SE510980C2 - Device for mounting a capsule on a mounting base and method for manufacturing such a device - Google Patents

Abstract

The invention relates to an apparatus for achieving good contact between earth legs (11b, 11d) of a microwave circuit (1) against a corresponding earth connection on a circuit board (3). Earth connection areas (15a, 15b) are shaped directly from a carrier (5) of the circuit board (3), said carrier (5) being manufactured of an electrically conducting material, such as brass or copper, at the location on the circuit board (3) where the microwave circuit (1) is mounted, so that the earth connection areas (15a, 15b) protrude up above the top side (13) of the carrier. The microwave circuit (1) is mounted against the circuit board (3) at the intended location by connecting its legs (11a, 11b, 11c, 11d) to the intended connection area on the circuit board (3), the earth legs (11b, 11d) of the microwave circuit being connected against the shaped earth connection areas (15a, 15b). A method for manufacturing the above apparatus is described.

Description

15 20 25 510 980 called microwave capsules, which operate at high frequencies, for example microwave transistors.

A known method for creating good contact to a ground connection is to manually mount a holder through a through-hole in a mounting base, the holder being fastened to the underside of the mounting base with a nut. The holder is then grounded against the carrier which is made of brass. The opposite part of the holder, which protrudes a bit from the top of the mounting base, consists of a ground connection. The microwave capsule is mounted with its corresponding legs against the holder's earth connection.

A disadvantage of the method above is that it is expensive to apply and that the method is done manually. Another disadvantage is that the contact between the legs of the microwave capsule and the earth connection is not always good.

One. other known. method is to start from a brass carrier, whereby a projecting mounting surface for the microwave capsule is milled from the carrier. A layer of PTFE (PolyTetraFluoroEthylene) is laminated to the carrier around the mounting surface and the microwave capsule is mounted with its corresponding legs against the mounting surface, or the so-called earth connection surface.

A disadvantage of this method is that it is cumbersome to apply and involves many work steps. Another disadvantage is that it is not possible to use a mounting base which comprises a pre-laminated PTFE layer on the carrier because the mounting surface must be milled out of the carrier before the PTFE layer is laminated solid. FIELD OF THE INVENTION The present invention relates to a problem of obtaining a good contact between a leg, intended to be connected to a ground connection, of a microwave circuit against a corresponding ground connection on a mounting base.

Another problem is to mount a microwave circuit capsule on a mounting base with a simple and reliable method so that the above-mentioned good contact is obtained.

An object of the present invention is thus to create with a simple and reliable device a good contact between a leg of a microwave circuit capsule, also called microwave capsule, against the corresponding earth connection on the mounting base.

A further object is to provide a method of manufacturing the device as above.

To achieve this, the present invention utilizes the design of surfaces from the bottom layer of the mounting base, the so-called carrier which is made of an electrically conductive material.

A device according to the invention comprises a microwave capsule mounted on said mounting base. The mounting base comprises a carrier made of an electrically conductive material such as brass or copper, an intermediate layer being fixed to the top of the carrier. A circuit recess is provided through the intermediate layer, the bottom of the circuit recess being part of the upper side of the carrier. Ground connection surfaces are formed from the carrier and project up through the circuit outlet. The microwave capsule is located above the circuit recess and each of the legs of the microwave capsule which is to be connected to a ground connection on the mounting base is connected to a correspondingly designed ground connection surface.

In more detail, the procedure involves milling a circuit outlet out of the mounting base at the location where the microwave capsule is to be placed. The bottom of the circuit recess consists of a part of the upper side of the carrier. Ground connection surfaces are designed from the carrier so that they protrude through the circuit outlet. Then mount the microwave capsule on the mounting base by connecting each of the microwave capsule legs to the corresponding connection surface on the mounting base. The legs that are to be connected to a ground connection on the mounting base are then connected to a correspondingly designed ground connection surface.

An advantage of the present invention is that it always provides a good contact between the legs of the microwave capsule and the ground connection surfaces because the ground connection surfaces are made of the same material as the carrier and because they protrude from the carrier.

