Electronic Component And Method For Producing An Electronic Component Of This Kind

Abstract

The disclosure relates to an electronic component that includes a printed circuit board with two opposite flat sides and a plurality of electronic components, and a base plate. A number of the electronic components are each fixed on and electrically conductively connected to a rear flat side of the printed circuit board and a further number of the electronic components are each fixed on and electrically conductively connected to a front flat side of the printed circuit board. The base plate has at least one first cutout for receiving electronic components that are arranged on the rear flat side of the printed circuit board. The disclosure also relates to a method for producing an electronic component of this kind.

Claims

1. An electronic component comprising: a printed circuit board including: two opposing flat sides being a rear flat side and a front flat side, and a plurality of electronic component parts, wherein a number of the electronic component parts is fixed and electrically conductively connected to the rear flat side of the printed circuit board and a further number of the electronic component parts is fixed and electrically conductively connected to the front flat side of the printed circuit board; and a base plate having at least one first recess for accommodating electronic component parts, which are arranged on the rear flat side of the printed circuit board.

2. The electronic component of claim 1, wherein the number of the electronic component parts is fixed in an integrally joined manner on the rear flat side by solder points and electrically conductively connected to the printed circuit board.

3. The electronic component of claim 1, wherein the further number of the electronic component parts is adhesively bonded to the front flat side by means of an electrically conductive adhesive and electrically conductively connected to the printed circuit board by wire contacting.

4. The electronic component of claim 1, wherein a position of one of the electronic component parts on one of the flat sides of the printed circuit board is dependent on a position of an electronic component part on the opposing flat side of the printed circuit board having a certain power loss.

5. The electronic component of claim 1, wherein the printed circuit board and the base plate are bonded to one another in an integrally joined manner by means of a thermally conductive adhesive.

6. The electronic component of claim 3, wherein the wire contacting comprises at least one thick bond wire.

7. The electronic component of claim 3, wherein the wire contacting comprises at least one thin bond wire.

8. A method for producing an electronic component, the method comprising: providing an unequipped printed circuit board, the printed circuit board having two opposing flat sides being a rear flat side and a front flat side; providing a plurality of electronic component parts; equipping the printed circuit board with the plurality of electronic component parts, wherein: a number of the electronic component parts from the plurality of electronic component parts is arranged on the rear flat side, fixed in an integrally joined manner, and electrically conductively connected to the printed circuit board, and subsequently a further number of the electronic component parts from the plurality of electronic component parts is arranged on the front flat side, fixed in an integrally joined manner, and electrically conductively connected to the printed circuit board; and integrally joined bonding of the printed circuit board equipped on both sides to a base plate, wherein the base plate is provided with at least one first recess for accommodating electronic component parts that are arranged on the rear flat side of the printed circuit board.

9. The method of claim 8, wherein the number of electronic component parts is soldered to the rear flat side and the further number of electronic component parts is adhesively bonded to the front flat side and is electrically conductively connected to the printed circuit board by wire contacting.

Description

DESCRIPTION OF DRAWINGS

[0025] FIG. 1 schematically shows a sectional illustration of an implementation according to the disclosure of an electronic component having a printed circuit board equipped on both sides.

[0026] FIG. 2 schematically shows a sectional illustration of an alternative implementation according to the disclosure of an electronic component having a printed circuit board equipped on both sides.

[0027] FIG. 3 shows a method flow chart of a method for producing an electronic component.

[0028] Parts corresponding to one another are provided with the same reference signs in all figures.

DETAILED DESCRIPTION

[0029] FIG. 1 shows a sectional illustration, in particular a cross section, of an electronic component E. The electronic component E may be arranged in a control unit for motor vehicles, for example, in a transmission control unit, where not all components of the electronic component E are shown.

[0030] The electronic component E includes a printed circuit board 1 having a plurality of electronic component parts 2 and a base plate 3. The base plate 3 is bonded in an integrally joined manner to the printed circuit board 1.

[0031] The printed circuit board 1 represents a substrate or circuit carrier and is used for the mechanical fastening of the electronic component parts 2 as well as their electrical connection. For example, the printed circuit board 1 is formed from electrically insulating, fiber-reinforced plastic and has a number of electrically conductive conductor tracks 1.1.

[0032] Furthermore, the printed circuit board 1 has two flat sides 1.2, 1.3, where a rear flat side 1.2 is a side facing the base plate 3 and a front flat side 1.3 is a side of the printed circuit board 1 facing away from the base plate 3.

