Molded shielding cap for electrical components

The invention relates to a Screening molding for electronic Components according to the preamble of claim 1 and a A method for the production thereof.

To electronic, electrical, magnetic and electromagnetic Components against external fields and radiations, the disturbances can cause to protect, that the components are receiving housing, for example the housing parts a telephone set, in many cases on the inside with a shielding metallic or metal-containing coating provided. This means that relatively large Surfaces to be coated, which is expensive. Furthermore is the shielding effect of such coatings limited, since the housing parts sometimes have larger openings through which interference or interfering fields to electronic can reach components. Above all, it is a disadvantage that the application of the coatings often therefore time-consuming is expensive and because the housing to treat particularly are.

For this reason, it is already known (see. For example WO 95/34423 A1 or EP 0597670 A1), shielding the moldings in the preamble provide the specified claim 1. which consists of a thermoformable plastic molding and consist on the inner wall and / or outer wall completely or partially with an electrically conductive coating are provided. According to Not all of the interior of the respective electrical or electronic device, for example, so the telephone set, shielded; Rather, in the interior of this housing only that group or those groups of components by specially assigned shield moldings ago Interference protected, in need of such screening.

With such shielding, however, moldings, the problem arises, as this mechanically held together in their edge regions and here a reliable electrical connection is created. In the Screening molding described in WO 95/34423 A1 This is accomplished in that which on a film laminate includes a metal layer, sprayed a plastic carrier becomes. The film laminate is on the edge and can with These projecting areas either to a circuit board or to a corresponding projecting portion of a Screening molding-counterpart welded or -gelötet.

Object of the present invention is to provide a Screening molding specified in the preamble of claim 1 type such that there is a reliable mechanical and simultaneously can form good conductive connection with a counterpart.

This object is achieved by the invention defined in claim 1 dissolved.

About the claimed through holes are electrically conductive connections between the two opposite sides of the contact-making and the mounting flange are made.

The latter possibility is in that configuration the invention is implemented, in which the walls of the openings metal in the contacting and mounting flange have coatings via which a metallic coating on one side of the contacting and mounting flange with a coating on the other side of Contacting and mounting flange is connected. Thus, these holes have the primary sense, the metallic Coatings on both sides of the contacting and mounting flange and thus on both sides of the screening molding electrically to bring each other. Are shielding moldings of the invention configured such then they can be made readily in the "multiple use" be without the mutual electrical connection the metallic coatings on opposite sides get lost.

A particularly preferred basic form of screening novel moldings is that in which the Screening molding is composed of two halves, the single piece along a molded hinge are interconnected. The two halves of the screening molding can along the Hinge from an open position to a closed position and transferred vice versa. The feedstock of the present invention Screening molding is done so in this embodiment in the open position of the two halves, which are then for operation of the electrical device to which the fenced Components include, be closed.

Expediently comprise two halves each have a contacting and mounting flange, which in the closed position an electrically conductive connection between at least Making each a coating of two halves. though , the metallic coatings of the two halves also over the two halves of the interconnecting hinge be connected.

In the composite of two halves embodiment the invention, the contacting and mounting flanges of the two halves with each other by an adhesive layer be connected, which is also electrically conductive, if necessary. In general, it is recommended, however, that the contacting and mounting flanges of the two halves together detachably are connected.

In this context, prove now the claim 1 according to the invention existing openings in the contacting and mounting again in handy: It is then namely an embodiment possible in which a the two contacting and mounting flanges with a Plurality of elastically deformable, integral pushbutton-like Surveys and the other of the two contacting and mounting flanges with a corresponding plurality complementary openings is provided through which the pushbutton-like Surveys under elastic deformation feasible are.

The contacting and mounting flanges of the two halves may be present in the closed position immediately adjacent. The inventive Screening molding surrounding in this embodiment a substantially closed group electronic Components, which then possibly by electrical interconnections is connected to other components.