Another advantage is that the manufacturing method is easy to apply and also inexpensive, since the invention enables automatic mounting of the microwave capsule on the mounting base while maintaining good contact between the legs of the microwave capsule and the ground connection surfaces and since no additional components such as holders need be used. In addition, no solder connections are required between the ground connection surfaces and the carrier. Another advantage is that the invention enables the use of a mounting base made with a pre-laminated PTFE layer on the brass carrier. The invention will now be described in more detail by means of preferred embodiments and with reference to the accompanying drawings.

DESCRIPTION OF THE FIGURES Figure 1 shows a schematic view from above of a microwave capsule according to the prior art, Figure 2 shows a schematic view from above of a microwave capsule mounted on a printed circuit board according to the invention, Figure 3 shows in a cross section the microwave capsule mounted on the printed circuit board according to the invention. of the printed circuit board according to the method of the invention, Figure 5 shows a cross section of the non-life board comprising a circuit socket according to the method of the invention, and Figure 6 shows a cross section of the printed circuit board with designed earth connection surfaces according to the method of the invention.

PREFERRED EMBODIMENTS Figure 1 shows an example of a hopper circuit capsule 1, also called a hopper capsule, according to the prior art comprising a bottom side, two pairs of mutually opposite legs 11a, 11c and 11b, 11d, respectively, being fixed to the underside of the microwave capsule, as shown.

When the microwave capsule 1 is mounted on a mounting base, each of these legs 11a, 11b, 11c, 11d is connected to a corresponding connection surface on the mounting base. 10 15 20 25 510 980 The connection surfaces on the mounting base can consist of earth connection surfaces or they can consist of so-called strip cables, which are framed from a pattern layer and which connect circuits to each other on the mounting base.

According to the example in Figure 1, a pair of legs of the microwave capsule 1 constitutes two signal legs 11a, 11c which are to be connected to belt lines on the mounting base, the signal legs 11a, 11c acting as the connecting link of the microwave capsule 1 to other circuits on the mounting base.

The second pair of legs of the microwave capsule 1 constitutes two ground legs 11b, 11d which are to be connected to ground connection surfaces on the mounting base.

All pairs of legs 11a, 11c and 11b, respectively, are placed symmetrically around the center of the microwave capsule, as shown in the figure.

The number of legs lla, llb, llc, lld is not limited to four but can be more or fewer. Likewise, the legs lla, llb, llc, lld need not be symmetrically placed around the center of the microwave capsule.

The microwave capsule 1 consists, for example, of microwave transistors.

The mounting base can consist of a printed circuit board on which circuits can be mounted.

Below will be an exemplary embodiment of the device according to the invention. is described in which, in connection with Figure 2-3, the microwave capsule 1 is to be mounted on the printed circuit board 3 so that the microwave capsule 1 has good contact with the corresponding earth connection surface on the printed circuit board 3. Figure 2 shows a top view of the microwave capsule 1 mounted on the printed circuit board 3.

The printed circuit board 3 comprises a carrier 5, an intermediate layer 7 and a pattern layer which are illustrated more clearly below in Figure 3.

The intermediate layer 7 is fixed to the carrier 5 and plated with the pattern layer.

The pattern layer comprises two pieces of pre-etched strip lines 9a, 9b, as shown in Figure 2, which strip lines 9a, 9b do not have contact with a circuit recess 17 described below.

The microwave capsule 1 is placed over a circuit recess 17 with its two signal legs 11a, 11c connected to the strip lines 9a and 9b, respectively, and with each of its two ground legs 11b, 11d connected to correspondingly designed ground connection surfaces in the form of two elevations 15a, 15b, as shown in figure 2. The circuit recess 17 and the earth connection surfaces will be described in more detail below in connection with figure 3.

Figure 2 shows an example of the location of the strip lines 9a, 9b on the printed circuit board 3. The number of strip lines 9a, 9b is not limited to the number shown in the figure.

Figure 3 shows a section A-A of figure 2 through the microwave capsule 1 and the printed circuit board 3 according to the invention.

