DE102007011293A1 - Electronic module, has movement-sensitive sensors on circuit support, where circuit support has two sections which are formed by cutting it and sections are mechanically decoupled - Google Patents

Abstract

The electronic module has movement-sensitive sensors (SK1,SK2,SK3) on a circuit support (1). The circuit support has two sections (1.1,1.2) which are formed by cutting it and the sections are mechanically decoupled. The sections are connected with one another by an electrical connection with a flexible cable. The sections are fastened independently in the module with different rigidity, elasticity and absorbability. Electronic elements are arranged on the sections. An independent claim is also included for a method for manufacturing electronic module with sensors on a carrier support.

Description

The The invention relates to an electronic assembly with at least one motion-sensitive sensor according to the preamble of claim 1.

A Such electronic assembly comes for example in vehicles as control devices for occupant protection equipment for use. The module has motion-sensitive sensors, For example, acceleration and / or rotation rate sensors. The for The acting movement sensitive sensor generates one of the Movement corresponding useful signal.

such Sensors need often attached particularly rigidly in the assembly and on this to a support. for example. the vehicle should be tethered to the desired payload spectrum correctly to be able to receive. Such a connection can, however, for the other electronic components rather disturbing be.

moreover there are sensors that are disturbed by movements, at least in certain frequency spectra, where so the useful signal is disturbed by the movement.

The Object of the present invention is therefore an electronic Assembly with a suitable structure and a corresponding method to indicate its production. This task is characterized by the features the independent one claims solved. Advantageous developments of the invention will become apparent from the Dependent claims, including combinations and developments of individual features are possible with each other.

One essential idea of the invention is that the circuit carrier at least two parts consisting of a common circuit board by Cutting the circuit carrier are mechanically decoupled, the sections over each other electrically are connected and the cuts each independently are mounted in the assembly.

Thereby will it be possible the cuts with mutually different stiffness, elasticity and / or damping to be mounted in the assembly.

So can in a particularly preferred embodiment for the acting Movement sensitive sensor can be placed on those section which is rigidly connected to the assembly and the other part attenuated contrast and / or resiliently mounted in the assembly and electronic on this portion Components are arranged.

One by the acting movement interfering sensor is against it arranged on that section, which is muted and / or elastically mounted in the assembly and another portion in contrast rigid is arranged in the assembly.

The Assembly, we preferably made from a common circuit board by the circuit carrier first in one piece with equipped with the / the sensors and other electronic components and below the sections cut and fastened differently in the assembly and be electrically connected to each other. Preferably is the unpopulated circuit support already locally limited and separated only by holding webs interconnected and will after loading the retaining bars severed.

The Electrical connection is preferably via flexible cable, eg. but can also over electrical connection elements in the housing, for example. Corresponding pin contacts respectively.

The Invention will now be described in part with reference to embodiments with the help of the figures closer explained. In the following you can for functional like elements may be designated by the same reference numerals. Show it

1 : First embodiment of a circuit carrier with two decoupled sections

2 : Second embodiment of a circuit carrier with two decoupled sections

3 : third embodiment of a circuit carrier with two decoupled sections

4 : Design of a circuit carrier with two decoupled sections with motion-sensitive sensors on both sections

5 : Design of retaining webs for the attachment of portions of the circuit substrate in the assembly

6 : Retaining webs and damping elements in the assembly

7 : Holding bridge as a component holder

1 shows an electronic module with a circuit carrier 1 consisting of a first section ( 1.1 ) and a second section ( 1.2 ), the cuts ( 1.1 . 1.2 ) generated from a common circuit carrier and in the finished Condition by severing the circuit carrier ( 1 ) are mechanically decoupled.