[0033] According to the disclosure, the printed circuit board 1 has electronic component parts 2 both on the front flat side 1.3 and also on the rear flat side 1.2. In other words, the printed circuit board 1 is equipped on both sides.

[0034] In some implementations, an electrical resistor 2.1, an electrical capacitor 2.2, and a housed semiconductor component 2.3, for example, a housed diode or bipolar transistor, are arranged as electronic component parts 2 on the rear flat side 1.2 and are each mechanically fixed on the rear flat side 1.2 and electrically conductively connected to the conductor tracks 1.1 by means of solder points 4.

[0035] Because the rear flat side 1.2 is the flat side of the printed circuit board 1 facing toward the base plate 3, the base plate 3 has a first recess 3.1 for accommodating the electrical resistor 2.1, the electrical capacitor 2.2, and the housed semiconductor component 2.3. The first recess 3.1 is provided with a filler material 9, for example, a thermally conductive paste or a potting compound.

[0036] A thermally conductive adhesive 8 is arranged between unequipped sections of the rear flat side 1.2 of the printed circuit board 1 and the base plate 3 for the integrally joined bonding of the printed circuit board 1 and the base plate 3. The printed circuit board 1 is therefore additionally thermally connected to the base plate 3. Alternatively, a solder point 4 can also be arranged instead of the thermally conductive adhesive 8. The base plate 3 is formed from metal, for example. Alternatively, the base plate 3 can also be formed as a plastic-metal hybrid.

[0037] In some implementations, as shown, two unhoused semiconductor components 2.4 and a further electrical resistor 2.1 are arranged as electronic component parts 2 on the front flat side 1.3.

[0038] An unhoused semiconductor component 2.4, which is arranged on the left in the observation direction, is electrically conductively connected by a thick bond wire 5, for example, an aluminum bond wire, to the conductor tracks 1.1 and is fixed in an integrally joined manner on the front flat side 1.3 by an electrically conductive adhesive 7.

[0039] An unhoused semiconductor component 2.4, which is arranged on the right in the observation direction, is electrically conductively connected by two thin bond wires 6, for example, two gold bond wires, to the conductor tracks 1.1 and is fixed in an integrally joined manner on the front flat side 1.3 by the electrically conductive adhesive 7.

[0040] The further electrical resistor 2.1 is both electrically conductively connected to the conductor tracks 1.1 and also fixed in an integrally joined manner on the front flat side 1.3 by the electrically conductive adhesive 7.

[0041] FIG. 2 shows an electronic component E in a sectional illustration, in particular in a cross section.

[0042] The electronic component E includes, similarly to the previous electronic component E described in FIG. 1, a printed circuit board 1 having a plurality of electronic component parts 2 and a base plate 3, which is bonded in an integrally joined manner to the printed circuit board 1.

[0043] Furthermore, as previously described with respect to FIG. 1, the printed circuit board 1 has a rear flat side 1.2 and a front flat side 1.3. In some implementations, two electrical resistors 2.1 and an electrical capacitor 2.2 are arranged on the rear flat side 1.2 as electronic component parts 2 and are each electrically conductively connected to conductor tracks 1.1 and are fixed in an integrally joined manner on the rear flat side 1.2 by solder points 4 and an electrically conductive adhesive 7.

[0044] The base plate 3 has two recesses 3.1, 3.2 in this case, where a first recess 3.1 accommodates the electrical capacitor 2.2 and one of the electrical resistors 2.1. A second recess 3.2 accommodates the other electrical resistor 2.1.

[0045] A thermally conductive adhesive 8 for the integrally joined bonding of the printed circuit board 1 to the base plate 3 is also arranged between unequipped sections of the rear flat side 1.2 and the base plate 3 in this case. The printed circuit board 1 is therefore additionally thermally connected to the base plate 3. Alternatively, a solder point 4 can also be provided instead of the thermally conductive adhesive 8.

[0046] As shown, two housed semiconductor components 2.3, for example, a housed field-effect transistor and a housed integrated circuit, an electrical capacitor 2.2, and an electrical resistor 2.1 are arranged on the front flat side 1.3 as electronic component parts 2.

[0047] The electronic component parts 2 arranged on the front flat side 1.3 are each bonded in an integrally joined manner and electrically conductively connected by means of solder points 4 to the front flat side 1.3.

