Device and method for forming a via in a layered substrate

Abstract

The invention relates to a device (100) and a method for forming a via in a layered substrate (101) having a through-hole (102) which is closed on a first face (101a) of the substrate (101) by means of a metal layer (103) and exits the substrate on a second face (101b) of the substrate (100). A metal is deposited in the through-hole (102) by means of electrochemical deposition. The device comprises a support (106) for receiving and positioning the substrate (101), an electrical contact for electrically contacting the metal layer (106), a metallization container (108) which can be filled with an electrolyte, and an anode (109) which is immersed in the electrolyte during the deposition process. The support (106) is preferably part of the metallization container (108) and / or is designed and / or positioned in such a way that the layered substrate (101) forms a boundary of the metallization container (108). In a first variant, the device is designed in such a way that only the second face (101b) of the substrate (100) comes into contact with the electrolyte during the deposition process. In a second variant, the support (106) is designed and / or positioned in such a way that the inserted substrate (100) forms a boundary of the metallization container (108). In a third variant, the support (106) is electrically conductive and serves as the electrical contact for electrically contacting the metal layer (103), or the electrical contact is integrated into the support (106) or is fixed to the support (106). In a fourth variant, an ultrasound generator (110) is provided on the first face (101a) of the substrate (101) and applies ultrasound to the substrate (101) during the deposition process. In a fifth variant, the device comprises a stationary sub-element (116) and a movable sub-element (115).

Description

[0001] DEVICE AND METHOD FOR FORMING A THROUGH-CONTACT IN A

[0002] LAYERED SUBSTRATE

[0003] AREA OF INVENTION

[0004] The invention relates to a device and a method for forming a through-hole in a layered substrate, in particular in a multilayered substrate with an integrated conductor structure.

[0005] BACKGROUND TO THE INVENTION

[0006] Printed circuit boards (PCBs) serve as carriers for electronic components in electronics, such as SMD components (Surface-Mount Device), BGA components (Ball Grid Array) or THT components (Through-Hole Technology).

[0007] Printed circuit boards (PCBs) typically have a multilayer structure with conductor structures in several levels. These conductor structures are separated from each other by dielectric layers. The dielectric layers are usually interrupted by vias (vias), which electrically connect conductor structures on opposite sides of the dielectric layers.

[0008] Traditionally, plastic-based films or sheets, often reinforced with fibers, are used as dielectric layers for printed circuit boards (PCBs). FR-4 (Flame Retardant 4) is probably the most commonly used material for PCBs. It consists of an epoxy resin matrix in which a woven glass fiber material is embedded. FR-4 is known for its excellent mechanical and electrical properties, as well as its heat resistance.

[0009] Instead of polymer-based dielectric layers, layers made of inorganic dielectric materials can also be of interest. In recent years, glass, ceramics, silicon, and glass-ceramics have increasingly played a role as suitable inorganic dielectric materials for dielectric layers. In printed circuit boards, dielectric layers made of these inorganic materials can be combined with other polymer-based layers, for example, made of FR4 or other materials.

[0010] Among the numerous advantages resulting from the use of the aforementioned inorganic materials, the following are particularly noteworthy:

[0011] In particular, glass, ceramics and glass-ceramics have a very low dielectric constant, which leads to lower signal losses and better signal integrity, especially in high-frequency applications.

[0012] The use of glass, ceramics and glass-ceramics results in low dielectric losses, which in turn is ideal for high-speed and high-frequency applications.

[0013] They are more thermally stable than, for example, plastics, which increases the reliability of printed circuit boards made from these materials in thermally demanding environments.

[0014] They have a comparatively low coefficient of thermal expansion, which leads to higher dimensional stability and reduces the stress on solder joints during temperature changes.

[0015] They are mechanically very resilient and tolerate vibrations and shocks very well.

[0016] In particular, glass, ceramics and glass-ceramics are chemically inert and resist corrosion and chemical attacks, which can extend the service life of printed circuit boards, especially in aggressive environments.

[0017] To create the aforementioned vias, holes are drilled into the dielectric layers and filled with a metal. Drilling the holes can be done mechanically. Very small holes, for example, with a diameter in the range of 10 pm to 100 pm, can also be drilled through the layer using a laser. Filling the holes can be done electroplating. However, filling very small diameter holes can be very time-consuming.

[0018] A conventional method for producing through-hole vias through a thin glass substrate involves drilling holes in the substrate, forming a titanium layer on both sides of the substrate and on the sidewalls of the holes, and then sputtering a copper seed layer onto the titanium layer. This is followed by electrochemical or electroless copper filling of the holes.

[0019] However, the process is complex, especially due to the required sputtering process, and only results in low-quality metal fillings in the through holes.

