Method for manufacturing a microphone unit

Abstract

Method for manufacturing a microphone unit (1; 101; 201) that can be contacted with a plug (501), comprising the steps: - Bending of contacts (2 - 5; 102 - 105; 202 - 205) held immovably relative to each other by a bridge (601), such that first contact ends (2a - 5a) of the contacts (2 - 5) formed side by side and as press-fit ends (7 - 10) enclose an angle (α) of at least 90° to second contact ends (2b - 5b) of the contacts (2 - 5) formed side by side and as contact pins (11 - 14) in pairs, - Overmolding a first assembly (31) comprising the contacts with a housing (6; 106; 206) such that the press-fit ends (7 - 10) of the contacts (2 - 5) protrude into a first cavity (18; 118) of the housing (6; 106; 206) and that the contact pins (11 - 14) of the contacts (2 - 5) protrude into a second cavity (15) of the housing (6; 106; 206), - Providing a second assembly (25), wherein this is formed by applying a microphone component (20) to a printed circuit board (19) as a surface-mounted component, - Formation of a press-fit connection between the press-fit ends (7 - 10) of the contacts (2 - 5) and the printed circuit board (19) equipped with the microphone component (20) when inserting the printed circuit board (19) into the first cavity (18; 118), such that the press-fit ends (7 - 10) of the contacts (2 - 5) are pressed into metallized through holes (28, 29) of the printed circuit board (19), characterized in that - the contacts (2 - 5) are overmolded to form the first assembly (31) by forming a retaining plate (30; 130) and - the bridge (601) is removed after the formation of the retaining plate (30; 130) and before the manufacture of the housing (6; 106; 206).

Description

[0001] The invention relates to a method for manufacturing a microphone unit according to the preamble of claim 1.

[0002] From DE 10 2013 014 526 A1 a microphone unit is known which can be connected via a plug.

[0003] From DE 10 2006 037 691 A1 a mold housing for an electronic circuit for installation in electronic devices and / or applications is known, which includes press-fit zones.

[0004] Furthermore, WO 2007 / 131374 A1 discloses a proximity sensor which comprises a printed circuit board which includes the sensor electronics, a sensor element and a sensor interface, wherein the electrical connections between the printed circuit board and the sensor interface and / or the sensor element are made via plug contacts.

[0005] Furthermore, DE 195 44 660 A1 discloses a plug arrangement for an electrical device with metallic plug tongues embedded in a plastic part, which can be connected to an electronic component or an electronic circuit arrangement, wherein the plug tongues are mechanically firmly connected to the component for easy adjustment of the plug arrangement.

[0006] From DE 43 40 280 A1 a component set is known in which pins are pressed into bores in a circuit carrier plate by means of spring clamps using a press-fit technique.

[0007] From DE 10 2006 055 086 B3, press-fit pins made of wire material for electrical contacts are known, which, for example, have curved shoulder elements that serve as support during pressing in.

[0008] Finally, a method for manufacturing a control unit housing with connector pins arranged therein is known from DE 10 2012 001 478 A1, wherein the connector pins with their contact ends form a press-fit connection with a printed circuit board to be inserted into the control unit.

[0009] The object of the invention is to propose a method for manufacturing a microphone unit and such a microphone unit, by which an effective manufacturing of the microphone unit is made possible.

[0010] This problem is solved by means of the characterizing features of claim 1, starting from the features of the preamble of claim 1. Advantageous and expedient embodiments are specified in the dependent claims.

[0011] The inventive method for manufacturing a microphone unit that can be contacted with a plug comprises the following steps: - Bending of contacts held immovably relative to each other by a bridge, such that contact ends formed side by side and as press-fit ends of the contacts enclose an angle of at least 90° to contact ends formed side by side and as contact pins of the contacts in pairs, - Overmolding a first assembly comprising the contacts with a housing, such that the press-fit ends of the contacts protrude into a first cavity of the housing and that the contact pins of the contacts protrude into a second cavity of the housing, - Providing a second assembly, which is formed by applying a microphone component to a printed circuit board as a surface-mounted component, - Creating a press-fit connection between the press-fit ends of the contacts and the circuit board equipped with the microphone component when inserting the circuit board into the first cavity, such that the press-fit ends of the contact pins are pressed into metallized through holes in the circuit board.

[0012] This manufacturing process for the microphone unit eliminates the need to assemble components in a multi-part housing. Instead, the complete microphone unit is built step-by-step, essentially from the inside out, and then completed with the pre-assembled circuit board. This reduces costs and increases quality.

