DE102016224949A1 - Method for producing mechatronic assemblies - Google Patents

Abstract

The invention relates to a method for producing a mechatronic assembly (E), wherein at least one flat side of a carrier circuit board (1) is equipped with a plurality of electronic components, at least one of the electronic components with at least one mechanical insert (4.1, 6) mechanically on the flat side of the carrier circuit board (1) is pressed, a curable encapsulating material (M) is pressed to a Kapselungsvorformteil (7), the Kapselungsvorformteil (7) is inserted and heated in a mold (10) and the plurality of electronic components and the at least one mechanical insert (4.1 , 6) in the closed mold (10) by encapsulation of the encapsulation preform (7) are encapsulated to an encapsulation (9), and when curing the encapsulation (9) with the electronic components and the at least one mechanical insert (4.1, 6) form and cohesively connected.

Description

The invention relates to a method for producing a mechatronic assembly.

It is known that in the manufacture of mechatronic assemblies, the populated side of the carrier circuit board of the assembly is immersed in a mold, the mold containing a thermoset which has been heated prior to the dipping phase. Such a mechanical assembly in this case comprises a support plate with at least one equipped flat side, on which a plurality of electronic components and at least one mechanical insert are arranged.

Furthermore, it is known that the thermosetting plastic is, for example, an epoxy-based plastic which additionally contains an inorganic filler ( WO 2016/128245 ). Furthermore, it is known that arranged on carrier plates module-like electronic components and electronic components are each enclosed by a separate housing. In this embodiment, outwardly routed electrical connections must be protected against metallic chips and / or aggressive media. This is possible by means of coatings of additional plastic parts or covers.

The invention is based on the object to provide an improved method for producing a mechatronic assembly.

The object is achieved by the features specified in claim 1.

In the method according to the invention, at least one flat side of a carrier circuit board is equipped with a plurality of electronic components, wherein at least one of the electronic components with at least one mechanical insert is fixed mechanically on the flat side of the carrier circuit board. According to the invention, a curable encapsulation material is pressed to form a encapsulation preform, wherein the mold of the encapsulation preform corresponds in particular to a negative mold of an encapsulation to be manufactured. Furthermore, the invention provides that the encapsulation preform is inserted and heated in a mold, wherein the plurality of electronic components and the at least one mechanical insert in the closed mold by molding the encapsulation preform to encapsulate by means of this encapsulation, in particular encapsulated.

When the encapsulation is cured, it is positively and materially connected to the electronic components and the at least one mechanical insert, whereby the components and the insert are encapsulated.

The advantages achieved by the invention are, in particular, that the degree of complexity of Kunststoffumhüllungsmaschinen used in the manufacturing process and the mold decreases, since the mold with the encapsulation preform can be automatically populated. This can be reduced compared to the prior art manufacturing costs and manufacturing costs. Another advantage achieved by the invention of the method according to the invention is that avoided by the forming, in particular hot pressing the encapsulation preform on the electronic components and the mechanical insert or vice versa impressions of the components and the insert in the preheated Kapselungsvorformteil, possible air pockets or at least reduced.

According to one embodiment of the invention, the encapsulating material is present as a granulate.

According to one embodiment of the invention, the encapsulation preform member is heated in the mold such that material softening of the encapsulation preform member occurs. As a result of this material softening the Trägerleitplatte can be pressed or immersed with the populated flat side in the heated and softened Kapselungsvorformteil.

According to one embodiment of the invention, the curable encapsulating material comprises a thermoset or other suitable plastic, which has electrically insulating properties, so that a short circuit between the electronic components is avoided. The thermosetting resin comprises, for example, an epoxy-based polymer.

According to one embodiment of the invention, the encapsulating material is provided with at least one inorganic filler. Suitable inorganic fillers are, for example, silicon dioxide or aluminum oxide. Depending on the amount and type of inorganic filler in the encapsulating material, a thermal expansion coefficient of the encapsulation may be adjusted to the carrier circuit board, in particular the materials comprising the carrier circuit board. By this adjustment, a delay can be avoided or at least reduced. Likewise, the thermal expansion of the encapsulation on the thermal properties, in particular thermal expansion, stiffness and glass transition temperature of the inorganic filler, can be adjusted.

According to a further embodiment of the invention, the encapsulation preform has at least one stiffening rib. The stiffening rib is designed for example in the form of a honeycomb or in the form of crossed ribs. Alternatively, other geometric shapes and / or multiple stiffening ribs are possible. The at least one stiffening rib increases the stability of the mechatronic assembly.

According to a further embodiment of the invention, the encapsulation preform is compression molded or injection-molded.

