WO2012045239A1

WO2012045239A1 - Electrical and mechanical connection

Info

Publication number: WO2012045239A1
Application number: PCT/CN2011/073750
Authority: WO
Inventors: Fredrik Ohlsson
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2010-10-08
Filing date: 2011-05-06
Publication date: 2012-04-12

Abstract

A device (3) for providing a mechanical and electrical connection between a radio frequency filter (RF filter) (1), with a radio frequency contact pin (11), and a printed circuit board (PCB) (2) is disclosed, where the contact pin (11) is adapted to be inserted through a pre-made hole (21) in the PCB (2) and where the device (3) is adapted prevent the contact pin (11) from leaving the PCB hole (21), thereby providing the mechanical and electrical connection. The device (3) is made out of a piece of sheet material (31), which has an opening (32) with a number of radial cut-outs (33a,33b,...,33n) forming a number of contact tabs (34a,34b,...,34n). The device (3) is adapted to be forced over the contact pin (11). The diameter (32a) of the opening (32) is smaller than the diameter of the contact pin (11) so that a radial contact force is created as the tabs (34a,34b,...,34n) are pressed back by the pin (11) when the device (3) is made out of an electrically conductible material (36), adapted to provided the electrical connection between the contact pin (11) and the PCB (2). The opening (32) is given a diameter in relation to the diameter of the contact pin (11) that will provide a contact force sufficiently strong to create a sufficient contact force and provide the mechanical connection.

Description

ELECTRICAL AND MECHANICAL CONNECTION

Field of invention

The present invention relates to a device for providing a mechanical and electrical connection between a radio frequency filter (RF filter), with a radio frequency contact pin, and a printed circuit board (PCB), where the contact pin is adapted to be inserted through a pre-made hole in the PCB and where the device is adapted prevent the contact pin from leaving the PCB hole, thereby providing the mechanical and electrical connection.

The present invention also relates to a PCB with a device, a method to manufacture the device and a method to use the device.

Description of background art

In order to provide means to connect a RF filter with a PCB it is known to put a contact pin on the RF filter and a hole on the PCB through which the contact pin is inserted. The contact pin can then be electrically connected and

mechanically secured to the PCB in different ways.

It is known to solder the contact pin to the PCB, in which case it is important to have a good fit between the diameter of the contact pin and the hole in the PCB so that not too much soldering is required to provide the sufficient mechanical connection.

It is also known to have a threaded tap in the RF filter positioned under the hole in the PCB, and to provide the mechanical and electrical connection through a screw which secures the PCB to the filter, which screw would be plated with an electrically conductive material to provide the electrical connection between the RF filter and the PCB.

It is also known to us a machined sleeve, which has been lathed or cut into shape to form the sleeve with the diameter of the inner hole drilled to be somewhat larger than the diameter of the contact pin to allow the pin to pass through the sleeve, where the sleeve is attached to the PCB over the hole by means of soldering or where the sleeve is even threaded and screwed into the PCB, to ensure good electrical contact and strength between the sleeve and the PCB, where the sleeve is cut at the distant opening from the PCB to form elastic tongues and where an inner lip at the end of the tongues and at the distant opening of the sleeve from the PCB provides a mechanical and electrical contact with a contact pin which forced through the hole of the PCB and the sleeve. The solution with the contact sleeve is expensive because of the sleeve design and manufacturing method.

Summary of the present invention

Problems

The main technical problem with known solutions is that because of the manufacturing method, the size and footprint on the PCB is large.

The manufacturing of a sleeve requires advanced machines to reach sufficient tolerances. The handling of mechanical tolerances in the solution with the sleeve is limited to +/- 0,3mm. In some applications larger tolerances must be handled.

