DE102019201404A1 - Electronics module - Google Patents

Abstract

The starting point is an electronics module comprising a circuit carrier with an upper side and an underside and with an electronic circuit arranged at least on the upper and / or lower side. In this case, the electronic circuit is enclosed by an encapsulation compound to form an outer module surface, with at least one sub-element within the electronics module being exposed by the encapsulation compound in at least a sub-area of the outer module surface. The at least one sub-element is a positioning element, which is designed to fix the position of the circuit carrier during the encasing of the electronic circuit with the encapsulating compound between at least two tool parts. For this purpose, the positioning element is exposed from the encapsulation compound at a respective end area on a sub-area of the outer module surface facing the underside and a sub-area facing the upper side, the respective end area having at least one effective tool area, which is formed in operative connection with a tool part facing the effective tool area a releasable force- and / or form a positive connection.

Description

The invention relates to an electronic module and a method for forming the electronic module according to the preambles of the independent claims.

State of the art

Electronic modules often require protection against environmental loads such as temperature, chemical influences, electrical voltages or mechanical stress. For this purpose, electronic modules are designed, for example, in such a way that an electronic circuit carrier that is equipped on one or both sides is sealed with a coating compound. Form-related methods are often used for this purpose, in which the negative of the outer geometry of the electronic module is depicted in a tool. The closed tool with inserted electronics is then filled with a flowable encapsulant under pressure or without pressure, which then solidifies. During filling there is a requirement that the inserted electronics, in particular a circuit carrier, be centered and held in a defined position in the closed tool. For centering, connecting elements on the product or on the tool are used, which enable the circuit carrier to be centered in the tool.

From the published application DE102005014427A1 a molding module is known which is kept free of molding material in the area of a semiconductor chip. For this purpose, an elastic dam is arranged on an upper side of the semiconductor chip, which is pressed in a sealed manner against a tool part within a closed tool and thereby forms a closed recess against the penetration of molding material.

The disclosure DE102013211100A1 shows a method for forming a molded electronic module. In this case, the electronic module has a circuit carrier which is connected to an auxiliary carrier in a resilient or flexible manner. For the encapsulation with a molding material, the circuit carrier is pressed in a sealing manner in the area of the auxiliary carrier via tool parts, so that when the molding material is introduced into the closed tool, it is sealed to the outside in the area of the auxiliary carrier against the escape of molding material.

In general, it is disadvantageous that when such electronic modules are designed for the required fixing and positioning, mechanical forces are introduced into the electronics, in particular into the circuit carrier. This always carries the risk of damage or deformation of important functional elements. As a result, functional impairment or, in the worst case, complete failure can occur as early as during manufacture or later during operation due to disadvantageous component voltages.

Methods are also known in which the circuit carrier is fixed and / or positioned during the introduction of the encapsulation compound by means of disengageable tool elements ("e.g. retracable pins"). In addition to the equally problematic introduction of force, in these cases there is also a considerable increase in the complexity of the systems and the tool technology, which results in increased manufacturing costs. In addition, there are restrictions on the number of electronic modules that can be trained in parallel, as well as increased maintenance and cleaning efforts. Furthermore, it is only possible to prevent the printed circuit boards from floating vertically to the tool parting plane within a certain tolerance. Precise positioning is not possible due to the tolerance chain without damaging the circuit carrier.

Disclosure of the invention

The invention has for its object to ensure the formation of an electronic module with high manufacturing accuracy and to keep or exclude the mechanical stress of electronic parts contained in a tool-bound encasing with a coating compound.

This object is achieved with an electronic module and with a method for forming the electronic module with the characterizing features of the independent claims.

The starting point is an electronic module comprising a circuit carrier with an upper side and a lower side and with an electronic circuit arranged at least on the upper and / or lower side. In this case, the electronic circuit is enclosed by an encapsulation compound to form an outer module surface, at least one partial element within the electronic module being exposed by the encapsulant compound in at least a partial region of the outer module surface. The at least one sub-element is a positioning element, which is designed to fix the position of the circuit carrier during the encapsulation of the electronic circuit with the encapsulation compound between at least two tool parts. For this purpose, the positioning element is in each case on a sub-area of the module outer surface facing the underside and a top side at a respective end area of the Envelope mass exposed, the respective end area having at least one tool knitting area, which is designed to form a releasable non-positive and / or positive connection in operative connection with a tool part facing the tool knitting area.

