JP6646943B2 - Method for manufacturing MID circuit carrier and MID circuit carrier - Google Patents

Description

  The present invention relates to a method for manufacturing an MID circuit carrier and to this type of MID circuit carrier.

  An MID (Molded Interconnect Devices) circuit carrier is an injection-molded circuit carrier that includes a three-dimensionally molded substrate and a metal conductive path formed in at least one surface region of the substrate. I have. This allows a sufficiently optional three-dimensional shaping of the substrate, or the incorporation of conductive paths into the surface of the structure to be configured in a sufficiently optional three-dimensional manner.

  Various MID manufacturing methods are known, for example two-component injection molding and laser MID methods such as, for example, laser direct structuring (LDS). In the case of LDS, a metal core, for example small metal particles, is received in a plastic material, which is then suitably shaped by an injection molding method. Next, laser structuring is performed, exposing the metal nuclei in the surface region to be structured. Next, the surface region or the entire injection molded body is exposed to passive plating in a plating bath, for example in a solution containing copper ions. In this way, a chemical coating is created based on the potential difference between the metal nucleus and the copper ions in the solution, which forms a first metallization layer, typically made of non-alloyed copper. You.

  Passive plating can be continued further to form thicker conductive paths. However, the vias can also grow in lateral width, resulting in small pitch or modular dimensions, ie, small lateral spacing between the centers of the vias, which can cause short circuiting after some processing time. In addition, the presence of passive contaminating particles can collectively settle into the structure via the solution, which limits material properties, especially ductility. Thus, the advantages of passive plating are, firstly, the possibility of forming fine modular dimensions or small spacing between conductive paths and narrow conductive paths, but the thickness and material quality of the conductive paths are limited. Limited.

  Subsequent to the formation of the first metal layer of passive plating, active plating can follow. For this purpose, an electric potential, that is, a voltage is applied to the individually formed conductive paths to an appropriate plating tank. Active plating can be constructed faster in process technology and allows the use of purposeful materials with higher ductility and better material properties, for example to form alloys of gold and nickel To

  However, if the conductor structure is configured to have small lateral conductors and fine modular dimensions, for example 150 μm or less, or for example 100 μm or less, the contact of the individual conductors for active plating is partially Difficult.

  According to the invention, the injection-molded body is configured to have a contact area, for example to have a terminal contact, on which at least one conductor consolidation with which at least two conductive paths contact is provided. Have been.

  In particular, only one conductor concentrator, i.e. the central conductor concentrator, has to be provided in order to make all the conductive paths contact. However, in principle, it is also possible to configure a plurality of conductors, for example a plurality of contact areas, each with one conductor.

  The formation of the conductor junction in the MID manufacturing method is performed for the active electrolytic deposition of the second metal layer, ie for applying a voltage to perform active plating. However, the wire connection is then removed again, so that the conductive paths are disconnected from one another.

  According to the present invention, several advantages are achieved.

  By performing active electroplating or by applying a voltage, a suitable material can be selected, and excellent material properties, particularly high ductility, and thus high mechanical stress resistance can be achieved. be able to. Active electrolytic deposition can take place under certain conditions, the layer thickness being determined by the load supply and thus by the current. Furthermore, the growth of the conductive tracks in the lateral direction can thus avoid or at least reduce the risk of short circuits.

  Narrow conductive tracks in the lateral direction and fine modular dimensions can be achieved, for example conductive tracks with a width of less than 60 μm and modular dimensions of less than 150 μm, for example less than 100 μm. This is because the conductor junctions or the connection contacts connected to the conductor junctions can be formed with a larger lateral width and can therefore make electrical contact without hindrance. Thus, the lateral width and the modular dimensions of the conductive path are not essentially limited by the electrolytic method.

  The conductive paths contact one another via one common conductor stack or several conductor collectors, the conductor collectors being provided only for active electrolytic deposition or active plating. Is then removed again. This is because the conductive path is used for a separate function as usual, for example to allow various contacts of a plurality of electrical elements.