Embodiments of the invention are explained in more detail below with reference to drawings.

• 1 eine schematische Schnittdarstellung einer mechatronischen Baugruppe gemäß dem Stand der Technik, und
• 2 eine schematische Schnittdarstellung eines Formwerkzeugs gemäß Stand der Technik, und
• 3 eine schematische und geschnittene Explosionsdarstellung einer beispielhaften mechatronischen Baugruppe nach 1, welche durch das erfindungsgemäße Herstellungsverfahren gefertigt wurde.

Show:

• 1 a schematic sectional view of a mechatronic assembly according to the prior art, and
• 2 a schematic sectional view of a mold according to the prior art, and
• 3 a schematic and sectional exploded view of an exemplary mechatronic assembly according to 1 , which was manufactured by the manufacturing method according to the invention.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows an exemplary mechatronic assembly e in a sectional view according to the prior art.

The mechatronic assembly e is for example a control device for a motor vehicle, in particular a transmission control unit.

The mechatronic assembly e includes an encapsulation 9 and a carrier circuit board 1 ,

The carrier circuit board 1 has in the embodiment shown on a flat side, a first sensor 3 with a first mechanical insert part 6 and a second sensor 4 with a second mechanical insert 4.1 on. Furthermore, on the carrier circuit board 1 a printed circuit board element 1.1 applied. On a flat side of the printed circuit board element 1.1 is a modular electrical circuit arrangement 2 applied.

The carrier circuit board 1 is, for example, a so-called Umstromungsleiterplatte and has at least one layer with electrically conductive copper tracks for electrical connection.

In an embodiment, not shown, the carrier circuit board 1 also be equipped and encapsulated on both sides.

The electrical circuit arrangement shown 2 is modular on the PCB element 1.1 designed and includes at least one electronic module 2.1 , For example, a circuit, components 2.2 to 2.n , such as transistors, electrical resistors or memory modules.

In the embodiment shown, the electrical circuit arrangement 2 using two bonding wires 2.0 with the carrier circuit board 1 electrically connected. The bonding wires 2.0 For example, an aluminum thick wire bond or an aluminum thin wire bond may be used. Alternatively, the bonding wires 2.0 also be formed of gold. Furthermore, instead of two bonding wires 2.0 even just a bonding wire 2.0 or more bonding wires 2.0 be arranged.

In an embodiment, not shown, the electrical circuit arrangement 2 with the carrier circuit board 1 be soldered or glued.

The electrical circuit arrangement 2 is over the PCB element 1.1 with the carrier circuit board 1 connected. The circuit board element 1.1 is with the carrier PCB 1 in the illustrated embodiment by means of an adhesive 5 , For example, a thermal adhesive, materially connected. The circuit board element 1.1 is, for example, a so-called high-density interconnect circuit board.

The first sensor 3 is on the flat side of the Trägerleitplatte 1 spaced from the electrical circuitry 2 arranged. The first sensor 3 is embodied for example as a Hall sensor, piezoelectric sensor or the like. The first mechanical insert 6 is designed as a hybrid injection molded part. The insert 6 comprises a metallic carrier 6.1 for electrical contacting and mechanical fixing of the first sensor 3 and a plastic jacket 6.2 , The plastic casing 6.2 electrically isolates part of the first mechanical insert 6 ,

The first mechanical insert 6 is in this case cohesively and / or non-positively and / or positively with the flat side of the Trägerleitplatte 1 connected. The second sensor 4 is on the flat side of the carrier circuit board 1 spaced from the first sensor 3 arranged and, for example, a pressure sensor. In the embodiment shown, the second mechanical insert is 4.1 formed as a busbar, by means of which the second sensor 4 mechanically and electrically conductive with the carrier circuit board 1 connected is. The busbar may be, for example, a foil or an overmoulded stamped grid.

The encapsulation 9 includes a stiffening rib 11 , The stiffening rib 11 is designed for example in the form of a honeycomb structure or in the form of crossed ribs. Alternatively, several stiffening ribs 11 be provided. The encapsulation 9 surrounds the circuit arrangement positively and materially 2 , Bonding wires 2.0 , the first sensor 3 , the first mechanical insert 6 , the plastic casing 6.2 , the second sensor 4 and the second mechanical insert 4.1. By encapsulation 9 the components mentioned are protected against external influences.

2 shows a mold 10 in a sectional view according to the prior art.

