DE102011119841A1 - Electronic unit for electronic measuring device e.g. fluid flow measurement sensor, has contact pins whose one end is soldered to pad on the printed circuit board in which carrier is provided - Google Patents

Abstract

The electronic unit has flexible printed circuit board (3) and two fixed contact pins (4). One end (5) of the contact pins is soldered to a pad (6) on the printed circuit board. The carrier provided with the flexible printed circuit board is folded to form a three-dimensional object. Other end (7) of the contact pins arranged over the flexible printed circuit board is supported above the carrier made of plastic. A portion of the flexible printed circuit board is electrically connected with a sense element. Independent claims are included for the following: (1) method for manufacturing electronic unit; and (2) electronic measuring device.

Description

The invention relates to an electronic unit, in particular for an electronic measuring device, with a flexible printed circuit board and with at least two rigid contact pins and a method for producing such an electronic unit. In addition, the invention also relates to an electronic measuring device with a housing, with a sensor element, with a measuring device connection and with a flexible printed circuit board and at least two rigid contact pins having electronic unit.

Electronic units are used in particular in electronic measuring devices. The measuring devices may be, for example, fluid sensors, in particular temperature, pressure or flow measuring devices or position sensors, in particular inductive or capacitive proximity switches, without thereby limiting the possible measuring devices within the scope of the present patent application.

As a rule, electronic measuring devices of this type consist of various components or assemblies which are each first preassembled for themselves before the individual components or assemblies are then mechanically and, if necessary, electrically connected to one another during final assembly. In particular, the components or subassemblies are the housing, which may possibly also be designed in several parts, at least one sensor element or a sensor unit, a measuring device connection, for example a plug or connection contacts for a cable connection, and the electronics unit. At least the sensor element and the measuring device connection or the individual contacts of the measuring device connection must be connected by means of soldering in the final assembly electrically to the electronics unit, which generally comprises a printed circuit board. If the electronic measuring device also has an operating unit or a display, these must also be electrically connected to the electronics unit, which requires further soldering operations - often by hand.

Since electronic measuring devices increasingly enable more and more functionalities and thereby have a compact design as possible, making the electrical connection between the individual components or assemblies by soldering is not only expensive but also error-prone. By using flexible circuit boards, which are often referred to as conductor films, instead of rigid printed circuit boards, it is possible to accommodate a populated flexible circuit board with the components soldered thereto by deftly falling even in small-volume housings. While the assembly of such flexible printed circuit boards, in particular by means of SMD technology is almost completely automated, remains the effort described above in the final assembly unchanged. In addition, when using flexible printed circuit boards, the production of the electrical connection of the flexible printed circuit board with other components, for example with a sensor element or a device plug, can not be automated due to the flexibility of the printed circuit board and therefore usually requires manual soldering ,

From the DE 100 09 509 A1 is a manufactured by punching a piece of sheet metal connection element known, with the aid of two circuit boards can be connected together, wherein one end of the connecting element in SMD technology connected to the one circuit board and the other, formed as a contact pin end into a corresponding hole in the other circuit board is pressed. However, on the one hand, the formation of a resilient central portion having connecting element is relatively expensive, on the other hand, the connecting element is provided only for connecting two rigid circuit boards.

The present invention has for its object to provide an electronic unit available that also simplifies the installation of an electronic measuring device with the simplest possible manufacture. In addition, a simple to manufacture measuring device is to be specified, which has a corresponding electronic unit.

This object is first achieved by an electronics unit described in the introduction with a flexible printed circuit board and at least two rigid contact pins, in which, according to claim 1, the first end of the contact pins is soldered to a respective pad on the printed circuit board by means of SMD technology, the flexible printed circuit board or parts the flexible printed circuit board are deformed by folding and / or bending in a three-dimensional body, wherein the body is held in its three-dimensional shape by means of a carrier, and the second end of the contact pins projects beyond the folded or bent flexible printed circuit board.