[0013] By overmolding the contacts to form the first assembly and thereby producing a retaining plate to fix the contacts, the first assembly formed can be handled particularly well in preparation for the overmolding process to form the housing, since the rigid retaining plate allows handling and orientation of the first assembly without the risk of bending the contact pins.

[0014] The bridge is removed after the mounting plate has been formed and before the housing has been manufactured. At this point, the first assembly is not yet installed and can still be easily handled for the removal operation.

[0015] The contacts are designed to be overmolded in such a way that the retaining plate is positioned on the contacts in such a way that the retaining plate encases the contacts between the bends where the contacts are angled and the contact ends, which are designed as contact pins. This ensures that the retaining plate is oriented in relation to the contact ends, allowing them to pass through the retaining plate without bending. Thus, the contact ends, which are designed as contact pins, are optimally supported by the retaining plate for easy insertion and removal of a connector.

[0016] If the contacts are overmolded with a retaining plate without prior overmolding, the bridge is intended to be removed only after the housing has been manufactured. This allows the contacts to be handled together with the housing before the overmolding process.

[0017] It is also planned to provide the circuit board with a dust cover after it has been mounted in the first cavity of the housing. This ensures that the microphone component is particularly well protected within the housing.

[0018] Furthermore, it is planned that during the manufacturing of the housing, at least one fastening pin designed like a press-fit end will be embedded in the housing in such a way that it projects into the first cavity parallel to the press-fit ends of the contacts. This makes it possible to connect the fastening pins to the housing in the same step in which the contacts or the first component unit are also connected to the housing.

[0019] Finally, the process involves creating a press-fit connection between the press-fit ends of the contact pins and the circuit board, as well as a press-fit connection between the press-fit end of the connecting pin(s). This allows the circuit board to be fixed at additional points during the contact-making process with the housing, thus ensuring a reliable and permanent hold within the second cavity of the housing.

[0020] In this microphone unit, the housing is manufactured as a single injection-molded part, and the first contact ends are designed as press-fit contacts. With this type of microphone unit, it is not necessary to close a multi-part housing after component assembly or to perform a soldering process to connect the contacts to the circuit board. This reduces costs and increases quality.

[0021] For the purposes of the invention, the process of overmolding is understood to be an injection molding operation corresponding to the so-called "insert molding" process, in which an insert part or inserts are arranged in a cavity of an injection mold and then overmolded with a plastic, resulting in a one-piece component whose individual components are firmly connected to each other.

[0022] For the purposes of this invention, a surface-mount device is understood to be a component, such as a microphone component, that is soldered directly onto solderable pads on a printed circuit board. In English, such a component is referred to as a "surface-mount device," abbreviated as "SMD."

[0023] For the purposes of the invention, a press-fit connection is understood to be a connection in which press-fit ends arranged on components are pressed into metallized holes of a printed circuit board in such a way that the press-fit ends are deformed during pressing and thus a permanent and reliable electrical connection is established between the press-fit ends and the metallized holes.

[0024] For the purposes of the invention, a press-fit end of a contact is understood to be a contact end which, by virtue of its shape and material properties, is suitable for being pressed into a suitable, metallized through-hole of a circuit board, thereby forming an electrical contact.

[0025] Further details of the invention are described in the drawing with reference to schematically illustrated embodiments.

[0026] This shows: Fig. 1: a perspective view of a first microphone unit according to the invention; Fig. 2: a top view of contacts held together by a bridge; Fig. 3: a top view of the area in the Fig. 2 shown contacts with an injection-molded mounting plate; Fig. 4: one of the Fig. 3 corresponding representation, with the bridge removed; Fig. 5: one of the Fig. 4 corresponding representation, with the contacts bent; Fig. 6: another representation of the in the Fig. 1 microphone unit shown; Fig. 7: a bottom view of the in the Fig. 1 and Fig. 6 microphone unit shown; Fig. 8: a second version of the microphone unit in bottom view with the circuit board removed; Fig. 9: a third variant of the microphone unit in bottom view with the circuit board removed and Fig. 10: a translucent, perspective view of the in the Fig. 8 shown design variant.

[0027] In the Fig. Figure 1 shows a first embodiment of a microphone unit 1 according to the invention in a perspective view. The microphone unit 1 comprises four microphones, also shown in the Fig. Two contacts 2, 3, 4 and 5 are shown, and a housing 6. The four contacts 2 to 5 pass through the housing 6. The first contact ends 2a to 5a of contacts 2 to 5 are each designed as press-fit ends 7 to 10, and the second contact ends 2b to 5b as contact pins 11 to 14. The contact pins 11 to 14 protrude – as shown in the Fig. 1 shown - into a second cavity 15 of the housing 6 and together with a rim 16 form a socket 17, into which a Fig. The schematically depicted connector 501 can be plugged in to integrate the microphone unit 1 into a communication system, for example in a vehicle.