Solution

With the purpose of solving one or more of the above indicated problems, and from the standpoint of the above indicated field of invention, the present invention teaches that the device is made out of a piece of sheet material, that the device has an opening with a number of radial cut-outs forming a number of contact tabs, that the device is adapted to be forced over the contact pin, that the diameter of the opening is smaller than the diameter of the contact pin so that a radial contact force is created as the tabs are pressed back by the pin when the device is pressed over the pin, that the inner surface of the tabs is made out of an electrically conductible material, adapted to provide the electrical connection between the contact pin and the PCB, and that the opening is given a diameter in relation to the diameter of the contact pin that will provide a contact force sufficiently strong to create a sufficient contact force and provide the mechanical connection.

With the purpose of providing a smooth contact surface that will not damage the contact pin it is proposed that the tabs have a raised shape so that each tab is flexible in a radial direction, where the inner tab surfaces forms the opening. The material of the device must have spring properties, such as a metal with spring properties. This material can be beryllium copper, spring steel or similar.

In order to provide the electrical contact it is proposed that at least the inner surface of the tabs, or in order to make it easier to manufacture, the hole device, is plated with a low contact resistance plating. This plating could for instance be gold or silver.

The present invention also relates to a printed circuit board (PCB) adapted to be mechanically and electrically connected to a radio frequency filter (RF filter) with a radio frequency contact pin, where the contact pin is adapted to be inserted through a pre-made hole in the PCB and where a device is adapted prevent the contact pin from leaving the PCB hole, thereby providing the mechanical and electrical connection. It is proposed that the PCB is provided with an inventive device where the plating can be soldered, and that the device is soldered to the PCB over the pre-made hole, adapted to receive and connect mechanically and electrically to a contact pin pressed through the pre-made hole and the device.

The present invention also relates to a method of manufacturing a device adapted to mechanically and electrically connect a contact pin belonging to a RF filter to a PCB with a pre-made hole for the contact pin, by cutting, stamping or punching a piece of sheet material, stamping or punching an opening in said sheet material and forming contact tabs around said opening by stamping or punching radial cut-outs from the opening.

According to one proposed embodiment, the opening is given a diameter which is smaller than the diameter of the contact pin so that a radial contact force is created as the tabs are pressed back by the pin when the device is pressed over the pin, the force being sufficiently strong to create a sufficient contact force and provide the mechanical and electrical connection.

Another proposed embodiment teaches that the piece is pressed to raise the tabs into a shape so that each tab is flexible in radial direction, where the inner tab surfaces forms the opening, giving the opening a diameter which is smaller than the diameter of the contact pin so that a radial contact force is created as the tabs are pressed back by the pin when the device is pressed over the pin, the force being sufficiently strong to create a sufficient contact force and provide the mechanical and electrical connection. It is proposed that a sheet material with spring properties is used, such as beryllium copper, spring steel or similar, to provide tabs with elastic properties.

It is also proposed that at least the inner surface of the device is plated with low contact resistance plating, such as gold or silver.

The present invention also relates to a method of establishing a mechanical and electrical connection between a radio frequency filter (RF filter), with a radio frequency contact pin, and a printed circuit board (PCB), where the contact pin is inserted through a pre-made hole in the PCB and where a device is adapted prevent the contact pin from leaving the PCB hole. It is proposed to use an inventive device, and pressing the device over the contact pin, thereby providing the mechanical and electrical connection.

It is also proposed that a mechanical and electrical connection is established between the radio frequency filter (RF filter) and the radio frequency contact pin by inserting the contact pin through a pre-made hole in the RF filter, and pressing an inventive device over the contact pin, thereby providing the mechanical and electrical connection.

Advantages

The advantages of a device according to the present invention are that contact device and contact pin as the interface between RF filters and PCB is a very efficient solution. The arrangement is simple, robust and can handle high power and relatively large mechanical tolerances between the PCB and RF filter. The manual assembly process of the PCB to the RF filter is very simple and safe.

A device according to the invention has a lower building height, less footprint, and can be manufactured to a much lower cost than a known contact sleeve.