The electronic unit according to the invention is initially distinguished by the fact that it itself can be made particularly simple, since the assembly of the flexible printed circuit board with the rigid contact pins whose extension direction parallel to the plane of the flexible printed circuit board during assembly, by means of SMD technology and thus fully automated can be done. By the subsequent folding or bending of the flexible printed circuit board to a three-dimensional body in connection with the fixation and stabilization of the body by means of a carrier is from the assembled flexible printed circuit board, which is essentially only in two Directions, a rigid three-dimensional body, which can then be further processed automatically. Be used as contact pins straight pins or pressfits, these are on the one hand very cost-effective, on the other hand, such straight contact pins as normal SMD components with conventional placement machines can be positioned on the flexible circuit board and soldered.

Due to the flexibility of the conductor film not only the shape of the conductor film can be adapted to different requirements, also the orientation and position of the soldered on the conductor film contact pins or the connection surfaces can be optimally adapted to the respective requirements. The contact pins or the pads can be used to realize the electrical interfaces of the flexible circuit board to the measuring device connection, the sensor element to a control unit, to a display or grounding to the housing, without necessarily further soldering operations are required during final assembly.

In order for the second ends of the contact pins to protrude beyond the folded or bent flexible circuit board, the contact pins can be positioned and soldered with their first ends to the circuit board such that the second ends already project beyond the planar circuit board, i. H. survive over an edge of the flexible circuit board. In addition, however, it is also possible that the contact pins are positioned and soldered with their first ends to the circuit board, that the second ends of the circuit board protrude only when the flexible circuit board has been folded or bent accordingly. The second ends of the contact pins are then initially not on the flat, unfolded or curved circuit board over.

The support provided for stabilizing the electronics unit is preferably made of plastic and is itself foldable, so that the flexible printed circuit board fixed to such a support can be reproducibly deformed into a predetermined three-dimensional body via predetermined folds. As an alternative to a one-piece, foldable carrier, the carrier can also consist of several parts, which can be brought into the desired shape, for example, by being plugged together and joined together.

According to an advantageous embodiment of the electronic unit according to the invention, the preferably one-piece, foldable carrier and the flexible printed circuit board fixed thereto are folded or bent such that in the finished state of the electronic unit, the flexible printed circuit board or at least the majority of the flexible printed circuit board is disposed within the carrier. This has the advantage that the carrier not only serves to stabilize the shape of the rigid electronic unit but also to protect the flexible printed circuit board and the electronic components arranged thereon. In this case, the flexible printed circuit board and the electronic components soldered thereon and the solder joints of the contact pins are mechanically protected both during storage and during transport of the electronic unit by the carrier.

According to a preferred embodiment of the electronic unit according to the invention, the second ends of the contact pins serve as parts of a measuring device connection, in particular a standardized measuring device plug, for example a connector according to FIG DIN EN 61076 , For this purpose, the ends of the contact pins protrude over the folded or bent carrier and are preferably designed as pin-shaped, round contact pins. With such an electronic unit as a component of an electronic measuring device, connection of the electronic unit to the measuring device connection, in particular a standardized measuring device plug, by soldering during final assembly is thus no longer necessary; the contact pins of the standardized measuring device plug are formed by the correspondingly arranged and soldered on the flexible printed circuit board with their first ends contact pins. At a trained such meter connector then a corresponding, standard mating connector can be connected. The meter plug can be in particular a standardized M8 or M12 plug.

According to a further preferred embodiment of the electronic unit according to the invention, in which the flexible printed circuit board on two different sides, for example, two opposite sides, each connected to a group of at least two rigid contact pins, the first group of contact pins serves as parts of a measuring device connection during the second group of contact pins for connecting a sensor element is used. The contact pins of the second group, which are used to connect a sensor element, are preferably designed as pressfits, which can be connected to the sensor element or connected to the sensor element rigid circuit board via a plug-in connection solderless electrically conductive.