[0020] Improved methods for forming through-holes in layered glass substrates are known from EP 4333028 A1 and US 2016 / 0113119 A1. Both documents describe how to temporarily seal through-holes in a substrate to create through-holes by applying a thin copper foil with an adhesive layer to one side of the substrate. The adhesive layer present at the bottom of the holes is removed, for example, in the case of EP 4333028 A1, using plasma technology to expose the copper foil at the bottom of the holes. The hole is then filled with copper by electrochemical deposition, starting from the copper foil at the bottom. Finally, the copper foil, including the adhesive layer, is completely removed, as shown in Fig. 2 of EP 4333028 A1 or Fig. 4 of US 2016 / 0113119 A1. The resulting substrate with the through-holes can then be further processed.

[0021] The as-yet-unpublished German patent application with file number DE 102024 115413.6 describes a further improved method for creating through-holes. In this method, holes are also electrochemically filled with a metal after being sealed on one side with a metal foil.

[0022] These methods result in high-quality metal fillings. However, filling the holes using electrochemical deposition is a lengthy process. Furthermore, it is difficult to selectively fill the holes during electroplating without metallizing unwanted areas. If a substrate, which, for example, has through holes sealed on one side with a metal foil, is immersed in an electrolyte for electroplating, metal is deposited not only in the through hole but also on both sides of the metal foil. This is undesirable in most cases and necessitates the removal of the deposited metal from the unwanted areas or the masking of these areas before electroplating. SUMMARY OF THE INVENTION

[0023] The invention described below was based on the objective of providing a device and a method for forming a via in a layered substrate. These should solve or at least reduce existing problems with the formation of vias.

[0024] To solve this problem, the invention proposes the device described below, in particular the preferred embodiment of the device with the features of claim 1, and the method with the features of claim 9. Further developments of the invention are the subject of dependent claims. The wording of all claims is hereby incorporated by reference into the content of this description.

[0025] The device according to the invention serves to form a through-hole in a layered substrate. This substrate has a through-hole which is sealed on one side by a metal layer and protrudes from the substrate on a second side. In the device, a metal is deposited in the through-hole by means of electrochemical deposition.

[0026] The device is characterized by the following features a. to d.: a. It comprises a support for receiving and positioning the layered substrate. b. It comprises an electrical contact for electrically connecting the metal layer to the pole of an electrical voltage source. c. It comprises a metallization vessel that can be filled with an electrolyte. d. It comprises an anode that is electrically connected or contactable with the voltage source and is immersed in the electrolyte during electrochemical deposition.

[0027] Preferably, the layered substrate has more than one through-hole, which is closed on the first side of the substrate by means of a metal layer, particularly preferably by means of the metal layer, and which exits from the substrate on a second side, for example, 2 to 200 through-holes. Accordingly, a large number of vias can also be formed simultaneously during electrochemical deposition.

[0028] The electrical voltage source is preferably a DC voltage source.

[0029] The anode is, for example, a titanium anode coated with a mixed metal oxide.

[0030] The layered substrate preferably comprises several superimposed substrate layers.

[0031] The layered substrate preferably consists of a dielectric organic material or a dielectric inorganic material, or it comprises at least one substrate layer of the dielectric organic or the dielectric inorganic material, which is penetrated by the through-hole or through-holes.

[0032] In further preferred embodiments, the substrate can comprise a conductor structure, preferably with conductor tracks in one plane of the substrate, or even several conductor structures in different planes. The conductor structures can, for example, be embedded in a substrate layer made of a dielectric material.

[0033] Regarding the dielectric inorganic material of which the substrate or at least one substrate layer preferably consists, the following features a. and / or b. are particularly preferred: a. The dielectric inorganic material is a material from the group consisting of glass, ceramics, glass-ceramics, and silicon. b. The substrate or substrate layer made of the dielectric inorganic material has a thickness in the range of 25 pm to 2000 pm, preferably a thickness in the range of 100 pm to 1100 pm.

[0034] It is preferred that the immediately preceding features a. and b. are realized in combination.

[0035] Borosilicate, aluminosilicate, quartz, or soda-lime glass are preferred as glass types. Depending on the application, photosensitive glasses (especially from the lithium silicate glass family) and glasses with a high refractive index may be preferred. Suitable ceramic substrates include those made of Al₂O₃, ZrOVAbCb, Al₃N₄, Si₃N₄, BeO, and BN.

[0036] A thickness within the aforementioned preferred range offers an optimal balance between mechanical stability and flexibility, enabling the substrate to better withstand mechanical stresses and thermal cycles.

[0037] Preferably, the substrate has a uniform thickness in one of the aforementioned areas.