Alternatively, it is also possible that between the two Contacting and mounting flanges of the two halves arranged a printed circuit board carrying the electronic components is. So this board runs between the two Halves of the screening molding therethrough and provides the external connection ago; it also forms the "carrier" for the Screening molding.

If in this case the already mentioned above pushbutton-like Surveys in contacting and mounting flange used a half, so they can push button type Surveys in the closed position (also) through holes be passed in the circuit board. To this Way allows mechanical fixing of the present invention Screening molding on the circuit board.

Generally, it is recommended that the pushbutton-like Surveys carry a metallic coating, over which in the closed position at least one metallic coating one half having at least one metallic coating the other half is electrically connected. The pushbutton-type elevations not provide in this case only the electrical contact between the coatings of the two halves of the screening molding forth; but dense - Provided that the distance of the pushbutton-type elevations not is too large - even the gap between the two halves often sufficiently against the penetration of interference from. It is of course possible, however, here optionally additionally yet resilient, possibly employ conductive gaskets.

Will durckknopfartigen surveys in the described Way to fix the screening molding on a circuit board used, is often the further step advantageous in that the pushbutton-type elevations by Holes in the conductor track on the circuit board passes such are that their metallic coating electrically is connected to the conductor track in combination. The pushbutton-like Surveys get in this way the electrical ground connection the metallic coatings on the two halves of the screening molding that for efficient screening the interference is indispensable.

The metallic coating of the screening molding is done preferably by<sl><li>a) spraying the plastic molding with a metal particle paint containing no masking of one side, whereby, on the one side of the plastic molding on the walls of the openings and the area of ​​the Openings adjacent seam forms a resist layer;</li><li>b) chemogalvanische metallization of the lacquer layer.</li></sl>

The particular advantage of this method of preparation of the coating is that the openings adjacent the hem on the "other side" of the contacting and mounting flange (Ie not directly molded side) "automatically" results without the Screening molding turned and would also be sprayed from the opposite side. The forming hem on the "other side" is sufficient in as required an electrical connection to a produce adjacent component.

Embodiments of the invention are hereinafter illustrated by the drawing; show it<dl tsize="16"><dt>characters 1a u. 1b</dt><dd>a two-part, provided with hinge Screening molding in the closed or in the open position; </dd><dt>figure 2</dt><dd>an enlarged partial section by fastening means, as used in the Screening molding the characters find 1a and 1b use;</dd><dt>figure 3</dt><dd>a section, similar to Figure 2, in the However, the two halves of the screening molding include an electronic circuit board;</dd><dt>figure 4</dt><dd>in perspective, another embodiment a shield;</dd><dt>figure 5</dt><dd>on an enlarged scale a partial section by contacting and mounting flange the shield of Figure 4;</dd><dt>figure 6</dt><dd>is a partial section, similar to Figure 6, by another embodiment of a contact-making and mounting flange.</dd></dl>

In the embodiment shown in Figures 1a and 1b is a Screening molding 211 of two halves 211 ', 211' 'is assembled, the integral over a integrally molded flexible hinge 221 connected to each other to stand.

Each of the two halves 211 ', 211' 'of the screening molding 211 comprises an approximately square-shaped design Plastic molding 212 ', 212' ', to each of which a Contacting and mounting flange 217 ', 217' ' is formed. The two halves 211 ', 211' 'linking flexible hinge 221 is located, as the figure 1b it can be seen at a common border of the two Contacting un d mounting flanges 217 ', 217' '.

The two contacting and mounting flanges 217 ', 217' 'of the two halves 211', 211 '' are complementary attachment means 219, 220 is provided, of which drawn out a pair in figure 2 on a larger scale is.

The fasteners 219 on contacting and mounting flange 217 '' of 1b in FIG right half 211 '' are each as an integrally at these contacting and mounting flange 217 '' molded, elastic knob-like elevations configured while the fasteners 220 at the contacting and mounting flange 217 'of the other half 211' complementary Openings. The pushbuttons 219 can simply the corresponding openings 220 with a certain Power development are pushed through, which then two contacting and mounting flanges 217 ', 217' ' releasably secured to one another are (Figure 1a).