Depending on the configuration of the sensor element, it may also be connected directly to a section of the flexible printed circuit board via the contact pins in an electrically conductive manner. For this purpose, a portion of the flexible printed circuit board on a corresponding pad on which the sensor element, preferably in the assembly, positioned and soldered by means of SMD technology. The sensor element may be, for example, a coil - with or without shell core - a inductive proximity switch or a temperature measuring resistor (Pt sensor element) of a temperature measuring device. Due to the flexibility of the flexible printed circuit board, the section of the flexible printed circuit board to which the sensor element is soldered can also be folded or bent in such a way that the sensor element is arranged in the desired position within the measuring device.

The above object is achieved in a method for producing an electronic unit with a flexible printed circuit board and with at least two rigid contact pins according to claim 7, characterized in that the first end of the contact pins is soldered to a respective pad on the circuit board by means of SMD technology that the such equipped flexible circuit board is fixed to a support and then the carrier is brought to the flexible circuit board by folding and / or bending in a three-dimensional body, the second ends of the contact pins on the flexible circuit board and project beyond the carrier.

The advantage of the method according to the invention for the production of an electronic unit consists - as already mentioned above in connection with the electronic unit according to the invention - first in that the rigid contact pins can be soldered like normal SMD components on the flexible circuit board, so that the assembly of the flexible circuit board the contact pins in the normal assembly of the flexible circuit board can be done with the SMD components. Due to the flexibility of the flexible circuit board, there are a variety of ways of arranging and aligning the contact pins by suitable folding or bending, with the use of the carrier from the flexible two-dimensional circuit board, a rigid, three-dimensional electronic unit can be produced, which then processed automatically in the final assembly can be.

The object underlying the invention is achieved in an aforementioned electronic measuring device according to claim 9, characterized in that the electronic unit is equipped according to the invention and the second ends of the contact pins are part of the measuring device connection. This eliminates the need for (manual) soldering of the electronics unit to the meter connection during final assembly. The meter connection is realized electrically by the rigid contact pins, so that in this regard no - additional - Lätverbindung with the populated flexible circuit board during final assembly is required.

The contact pins are preferably arranged and designed so that the measuring device connection formed by them a standardized connector, in particular according to DIN EN 61076 represents, which can then be connected to a corresponding, standardized mating connector.

According to an advantageous embodiment of the electronic measuring device, the flexible printed circuit board on two different sides each connected to a group of at least two rigid contact pins, wherein the first group of contact pins is part of the measuring device connection and the second group of contact pins with a rigid connected to the sensor element Printed circuit board solderless electrically conductively connected. In such an electronic measuring device, a solder connection is thus required during the final assembly neither for the electrical connection of the electronic unit to the measuring device connection nor for the electronic connection of the electronic unit to the sensor element. The solderless electrically conductive connection of the electronics unit to the sensor element is preferably carried out in that in the rigid circuit board connected to the sensor element a corresponding number of corresponding to the contact pins metallized holes are formed, in which the second ends of the contact pins are pressed.

In particular, there are a variety of ways to design and further develop the electronic unit according to the invention and the electronic measuring device according to the invention. In this regard, reference is made to the subordinate claims as well as to the following description of preferred embodiments in conjunction with the drawings. In the drawings show

1 A first embodiment of a flexible printed circuit board with a plurality of contact pins,

2 A second embodiment of a flexible printed circuit board with a plurality of contact pins and a sensor element,

3 a support for the flexible circuit board according to 2 .

4 the carrier according to 3 with flexible printed circuit board fixed thereon, in the unfolded state and in the folded state,

5 A first embodiment of an electronic measuring device, in longitudinal section and in perspective,

6 a further embodiment of a carrier with a flexible printed circuit board attached thereto, in the unfolded state and in the folded state,

7 a longitudinal section through a second embodiment of an electronic measuring device,

8th the process connection and the sensor element of the meter according to 7 .

9 one on the process connection according to 8th assembled electronic unit, without and with attached contact carrier,

10 a longitudinal section through a third embodiment of an electronic measuring device,

11 the electronic unit and the process connection with sensor element of the electronic measuring device according to 10 in the unconnected state, and

12 the electronic unit and the process connection with sensor element according to 11 , in assembled state, in longitudinal section.