[0028] The Fig. 6 and Fig. Figure 7 shows microphone unit 1 in further views. In the Fig. Figure 7, which shows the microphone unit 1 obliquely from below, reveals not only the second cavity 15, but also a first cavity 18, which is partially closed by a circuit board 19. On the upper side of this circuit board, facing away from the viewer, a microphone component 20, schematically indicated by dashed lines and designed as a so-called SMD component, is soldered. Four metallized through-holes 21 to 24 are formed in the circuit board 19, through which the press-fit ends 7 to 10 of the contacts 2 to 5 projecting into the first cavity 18 are visible. Fig. Figure 7 shows the circuit board 19 in its fully assembled position, in which electrical connections between contacts 2 to 5 and the circuit board 19 are already completely established, so that contacts 2 to 5 also mechanically hold the circuit board 19 in the position shown. For additional fixation of the circuit board 19, which together with the microphone component 20 forms a second assembly 25, the housing 6 includes two cast-in mounting pins 26, 27, which protrude through further through-holes 28, 29 in the circuit board 19 and, when the circuit board 19 is pressed into the first cavity 18, form a frictional connection with it.

[0029] Before contacts 2 to 5 are overmolded with the housing 6 in a so-called "insert molding" process, they are first overmolded with a retaining plate 30 in a preceding "insert molding" process such that the retaining plate 30 - as shown in the Fig. Figures 3 to 5 show the contacts 2 to 5 fixed to each other. To facilitate the insertion of the four contacts 2 to 5 into a cavity of an injection mold for the first "insert molding" process, the contacts 2 to 5 are first fixed, as shown in the Fig. 2 and Fig. 3 shown, connected by a bridge 601. As can be seen from the overview of the Fig. 3 and Fig. As shown in Figure 4, bridge 601 will be removed after the production of the retaining plate 30. A summary of the Fig. 4 and Fig. Figure 5 shows that the first contact ends 2a to 5a of contacts 2 to 5, which are designed as press-fit ends 7 to 10, are bent after the removal of the bridge 601 in preparation for a second insert molding process step such that the individual contacts 2 to 5, with their first contact ends 2a to 5a and second contact ends 2b to 5b, each enclose a 90° angle α. As the Fig. As shown in Figure 5, the retaining plate 30 is fixed to the contacts 2 to 5 between bends B2 to B5 of the contacts 2 to 5 and the contact ends 2b to 5b of the contacts 2 to 5, which are designed as contact pins 11 to 15, by the insert molding process. In a first variant of the process, the contacts 2 to 5 are bent before the retaining plate 30 is manufactured. In a second variant of the process, the contacts 2 to 5 are bent after the retaining plate 30 has been manufactured. Accordingly prepared, a first assembly 31 formed from the bent contacts 2 to 5 and the retaining plate 30 is then inserted into a cavity of a second injection mold (not shown) and overmolded in such a way that the material in the Fig. 1, Fig. 6 and Fig. The housing 6 shown in Figure 7 is created, and after overmolding, the circuit board 19 still needs to be mounted on it to complete the microphone unit 1. The circuit board 19 (see Figure 7) Fig. 7) is assembled by pressing it into the first cavity 18 in the direction of the press-fit ends 7 to 10, thereby establishing electrical contacts between the press-fit ends 7 to 10 and the conductor tracks (not shown) on the circuit board 19. The housing 6 is designed such that the first cavity 18 and the second cavity 15 are hermetically and liquid-tightly separated from each other.

[0030] In the Fig. 8 is analogous to the representation of the Fig. Figure 7 shows a second embodiment of a microphone unit 101, in which no printed circuit board is yet mounted on a housing 106. However, in the perspective view, a retaining plate 130 cast into the housing 106 is visible, which partially projects into a first cavity 118. Furthermore, press-fit ends 107 to 110 are visible, which project from a casting compound GM106 of the housing 106 into the first cavity 118. Mounting pins 126, 127 are formed with press-fit ends 126a, 127a, so that further press-fit connections are made for the additional fastening of the printed circuit board (not shown). These connections have no electrical function and serve only for the mechanical retention of the printed circuit board.

[0031] In the Fig. 9 is analogous to the representation of the Fig. 7 or the Fig. Figure 8 shows a third embodiment of a microphone unit 201, in which no circuit board is yet mounted on a housing 206. In this embodiment, the contacts 202 to 205 are overmolded with the housing 206 without having been previously overmolded with a retaining plate. Accordingly, the contacts 202 to 205 were still connected by a bridge during the manufacture of the housing 206 in order to be able to handle them together despite the missing retaining plate. Otherwise, the third embodiment of the microphone unit 201 is comparable to the second embodiment of the microphone unit 101.