In particular, the circuit carrier is first in one piece ( 1 ) equipped with the / the sensors and other electronic components (Sk1 ...) and subsequently the sections ( 1.1 . 1.2 ) cut free. In this case, the bare circuit carrier is already preferably pre-cut locally limited, such as the free cutting 1.4 show and only by remaining holding webs 1.5 interconnected. After loading, the retaining bars ( 1.5 ) and so the cuts ( 1.1 . 1.2 ) mechanically decoupled.

The cuts ( 1.1 . 1.2 ) are each independently mounted in the assembly, preferably with mutually different stiffness, elasticity and / or damping. While the section 1.1 conventionally attached as a circuit board in the housing of the assembly are for the section 1.2 separate fastening means provided to the at least one motion-sensitive sensor Sk1, ... and the corresponding section 1.2 To attach particularly rigid in the assembly and thus to allow a good transmission of the movement forces.

For the electrical function further components are required, which in this embodiment on the section 1.2 are arranged, wherein the sections via a flexible electrical connection 2 are electrically connected to each other.

2 shows a modified embodiment in which the smaller portion 1.2 completely from the larger section 1.1 surrounded by the circuit board. In the embodiments according to 1 and 3 a part of the outer edge of the circuit board is true with a part of the edge of the smaller portion 1.2 match. As a result, in a particularly simple manner, the smaller portion 1.2 already partially cut free, so that for mechanical decoupling only the remaining holding webs 1.5 must be severed at the outlined dividing line. As particularly preferred is the embodiment according to 3 considered, as this is the smaller section 1.2 of the circuit board 1 already on 2 Sides coincides with the outer edge, leaving with a straight incision 1.4 the section 1.2 already on 3 Pages exposed and for mechanical decoupling only the remaining fourth side of the dividing line 1.5 can be separated by a straight cut.

The The invention thus describes an electronic control unit with integrated Sensor components SK1..n, distinguished by a method and a Arrangement for mechanical decoupling of a defined area the circuit board with the aim of mechanical vibrations in the decoupled Be able to design and absorb targeted areas. Mechanical vibrations arise in the circuit board z. B. by vibrations caused by transfer mechanical coupling from the vehicle to the control unit be, but also by sound or impact effect. The circuit board has a resonance behavior, essentially due to its material properties as well as by mechanical properties such as mass distribution of applied components, thickness, location of the breakpoints u. s. w. certainly is. This resonance behavior can lead to significant elevations of the Lead oscillation amplitude.

By the mechanical decoupling, ie separation of a range of PCB will be the vibrations of the remaining part of the PCB not transferred to this area. The decoupled area has its own resonance behavior, which independently designed specifically by the circumstances on the rest of the circuit board can be, for. B. by vibration-absorbing brackets and Number and location of breakpoints. The fixations can become z. B. differ in elasticity, Stiffness, vibration absorption, thermal conductivity, strength, etc. This decoupled area is intended for the placement of sensor components whose operation is sensitive be influenced by mechanical vibrations are used. The sensor components can z. B. rotation rate sensors or acceleration sensors.

The electrical contacting of the decoupled area to the rest The circuit board is made by separate wires outside led the PCB level Be flexible and designed so that they have mechanical vibrations not transmitted or only strongly attenuated can. Alternatively, could These are done by electrical contacts, for example. On the housing.

The Circuit board thus has one or more areas, the one own area, which is intended to be during the Manufacturing process mechanically separated from the rest of the PCB to become. These areas are electrically flexible with the rest of the circuit board Connections have their own Breakpoints for mounting in the assembly. The circuit board is added severed at one or more points after the circuit board stocked and in the case was attached.

For this purpose, the relevant area on the circuit board, z. B. a rectangle, already in the circuit board manufacturing process on several, z. B. three sides separated from the rest of the circuit board. The remaining connected pages or the fourth page is designed so that the area to be disconnected still so well attached to the circuit board that the entire circuit board can be equipped in all areas in one process step. In addition, the fourth side is such that this side can be severed after the assembly and after mounting the circuit board in the housing, without affecting or damaging other functions, such. B. by cutting technology.