The figures show various embodiments of an electronic unit 1 as a component of an electronic measuring device 2 , where in 1 from the electronics unit 1 only the flexible circuit board 3 and several on the circuit board 3 Contact pins soldered using SMD technology 4 are shown. The individual contact pins 4 are there with their first end 5 on corresponding connection surfaces 6 on the circuit board 3 soldered that the longitudinal extent of the contact pins 4 parallel to the plane of the flexible circuit board 3 runs and the second ends 7 the contact pins 4 laterally over the flexible circuit board 3 survive. In addition to the embodiment shown here, in which the second ends 7 the contact pins 4 laterally over the flat flexible circuit board 3 can survive the contact pins 4 also be arranged so that their second ends 7 only then via the flexible circuit board 3 survive if folded or bent.

While in the embodiment according to 1 on two opposite sides of the flexible circuit board 3 in each case a plurality of contact pins designed as pressfits 4 are soldered, are in the embodiment according to 2 only on one side of the flexible circuit board 3 contact pins 4 arranged, which are designed as round contact pins. The loading and subsequent soldering of the contact pins 4 takes place in the "normal" SMD process, that is, then, although the other - not shown here - electronic components on the flexible circuit board 3 be positioned and soldered on this. By equipping the contact pins 4 on the flexible circuit board 3 and then contour cutting the circuit board 3 For example, by laser, is any shape of the flexible circuit board 3 produced. By doing that, the second end 7 the contact pins 4 over the side surface of the flexible circuit board 3 protrudes, the contact surface is freely accessible, so that in particular designed as pressfits contact pins 4 according to 1 can be connected to corresponding mating contact elements or pressed into corresponding holes in a second circuit board.

In 3 is a foldable vehicle 9 made of plastic, on which the assembled flexible printed circuit board 3 can be mounted, the carrier 9 two fixing domes 10 for positioning the flexible circuit board 3 has, in the corresponding recesses 11 are introduced.

4 shows an embodiment of an electronic unit 1 consisting of the in 2 shown populated flexible circuit board 3 and in 3 illustrated foldable carrier 9 , where in 4a the electronics unit 1 in the unfolded, ie in a substantially two-dimensional form, while 4b the assembled and folded electronics unit 1 shows, by folding it around a rigid three-dimensional body 8th is. At the in 4 illustrated electronic unit 1 serve the second ends 7 the four round contact pins 4 as parts of a plug 12 and thus as a measuring device connection of the in 5 illustrated electronic measuring device 2 , At the plug 12 of the electronic measuring device 2 this is a standardized plug, in particular an M12 plug, so that this plug 12 a commercial, also standardized mating connector can be connected.

On the contact pins 4 opposite side of the flexible circuit board 3 is a sensor element 13 on a section 14 the flexible circuit board 3 arranged and electrically conductive with the circuit board 3 connected. In the in the 2 to 5 illustrated sensor element 13 it is one in a pot core 15 arranged coil 16 also using SMD technology on the flexible circuit board 3 positioned and soldered to it. At the in 5 illustrated electronic measuring device 2 which is the electronics unit 1 according to 4b contains, it is accordingly an inductive proximity switch. Next to the electronics unit 1 belongs to the meter 2 another case 17 which is the electronics unit 1 so surrounds that only the second ends 7 the contact pins 4 on an end face of the housing 17 protrude from this as plug contacts.

The 6 to 9 and 10 to 12 show two further Ausfürungsbeispiele a measuring device according to the invention 2 or the individual assemblies of the measuring instruments 2 , where it is in the in the 7 and 10 illustrated measuring devices 2 each are pressure gauges. Accordingly, the measuring devices 2 next to the electronic units 1 ( 6 and 11a ) another process connection 18 ( 8th and 11b ) with a pressure measuring cell as a sensor element 13 on.