Accordingly, the positioning element is part of the electronics module, as a result of which assembly on the circuit carrier can take place together with all other electrical and / or electronic components which form the electronic circuit. This is then made possible in a simple and cost-effective manner, in particular through standardized assembly processes. In addition, the positioning element in this way represents a reference position with high placement accuracy on the circuit carrier. A very precise positional relationship with respect to a tool part can be established for the assembled circuit carrier via this reference position. The positioning element is advantageously freely accessible from one tool part both from the top and from the bottom of the circuit carrier. In this way, a fixed fixation or a spatial positional positioning of the assembled circuit carrier can be achieved by bilaterally acting action and / or a form-related engagement of the tool parts in the respective tool effective areas of the positioning element when the tool is closed.

The positioning element is used as a kind of mechanical dummy part, which is in no electrical connection to the electronic circuit. Alternatively, in addition to the mechanical function during the manufacturing process of the electronic module, the positioning element can also have an electrical function during operation of the electronic module for some applications. In this case, the positioning element is preferably connected to a conductor structure of the electronic circuit. The positioning element is designed, for example, as an external power connection. Alternatively, it is available as a ground connection.

Advantageous further developments and improvements of the electronic module according to the invention are possible through the measures listed in the dependent claims.

An advantageous embodiment of the electronic module results from the fact that the positioning element penetrates the circuit carrier through a cutout, an immediately closed force path being formed between the tool effective areas when the tool effective areas of the positioning element are acted upon. Accordingly, the circuit carrier has no involvement in a power line. Because the positioning element is designed mechanically for the force that occurs, there are no damaging, mechanically induced loads on electronically relevant components of the electronic module. In this way, a risk of mechanical damage can basically be ruled out, which greatly increases manufacturing safety.

A further improvement results from the fact that the two tool effective areas and the cutout in the circuit carrier are arranged along a common alignment axis, the common alignment axis preferably being directed perpendicular to the top and / or bottom. This advantageously results in a clear position setting perpendicular and horizontal to the circuit carrier level, as a result of which high manufacturing accuracy can be achieved.

In an advantageous further development of the electronics module, the common alignment axis and a force axis formed when the force acts on the tool effective areas of the positioning element are almost - preferably - completely congruent, forming the immediately closed force path. This advantageously ensures that no transverse forces and / or bending moments occur and that the electronic circuit and / or the tool can be dimensioned to be mechanically very compact.

In a preferred embodiment of the electronics module, the positioning element is firmly connected to the circuit carrier in the region of the cutout, in particular by means of a solder, adhesive, press-in and / or snap-in connection. In this way, a cost-effective and fixed connection can be ensured using a common connection technology. In principle, other embodiments of a form, force and / or material connection are also possible as an alternative.

In a favorable further development of the electronics module, each tool effective area of the positioning element has a tool support surface that can be subjected to force and / or a complementary shaped element for the positive engagement of a counter-shaped element of a tool part, for example a pin, a recess and / or an internal or external thread. In particular, pairings on the part of the positioning element and the tool part are suitable here, which enable a detachable fitting into one another with as little or no play as possible. Combinations are also conceivable here, such as an inner or outer cone, which provides a tool support surface and at the same time forms a position-positioning shaped surface. Alternatively, the effective area can be a tool support surface and a separate, adjacent or objectionable one Include molded element. In addition to a fixing and / or positioning function during the manufacturing process, an internal or external thread can additionally or exclusively provide a mechanical connection element of the electronic module formed.