As the figure 2 reveals, is the contacting and mounting flange 217 '' of the right in Figure 1b Half 211 '' both on the inside wall with a metallic Coating 214 '' as well as on the outer wall '' Provided with a metallic coating 216th These Coatings 214 '' and 216 '' are also found in the area the snaps 219th

The contacting and mounting flange 217 'of the in 1b left half 211 ', however, is only on its Inner wall with a metallic coating 214 ' provided, however, that the in the lateral surfaces Openings 220 into stretches.

The illustrated in Figures 1a and 1b Screening molding 211 is used as follows:

The shielded electronic components which in this case, not necessarily on an electronic need to be arranged circuit board, are in the Screening molding 211 in the 1b shown in Figure unfolded state ( "open position") introduced. Then, one half 211 'along the hinge 221 211 '' folded over the other half; pushbuttons 220 on contacting and mounting flange 217 'are' into the corresponding openings 220 of the other half 211 'is pressed, whereby the position shown in Figure 1a Closed position is reached. Between the metallic Coatings 214 'and 214' 'of the contacting and Mounting flanges 217 ', 217' 'on the one hand by direct surface juxtaposition, but in particular also through contact in the field of pushbuttons 219 and the openings 220, an electrical connection is established, so that, overall, the interior of the closed Screening molding 211 entirely covered by a metallization surrounded.

The distance between adjacent fastener pairs 219, 220 to the contacting and mounting flanges 217 ', 217' 'is set to the frequency of the shielded Radiation tuned so that penetration of electromagnetic Radiation in the interior of the screening molding 211 completely prevented.

Figure 3 shows a variant of the screening molding of Figures 1A and 4b, which together with an electronic PCB is used. Corresponding parts in Figure 3, which shows a section similar to Figure 2, are the same reference numerals as in Figure 2 but increased by 100, respectively.

In Figure 3 are recognizable: the contacting and mounting flanges 317 ', 317' 'of the two halves of the Screening molding, a resilient push button as an elastically 319 formed attachment means to the contact- and mounting flange 317 '', a corresponding Opening 320 at the other contacting and mounting flange 317 '', a metallic coating 314 '' on the inner wall of a contact-making and mounting flange 317 '' and a metallic Coating 316 'on the outer wall of the other contacting and mounting flange 317 ', the up extends into the opening 320th

Between the two contacting and mounting flanges 317 '. 317 '' is now also an electronic PCB arranged 301, which shielded the Components (not shown) wears. The PCB 301 is provided with through holes 330, which of the push buttons 319 in the closed position of the screening molding are penetrated, as shown in Figure 6 is shown. In addition, the printed circuit board carries 301 a at ground potential interconnect 302 is also provided with holes 331 through which passed in the closed position in each case a push button 319 is.

made clear from consideration of Figure 3 readily is, in the exemplary embodiment illustrated here, of the screening molding by complementary snaps 319 or openings 320 not only an electrically conductive connection between the metallic coatings 314 '' and 316 'of the two halves produced. Furthermore, the metallic coating contacts 314 '' in the field of pushbuttons 319 also at ground potential lying conductor track 302 and causes this Thus, the required grounding of the actual shielding acquiring metallic coatings 314 '' and 316 '. Through the complementary fastening means 319 and 320 are in this embodiment the two halves of the screening molding not only to each other but also to the electronic circuit board 301 attached. For the distance between adjacent pairs of complementary Fastening means 319, 320 is considered the embodiment of Figure 3 is the same thing for the top Embodiment was told by FIG. 2

Of course, even with the two halves composite embodiment of a screening molding Instead of the releasable attachment means 219, 220 and 319, 320, an electrically conductive, elastic sealing and adhesive are used, the point-like or is strand-like applied intermittently and either on both contacting and mounting flanges or also firmly adheres only one. Here too is the distance between adjacent sealing and adhesive strands the frequency of the radiation to be shielded Spektrumes adapted. It need hardly be pointed, that the just mentioned, not shown in the drawing Sealants, adhesives with the releasable Fastening means of Figures 2 and 3 combined can.