  The removal of the conductor bundle can advantageously be effected by the removal of the entire contact area, so that the contact area is formed as a thin terminal contact which is formed only temporarily as part of the injection molding and is subsequently removed. It may be formed.

  For this purpose, the contact area or the terminal contact can be configured with a defined disconnection point, where they are subsequently disconnected. The individual conductor paths thus extend via the defined disconnection points to at least one conductor connection provided in the contact area, so that when the defined disconnection points are disconnected, the individual conductor paths are already disconnected or separated. Electrical singulation is performed. In this case, the defined breaking points can be formed as mechanically thin sections, in particular as defined breaking points, so that the mechanical breaking step can be carried out, for example, by bending or by mechanical cutting. Furthermore, the defined cut-off points can be cut off by laser cutting or laser cutting.

  This allows for further advantages.

  It is only necessary to structure and plate a relatively large surface area. The relatively large surface area has, in addition to the circuit surface area of the substrate, a terminal contact surface area for the conductor consolidation and possibly the connection contacts, but does not slow down the process.

  By decoupling the contact areas, an electrical decoupling or individualization of the individual conductive paths is achieved with a high degree of certainty.

  Thus, the method according to the invention allows for high process reliability with very low added costs, and offers significant advantages, in particular, improved plating processes and material selection and rapid process control.

  As an alternative to disconnecting the contact area, only the wire connection and possibly additional connection contacts may be removed from the contact area, for example by laser ablation. In this way, the contact area can be subsequently utilized, for example, for positioning the operation of the MID circuit carrier.

  The conductor junction can be particularly straight, for example, if the defined disconnection points are provided as defined breakpoints for directly breaking or cutting the contact area. However, non-linear or non-straight configurations of the conductor concentrator are also possible, in which case, for example, cutting or punching out or laser cutting as described above.

FIG. 3 is a detailed enlarged view of the MID circuit carrier according to the embodiment of the present invention before disconnecting the terminal contacts. FIG. 3 illustrates one of a series of steps of a method of manufacturing a MID circuit carrier according to one embodiment of the present invention. FIG. 3 illustrates one of a series of steps of a method of manufacturing a MID circuit carrier according to one embodiment of the present invention. FIG. 3 illustrates one of a series of steps of a method of manufacturing a MID circuit carrier according to one embodiment of the present invention. FIG. 3 illustrates one of a series of steps of a method of manufacturing a MID circuit carrier according to one embodiment of the present invention. FIG. 3 illustrates one of a series of steps of a method of manufacturing a MID circuit carrier according to one embodiment of the present invention.

  According to FIG. 1, the three-dimensional injection molded body 3 is formed from a plastic material or a molding material. On at least one surface region 4 of the injection molding 3, a conductive path structure 5 with a plurality of individual conductive paths 6 is formed. According to the embodiment shown in the figures, the surface area 4 structured by the conductive path 6 is formed substantially flat or planar, but basically on a curved surface or The conductive path 6 may be formed on the three-dimensional forming surface, for example, may be formed in a cylindrical region shown on the lower side in FIG.

  The integral injection-molded body 3 has, as a partial area, a substrate 7 and terminal contacts 2, which are connected to one another via defined breaks 8. The defined breaking point 8 may be formed, for example, as a thin-walled part, as indicated, for example, by a notch 9, a recess or a notch in FIG. The structured surface area 4 extends from the substrate to the terminal contact 2 via a defined break 8, so that a circuit surface area 4 a is formed on the substrate 7, and the terminal contact surface area is formed on the terminal contact 2. 2a are formed, and the circuit surface area and the terminal contact surface area are formed by one or more common continuous metallization layers extending through defined breaks 8.

  The individual conductive paths 6 extend through a connection plate 10 that is bent at a right angle here, from the connection plate 10 via a defined breaking point 8 on the terminal contact surface area 2a and all the conductive paths 6 6 to one common wire junction 12 that is in electrical contact with 6. The conductor junction 12 transitions to or is connected to a connection contact 14 formed on the terminal contact surface area 2a. The central connecting plate 10 may extend, for example, over the entire terminal contact 2, but such an arrangement is expensive and costly.