[0032] With regard to connectors 117 and 217, the second and third microphone units 101 and 201, respectively, are designed in accordance with the first microphone unit 1. Views 7 to 9 show microphone units 1, 101, and 201 such that the second contact ends of the contacts are not visible.

[0033] The Fig. Figure 10 shows the second version of the microphone unit 101 as a perspective glass model with visible and hidden edges. This view shows how the contacts 102 to 105 extend through the housing 106 and how the mounting plate 130 is embedded in the housing 106. A circuit board with a microphone component mounted on it is shown in the Fig. 10 not shown, but is corresponding to the representation of the Fig. 7, wherein the circuit board naturally has through holes suitable for the fastening pins 126, 127. Reference symbol list: 1 microphone unit 1 2 - 5 Contact 2a - 5a End of contact 2b - 5b End of contact 6 cases 7 - 10 Pressfit end 11 - 14 Contact pin 15 second cavity of 6 16 Border of 17 17 socket 18 first cavity 19 printed circuit board 20 microphone components 21 - 24 metallized through hole 25 second assembly 26, 27 Fastening pin 28, 29 Through hole 30 Mounting plate 31 first assembly B2 - B5 Bending from 2 to 5 α Angle between 2a - 5a and 2b - 5b 101 microphone unit 102 - 105 Contact 107 - 110 Pressfit end 106 cases 107 - 110 Pressfit end 117 Socket 118 first cavity 126, 127 Fastening pin 126a, 127a Pressfit end 130 Mounting plate GM106 casting compound 201 Microphone unit 202 - 205 Contact 206 cases 217 Socket 501 plug 601 Bridge

Claims

[1] Method for manufacturing a microphone unit (1; 101; 201) that can be contacted with a plug (501), comprising the steps: - Bending of contacts (2 - 5; 102 - 105; 202 - 205) held immovably relative to each other by a bridge (601), such that first contact ends (2a - 5a) of the contacts (2 - 5) formed side by side and as press-fit ends (7 - 10) enclose an angle (α) of at least 90° to second contact ends (2b - 5b) of the contacts (2 - 5) formed side by side and as contact pins (11 - 14) in pairs, - Overmolding a first assembly (31) comprising the contacts with a housing (6; 106; 206) such that the press-fit ends (7 - 10) of the contacts (2 - 5) protrude into a first cavity (18; 118) of the housing (6; 106; 206) and that the contact pins (11 - 14) of the contacts (2 - 5) protrude into a second cavity (15) of the housing (6; 106; 206), - Providing a second assembly (25), wherein this is formed by applying a microphone component (20) to a printed circuit board (19) as a surface-mounted component, - Forming a press-fit connection between the press-fit ends (7 - 10) of the contacts (2 - 5) and the printed circuit board (19) equipped with the microphone component (20) when inserting the printed circuit board (19) into the first cavity (18; 118), such that the press-fit ends (7 - 10) of the contacts (2 - 5) are pressed into metallized through holes (28, 29) of the printed circuit board (19), characterized by , that - the contacts (2 - 5) are overmolded to form the first assembly (31) by forming a retaining plate (30; 130) and - the bridge (601) is removed after the formation of the retaining plate (30; 130) and before the manufacture of the housing (6; 106; 206). [2] Method according to claim 1, characterized by, that the contacts (2 - 5) are overmolded in such a way that the retaining plate (30; 130) is formed on the contacts (2 - 5) between bends (B2 - B5) of the contacts (2 - 5) and the contact ends (2b - 5b) of the contacts (2- 5) which are designed as contact pins (11 - 14). [3] Method according to claim 1, characterized by , that the bridge (601) is removed after the manufacture of the housing (6; 106; 206). [4] Method according to at least one of the preceding claims, characterized by , that the circuit board (19) is provided with a dust cover after assembly in the first cavity (18; 118) of the housing (6; 106; 206). [5] Method according to at least one of the preceding claims, characterized by, that during the manufacture of the housing (106; 206) at least one fastening pin (126, 127) designed in the manner of a press-fit end (126a, 127a) is embedded in the housing (106; 206) in such a way that it projects into the first cavity (118) parallel to the press-fit ends (107 - 110) of the contacts (102 - 105). [6] Method according to claim 5, characterized by , that when making the pressfit connection between the pressfit ends (107 - 110) of the contact pins (102 - 105) and the printed circuit board, a pressfit connection is also made between the pressfit end (126a, 127a) of the fastening pin (126, 127) or the pressfit ends of the fastening pins (126, 127).

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