The electrical contacting of the decoupled area to the rest of the PCB is z. B. by flexible cables that no or hardly transmit vibrations, z. B. cable ties or through contacts on the housing.

• • Form, Größe und Anzahl der abgetrennten Bereiche
• • Form, Länge und Ausführungsform der Trennlinie, entlang der der abzukoppelnde Bereich von dem Rest der Platine abgetrennt wird.
• • Art der elektrischen Anbindung des abgekoppelten Bereiches
• • Form, Größe, Anzahl und Eigenschaften der Fixierungen des abgekoppelten Bereiches.
• • Art des Abtrennprozesses
• • Lage des abzutrennenden Bereiches auf der Gesamtleiterplatte (mittig, am Rand, in der Ecke)

Depending on the application, there are numerous design options for the arrangement, in particular with regard to

• • Shape, size and number of separated areas
• Shape, length and embodiment of the dividing line, along which the area to be decoupled is separated from the rest of the board.
• • Type of electrical connection of the decoupled area
• • Shape, size, number and properties of the fixations of the decoupled area.
• • Type of separation process
• • Location of the area to be separated on the overall board (center, edge, corner)

The method described here offers over a circuit board without decoupled range an optimized vibration and resonance behavior, because the decoupled area in its vibration and resonance behavior can be specifically designed and optimized without the vibration behavior to influence the remaining circuit board. Besides, this is here described method technically easy to implement and based on for a long time known and successfully applied manufacturing process. It can be different Requirements for influenceable parameters simply in one casing be realized, for. B. different stiffnesses to short, to transmit high acceleration values.

The susceptibility The assembly is reduced because the sensors are frequency optimized can be attached and on the other hand, the remaining circuit components independently as well frequency-optimized to their needs can be attached. It reduces logistics costs, as only one circuit board is purchased. The litigation is easy because the circuit board is populated in one go and can be mounted and the separation only after assembly and Assembly (fixation) takes place.

A special design shows now 4 in which the module has at least two sensors (SK1, SK5) which are sensitive to different frequency ranges of the acting movement and the sensors (SK1, SK5) on different sections ( 1.1 . 1.2 ) of the circuit substrate are arranged, wherein the sections ( 1.1 . 1.2 ) are mounted differently adapted according to the respective frequency range.

The following 5 - 7 Now still show devices for mounting parts of circuit boards or possibly. Integrally formed complete circuit carriers according to the prior art. These devices are used in addition to a defined attachment for damping of mechanical vibrations on printed circuit boards. The device consists of a headband, the z. B. is attached to the PCB mounting points and extends over the circuit board. The attachment of the bracket should be such that the bracket does not contribute even to unwanted vibrations. At the headband preferably damping elements are attached, which touch the circuit board and can absorb mechanical vibrations of the circuit board. Mechanical vibrations of the printed circuit board can lead to resonances that affect the functionality of individual components such. B. rotation rate sensors can severely affect. This effect can not be completely corrected by software filters and requires additional mechanical damping. The device is particularly advantageous where sensitive yaw rate sensors and acceleration sensors are installed on a printed circuit board and where a mechanical damping of the printed circuit board in all directions would affect the functioning of the sensor system (eg the board level acceleration sensor, if the printed circuit board) would be stored completely dampening). In particular, a selective damping of low-frequency vibrations of the printed circuit board can take place perpendicular to the printed circuit board plane. This optimizes the operation of yaw rate sensors without affecting the acceleration characteristics of the acceleration sensors in the direction parallel to the PCB level.

That's how it shows 5 two embodiments of retaining clips 3.3.2 and 3.3.3. which with 2 respectively. 3 Breakpoints on the circuit board, so for example. A section 1.1 are attached to the circuit board. By three in the circuit board level not arranged on a common line breakpoints can as in the example of the retaining clip 3.3.3 a particularly good stiffening in all directions can be achieved.