6 shows an embodiment of an electronic unit 1 in the unfolded state ( 6a ) and in the folded state ( 6b ). The electronics unit 1 consists in turn of one with the contact pins 4 equipped flexible printed circuit board 3 and a foldable carrier 9 made of plastic, the carrier 9 with the flexible circuit board 3 is folded so that after folding most of the flexible circuit board 3 inside the vehicle 9 arranged and thus by the carrier 9 against damage during storage and transport of the electronics unit 1 is protected. A section 14 the flexible circuit board 3 on the contact pins 4 opposite side of the circuit board 3 from the carrier 9 protrudes, serves for electrically conductive connection with the formed as a pressure measuring meter sensor element 13 , These are on the the section 14 the flexible circuit board 3 facing top of the sensor element 13 pads 19 applied, with corresponding pads on the section 14 the flexible circuit board 13 can be soldered.

In the 11a illustrated electronic unit 1 in which the bulk of the flexible circuit board 3 also from the folded carrier 9 is different from the electronics unit 1 according to 6b essentially in that the flexible circuit board 3 on two opposite sides, each with multiple contact pins 4a . 4b connected is. The round contact pins 4a form - in accordance with the embodiment according to 6b - the pins of the plug 12 of the meter 2 , The additionally available on the opposite side formed as pressfits contact pins 4b On the other hand, they serve for the electrically conductive connection with the pressure measuring cell 13 ,

This is the particular in 11b illustrated pressure cell 13 with one on another carrier 20 fixed rigid circuit board 21 electrically conductive, for example by means of bonding, connected. For solderless connection with the second ends 7 the contact pins 4b are in the rigid circuit board 21 formed a corresponding number of corresponding metallized holes into which the second ends 7 the contact pins 4 be pressed in, so that during the final assembly of electronic unit 1 and process connection 18 no soldering for electrical connection of the pressure cell 13 with the flexible circuit board 3 is required. For mechanical connection of the electronics unit 1 with the process connection 18 instructs the wearer 9 four fixing pins 23 on that in corresponding openings 24 of the carrier 20 or the rigid circuit board 21 are pluggable.

Like from the 9 and 12 can be seen, is the final assembly of the electronic measuring device 2 first the prefabricated electronic unit 1 with the process connection 18 electrically and mechanically connected. For this purpose - as previously stated - either the section 14 the flexible circuit board 3 with the pressure measuring cell 13 of the process connection 18 connected ( 9 ) or with the flexible circuit board 3 connected contact pins 4b get into the metallized holes of the pressure cell 13 connected rigid circuit board 21 pressed in ( 12 ). Subsequently, a contact carrier 25 made of plastic on the second ends 7 the contact pins 4a plugged before the cylindrical housing 17 is pushed over the pre-assembled module.

The cylindrical connector housing 26 in the mounted state, the contact carrier 25 surrounds, either together with the housing 17 on the in 9b shown assembly are pushed, or the connector housing 26 is before with the contact carrier 25 preassembled and then together with this on the second ends 7 the contact pins 4 attached and then with the housing 17 connected. For fixing the position of the contact carrier 25 on the second ends 7 the contact pins 4 can still a holding disk 27 ( 7 ) on the second ends 7 the contact pins 4 be deferred. Also in the in the 7 and 10 illustrated pressure gauges 2 is it the plug 12 to a standardized plug, which can be connected to a standard commercial mating connector, which is connected for example with a connection cable.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10009509 A1 [0005]

Cited non-patent literature

• DIN EN 61076 [0013]
• DIN EN 61076 [0019]

Claims (14)