  The substrate 7 provided with the circuit surface area 4a forms the MID circuit carrier 1 up to the specified breaking point 8. In this case, the plurality of conductive paths 6 in the circuit surface region 4a are initially electrically connected or short-circuited via the conductor connecting portion 12.

  As an alternative to the embodiment of FIG. 1, it is also possible to configure the MID circuit carrier 1 with a plurality of terminal contacts 2, so that the central connecting plate 10 of each terminal contact 2 is a conductor. 6 and is in contact with a part thereof.

  The manufacture of the MID circuit carrier 1 will be described with reference to one embodiment of FIGS. Basically, the MID circuit carrier 1 can be formed by various MID manufacturing methods. In the following, laser direct structuring (LDS) will be described in particular, but is generally not limited to this.

  First, according to FIG. 2, an injection molded body 3 made of a plastic material or a molding material mixed with an additive is formed by an injection molding method.

  In this case, the injection molded body 3 can be formed in one step, or the substrate 7 can be formed first and the terminal contact 2 can be injected.

  Next, in FIGS. 3 to 5, the surface region 4 is structured. This can be done in particular by laser direct structuring (LDS) using the laser beam 13 suggested here, but other MID processes are also possible. Therefore, the metal nucleus 16 (indicated in FIG. 3) is first exposed and activated by the laser direct structuring of FIG. In this manner, first, the conductive path region 106 of the later conductive path 6 is exposed, and further, the gathering region 112 is exposed at the location of the conductive wire gathering portion 12 to be formed, and the location of the connection contact 14 formed later is formed. To expose the connection contact region 114.

  Next, according to FIG. 4, a short metal layer 21 with no external current is applied, in particular a copper (Cu) layer 21 as conductive material. Therefore, in the step of FIG. 4, chemical plating is performed by a potential difference without applying an external voltage. The step of FIG. 4 is thus carried out by dipping into a suitable bath 13, in particular into a solution containing copper ions having a higher voltage potential than the metal core 16.

  Next, according to FIG. 5, the injection molding 3 is electrolytically coated actively. For this reason, the injection molded body 3 is generally placed in a suitable electrolytic cell containing appropriate metal ions (for example, copper ions, nickel ions, and gold ions (Cu, Ni, Au)), and an appropriate potential is applied. V is applied to the connecting contacts 14 of the terminal contacts 2 and thus to the central connecting plate 10 and is generally applied to the connecting contacts 14 at a negative potential V with respect to the other electrodes 20 immersed in the electrolytic cell. Let it. By the application of the voltage U, the connection contacts 14 are set at a common negative potential with respect to the other electrodes 20 in the cell or electrolytic cell 17, together with the central connection plate 10 and all the conductive paths 6. In this way, a metal layer 18 is formed which, according to the structuring, forms the conductive path structure 5 with the conductive path 6, the conductor concentrator 12 and the connection contacts 14 according to FIG.

  Next, according to FIG. 6, the terminal contact 2 is disconnected. This takes place in particular as a mechanical decoupling by breaking off the terminal contacts 2, ie, for example by bending. This is because a predetermined break is formed at the predetermined break 8. After the terminal contacts 2 and the central conductor connection 12 have been removed, the individual conductive paths 6 no longer contact each other, since the individual conductive paths 6 extend through the defined breaking points 8, and the individual connecting plates 10 Can contact.

  Instead of mechanical breaking, the terminal contacts 2 may be cut off via laser cutting (laser treatment) or mechanical cutting may be performed. In addition, other destructive disconnections are possible.

  In the alternative embodiment of FIG. 6, the terminal contact 2 remains consequently held. Correspondingly, a defined break 8 is basically not required, and is advantageously not provided in this variant. In a step subsequent to FIG. 5, the plurality of conductive paths 6 are electrically disconnected from each other by selectively removing at least the central wire junction 12, for example also the connection contacts 14, for example by laser ablation. Subsequently, the terminal contacts 2 can be used for positioning the MID circuit carrier 1.