[0038] Regarding the through-hole or, where applicable, the through-holes, the following features a. and b. are preferred: a. The through-hole or through-holes is / are formed by means of a laser. b. The through-hole or through-holes have / have a diameter in the range of 5 pm to 200 pm.

[0039] It is preferred that the immediately preceding features a. and b. are realized in combination.

[0040] Laser technology enables the precise and clean formation of very small holes, which increases the miniaturization and packing density of the multilayer substrate being produced. Furthermore, this reduces the risk of mechanical damage to the substrate made of dielectric inorganic material.

[0041] It is also possible to create the through-hole(s) by locally treating the substrate with a laser and / or subsequently forming the through-holes by an etching process, for example using heated KOH solution or hydrogen fluoride. This approach is based on the principle of making the substrate locally more sensitive to an etching solution, for example by inducing a phase change using the laser.

[0042] The aforementioned preferred hole size enables a high packing density and improves the electrical connection between the layers.

[0043] Regarding the dielectric organic material of which the substrate or at least one substrate layer preferably consists, the following additional features a. to c. are preferred: a. The dielectric organic material is an epoxy resin-based or a polyimide-based material. b. The substrate or substrate layer of the dielectric organic material has a thickness in the range of 5 pm to 100 pm, preferably from 8 pm to 50 pm. c. The substrate or substrate layer of the dielectric organic material is a plastic film.

[0044] The aforementioned features a. to c. can be implemented independently of one another. However, it is preferred that the immediately preceding features a. to c. are implemented in combination.

[0045] Epoxy resin and polyimide offer excellent electrical insulation properties and high thermal stability. They are also chemically resistant.

[0046] The preferred thickness of the substrate or substrate layer allows for flexible adaptation to different application scenarios, offering a good balance between insulation and mechanical stability.

[0047] In a particularly preferred embodiment of an epoxy resin-based substrate or an epoxy resin-based substrate layer, the substrate or substrate layer is an ABF film (ABF = Ajinomoto Build-up Film).

[0048] Preferably, the substrate is rectangular or square. For example, it can have a square base shape with side lengths ranging from 20 to 80 cm.

[0049] Regarding the metal layer, the following additional features a. to d. are preferred: a. The metal layer consists of copper. b. The metal layer has a thickness in the range of 0.3 pm to 20 pm, preferably from 0.5 pm to 5 pm. c. The metal layer is a metal foil. d. The metal layer is a gas-phase deposited, chemically deposited, or sputtered metal layer.

[0050] The aforementioned features a. to d. can be implemented independently of one another. However, it is preferred that the immediately preceding features a. to c. are implemented in combination. It is particularly preferred that the immediately preceding features a. to d. are implemented in combination.

[0051] Copper offers excellent electrical conductivity and is also cost-effective, making it an ideal material for conductive traces. In this context, it is worth noting that it can be advantageous to structure the metal layer after the formation of the via(s) to create a conductor structure.

[0052] The metallization container is preferably a metallization chamber, in particular a closed metallization chamber. However, the container can also be an open container.

[0053] In a first embodiment of the device according to the invention (device embodiment 1), the device is characterized by the following additional feature: e. The device is designed such that, during electrochemical deposition, only the second side of the substrate comes into contact with the electrolyte in the metallization container, preferably in the metallization chamber.

[0054] This feature has the advantage that the aforementioned problem of metal deposition in undesired areas does not occur. Deposition preferably takes place exclusively in the through-holes that are filled by the metal layer during electrochemical deposition. No deposition occurs on the back side of the metal layer, the first side of the substrate. This significantly reduces electrolyte consumption. Removal of unwanted deposited metal can be largely or completely avoided. Furthermore, there is no need for masking the metal layer.

[0055] In a second embodiment of the device according to the invention (device embodiment 2) or in a possible further development of the first device embodiment, the device is characterized by at least one of the following additional features a. to d.: a. The support is designed as a frame into which the layered substrate can be inserted, for example as a rectangular or circular frame. b. The support is a component of the metallization container, preferably the metallization chamber. c. The support is designed and / or arranged such that the layered substrate, in particular the layered substrate inserted into the frame, forms a boundary of the metallization container, preferably the metallization chamber. d. The device includes a sealing means by which the substrate can be inserted into the frame in a sealing manner.

[0056] The immediately preceding features a. to d. can be implemented independently of one another. However, it is preferred that the immediately preceding features a. to c., and especially the immediately preceding features a. to d., are implemented in combination.