In the prior art, the encapsulating material M in a mold 10 filled. The encapsulating material M , For example, a thermoset must either be present at least viscous or heated. The encapsulating material M softens so that the populated flat side of the carrier circuit board 1 , in a manufacturing step, not shown, in the mold 10 , in particular in the encapsulating material M , can be dipped. After the encapsulating material M is cured, forms the encapsulating material M as an encapsulation 9 a media-tight, form-fitting and material-coherent composite with the equipped carrier circuit board 1 ,

3 shows analogously to 1 for example, the carrier circuit board 1 with the populated flat side, an exemplary encapsulation preform 7 as well as an exemplary encapsulating material M ,

In the process for producing a mechatronic assembly e At first, at least one flat side of a carrier circuit board 1 is equipped with a plurality of electronic components. For example, the carrier circuit board 1 with a printed circuit board element 1.1 , a first sensor 3 , a second sensor 4 and at least one mechanical insert 4.1 . 6 stocked.

The circuit board element 1.1 comes with an electrical circuit 2 Mistake. The electrical circuit arrangement 2 For example, includes an electrical assembly 2.1, at least one bonding wire 2.0 and / or components 2.1 to 2.n. The components 2.1 to 2.n are, for example, circuits, transistors, electrical resistors or memory devices.

Furthermore, at least one of the electronic components, for example the sensors 3 and 4 , with at least one mechanical insert 4.1 . 6 on the flat side of the carrier circuit board 1 fixed.

In a further production step, the curable encapsulating material M to an encapsulation preform 7 pressed. For this purpose, the encapsulating material M , For example, a granulate, in a production step, not shown in a negative mold 8th for the encapsulation 9 filled, in particular injection molded or cast, and the encapsulation preform 7 shaped, in particular pressed. Possible methods for this production step are, for example, transfer molding or compression molding.

The encapsulation preform 7 gets into a mold 10 inserted. The insertion of the encapsulation preform 7 in the mold 10 can be done for example by means of a placement machine or the like. The inserted encapsulation preform 7 is heated so that material softening of the encapsulation preform 7 comes. As a result of this material softening the Trägerleitplatte 1 with the fitted flat side in the heated and softened encapsulation preform 7 be pressed or dipped. As a result, the plurality of electronic components and the at least one mechanical insert 4.1 . 6 in the closed mold 10 by shaping the encapsulation preform 7 to an encapsulation 9 encapsulated by this.

When curing the encapsulation 9 this is the electronic components, such as the electrical circuitry 2 and the sensors 3,4 and the at least one mechanical insert 4.1 . 6 positively and materially connected.

The encapsulating material M is a granulate, such as a thermoset, which is provided with an inorganic filler.

The encapsulation preform 7 and / or the encapsulation 9 have at least one stiffening rib 11 on. The stiffening rib 11 increases the stability of the mechatronic assembly e ,

LIST OF REFERENCE NUMBERS

1

Mother board

1.1

PCB element

2

electrical circuit arrangement

2.0

bonding wire

2.1

electronic assembly

2.2

module

2.3

module

2.4

module

2.n

module

3

first sensor

4

second sensor

4.1

second mechanical insert

5

adhesive

6

first mechanical insert

6.1

metallic carrier

6.2

Plastic sheathing

7

Kapselungsvorformteil

8th

Negative mold encapsulation

9

encapsulation

10

mold

11

stiffening rib

e

mechatronic assembly

M

encapsulation

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

• WO 2016/128245 [0003]

Claims (7)

Method for producing a mechatronic assembly (E), wherein - At least one flat side of a carrier circuit board (1) is equipped with a plurality of electronic components, at least one of the electronic components having at least one mechanical insert part (4.1, 6) is mechanically fixed on the flat side of the carrier printed circuit board (1), a curable encapsulation material (M) is pressed to form an encapsulation preform part (7), - The encapsulation preform (7) is inserted and heated in a mold (10) and the plurality of electronic components and the at least one mechanical insert (4.1, 6) in the closed mold (10) by forming the Kapselungsvorformteils (7) to an encapsulation ( 9) are encapsulated, and - During curing, the encapsulation (9) with the electronic components and the at least one mechanical insert (4.1, 6) is positively and materially connected. Method according to Claim 1 , characterized in that the curable encapsulating material (M) is a granulate. Method according to Claim 1 , characterized in that the encapsulation preform part (7) is heated in such a way that material softening of the encapsulation preform part (7) occurs, with the support plate (1) with the fitted flat side being immersed in the encapsulation preform part (7). Method according to Claim 1 , characterized in that the curable encapsulating material (M) comprises a thermoset. Method according to Claim 1 , characterized in that the curable encapsulating material (M) is provided with at least one inorganic filler. Method according to Claim 1 , characterized in that the encapsulation (9) has at least one stiffening rib (11). Method according to Claim 1 , characterized in that the encapsulation preform member (7) is compression molded or injection molded.

Images