An improved embodiment of the electronic module results from the fact that the positioning element has an embossing zone in at least or only one tool effective area for compensating the position tolerance of the circuit carrier. A tool knitting area is preferably provided as a fixed bearing, whereas the further tool knitting area has an oversize such that when the tool is closed, the oversize is brought to a desired dimension by the stamping. The embossing always ensures that the circuit carrier is fixed in place under load and is gentle on the load. The stamping is preferably carried out parallel to a vertical and / or horizontal circuit carrier level.

In one embodiment variant of the electronic module, at least one or all of the tool effective areas of the positioning area protrude beyond the module outer surface. A positive and / or non-positive connection results, for example, in that the end region or tool active region of the positioning element projecting beyond the module outer surface engages in a complementary recess in the tool part facing the end region or tool active region. In the electronics module then formed, the outstanding end region of the positioning element that remains in this way can offer favorable access as, for example, a mechanical connection element and / or an electrical connection element.

In another embodiment variant of the electronic module, at least one or all of the active tool areas of the positioning element are closed below or with the outer surface of the module. An advantage arises in particular in a compact design. Furthermore, the electronics module can be formed with a completely flat module outer surface, which results in a better possibility of connecting the electronics module to a support structure or substrate for some applications.

The positioning element is generally preferably pin-shaped or sleeve-shaped, for example with a round, oval, rectangular or polygonal basic shape. This advantageously enables the positioning element to be formed from a semi-finished bar material. By means of additional machining processes, step shoulders can also be introduced into the positioning element. Furthermore, respective sections of the positioning element on the top and bottom can have different cross-sectional shapes and / or sizes. Overall, the positioning element can thereby be optimized for simple assembly on the circuit carrier. The positioning element is preferably formed in one piece. In the case of a multi-part design of the positioning element, partial elements can be joined together prior to assembly on the circuit carrier or after a partial element has already been connected to the circuit carrier on the top or bottom.

An advantageous embodiment of the electronics module provides that the positioning element is formed from a force-deformable plastic in at least one of the tool effective areas, for example by a connected end element made from plastic. This can be stamped easily and with little force to compensate for the position tolerance of the circuit carrier. Alternatively, the positioning element is made entirely of plastic or metal.

In general, the electronics module has only one, two or further positioning elements, preferably three or four. More preferably, several positioning elements are arranged in an edge region of the circuit carrier. Several positioning elements are also preferably of the same design. Alternatively, at least two positioning elements can differ. The previously described designs of positioning elements can be provided in any desired pair.

1. a) Bereitstellen eines Schaltungsträgers mit einer elektronischen Schaltung, wobei mit dem Schaltungsträger zumindest ein Positionierelement fest verbunden wird, insbesondere innerhalb einer Aussparung des Schaltungsträgers, welches auf der Ober- und der Unterseite des Schaltungsträgers jeweils frei zugängliche Endbereiche mit jeweils zumindest einem Werkzeugwirkbereich aufweist,
2. b) Einlegen des bereitgestellten Schaltungsträgers innerhalb von zumindest zwei Werkzeugteilen, wobei jeweils ein Werkzeugwirkbereich einem verschiedenen Werkzeugteil zugewandt ist,
3. c) Verschließen der Werkzeugteile, wobei zwischen zumindest einem Teilbereich jeweils eines Werkzeugteiles mit dem ihm zugewandten Werkzeugwirkbereich des Positionierelementes eine lösbare form- und/oder kraftschlüssige Verbindung ausgebildet wird, durch welche die Lage des Schaltungsträgers innerhalb des verschlossenen Werkzeuges ortfest festgelegt wird,
4. d) Einbringen einer Umhüllungsmasse in fließfähigem Zustand in das verschlossene Werkzeug und Umschließen der elektronischen Schaltung durch die Umhüllungsmasse, wobei eine Modulaußenfläche des Elektronikmodules abgeformt wird und das Positionierelement an den Endbereichen durch den mit dem jeweiligen Werkzeugwirkbereich zusammenwirkenden Teilbereich eines Werkzeugteiles von Umhüllungsmasse freigehalten wird,
5. e) Verfestigen der Umhüllungsmasse des Elektronikmodules.