[0057] In preferred embodiments, the aforementioned features a. to d., in particular feature c., constitute a further development of feature e. of device variant 1. If the layered substrate used forms a boundary of the metallization vessel containing the electrolyte and in which the electrochemical deposition takes place, it is ensured that only the side of the substrate facing into the vessel comes into contact with the electrolyte. Accordingly, the substrate is preferably inserted into the frame such that the second side of the substrate with the exposed through-holes faces into the interior of the vessel and the first side with the metal layer faces outwards. This, in turn, has the advantage that the metal layer can be easily contacted and no metal is deposited on the metal layer.

[0058] In further preferred embodiments, each of the aforementioned features a. to d. can also be implemented as an alternative to feature e. of device variant 1. None of the features of the second device variant necessarily entails an implementation of feature e. of device variant 1.

[0059] In a third embodiment of the device according to the invention (device embodiment 3) or in a possible further development of the first embodiment or the second embodiment of the invention, the device is characterized by one of the following additional features a. or b.: a. The frame is electrically conductive and serves as the electrical contact for electrically contacting the metal layer. b. The electrical contact for electrically contacting the metal layer is integrated into the frame or fixed to the frame.

[0060] Both designs are advantageous in that the metal layer can be automatically electrically contacted when the substrate is inserted into the frame, and no separate additional electrical contact is required.

[0061] Multiple electrical contacts can also be provided for electrically connecting the metal layer. For example, these can be integrated into the frame or fixed to the frame.

[0062] In preferred embodiments, one of the aforementioned features a. and b. constitutes a possible further development of the device according to device variant 1 and / or a further development of the device according to device variant 2.

[0063] In further preferred embodiments, each of the aforementioned features a. and b. can also be implemented as an alternative to feature e. of device variant 1 and / or as an alternative to features a. to d. according to device variant 2. None of the features of the third device variant necessarily entails an implementation of feature e. of device variant 1 or an implementation of features a. to d. according to device variant 2.

[0064] In a fourth embodiment of the device according to the invention (device embodiment 4) or in a possible further development of the first device embodiment and / or the second device embodiment and / or the third device embodiment of the invention, the device is characterized by at least one of the following additional features a. to c.: a. The device comprises an ultrasonic generator. b. The ultrasonic generator is mounted in a container filled with a liquid medium. c. The support is designed and / or arranged such that the layered substrate used forms a boundary of the container with the ultrasonic generator.

[0065] The immediately preceding features a. to c. can be implemented independently of one another. However, it is preferred that the immediately preceding features a. and b., and especially the immediately preceding features a. to c., are implemented in combination.

[0066] Embodiments with an ultrasonic generator are advantageous in that they improve electrolyte exchange in the through-holes, thereby accelerating deposition. Ultrasound propagates with low attenuation in liquids. Therefore, embedding the ultrasonic generator in the liquid medium is particularly advantageous. The liquid medium is preferably water.

[0067] The ultrasound generator preferably produces sound waves in the frequency range of 20 kHz to 400 kHz.

[0068] In further, particularly preferred embodiments, the ultrasonic generator produces sound waves in the frequency range from 400 kHz to 5 MHz (megasonic range).

[0069] The support is specifically designed and / or arranged such that the layered substrate positioned in, on, or within the support forms a boundary for both the ultrasonic generator container and the metallization vessel. The substrate thus also forms a barrier separating the liquid medium in the ultrasonic generator container from the electrolyte in the metallization vessel. The first side of the substrate, bearing the metal layer, comes into contact only with the liquid medium in the ultrasonic generator container. The second side of the substrate comes into contact exclusively with the electrolyte.

[0070] In preferred embodiments, the aforementioned features a. to c. constitute possible further developments of the device according to device variant 1 and / or possible further developments of an embodiment of the device according to device variant 2 or according to device variant 3.

[0071] In further preferred embodiments, the aforementioned features a. to c. can also be implemented as an alternative to feature e. of device variant 1 and / or as an alternative to features a. to d. of device variant 2 and / or as an alternative to features a. or b. of device variant 3. None of the features of the fourth device variant necessarily entails an implementation of feature e. of device variant 1, an implementation of features a. to d. of device variant 2, or an implementation of features a. to c. of device variant 3.

[0072] In a fifth embodiment of the device according to the invention (device embodiment 5) or in a possible further development of the first device embodiment and / or the second device embodiment and / or the third device embodiment and / or the fourth device embodiment of the invention, the device is characterized by at least one of the following additional features a. to d.: a. The device comprises a stationary and a movable sub-element. b. The movable sub-element is designed to pivot, slide, or lift. c. The stationary sub-element comprises the support, the electrical contact for electrically contacting the metal layer, and, in preferred embodiments, also the container with the ultrasonic generator and the liquid medium. d. The movable sub-element comprises the anode, at least a part of the metallization container, and, in preferred embodiments, also the diaphragm and / or the sponge.