  In the case of the embodiment according to FIGS. 2 to 6 also, the detaching step according to FIG. 6 after the mounting can be carried out, so that the terminal contacts 2 can subsequently be used for positioning the MID circuit carrier 1.

  The conductive path component 5 may have a large number, for example, ten or more, of the conductive paths 6, wherein the individual conductive paths 6 have a conductive path width L of, for example, less than 60 μm and a pitch spacing of less than 100 μm. d (distance between individual conductive paths 6 or distance between conductive path centers).

1 MID circuit carrier 2 terminal contact (contact area)
2a Terminal contact surface area 3 Injection molded body 4a Circuit surface area 6 Conductive path 7 Substrate 8 Specified breaking point (specified disconnecting point)
REFERENCE SIGNS LIST 9 notch 12 conductive wire concentrating part 13 first tank 14 connection contact 16 metal core 17 second tank 18 second metal layer 20 electrode 21 first metal layer 106 conductive path area d pitch interval (interval of conductive path)
L Conductor path width U Voltage V Electric potential

Claims (6)

In a method for producing an MID circuit carrier (1),
Forming an integral injection molded body (3) having a substrate (7) and a contact area (2) by an injection molding technique;
Structuring a circuit surface area (4a) on the substrate (7) and a terminal contact surface area (2a) on the contact area (2) under the action of metal nuclei (16). Structuring a conductive path area (106) on said circuit surface area (4a) extending to said terminal contact surface area (2a) of said contact area (2);
On the structured circuit surface area (4a) and on the terminal contact surface area (2a), a first metal layer (21) is deposited without external current as follows, ie at least two conductive paths. (6) extends from the circuit surface area (4a) to at least one conductor junction (12) formed on the terminal contact surface area (2a), wherein the conductive path (6) is Applying the first metal layer (12) by applying an electric potential (V) to the conductive wire concentrating portion (12) so as to contact each other via the at least one conductive wire concentrating portion (12); 21) electrochemically forming a second metal layer (18) on or with the first metal layer (21);
Removing at least the conductor concentrator (12) to electrically disconnect the conductive path (6);
Containing
Forming a prescribed disconnection point (8) between the substrate (7) which is formed in the connection plate (10) and said formed in the contact region (2) the contact plate (10) and the swash plate at an acute angle, At this time, the plurality of conductive paths (6) extend from the circuit surface area (4a) to the conductor gathering portion (12) through the connection plate (10), the specified disconnection point (8), and the swash plate in this order. Doing things,
By separating the contact area (2) from the substrate (7) along the specified disconnection point (8), the conductor concentration part (12) is removed and the electric current of each of the conductive paths (6) is removed. That separation is performed,
A method characterized by the following.   The specified separating point (8) is formed as a specified breaking point (8) so as to include a thin material portion, for example, a notch (9), and the contact area (2) is connected to the conductor collecting part (12). Method according to claim 1, characterized in that it is mechanically detached with it, for example by bending.   Method according to claim 1, characterized in that the contact area (2) is separated by laser cutting at the defined separation point (8).   The first metal layer (21) is formed in a first tank (13), particularly in a first tank (13) containing copper ions, and the second metal layer (18) is formed in a second tank (13). In the second tank (17) containing gold ions, in particular, the electrode (20) used in the second tank (17) and the first tank (17). 4. The method according to claim 1, wherein a voltage (U) is applied to the metal layer (21).   On the contact area (2), a connection contact (14) is in contact with the at least one conductor junction (12), the connection contact (14) being larger than the individual said conductive path (6). 5. The method according to claim 1, wherein the second metal layer has a width and is provided for installing an electrical contact for electrolytically depositing the second metal layer. The method described in the section.   The plastic material forming the injection-molded body (3) has metal nuclei (16), which are exposed during structuring by laser structuring, in particular by laser direct structuring, and Method according to claim 5, characterized in that it is provided for forming 6), the at least one wire junction (12) and preferably the connection contact (14).

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