The device according to the invention can reduce the cost of a RF interface to 1/3 or less compared to the solution with the sleeve. In a typical transceiver unit 4-6 interfaces of this kind can be present.

The available PCB area can also be increased since the size of the device can be minimized and adjusted to the required power. Different requirements for tolerance handling can also be handled by adjusting the size.

Brief description of the drawings A device, a PCB, a method of manufacturing a device and a method of establishing a mechanical and electrical connection between a RF filter and a PCB according to the present invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 is a simplified side sectional view of the connection of a RF filter to a PCB with an inventive device,

Figure 2 is a view of a first embodiment of an inventive device,

Figure 3 is a side sectional view of a second embodiment of an

inventive device,

Figure 4 is a side sectional view of an inventive PCB, and

Figure 5 is a side sectional view of a contact pin connected to an RF filter by means of an inventive device.

Description of embodiments as presently preferred

The present invention will now be described with reference to figure 1 showing a radio frequency filter (RF filter) 1 , with a radio frequency contact pin 1 1 , and a printed circuit board (PCB) 2 with a pre-made hole 21 . The contact pin 11 is adapted to be inserted through the pre-made hole 21 in the PCB 2.

A device 3 is adapted prevent the contact pin 11 from leaving the PCB hole 21 , thereby providing a mechanical and electrical connection between the RF filter 1 and the PCB 2.

Figure 2 shows an inventive device 3 that is made out of a piece of sheet material 31 and that it has an opening 32 with a number of radial cut-outs 33a, 33b, 33n forming a number of contact tabs 34a, 342, 34n.

The device 3 is adapted to be forced over the contact pin 1 1 from the RF filter 1 and it is proposed that the diameter 32a of the opening 32 is smaller than the diameter 1 1 a of the contact pin 1 1 so that a radial contact force is created as the tabs 34a, 34b, 34n are pressed back by the pin 11 when the device 3 is pressed over the pin 11 .

At least the inner surface 35 of the device 3, that is the surface facing the

PCB 2 and the contact pin 1 1 after that the device 3 has been pressed over the contact pin 1 1 , is made out of an electrically conductible material 36 adapted to provide the electrical connection between the contact pin 1 1 and the PCB 2. The opening 32 is given a diameter 32a in relation to the diameter 1 1 a of the contact pin 1 1 that will provide a contact force sufficiently strong to create a sufficient contact force and provide the mechanical connection.

As the device 3 is pressed over the contact pin 1 1 all the way down to make contact with the PCB 2 the device 3 will provide an electrical connection between the contact pin 11 and the PCB 2.

Figure 3 shows a sectional view of a device 3' illustrating an exemplifying embodiment where smooth contact surface between the device 3' and the contact pin 1 1 is provided by giving tabs 34a', 34x' on the device 3' a raised shape so that each tab 34a', 34x' is flexible in a radial direction, where the inner tab surfaces forms the opening 32' of the device 3, which thus formed opening 32' has a diameter 32a' in relation to the diameter 1 1a of the contact pin 11 that will provide the radial contact force between the tabs 34a', 34x' and the contact pin 11 required to provide the electrical and mechanical contact between the device 3' and the contact pin 1 1.

Regardless of if the tabs have a raised shape or not, it is proposed that the material of the device 3, 3' is metal with spring properties, such as beryllium copper, spring steel or similar.

In order to provide the electrical contact between the device 3, 3' and the contact pin 1 1 , and between the device 3, 3' and the PCB 2, it is proposed that at least the inner surface 35, 35' of the device 3, 3' is plated with low contact resistance plating 36, 36', such as gold or silver.

Figure 4 shows that the present invention also relates to a printed circuit board (PCB) 4 adapted to be mechanically and electrically connected to a radio frequency filter (RF filter) with a radio frequency contact pin, where said contact pin is adapted to be inserted through a pre-made hole 41 in the PCB 4 and where a device 5 is adapted prevent the contact pin from leaving the PCB hole 41 , thereby providing the mechanical and electrical connection.