[0073] It is preferred that the immediately preceding features a. to c., and especially preferably the immediately preceding features a. to d., are realized in combination.

[0074] The movable component is preferably a hood or a cover, in particular a liftable, sliding, or pivotable hood or cover. For example, to introduce a substrate into the device, the movable component can be detached from the stationary component.

[0075] In preferred embodiments, the aforementioned features a. to d. constitute possible further developments of the device according to device variant 1 and / or a further development of an embodiment of the device according to device variant 2 or according to device variant 3 or according to device variant 4.

[0076] In further preferred embodiments, the aforementioned features a. to d. can also be implemented alternatively to feature e. of claim 1 and / or alternatively to features a. to d. according to device variant 2 and / or alternatively to features a. or b. according to device variant 3 and / or alternatively to features a. to c. according to device variant 4. None of the features of the fifth device variant necessarily entails an implementation of feature e. of device variant 1, or an implementation of features a. to d. according to device variant 2, or an implementation of features a. to c. according to device variant 3, or an implementation of features a. to c. according to device variant 4.

[0077] In preferred embodiments of variants 1 to 5, the device is characterized by at least one of the following additional features a. to c.: a. The metallization vessel is coupled to an electrolyte reservoir from which it can be filled with an electrolyte for electrochemical deposition. b. The metallization vessel is coupled to a rinsing agent reservoir from which it can be filled with a rinsing agent after and / or before electrochemical deposition. c. The metallization vessel includes inlets and outlets for the electrolyte and / or the rinsing agent.

[0078] The immediately preceding features a. to c. can be implemented independently of each other. However, it is preferred that the immediately preceding features a. to c. are implemented in combination.

[0079] After introducing a substrate into the device, the metallization vessel can be rinsed with the rinsing agent. Subsequently, the metallization vessel can be filled with electrolyte from the electrolyte reservoir. The device may include a suitable pump for this purpose.

[0080] The dishwashing liquid could be, for example, water or an acid.

[0081] The electrolyte could, for example, be a copper salt solution.

[0082] In further preferred embodiments of device variants 1 to 5, the device is characterized by at least one of the following additional features a. to e.: a. The anode, which is electrically connected or contactable with the voltage source, is arranged in the metallization container. b. The device comprises a diaphragm arranged in the metallization container. c. The device comprises a sponge arranged in the metallization container. d. The diaphragm divides the metallization container into a first compartment in which the anode is arranged and a second compartment bounded by the layered substrate inserted into the support. e. The sponge is arranged between the diaphragm and the layered substrate.

[0083] The immediately preceding features a. to c. can be implemented independently of one another. The immediately preceding features b. and d. as well as c. and e. are preferably implemented in combination. Particularly preferably, features a. to e. are all implemented in combination.

[0084] The diaphragm serves the purpose of keeping any decomposition products that may form at the anode away from the second compartment containing the substrate. It allows electrolyte conduction between the compartments but prevents electrolyte from the first compartment from mixing with electrolyte from the second compartment.

[0085] The sponge serves the purpose of preventing direct contact between the diaphragm and the substrate.

[0086] In further preferred embodiments of device variants 1 to 5, the device is characterized by the immediately following additional feature a.: a. The device comprises temperature control means with which the temperature of the electrolyte and the liquid medium in the container for the ultrasonic generator can be controlled.

[0087] For example, the electrolyte can heat up as a result of the operation of the ultrasonic generator. Therefore, there is a need for temperature control of the electrolyte.

[0088] The method according to the invention, like the device described above, serves to create a through-hole in a layered substrate that has a through-hole which is closed on a first side of the substrate by means of a metal layer and protrudes from the substrate on a second side. The method according to the invention is particularly preferably carried out in a device according to the invention.

[0089] The process comprises the following steps a. to d.: a. The layered substrate is inserted into, positioned on, or fixed to a support. b. The metal layer is connected to the pole of an electrical voltage source via an electrical contact. c. The other side of the substrate is exposed to an electrolyte into which an anode, electrically connected or contactable with the voltage source, is immersed. d. For the purpose of electrochemical deposition of a metal in the through-hole, an electrical voltage is applied between the anode and the metal layer.

[0090] The substrate, the support, the metal layer, the voltage source, the electrolyte and the anode have already been described in connection with the device according to the invention.

[0091] In a first variant of the method according to the invention (method variant 1), the method is characterized by the following feature e.: e. Only the second side of the substrate is exposed to the electrolyte.

[0092] This variant corresponds to the first variant of the device according to the invention. The advantages of this approach have already been discussed.