The lowest layer in the printed circuit board 3, see figure 3, consists of the carrier 5, which carrier 5 is made of a suitable conductive material, for example brass or copper. According to the invention, the carrier 5 comprises on a top side 13 two ground connection surfaces 15a, 15b formed from the carrier 5, which project from the top side 13 of the carrier. 15b are these ground connection surfaces 15a, placed directly below the ground legs 11b, 11d of the microwave capsule. In the example according to Figure 3 and as can be seen in more detail in Figure 2, the earth connection surfaces 15a, 15b are circularly formed from the carrier 5 so that they have a diameter d. The earth connection surfaces 15a, 15b are not limited to be circular but they can also be designed in another way. The number of ground connection surfaces l5a, 15b is equal to the number of ground legs llb, lld of the corresponding microwave capsule 1.

The intermediate layer 7 is fixed to the upper side 13 of the carrier and according to the invention preferably consists of a layer of a PTFE material (PolyTetraFluoroEthylene), but other materials similar to the PTFE material can also be used.

The intermediate layer 7 is as described above plated on a top side 19 with. the pattern layer (not shown in Figure 3), the pattern layer being made of an electrically conductive material, for example copper.

A circuit recess 17 is according to the invention arranged through the intermediate layer 7 and the pattern layer, the bottom of the circuit recess being constituted by "the part of" the upper side 13 of the carrier which comprises the two earth connection surfaces 15a, 15b formed as described above.

As described above, the earth connection surfaces 1a, 15b project through the circuit recess 17, and the earth connection surfaces 15a, 15b project so that they are substantially level with the upper side of the pattern layer.

The circuit recess 17 can be designed in several different ways, for example circular, rectangular, etc. An example is shown above in figure 2, wherein the circuit recess 17 is rectangular. The length l of the circuit recess 17 is greater than the sum of the distance a between the earth connection surfaces l5a, 15b and twice the diameter d of the earth connection surfaces l0 15 20 25 51Û 980. The width 19 of the circuit recess 17 is larger than the diameter d of the earth connection surfaces.

Various methods can be used to form the ground connection 15a, 15b from the surfaces of the carrier 5, for example embossing or shearing. It is required that the circuit recess 17 is large enough to make room for the embossing or shearing tool.

The earth legs 11b, 11d of the microwave capsule are, as described above, arranged directly against the earth connection surfaces 15a, 15b formed from the carrier 5.

Since the earth connection surfaces 15a, 15b are made of the same material as the carrier 5 and since they protrude from the carrier É, the invention provides a very good contact between microwave and the corresponding earth legs 11b, the earth connection surface 15a, 15b.

The following examples describe a method according to the invention for mounting the microwave capsule 1, comprising the two signal legs 11a, 11c and the two ground legs 11b, 11d, on the printed circuit board 3 so that the microwave capsule 1 has good contact with the corresponding ground connection surface on the printed circuit board 3, as above described examples. The method is described in connection with Figures 2 and 3 described above and Figures 4-6.

A cross section of the printed circuit board 3 is shown in Figure 4, the printed circuit board 3 comprising a carrier 5, an intermediate layer 7 and a printed circuit layer 8.

The carrier 5 is as described above made of a suitable electrically conductive material, for example brass or copper.

According to the invention, the intermediate layer 7 consists of a PTFE material, but other materials can also be used. The intermediate layer 7 is fixed to an upper side 13 of the carrier 5 and plated with the pattern layer 8.

The method is based on the printed circuit board 3 described in Figure 4.

Belt lines 9a, 9b are etched out of the pattern layer 8, as described in the previous example.

The next step in the manufacturing process is to mill out a circuit recess 17 through the intermediate layer 7 and the pattern layer 8, as shown in Figure S, the bottom 'of the circuit recess being formed by a part of the upper side 13 of the carrier.

Thereafter, two ground connection surfaces 15a, 15b are formed from the part of the carrier 5 which forms the bottom of the circuit recess 17, so that the ground connection surfaces 15a, 15b project through the circuit recess 17 so that they are substantially level with the top of the pattern layer 8 (not shown in Figure 5). . See also figure 6. These earth connection surfaces 15a, 15b can be circularly shaped so that they have a diameter d as shown in the figure. The distance a between the earth connection surfaces 15a, 15b is also marked in the figure.