The present invention teaches that the device 5 is an inventive device 3, 3' as previously described, that the plating 51 of the device can be soldered, and that the device 5 is soldered to the PCB 4 over the pre-made hole 41 .

The inventive PCB 4 is thus adapted to receive and connect mechanically and electrically to a contact pin that is pressed through the pre-made hole 41 and the device 5. The present invention also relates to a method of manufacturing a device adapted to mechanically and electrically connect a contact pin belonging to a RF filter to a PCB with a pre-made hole for the contact pin, which will be described with renewed reference to figure 2.

The method of manufacturing comprises cutting, stamping or punching a piece of sheet material 31 , stamping or punching an opening 32 in the sheet material 31 and forming contact tabs 34a, 34b, 34n around the opening 32 by stamping or punching radial cut-outs 33a, 33b, 33n from the opening 32. It should be understood that depending on used technique for this method several of these steps can be performed at the same time, for instance, if punching, it is possible to punch both the piece of sheet material 31 , the hole 32, and the cutouts 33a, 33b, 33n in one punch.

In this method of manufacturing it is proposed that the opening 32 is given a diameter 32a which is smaller than the diameter 1 1a of the contact pin 1 1 so that a radial contact force is created as the tabs 34a, 34b, 34n are pressed back by the pin 1 1 when the device 3 is pressed over the pin 1 1 , the force being sufficiently strong to create a sufficient contact force and provide the mechanical and electrical connection.

As illustrated in figure 3 it is also proposed that the method of

manufacturing comprises pressing the piece 31 ' to raise the tabs 34a', 34x' into a shape so that each tab is flexible in radial direction, where the inner tab surfaces forms the opening 32', giving the opening 32' a diameter 32a' which is smaller than the diameter 11 a of the contact pin 11 so that a radial contact force is created as the tabs 34a', 34x' are pressed back by the pin 1 1 when the device 3' is pressed over the pin 11 , the force being sufficiently strong to create a sufficient contact force and provide the mechanical and electrical connection.

As an example of the present invention it is proposed that a sheet material with spring properties is used for the manufacturing of the device 3. 3', such material could be beryllium copper, spring steel or similar.

It is proposed to de-burr the device after forming the device through cutting, stamping or punching in order to take away any sharp or harmful edges from the device.

It is also proposed that the method of manufacturing comprises plating the device with low contact resistance plating 36, 36', such as gold or silver. Plating can be done to the sheet material before or after the cutting, stamping or punching of the device.

With renewed reference to figure 1 it is shown that the present invention also relates to a method of establishing a mechanical and electrical connection between a radio frequency filter (RF filter) 1 , with a radio frequency contact pin 1 1 , and a printed circuit board (PCB) 2, where the contact pin 11 is inserted through a pre-made hole 21 in the PCB 2 and where a device 3 is adapted to prevent the contact pin 1 1 from leaving the PCB hole 21 . For this purpose it is proposed to use an inventive device 3, 3' as described above, and to press the device 3, 3' over the contact pin 1 1 , thereby providing the mechanical and electrical connection.

A shown in figure 5 it is also proposed that a mechanical and electrical connection between the radio frequency filter (RF filter) 1 ' and the radio frequency contact pin 1 1 ' can be established by inserting the contact pin 1 1 ' through a pre- made hole 12' in the RF filter 1 ', and pressing an inventive device 3, 3' as described above over the contact pin 11 ', thereby providing the mechanical and electrical connection.

It will be understood that the invention is not restricted to the aforede- scribed and illustrated exemplifying embodiments thereof and that modifications can be made within the scope of the invention as defined by the accompanying Claims.