[0093] In a second embodiment of the method according to the invention (method embodiment 2), the method is characterized by at least one of the following features a. and b.: a. An ultrasonic generator is arranged on the first side of the substrate, which subjects the substrate to ultrasound during electrochemical deposition. b. The first side of the substrate is in contact with a liquid medium in which an ultrasonic generator is arranged during electrochemical deposition.

[0094] The ultrasound generator and the liquid medium have already been discussed in connection with the device according to the invention.

[0095] The features a. and b. immediately preceding are preferably implemented in combination.

[0096] This variant corresponds to the fourth variant of the device according to the invention. The advantages of this approach have already been discussed.

[0097] The features of process variant 2 can be implemented as an alternative to feature e. of process variant 1. The implementation of the features of process variant 2 and the implementation of feature e. of process variant 1 are not linked.

[0098] In preferred embodiments, the method according to the invention is characterized by at least one of the following features a. to c.: a. The electrochemical deposition takes place in a metallization vessel containing the electrolyte into which the anode is immersed during the electrochemical deposition. b. The metallization vessel is divided by means of a diaphragm into a first compartment, in which the anode is arranged, and into a second compartment, in which the second side of the layered substrate inserted into the support is exposed to the electrolyte. c. A sponge is arranged between the diaphragm and the layered substrate.

[0099] The diaphragm, the sponge and the compartments have already been described in connection with the device according to the invention.

[0100] Preferably, the features a. to c. immediately preceding this text are implemented in combination.

[0101] In a third variant of the method according to the invention (variant 3), the method is characterized by at least one of the following features a. and b.: a. The method is carried out in a device comprising a stationary and a movable component, wherein the stationary component comprises the support, the electrical contact for electrically contacting the metal layer, and, in preferred embodiments, also the container with the ultrasonic generator and the liquid medium, and wherein the movable component comprises the anode, at least a part of the metallization container, and, in preferred embodiments, also the diaphragm and / or the sponge. b. After the substrate has been inserted into the frame, the movable component is placed onto the stationary component.

[0102] The individual components have already been discussed in connection with the device according to the invention.

[0103] The features a. and b. immediately preceding are preferably implemented in combination.

[0104] This method variant corresponds to the fifth device variant of the device according to the invention. The advantages of the procedure according to the immediately preceding features a. and b. have already been discussed.

[0105] The features of process variant 3 can be implemented as an alternative to feature e. of process variant 1 or as an alternative to the features of process variant 2. The implementation of the features of process variant 3 and the implementation of feature e. of process variant 1 or the implementation of the features of process variant 2 are not necessarily linked.

[0106] In preferred embodiments, the method according to the invention is characterized by at least one of the following features a. and b.: a. The metallization vessel is filled with an electrolyte from an electrolyte reservoir for electrochemical deposition, in particular after the movable component has been placed on the stationary one. b. The metallization vessel is filled with a rinsing agent after and / or before the electrochemical deposition.

[0107] The advantages of these approaches have already been discussed.

[0108] The invention is particularly suitable in the context of manufacturing advanced packaging substrates. These are advanced carriers used in the semiconductor and electronics industries to mount and connect integrated circuits (ICs). They serve as a mechanical base and provide a platform for the electrical connection between the ICs and the external circuitry. Advanced packaging substrates can contain multiple conductor layers to support the high density and complex interconnects required by modern ICs.

[0109] BRIEF DESCRIPTION OF THE DRAWINGS

[0110] An embodiment of the invention is explained in more detail below with reference to a drawing.

[0111] Figure 1 schematically shows an example of a device according to the invention.

[0112] DESCRIPTION OF A PREFERRED EXECUTION EXAMPLE

[0113] The device 100 serves to form a through-hole in a layered substrate 101.

[0114] The substrate 101 is rectangular and has a through-hole 102, which is sealed on one side 101a of the substrate 101 by a metal layer 103 and protrudes from it on a second side 101b. The substrate 101 comprises several substrate layers. In addition to a glass substrate layer 104, it includes a dielectric polymer layer 105, which is located between layer 104 and the metal layer 103. However, the bare metal layer 103 is exposed at the bottom of the through-hole 102. Here, the polymer layer 105 has been removed, for example, by means of a plasma. To form the via, a metal is to be deposited in the through-hole 102 by electrochemical deposition.

[0115] The device 100 comprises a rectangular carrier 106 into which the layered substrate 101 is inserted. Electrical contacts for electrically connecting the metal layer 103 to the pole of the DC voltage source 107 are integrated into the carrier 106. Furthermore, the device 100 comprises a metallization vessel 108 that can be filled with an electrolyte and an anode 109 that is electrically connected to the DC voltage source 107 and is immersed in the electrolyte during electrochemical deposition.