The above-milled circuit recess 17 can be, for example, circular or rectangular. In connection with Figure 2, an example of the dimensions of the circuit recess 17 has been described above, but the circuit recess 17 can also be dimensioned in other ways.

Various methods can be used to design the ground connection surfaces 15a, 15b from the carrier 5, for example embossing or shearing. It is required that the circuit recess 17 is large enough to make room for the embossing or shearing tool.

The plated details on the printed circuit board 3 and. the top of the earth connection surfaces 15a, 15b can be surface treated with a suitable material, for example tin, lead or gold, to protect the details against corrosion and to create solderable surfaces.

Finally, the microwave capsule 1 is placed over the circuit recess 17, the two signal legs 11a, 11c of the microwave capsule being connected to the strip lines 9a, 9b and each of the two earth legs 11b, 11d of the microwave capsule being connected to correspondingly designed ground connection surfaces in the form of two elevations. A cross section of the printed circuit board 3 together with the microwave capsule 1 mounted on the printed circuit board 3 is shown in figure 3.

In this way, the ground legs 11b, 11d of the microwave capsule are arranged directly against the ground connection surfaces 15a, 15b formed from the carrier 5.

The signal legs lla, llc and ground legs llb, lld of the microwave capsule are connected to the desired connection surfaces, for example by soldering.

According to a modified method of the invention, the carrier 5 and the intermediate layer 7 according to the examples described above can be manufactured separately.

In this case, a carrier 5, as described above, made manufactured is used. in a suitable electrically conductive material, for example netting or 'copper intermediate layer 7' is plated with the pattern layer 8 and consists, for example, of a PTFE material.

The method begins by forming two ground connection surfaces 15a, 15b from the part of the carrier 5 over which the microwave capsule 1 is to be placed on the non-return card 3, so that the ground connection surfaces 15a, 15b project over the upper side 13 of the carrier, see figure 6 where in this case the intermediate layer 7 is not yet applied. Various methods can be used to form the ground connection surfaces 15a, 15b from the carrier 5, for example embossing or shearing, as described above.

The next step in the manufacturing process is to separately mill out a continuous circuit recess 17 through the plated intermediate layer 7.

The above-cut-out circuit recess 17 may, for example, be designed as described above in connection with Figure 2, but other alternatives are also possible.

Thereafter, the plated intermediate layer 7 is fixed to the upper side 13 of the carrier so that the earth connection surfaces 15a, 15b project through the circuit recess 17.

The earth connection surfaces l5a, l5b are then substantially level with the upper side of the pattern layer 8. The fixation can be done by, for example, lamination. See Figure 6.

Belt lines 9a, 9b are etched out of the pattern layer 8, as described in the previous example.

Finally, the microwave capsule 1 is placed over the circuit recess 17, in the same way as described above, the two signal legs 11a, 11c of the microwave capsule being connected to the corresponding strip lines 9a, 9b and each of the two microwave legs 11b, 11d of the microwave capsule being connected to correspondingly formed ground connection surfaces. l5a, l5b. A cross section of the printed circuit board 3 together with the microwave capsule 1 mounted on the printed circuit board 3 is shown in figure 3.

Claims (18)