Claims

1 . Device for providing a mechanical and electrical connection between a radio frequency filter (RF filter), with a radio frequency contact pin, and a printed circuit board (PCB), where said contact pin is adapted to be inserted through a pre-made hole in said PCB and where said device is adapted prevent said contact pin from leaving said PCB hole, thereby providing said mechanical and electrical connection, characterized in, that said device is made out of a piece of sheet material, that said device has an opening with a number of radial cut-outs forming a number of contact tabs, that said device is adapted to be forced over said contact pin, that the diameter of said opening is smaller than the diameter of said contact pin so that a radial contact force is created as said tabs are pressed back by said pin when said device is pressed over said pin, that the inner surface of said device is made out of an electrically conductible material, adapted to provide said electrical connection between said contact pin and said PCB, and that said opening is given a diameter in relation to the diameter of said contact pin that will provide a contact force sufficiently strong to create a sufficient contact force and provide said mechanical connection.

2. Device according to claim 2, characterized in, that said tabs have a raised shape so that each tab is flexible in a radial direction, where the inner tab surfaces forms said opening.

3. Device according to claim 1 or 2, characterized in, that the material of said device is metal with spring properties.

4. Device according to claim 3, characterized in, that the material is beryllium copper, spring steel or similar.

5. Device according to any preceding claim, characterized in, that at least the inner surface of said device is plated with low contact resistance plating.

6. Device according to claim 5, characterized in, that said plating is gold or silver.

7. Printed circuit board (PCB) adapted to be mechanically and electrically connected to a radio frequency filter (RF filter) with a radio frequency contact pin, where said contact pin is adapted to be inserted through a pre-made hole in said PCB and where a device is adapted prevent said contact pin from leaving said PCB hole, thereby providing said mechanical and electrical connection,

characterized in, that said device is a device according to claim 5 or 6, where said plating can be soldered, and that said device is soldered to said PCB over said pre-made hole, adapted to receive and connect mechanically and electrically to a contact pin pressed through said pre-made hole and said device.

8. Method of manufacturing a device adapted to mechanically and electrically connect a contact pin belonging to a RF filter to a PCB with a pre-made hole for said contact pin, characterized in, cutting, stamping or punching a piece of sheet material, stamping or punching an opening in said sheet material and forming contact tabs around said opening by stamping or punching radial cut-outs from said opening.

9. Method according to claim 8, characterized in, giving said opening a diameter which is smaller than the diameter of said contact pin so that a radial contact force is created as said tabs are pressed back by said pin when said device is pressed over said pin, said force being sufficiently strong to create a sufficient contact force and provide said mechanical and electrical connection.

10. Method according to claim 8, characterized in, pressing said piece to raise said tabs into a shape so that each tab is flexible in radial direction, where the inner tab surfaces forms said opening, giving said opening a diameter which is smaller than the diameter of said contact pin so that a radial contact force is created as said tabs are pressed back by said pin when said device is pressed over said pin, said force being sufficiently strong to create a sufficient contact force and provide said mechanical and electrical connection.

1 1 . Method according to any one of claims 8 to 10, characterized in, using a sheet material with spring properties.

12. Method according to claim 1 1 , characterized in, that using beryllium copper, spring steel or similar.

13. Method according to any one of claims 8 to 12, characterized in, plating at least the inner surface of said device with low contact resistance plating.

14. Method according to claim 13, characterized in, using gold or silver for plating.

15. Method of establishing a mechanical and electrical connection between a radio frequency filter (RF filter), with a radio frequency contact pin, and a printed circuit board (PCB), where said contact pin is inserted through a pre-made hole in said PCB and where a device is adapted prevent said contact pin from leaving said PCB hole, characterized in, using a device according to any one of claims 1 to 6, and pressing said device over said contact pin, thereby providing said mechanical and electrical connection.

16. Method according to claim 15, characterized in, establishing a

mechanical and electrical connection between said radio frequency filter (RF filter) and said radio frequency contact pin by inserting said contact pin through a pre- made hole in said RF filter, and pressing a device according to any one of claims 1 to 6 over said contact pin, thereby providing said mechanical and electrical connection.