6 now outlines the combination of headband 3.3 with damping agents 3.1 with which the section or a piece arranged on the section Component (Sk1 ..) damped in the assembly is attached. The damping means 3.1 can be arranged on one side of the circuit board or on both sides, as in the damping means 3.2 the case.

Furthermore, the headband 3.2.1 optionally also be used for mounting capacitors C. With suitable mounting and material selection, the headband can also be used to dissipate heat from within the assembly.

Also Here are numerous design options in the arrangement in terms of shape, size, number, Materials of hangers and damping material and their arrangement on one or both sides of the printed circuit board, with or without bracket for Capacitor, without and with thermal coupling to the housing, without or with mechanical coupling to the housing, with and without mechanical damping the fixations of the temple.

It is an adjustable selective mechanical damping of a circuit board vertical to the PCB level by using the mounting bracket construction and damping elements possible. This results in an improvement in the quality of rotation rate sensor data without impairment the signal quality of acceleration sensors due to falsification of the acceleration values.

Claims (10)

Electronic assembly with at least one sensor (Sk1, ...) on a circuit carrier ( 1 ), wherein at least one sensor (Sk1, ...) is sensitive to movement acting on the assembly, characterized in that - the circuit carrier ( 1 ) from a first section ( 1.1 ) and at least a second section, ( 1.2 ) - the cuts ( 1.1 . 1.2 ) are produced from a common circuit carrier by severing the circuit carrier and mechanically decoupled, - the sections ( 1.1 . 1.2 ) via at least one electrical connection ( 2 ) are electrically connected to each other and - the sections are each independently mounted in the assembly. Electronic assembly according to claim 1, characterized in that the sections ( 1.1 . 1.2 ) are fastened with mutually different stiffness, elasticity and / or damping in the assembly. Electronic assembly according to claim 1 or 2, characterized marked that for the acting movement sensitive sensor corresponding to the movement Generated useful signal and is arranged on that portion which is rigidly connected to the assembly and the other portion attenuated contrast and / or resiliently mounted in the assembly and electronic on this portion Components are arranged. Electronic assembly according to claim 1 or 2, characterized characterized in that the useful signal of the acting movement sensitive sensor is disturbed by the movement and the sensor on those section is arranged, which is steamed and / or elastically mounted in the assembly and another portion in contrast rigid is arranged in the assembly. Electronic assembly according to one of the preceding claims, characterized in that the assembly has at least two sensors (Sk1, SK5), which are sensitive to different frequency ranges of the acting movement and the sensors (SK1, SK5) on different sections ( 1.1 . 1.2 ) of the circuit substrate are arranged, wherein the sections ( 1.1 . 1.2 ) are mounted differently adapted according to the respective frequency range. Electronic assembly according to one of the preceding claims, characterized in that at least one retaining bracket ( 3.3 ) is provided, with which at least a portion of the circuit substrate is mounted in the assembly. Electronic assembly according to one of the preceding claims, characterized in that for at least a portion of the circuit substrate, a damping element ( 3.1 . 3.2 ) is provided, with which the portion or a component arranged on the component (Sk1) is damped mounted in the assembly. Electronic assembly according to one of the preceding claims, characterized in that the electrical connection ( 2 ) between the sections ( 1.1 . 1.2 ) is done by a flexible cable. A method for producing an assembly with at least one sensor on a circuit carrier according to one of the preceding claims, wherein the circuit carrier is first in one piece ( 1 ) equipped with the / the sensors and other electronic components (Sk1 ...) and subsequently the sections ( 1.1 . 1.2 ) and are fastened differently in the assembly, the parts ( 1.1 . 1.2 ) are electrically flexible with each other ( 2 ) get connected. Method according to claim 9, wherein the sections ( 1.1 . 1.2 ) at the bare circuit carrier already locally isolated ( 1.4 ) and Hal testege ( 1.5 ) are interconnected and after loading the holding webs ( 1.5 ) are severed.