10 15 20 25 5 510 980 PATENT CLAIMS Device for mounting a capsule (1) (3), on a mounting base which comprises a carrier (5) of an electrically conductive material coated with an intermediate layer (7), the capsule (1) comprising at least one leg ( llb) intended to be connected to (3), a ground connection on the mounting base characterized by a) that a connection area (17) on the carrier (5) is not coated with the intermediate layer (7); b) that said earth connection consists of at least one earth connection surface (15a) on said carrier (5); and c) that said. ground connection surface (15a) is formed directly from the carrier (5) in the connection area (17) and forms part of the carrier (5), (13), the ground connection surface (15a) projecting from a top side of the carrier (5). Device according to claim 1, characterized in that the intermediate layer (7) is plated with a pattern layer, and that said earth connection surface (15a) protrudes from the upper side (13) of the carrier so that the earth connection surface (15a) is substantially equal to the level of the pattern layer. top. Device according to claim 1, characterized in that the earth connection surface (15a) is constituted by the upper surface of a part projecting from the mounting base (3). Device according to claim 3, characterized in that said part consists of an elevation with a circular cross-section. Device according to claim 3, characterized in that said part consists of an elevation with a rectangular cross-section. lO 15 20 25 510 980 M Device according to claim 1, characterized in that said capsule (1) has at least one pair of legs (11b, 11d) intended to be connected to the corresponding pair of ground connection surfaces (15a, 15b), and that each of these legs (11b) , lld) is connected to the corresponding earth connection surface (l5a, l5b). Device according to one of Claims 1 to 6, characterized in that each of the legs of the canister (11b, 11d), intended to be connected to a ground connection on the mounting base (3), is soldered to the corresponding ground connection surface. (l5a, l5b). A method of manufacturing a device according to claim 1 or 6, wherein the intermediate layer (7) is (8), plated with a pattern layer characterized by a) that the connection area (17) is milled out of said pattern layer (8) and intermediate layer ( 7) (5); corresponding to the location of the device on the carrier b) that earth connection surfaces (15a, 15b) are formed directly from the carrier (5) in the connection area (17), in such a way that these protrude from a top side (13) of the carrier (5), whereby, earth connection - the surfaces (l5a, l5b) form part of the carrier (5); and c) that the capsule (1) is mounted against the device. Method according to claim 8, characterized in that said design of the earth connection surfaces (15a, 15b) so that they protrude from the upper side (13) of the carrier takes place so that the earth connection surfaces (15a, 15b) are substantially level with the pattern layer ( 8) top. 10 l5 20 25 / š 10. A method according to claim 8 or 9, 510 980, characterized in that said design of the earth connection surfaces (15a, 15b) from the carrier (5) takes place by shearing or embossing. A method according to claim 8, characterized in that said mounting of the capsule (1) to the device comprises the step of connecting each of the legs of the capsule (11b, 11d). intended to be connected to a ground connection on the mounting base (3), to a corresponding ground connection surface (l5a, 15b). Method according to claim 11, characterized in that said connection of each of the legs of the capsule (11b, 11d), intended to be connected to a ground connection on the mounting base (3), to the corresponding ground connection surface (15a, 15b) takes place by soldering. A method of manufacturing a device according to claim 1 or 6, wherein the intermediate layer (7) is plated with a pattern layer characterized by (8), a) that the connection area (17) is milled out of said pattern layer (8) and intermediate layer (7) (5): corresponding to the location of the device on the carrier b) that earth connection surfaces (15a, 15b) are formed separately directly from the carrier (5) in the connection area (17) in such a way that they protrude from a top side (13) of the carrier (5), the earth connection surfaces (15a, 15b) forming part of the carrier (5): c) that the intermediate layer (7) is fixed to the upper side (13) of the carrier; and d) that the capsule (1) is mounted against the device. 10 15 20 510 980 ^ / Ö A method according to claim 13, characterized in that said design of the ground connection surfaces (15a, 15b) so that they project the upper side (13) of the carrier takes place so that out of the ground connection surfaces (15a, 15b) is substantially level with the pattern. top of the layer (8). Method according to claim 13 or 14, characterized in that said design of the earth connection surfaces (15a, 15b) from the carrier (5) takes place by shearing or embossing. Method according to claim 13, characterized in that said fixing of the intermediate layer (7) against the upper side (13) of the carrier takes place by lamination. Method according to claim 13, characterized in that said mounting of the capsule (1) to the device comprises the step of connecting each of the legs of the capsule (11b, 11d), intended to be connected to a ground connection on the mounting base (3) , against a corresponding earth connection surface (15a, 15b). Method according to claim 17, characterized in that said connection of each of the legs of the capsule (11b, 11d), intended to be connected to a ground connection on the mounting base (3), to the corresponding ground connection surface (15a, 15b) takes place by soldering.