[0116] The device 100 further comprises an ultrasonic generator 110, which is stored in a container 111 filled with water.

[0117] The device 100 is designed such that, during electrochemical deposition, only the second side 101b of the substrate 100 in the metallization vessel 108 comes into contact with the electrolyte. For this purpose, the support 106 is designed and / or arranged such that the layered substrate 101 inserted into the support 106 forms a boundary of the container 111 with the ultrasonic generator 110 and a boundary of the metallization vessel 108. The substrate 101 thus also forms a barrier that separates the liquid medium in the container 111 with the ultrasonic generator 110 from the electrolyte in the metallization vessel 108. The first side 101a of the substrate 101 with the metal layer 103 comes into contact only with the liquid medium in the container 111 with the ultrasonic generator 110. The second side 101b of the substrate 100 comes into contact exclusively with the electrolyte.The anode 109, electrically connected to the voltage source 107, is arranged in the metallization vessel 108. A diaphragm 112 divides the metallization vessel 108 into a first compartment 113 in which the anode 109 is arranged and into a second compartment 114, which is bounded by the layered substrate 101 inserted into the support 106.

[0118] The device 100 further comprises the sponge 117, which is arranged between the diaphragm 112 and the layered substrate 101.

[0119] The device 100 comprises a movable sub-element 115 in the form of a liftable hood. The anode 109, the first compartment 113 of the metallization vessel 108, the diaphragm 112, and the sponge 117 are integrated into this hood. Furthermore, the device 100 comprises a stationary sub-element 116, which includes the support 106, the electrical contact integrated therein for electrically contacting the metal layer, the container 111 with the ultrasonic generator 110, and the water.

[0120] Each time the substrate 100 to be treated is changed, the movable sub-element 115 is lifted and, after an untreated substrate 100 is inserted into the frame 106, placed back onto the stationary sub-element 116. After closing the device 100, the metallization vessel 108 can be filled with electrolyte from the electrolyte reservoir 118. For this purpose, the electrolyte reservoir 118 is connected to the compartment 114 via line 119. The electrolyte flows via line 120 into the compartment 113 containing the anode 109 and from there, via line 121, back into the electrolyte reservoir 118 in a closed loop. If necessary, it is treated before being reintroduced into the electrolyte reservoir 118. The flow is driven by the pump 125.

[0121] The metallization vessel 108 is further coupled to a rinsing agent reservoir 122. The compartments 113 and 114, and in particular side 101b of the substrate 101, can be cleaned with a rinsing agent, especially water, via lines 123 and 124 as needed.

Claims

PATENT CLAIMS 1. Device (100) for forming a through-hole in a layered substrate (101) having a through-hole (102) which is closed on a first side (101a) of the substrate (100) by means of a metal layer (103) and opens out of the substrate (100) on a second side (101b) by depositing a metal in the through-hole (102) by means of electrochemical deposition, comprising the features: a. The device (100) comprises a support (106) for receiving and positioning the layered substrate (101); b. The device (100) comprises an electrical contact for electrically contacting the metal layer (103) with the pole of an electrical voltage source (107); c. The device (100) comprises a metallization vessel (108) that can be filled with an electrolyte; and d.The device (100) comprises an anode (109) electrically connected or contactable with the voltage source (107), which is immersed in the electrolyte during electrochemical deposition; characterized by the following additional features: e. The device (100) is designed such that, during electrochemical deposition, only the second side (101 b) of the substrate (100) in the metallization vessel (108) comes into contact with the electrolyte, and f. the support (106) is a component of the metallization vessel (108) and / or it is designed and / or arranged such that the layered substrate (101) forms a boundary of the metallization vessel (108).

2. Device according to claim 1 or according to the preamble of claim 1, comprising at least one of the following additional features: a. The support (106) is designed as a frame into which the layered substrate (101) can be inserted. b. The device (100) comprises a sealing agent by means of which the substrate (101) can be inserted into the frame in a sealing manner.

3. Device according to claim 1 or claim 2 or the preamble of claim 1, with at least one of the following additional features: a. The support (106), in particular the frame, is electrically conductive and serves as the electrical contact for electrically contacting the metal layer. b. The electrical contact for electrically contacting the metal layer (103) is integrated into the support (106), in particular the frame, or fixed to the support (106), in particular the frame.

4. Device according to any one of claims 1 to 3 or according to the preamble of claim 1, with at least one of the following additional features: a. The device (100) comprises an ultrasonic generator (110). b. The ultrasonic generator (110) is mounted in a container (111) filled with a liquid medium, preferably water. c. The support (106) is designed and / or arranged such that the inserted layered substrate (101) forms a boundary of the container (111) with the ultrasonic generator (110).