The invention also leads to a method according to the invention for forming an electronic module, in particular in one of the embodiments described above, with the method steps:

1. a) providing a circuit carrier with an electronic circuit, at least one positioning element being firmly connected to the circuit carrier, in particular within a recess of the circuit carrier, which has freely accessible end regions with at least one tool effective region on the top and bottom of the circuit carrier,
2. b) inserting the circuit carrier provided within at least two tool parts, one tool effective area in each case facing a different tool part,
3. c) closing the tool parts, a detachable positive and / or non-positive connection being formed between at least one partial area of each tool part with the tool effective area of the positioning element facing it, by means of which the position of the circuit carrier within the closed tool is fixed in place,
4. d) introducing a coating compound in a flowable state into the closed tool and enclosing the electronic circuit by the coating compound, an outer module surface of the electronic module being molded and the positioning element at the end regions being kept free of coating compound by the partial region of a tool part interacting with the respective tool effective region,
5. e) solidifying the encapsulation mass of the electronic module.

In an advantageous development of the method, in method step c), when the tool parts are closed, a closed direct force path is formed exclusively between them and the at least one positioning element, the circuit carrier remaining free of any power line.

In a favorable embodiment of the method, in method step c), when the tool parts are closed in at least one tool effective area of at least one positioning element, plastic embossing takes place to compensate for the position tolerance of the circuit carrier.

The method shows the same advantages that have already been mentioned in the electronic module according to the invention.

Figure list

• 1: einen Teilausschnitt eines Elektronikmodules in einer seitlichen Schnittdarstellung.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing. This shows in:

• 1 : a partial section of an electronic module in a side sectional view.

Embodiments of the invention

In the 1 is a partial section of an electronic module 100 shown. The electronics module 100 includes a circuit carrier equipped on one or two sides 10th . Examples are on a top 11 and on a bottom 12th arranged electrical and / or electronic components 20 shown. The circuit carrier 10th also has a conductor structure (not shown), which with the electrical and / or electronic components 20 with the formation of an electronic circuit 30th is electrically connected. The electronic circuit 30th is together with the circuit carrier 10th from a wrapping mass 40 enclosed, for example a solidified molding material. Due to the solidified coating mass 40 points the electronics module 100 a module housing 50 on which particular the electronic circuit 30th and the circuit carrier 10th protects from external influences, for example a mechanical force, media influences, direct electrical contact and / or against others. The electronics module 100 has an outer module surface 55 which is preferably largely closed. With the circuit board 10th is a positioning element 60 firmly connected, for example by a solder, adhesive, press-fit and / or a snap-in connection. The circuit carrier 10th also has a recess 15 on, for example a round opening which is from the positioning element 60 is at least so penetrated that this is from both sides of the circuit carrier 10th is accessible. For a simple execution it is advisable that the positioning element 60 is pin or sleeve-shaped, with an alignment axis A the pin or a sleeve perpendicular to the circuit board sides 11 , 12th is aligned. In the present exemplary embodiment there are partial sections 60a , 60b of the positioning element 60 from the top or bottom 11 , 12th of the circuit carrier 10th from. One end area is sufficient 61 finally at least up to the outer surface of the module 55 . For example, the end area closes 61 on the side of the section 60b of the positioning element 60 just with the module outer surface 55 from. Alternatively, at least one of the end areas 61 also over the outer surface of the module 55 protrude, such as on the side of the section 60a of the positioning element 60 shown. Basically, however, is a respective partial area of the module outer surface 55 in the end areas 61 of the positioning element 60 from the wrapping mass 40 exposed. The positioning element 60 is designed, the position of the circuit carrier 10th while enclosing the electronic circuit 30th or the circuit carrier 10th with the coating mass 40 between at least two tool parts 201 , 202 fix and keep stationary. A respective end region has this 61 a tool knitting area 62 which, in a tool-based encapsulation process, is in an operative connection with the module housing 50 forming tool parts 201 , 202 brought. In the 1 is schematically a closed multi-part tool 200 (dashed). The assembled circuit board 10th is inserted into the tool for a wrapping process in such a way that a tool effective area in each case 62 a different tool part 201 , 202 is facing. When closing the tool parts 201 , 202 is between at least a partial area of a tool part 201 , 202 with the tool knitting area facing it 62 of the positioning element 60 a releasable non-positive and / or positive connection 262 educated. A tool knitting area 62 includes, for example, a tool support surface that can be subjected to force 62a on which a tool counter surface with a Tool clamping force F presses. The tool support surface 62a is, for example, conical, for example as a cone or truncated cone. Alternatively or additionally, a tool knitting area 62 a complementary feature 62b for positive engagement in a counter-shaped element of a tool part 201 , 202 on, for example a pin, a recess and / or an internal or external thread. Overall, such a releasable positive and / or non-positive connection 262 the location of the populated circuit carrier 10th inside the locked tool 200 fixed. At the same time, there is only an immediately closed force path K between the tool effective areas 62 educated. This enables the circuit carrier 10th does not have to be involved in any power transmission. The alignment axis is preferred A and one when the force acts on the tool effective areas 62 of the positioning element 60 trained power axis F ' almost or preferably completely congruent. Optionally, the positioning element 60 in at least or only one tool knitting area 60a , 60b a stamping zone 62c for position tolerance compensation of the circuit carrier 10th exhibit. When the tool is closed 200 is over the stamping zone 62c the positioning element 60 pressed to a target dimension. Every constructive implementation of a stamping zone 62c What is common is that plastic compression and, if necessary, displacement of the material of the positioning element 60 within the tool effective range 62 in the direction of the closing force F is made possible, for example by small, mechanically weak, protruding embossed structures. For this, the positioning element 60 be made of metal or alternatively in at least one of the tool effective areas 62 be made of a deformable plastic.