[0048] FIG. 3 shows a method flow chart of a method according to the disclosure for producing the electronic component E.

[0049] The method is described in greater detail hereafter based on the electronic component E shown in FIG. 1.

[0050] In a first method step S1, the rear flat side 1.2 of the printed circuit board 1 is equipped with electronic component parts 2, the power loss of which is low in relation to other electronic component parts 2, because these electronic component parts 2 cannot be directly thermally connected to the base plate 3 and a heat loss arising in this case cannot be efficiently dissipated.

[0051] In some examples, a soldering process is carried out for the fixing and electrical contacting of the electronic component parts 2. Alternatively, the electronic component parts 2 can also be adhesively bonded and electrically conductively connected by means of a conductive adhesive to the rear flat side 1.2. Wire contacting (wire bonding) is not possible on the rear flat side 1.2, because a required cleanness of the surfaces cannot be ensured due to the soldering processes.

[0052] The position of the electronic component parts 2 on the rear flat side 1.2 is selected depending on a future position of electronic component parts 2 on the front flat side 1.3 which have high power loss and therefore generate a high level of waste heat in relation to the other electronic component parts 2.

[0053] In a second method step S2, the electrically conductive adhesive 7 is applied, for example, by means of screen printing, to the front flat side 1.3 of the printed circuit board 1. Subsequently thereto, all electronic component parts 2, which are provided for wire contacting and have high power loss, are adhesively bonded to the front flat side 1.3.

[0054] In this case, one of the unhoused semiconductor components 2.4 is electrically conductively connected to the conductor tracks 1.1 by means of the thick bond wire 5 after the curing of the electrically conductive adhesive 7.

[0055] The other of the unhoused semiconductor components 2.4 is electrically conductively connected to the conductor tracks 1.1 by means of the thin bond wires 6 after the curing of the electrically conductive adhesive 7.

[0056] The second electrical resistor 2.1 is exclusively electrically conductively connected to the conductor tracks 1.1 and also fixed in an integrally joined manner on the front flat side 1.3 by means of the electrically conductive adhesive 7, as already described in FIG. 1.

[0057] A contamination on the front flat side 1.3 may be minimized by the use of the electrically conductive adhesive 7 on the front flat side 1.3, so that an optimum contact surface for wire contacting is ensured.

[0058] In a third method step S3, the printed circuit board 1 equipped on both sides is bonded in an integrally joined manner to the base plate 3, for example, by the thermally conductive adhesive 8 or alternatively by a further soldering process.

[0059] The base plate 3 has the recess 3.1 for accommodating the electronic component parts 2 on the rear flat side 1.2, as already described. A total height of the electronic component E thus remains equal, so that no additional installation space requirement results.

[0060] The recess 3.1 can optionally be filled using the filler material 9. The filling is performed either before the integrally joined bonding of the base plate 3 to the printed circuit board 1 or by channels introduced into the base plate 3 (not shown here).

[0061] A thermal connection of the entire circuit assembled on the printed circuit board 1 is increased in relation to the prior art by the filler material 9. The above-mentioned channels in the base plate 3 and/or channels in the printed circuit board 1 enable air bubbles to be avoided or at least reduced.

[0062] The described solution according to the disclosure enables a combination of different connection technologies with the option of spatially separated processes, i.e., for example, soldering processes on the rear flat side 1.2 and adhesive bonding and wire contacting on the front flat side 1.3. In addition, a temperature control of the circuit on the printed circuit board 1 is possible as a function of a power loss of individual electronic component parts 2. In other words: the solution according to the disclosure enables partial heating of the circuit on the printed circuit board 1 in thermally relevant regions.

[0063] Furthermore, the solution according to the disclosure enables a reduction of a component part density on a flat side of the printed circuit board 1 due to the two-sided equipping of the printed circuit board 1.

[0064] Furthermore, in spite of the use of the electrically conductive adhesive 7, electronic component parts 2 may be soldered. It is therefore also possible to integrate low-power-loss, housed semiconductor components 2.3 in the circuit by soldering. Mechanically and chemically sensitive thin bond wires 6 and thick bond wires are protected, because they are first applied after the soldering process. Therefore, chip resistors and chip capacitors and also special component parts may be used, which have a more cost-effective termination than the prior art. For example, terminations made of cost-effective tin can be used, wherein the component parts that have such terminations have a high availability.

[0065] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.