5. Device according to any one of claims 1 to 4 or according to the preamble of claim 1, with at least one of the following additional features: a. The device (100) comprises a stationary sub-element (116) and a movable sub-element (115). b. The movable sub-element (115) is designed to pivot, slide, or lift. c. The stationary sub-element (116) comprises the support (106), the electrical Contact for electrical contacting of the metal layer and, in preferred embodiments, also the container (111) with the ultrasonic generator (110) and the liquid medium. d. The movable sub-element (115) comprises the anode (109), at least a part of the metallization container (108), and, in preferred embodiments, also a diaphragm (112) and / or a sponge (117).

6. Device according to any one of claims 1 to 5, with at least one of the following additional features: a. The metallization vessel (108) is coupled to an electrolyte reservoir (118) from which it can be filled with an electrolyte for electrochemical deposition. b. The metallization vessel (108) is coupled to a rinsing agent reservoir (122) from which it can be filled with a rinsing agent after and / or before electrochemical deposition. c. The metallization vessel (108) comprises inlets and outlets for the electrolyte and / or the rinsing agent.

7. Device according to any one of claims 1 to 6 with at least one of the following additional features: a. The anode (109), which is electrically connected or contactable with the voltage source (107), is arranged in the metallization container (108). b. The device comprises a diaphragm (112) arranged in the metallization container (108). c. The device comprises a sponge (117) arranged in the metallization container (108). d. The diaphragm (112) divides the metallization container (108) into a first compartment (113) in which the anode (109) is arranged and into a second compartment (114) which is bounded by the layered substrate (101) inserted into the support (106). e. The sponge (117) is arranged between the diaphragm (112) and the layered substrate (101).

8. Device according to one of claims 1 to 7, with at least one of the following additional features: a. The device (100) comprises temperature control means with which the temperature of the electrolyte and the liquid medium in the container for the ultrasonic generator (110) can be controlled.

9. Method for forming a through-hole in a layered substrate (101) having a through-hole (102) which is closed on a first side (101a) of the substrate (101) by means of a metal layer (103) and protrudes from it on a second side (101b) of the substrate (101), comprising the steps of: a. The layered substrate (101) is inserted into a support (106) or positioned or fixed on or to a support (106); b. The metal layer (103) is connected to the pole of an electrical voltage source (107) via an electrical contact; c. The second side (101b) of the substrate (101) is exposed to an electrolyte into which an anode (109) electrically connected or contactable with the voltage source (107) is immersed; and d.For the purpose of electrochemical deposition of a metal in the through-hole (102), an electrical voltage is applied between the anode (109) and the metal layer (103); characterized by the following additional feature: e. Only the second side (101 b) of the substrate (101) is exposed to the electrolyte.

10. The method of claim 9 or of the preamble of claim 9, with at least one of the following additional features: a. An ultrasonic generator is placed on the first side (101a) of the substrate (101). (110) is arranged, which applies ultrasound to the substrate (101) during electrochemical deposition. b. The first side of the substrate (101a) is in contact with a liquid medium in which the ultrasound generator (110) is arranged during electrochemical deposition.

11. A method according to claim 9 or 10 with at least one of the following additional features: a. The electrochemical deposition takes place in a metallization vessel (108) containing the electrolyte into which the anode (109) is immersed during the electrochemical deposition. b. The metallization vessel (108) is divided by means of a diaphragm (112) into a first compartment (113) in which the anode (109) is arranged and into a second compartment (114) in which the second side (101b) of the layered substrate (101) inserted into the support (106) is exposed to the electrolyte. c. A sponge (117) is arranged between the diaphragm (112) and the layered substrate (101).

12. A method according to claim 9 or 10 or according to the preamble of claim 9, with at least one of the following additional features: a. The method is carried out in a device (100) comprising a stationary sub-element (116) and a movable sub-element (115), wherein the stationary sub-element (116) comprises the support (106), the electrical contact for electrically contacting the metal layer (103) and, in preferred embodiments, also the container (111) with the ultrasonic generator (110) and the liquid medium, and wherein the movable sub-element (115) comprises the anode (109), at least a part of the metallization container (108) and, in preferred embodiments, also the diaphragm (112) and / or the sponge (117). b. The movable sub-element (115) is placed on the stationary sub-element (116) after the substrate (101) has been inserted into the support (103), in particular the frame.

13. A method according to claim 11 or 12, comprising at least one of the following additional features: a. The metallization vessel (108) is filled with an electrolyte from an electrolyte reservoir (118) for electrochemical deposition, in particular after the movable sub-element (115) has been placed onto the stationary sub-element (116). b. The metallization vessel (108) is filled with a rinsing agent after and / or before electrochemical deposition.

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