The now determined position of the circuit carrier 10th can in this way by means of at least one, two or more positioning elements 60 for a subsequent encapsulation process to form the module housing 50 be kept stationary. This is a coating mass 40 in a flowable state under pressure or without pressure into the interior of the closed tool 200 brought and then solidified. When opening the tool parts 201 , 202 the non-positive and / or form-fitting connection is released, the positioning element 60 at the end areas 61 through with the respective tool knitting area 62 interacting part of a tool part 201 , 202 of coating mass 40 was kept free.

Basically, at least one end area 61 a positioning element 60 have an internal or external thread. In principle, this can also function as a tool effective area for the coating process 62 take over. In the trained electronics module 100 is the positioning element 60 then usable via the internal or external thread as a mechanical fastening connection, for example for fastening to a further support structure. Alternatively, the positioning element 60 usable as an electrical connection, for example as a power connection or ground connection. In this case, the positioning element in question 60 additionally with the conductor structure of the electrical circuit 30th electrically contacted.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102005014427 A1 [0003]
• DE 102013211100 A1 [0004]

Claims (15)

Electronic module (100), comprising a circuit carrier (10) with an upper side (11) and a lower side (12) and with an electronic circuit (30) arranged at least on the upper and / or lower side (11, 12), the electronic Circuit (30) is enclosed by an encapsulation compound (40) to form an outer module surface (55), at least one partial element within the electronic module (100) being exposed by the encapsulant compound (40) in at least a partial area of the outer module surface (55), characterized in that that the at least one sub-element is a positioning element (60) which is designed to fix the position of the circuit carrier (10) during the encapsulation of the electronic circuit (30) with the encapsulation compound (40) between at least two tool parts (201, 202), the positioning element (30) on one of the underside (12) and one on the top (11) facing portion of the module outer surface (55) on one the respective end area 61 is exposed from the encapsulation compound (40), the respective end area (61) having at least one tool knitting area (62, 62a, 62b, 62c) which is designed in operative connection with one of the tool knitting area (62, 62a, 62b, 62c) ) facing tool part (201, 202) to form a releasable non-positive and / or positive connection (262). Electronics module (100) after Claim 1 , characterized in that the positioning element (60) penetrates the circuit carrier (10) through a recess (15), with an immediately closed force path (60) when the force acting on the tool effective areas (62, 62a, 62b, 62c) of the positioning element (60) K) is formed between the tool effective areas (62, 62a, 62b, 62c). Electronics module (100) after Claim 2 , characterized in that the two tool effective areas (62, 62a, 62b, 62c) and the recess (15) in the circuit carrier (10) are arranged along a common alignment axis (A), the common alignment axis (A) preferably perpendicular to the top - And / or bottom (11, 12) is directed. Electronics module (100) after Claim 3 , characterized in that the common alignment axis (A) and a force axis (F) formed when the force acts on the tool effective areas (62, 62a, 62b, 62c) of the positioning element (60) are almost or preferably completely congruent. Electronic module (100) according to one of the Claims 2 to 4th , characterized in that the positioning element (60) is firmly connected to the circuit carrier (10) in the region of the cutout (15), in particular by means of a solder, adhesive, press-in and / or snap-in