Electronic unit, in particular for an electronic measuring device ( 2 ), with a flexible printed circuit board ( 3 ) and with at least two rigid contact pins ( 4 ), characterized in that the first end ( 5 ) the contact pins ( 4 ) on one pad each ( 6 ) on the printed circuit board ( 3 ) is soldered by means of SMD technology that the flexible printed circuit board ( 3 ) or parts of the flexible printed circuit board ( 3 ) by folding and / or bending in a three-dimensional body ( 8th ) is deformed, that the body ( 8th ) by means of a carrier ( 9 ) is held in its three-dimensional shape, and that the second end ( 7 ) the contact pins ( 4 ) over the folded or bent flexible printed circuit board ( 3 ) survives. Electronics unit according to claim 1, characterized in that the carrier ( 9 ) is made of plastic and is foldable. Electronics unit according to claim 1 or 2, characterized in that the flexible printed circuit board ( 3 ) on the carrier ( 9 ) and at least the majority of the flexible printed circuit board ( 3 ) within the carrier ( 9 ) is arranged. Electronics unit according to one of claims 1 to 3, characterized in that the second ends ( 7 ) the contact pins ( 4 ) the folded or curved support ( 9 ) and as parts of a measuring device connection ( 12 ), in particular a standardized connector which. Electronic unit according to one of claims 1 to 4, wherein the flexible printed circuit board ( 3 ) on two different sides each with a group of at least two rigid contact pins ( 4a . 4b ), characterized in that the first group of contact pins ( 4a ) as parts of a meter connection ( 12 ) and the second group of contact pins ( 4b ) for connecting a sensor element ( 13 ) serves. Electronics unit according to one of claims 1 to 4, characterized in that a section ( 14 ) of the flexible printed circuit board ( 3 ) electrically conductive with a sensor element ( 13 ) connected is. Method for producing an electronic unit, in particular for an electronic measuring device ( 2 ), with a flexible printed circuit board ( 3 ) and with at least two rigid contact pins ( 4 ), characterized in that the first end ( 5 ) the contact pins ( 4 ) on one pad each ( 6 ) on the printed circuit board ( 3 ) is soldered by means of SMD technology that the thus equipped flexible printed circuit board ( 3 ) on a support ( 9 ) and then the carrier ( 9 ) with the flexible printed circuit board ( 3 ) by folding and / or bending in a three-dimensional body ( 8th ), the second ends ( 7 ) the contact pins ( 4 ) via the flexible printed circuit board ( 3 ) and the wearer ( 9 ). Method according to claim 7, characterized in that a sensor element ( 13 ) with a section ( 14 ) of the flexible printed circuit board ( 3 ) is electrically connected. Electronic measuring device with a housing ( 17 ), with a sensor element ( 13 ), with a meter connection ( 12 ) and with a flexible printed circuit board ( 3 ) and at least two rigid contact pins ( 4 ) having electronic unit ( 1 ) according to one of claims 1 to 6, characterized in that the second ends ( 7 ) the contact pins ( 4 ) Part of the meter connection ( 12 ) are. Electronic measuring device according to claim 9, characterized in that a section ( 14 ) of the flexible printed circuit board ( 3 ) electrically conductive with the sensor element ( 13 ) connected is. Electronic measuring device according to claim 9, wherein the flexible printed circuit board ( 3 ) on two different sides each with a group of at least two rigid contact pins ( 4a . 4b ), characterized in that the first group of contact pins ( 4a ) Part of the meter connection ( 12 ) and the second group of contact pins ( 4b ) with the sensor element ( 13 ) or one with the sensor element ( 13 ) connected rigid circuit board ( 21 ) is solderless electrically connected. Electronic measuring device according to claim 11, with one with the sensor element ( 13 ) connected rigid circuit board ( 21 ), characterized in that in the rigid printed circuit board ( 21 ) at least two to the contact pins ( 4b ) are formed corresponding metallized holes into which the second ends ( 7 ) the contact pins ( 4b ) of the second group are pressed. Electronic measuring device according to one of claims 9 to 12, characterized in that the measuring device connection as a plug ( 12 ), in particular as a standardized plug, and the second ends ( 7 ) the contact pins ( 4 ) of a sleeve-shaped connector housing ( 26 ), which are connected to the housing ( 17 ) connected is. Electronic measuring device according to one of claims 9 to 13, characterized in that a section ( 14 ) of the flexible printed circuit board ( 3 ) or more with the flexible printed circuit board ( 3 ) connected rigid contact pins ( 4 ) with a control unit, a Display and / or the housing ( 17 ) are electrically connected.

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