upper plate surface 354.

[0072] The bevelled angle lies in the range of 0 to 10 degrees.

[0073] The bevelled portion 358 extends along the entire lateral periphery of the cover lid plate 352. However, this is not a limiting example and the bevelled portion 382 may extend along part of the lateral periphery, e.g. along two opposite lateral walls, or only one lateral wall.

[0074] Also not seen on figure 9, the first lateral lid surface 356 may comprise a plurality of recesses spaced apart along the first lateral lid surface 356. Similarly, the cover lid plate 352 has four corners 362. At least one of the corners 362 may be provided with a truncation or a curved profile.

[0075] As can be seen on figure 9, the bottom base 315 of the housing comprises a plurality of electrical parts 382, located on a circuit board 383 within the housing 310 when the housing 310 is closed by the cover lid 350, press fitted into the housing 310. Radiating elements 384 of the antenna 301 are located on the outside, i.e. on the other side of the bottom base 301. [0076] In the example of figure 9, the circuit board 383 is fixed to the bottom base 315. In other embodiments, the bottom base 315 may be formed integrally with the circuit board 383 or the circuit board 383 may form the bottom base 3115.

[0077] The radiating elements 384 of the antenna 301 of figure 9 form a dipole mounted on a support structure. This is not a limiting example and the radiating elements may have any other configuration, such as a planar radiating element or a plurality of dipoles.

[0078] The bottom base 315 of the housing 310 shown on figure 9 comprises a reflection element for the antenna 301, but this is not a limiting example. [0079] The cover lid 350 in the example of figure 9 serves as an isolation element which, when closing the housing 310, isolates the electrical circuit with the electrical parts 382 from the radiating elements 384. [0080] A closing of the housing 310 is easily achieved by press-fitting the cover lid 350 into the cover lid reception space 320. The fixation and closing of the housing is facilitated with respect to a closing with, e.g., screws.

[0081] Figure 10 shows a method of assembling a housing comprising a bottom base with four lateral housing walls defining a cover lid reception space. The method of assembly is described with reference to the housing 10 and the cover lid 50 of the coupler 1 of figures 1 to 3.

[0082] In a first step SI, the cover lid 50 is press-fitted into the housing 10. The cover lid 50 is press-fitted into the cover lid reception space 20 to close the housing. Preferably, a press- fitting force is applied on the upper plate surface 54 of the cover lid 50, over the entire surface or over some application points located on the upper plate surface 54, such that the cover lid is press fitted in a homogeneous and regular manner, the cover lid being parallel and remaining parallel to the housing's bottom base 10 during the press-fitting.

[0083] During press-fitting, at least one electrical parameter is monitored to define a final position of the cover lid 50. In the example of the coupler 1, the four connectors 80 are connected to an impedance of 50 Ohms. The reflections between the different paths and connectors are measured and monitored to derive the electrical parameters (step S2).

[0084] Electrical parameters which could be monitored include but are not limited to a return loss of the four ports where the connectors are located, a coupling factor, an isolation between ports. [0085] A final position of the cover lid 50 is a position where the electrical parameters correspond to an optimized value of the at least one electrical parameter being monitored, such as a value of isolation. [0086] The method of assembly according to the present invention allows optimizing the coupler's performances, when the at least one electrical parameter is tuned with the cover lid position during the cover lid assembly. [0087] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant arts that various changes in form and detail can be made therein without departing from the scope of the invention.

Claims

Claims A cover lid (50) for a housing (1) for electric or electromagnetic applications, wherein the cover lid comprises a cover lid plate (52) having a bottom plate surface (53), an upper plate surface (54), the upper plate surface being arranged substantially parallel to the bottom plate surface, and a lateral lid surface (55) joining the bottom plate surface and the upper plate surface, wherein the lateral lid surface (55) comprises a bevelled portion (58). The cover lid according to claim 1 , wherein the lateral lid surface (55) comprises a first lateral lid surface (56), extending from the upper plate surface (54) and being substantially perpendicular to the upper plate surface (54), and a second lateral lid surface (57), extending from the first lateral lid surface (56) to the bottom plate surface (53), at a bevelled angle with respect to the first lateral lid surface (56), thereby forrning the bevelled portion (58). The cover lid according to claim 2, where the bevelled angle lies in the range of 3° to 45°, preferably in the range of 5 to 15°. The cover lid according to anyone of claims 1 to 3, wherein the bevelled portion (58) extends along the entire periphery of the cover lid, in particular forming said lateral lid surface (55). The cover lid according to anyone of claims 1 to 4, comprising a plurality of recesses (66) spaced apart along the lateral lid surface (55). The cover lid according to claim 5, wherein the plurality of recesses extends along the first lateral lid surface (56). The cover lid according to anyone of claims 1 to 6, comprising at least one groove on the upper plate surface, the groove being preferably peripheral. The cover lid according to anyone of claims 1 to 7, wherein the cover lid plate (32) comprises at least three corners (62) and wherein at least one of the corners (62) comprises a profile including at least one of a truncation and a curved profile. The cover lid according to anyone of claims 1 to 7, wherein the cover lid plate (52) has a rounded, oval or curved profile. A housing (10) for electric or electromagnetic applications, comprising:

- a bottom base (15),

- a lateral peripheral housing wall (17), extending from the bottom base (15),

- the lateral housing wall (17) having a peripheral internal edge (19) defining a cover lid reception space (20), and

- a cover lid (50) according to any one of claim 1 to 9, wherein the cover lid is press fitted into the cover lid reception space (20). The housing according to claim 10, wherein the cover lid (50) is dimensioned to be larger than the cover lid reception space (20). The housing according to claim 10 or 11, comprising a protection cover (60) resting on top of the lateral housing wall (17), above the cover lid (50). The housing according to claim 12, wherein the protection cover (60) is integrally formed with the cover lid (50). A method of assembling a housing (50) for electric or electromagnetic applications, the housing comprising a bottom base (15) with a peripheral lateral housing wall (17) denning a cover lid reception space (20), the method comprising

press-fitting a cover lid (50) into the cover lid reception space (20) to close the housing, and

monitoring at least one electrical parameter to define a final position of the cover lid (50) into the housing (10). A method of assembling a housing (50) for electric or electromagnetic applications, the housing comprising a bottom base (15) with a peripheral lateral housing wall (17) defining a cover lid reception space (20), the method comprising

press-fitting a cover lid (50) into the cover lid reception space (20) to close the housing, wherein the cover lid comprises a cover lid plate (52) having a bottom plate surface (53), an upper plate surface (54), the upper plate surface being arranged substantially parallel to the bottom plate surface, and a lateral lid surface (SS) joining the bottom plate surface and the upper plate surface, wherein the lateral lid surface (SS) comprises a bevelled portion (58),

wherein the press fitting comprises pressing on the upper plate surface (54),

and

monitoring at least one electrical parameter to define a final position of the cover lid (50) into the housing (10). A method according to claim 15, wherein the housing has a bottom base (10) and wherein the method comprises maintaining the cover lid (SO) mainly parallel to said bottom base (10) during press-fitting,

wherein the lateral lid surface (55) comprises a first lateral lid surface (56), extending from the upper plate surface (54) and being substantially perpendicular to the upper plate surface (54), and a second lateral lid surface (57), extending from the first lateral lid surface (56) to the bottom plate surface (S3), at a bevelled angle with respect to the first lateral lid surface (56), thereby forming the bevelled portion (58).