connection. Electronic module (100) according to one of the preceding claims, characterized in that in each case a tool effective area (62, 62a, 62b, 62c) of the positioning element (60), a tool support surface which can be acted upon by force and / or a complementary shaped element for the positive engagement of a counter-shaped element of a tool part (201, 202), for example a pin, a recess and / or an internal or external thread. Electronic module (100) according to one of the preceding claims, characterized in that the positioning element has at least or only one tool effective area (62, 62a, 62b, 62c) an embossing zone for a position tolerance compensation of the circuit carrier (10). Electronic module (100) according to one of the preceding claims, characterized in that at least one or all tool effective areas (62, 62a, 62b, 62c) of the positioning area (60) protrude beyond the module outer surface (55). Electronic module (100) according to one of the Claims 1 to 7 , characterized in that at least one or all of the active tool areas (62, 62a, 62b, 62c) of the positioning element (60) end below or with the outer module surface (55). Electronic module (100) according to one of the preceding claims, characterized in that the positioning element (60) is designed in the form of a pin or sleeve. Electronic module (100) according to one of the preceding claims, characterized in that the positioning element (60) is formed in one piece. Electronic module (100) according to one of the preceding claims, characterized in that the positioning element (60) is formed from a force-deformable plastic in at least one of the tool effective areas (62, 62a, 62b, 62c). Method for forming an electronic module (100), in particular according to one of the Claims 1 to 12th , with the method steps: a) providing a circuit carrier (10) with an electronic circuit (30), at least one positioning element (60) being firmly connected to the circuit carrier (10), in particular within a recess (15) of the circuit carrier (10) , which on the top and bottom (11, 12) of the circuit carrier (10) each having freely accessible end regions (61) each with at least one tool effective region (62, 62a, 62b, 62c), b) inserting the circuit carrier (10) provided within at least two tool parts (201, 202), wherein each tool effective area (62, 62a, 62b, 62c) faces a different tool part (201, 202), c) closing the tool parts (201, 202), with a tool part (201, 202) with the the tool effective area (62, 62a, 62b, 62c) of the positioning element (60) facing it is designed to have a releasable non-positive and / or positive connection, by means of which the position of the circuit carrier (10) within the closed tool (200) is fixed in place, d ) Introducing an encapsulation compound (40) in a flowable state into the closed tool (200) and enclosing the electronic circuit (10) by the encapsulation compound (40), one module outer surface (55) of the electronic module (100) is molded and the positioning element (60) at the end regions (61) through the partial region of a tool part (201, 202) of the encapsulation compound that interacts with the respective tool effective region (62, 62a, 62b, 62c) ( 40) is kept free, e) solidifying the encapsulation mass (40) of the electronic module (100). Procedure according to Claim 13 , characterized in that in method step c) when the tool parts (201, 202) are closed, a closed direct force path (K) is formed exclusively between them and the at least one positioning element (60), the circuit carrier (10) remaining free of any power line . Procedure according to Claim 13 or 14 , characterized in that in method step c) when the tool parts (201, 202) are closed in at least one tool effective area (62, 62a, 62b, 62c) at least one positioning element (60) is plastic embossed to compensate for the position tolerance of the circuit carrier (10).

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