The embodiment illustrated in Figures 4 and 5 a screening molding is provided as one side on a electronic circuit board to be mounted screening configured. It can, however, also as a half a two-part screening molding according to the Figures 1a and 1b understand. Corresponding parts in figures 4 and 5 are again the same reference numerals as in Figure 1, however, plus 200, in. The embodiment of Figures 4 and 5 differs from the embodiments described above in two respects:

First, in this embodiment again cuboid-shaped plastics molding 412 on its top side provided with a plurality of apertures 440th About these can accommodated inside the shield 411 electronic components after the fact using a screwdriver or an appropriate tool be manipulated without the shield would have to be removed 411 from the circuit board. The Breakthroughs 440 are also used to perform electrical Interconnectors or plug contacts (not shown) and allow air circulation.

The second difference relates to the type of metallic Coating 416 in the embodiment of FIGS 4 and 5 is applied over the entire outer wall, and the process for their application. The conditions with particular reference to Figure 5 clearly that in enlarged scale a partial section through an area the contacting and mounting flange 417 of the Shield 411 of Figure 4 illustrates.

The whole contacting and mounting flange 417 is traversed by a series of elongated apertures 450, whose meaning will become clear below. The previously mentioned metallic coating 416 is the embodiment of Figures 4 and 5 are not directly on the plastic material the plastic molded body 412, but closed on a, Metal pigments containing lacquer layer 451st The application of the metallic coating 416 happens in this case as follows:

The entire outer surface of the plastic molding 412 is first, for example in Figure 4 from above, with the Paint splashed 451. This permeates through the series of elongated openings 450 to the other side of the contacting and the mounting flange 417 and is reflected in a Lacksaum 451a on the opposite side the contacting and mounting flange 417 down. The walls of the openings 450 are thereby a Resist layer is. The vast area of ​​the inner wall the plastic molding 412, however, remains free of lacquer. is in the subsequent chemotherapeutic galvanic metallization then the actual metallic coating 416 applied, everywhere there and only there is deposited, where previously a layer of lacquer was applied 451. This means that the metallic coating 416, the entire Outer wall 415 of plastic molding 412, the walls the openings 450 and a seam 416 along the openings 450 covered. On the outer wall 415 of the plastic molding 412 lying metallic coating 416 is So with the hem 416a on the lateral surfaces of the openings 450 in electrically conductive connection. this has the advantage that the screening caps 411 in multiple benefits can be prepared: The electrically conductive Connection on the lateral surfaces of the openings 450 remains in the severing into individual screening caps 411 received.

In Figure 6, finally, is the contacting and mounting flange 517 a screening or half a Screening molding shown that the left in 4b shown half 211 'of the screening molding 211 closely related. Corresponding parts of Figure 6 are with the same reference numerals as in Figure 1, however, plus 300, in.

In Figure 6 are recognizable: the contacting and Mounting flange 517 of the plastic molding 512, a as fastening means serving hole 520, one on the outer wall 515 applied metal coating 516, which extends through the bore 520 and the right of the hole 520 on the inner wall 513 of the Contacting and mounting flange 517 a seam forms.

New in Figure 6 is a closed circulating, not metal-elastic strand 560 of sealing material. This strand is in turn provided with a metallic Coating 561 is provided, which via the bores 520 Away with the metallic coating 516 in conjunction stands. The high frequency leak in the gap between the Contacting and mounting flange 517 and the component, at which this contacting and mounting flange is secured 517 (eg, an electronic circuit board or to a second half of the corresponding screening molding) Thus, in this embodiment, by the metallic coating 561 on the sealing strand 560 causes. Of course, this is itself electrically nonconductive sealing strand 560 with subsequent a metallic coating 561 with other Mounting types of screening molding (without pushbuttons and complementary holes) can be used, for example, at a bonding.