Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
  • C25D17/001—Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
  • C25D17/007—Current directing devices
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
  • C25D17/10—Electrodes, e.g. composition, counter electrode
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
  • H05K3/42—Plated through-holes or plated via connections
  • H05K3/423—Plated through-holes or plated via connections characterised by electroplating method
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
  • H05K2203/15—Position of the PCB during processing
  • H05K2203/1518—Vertically held PCB
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
  • H05K2203/15—Position of the PCB during processing
  • H05K2203/1572—Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides

Definitions

• the invention is initially based on a method for electroplating workpieces provided with holes, such as plates, in particular printed circuit boards, the workpiece to be treated being located between a first and a second anode (preamble of claim 1).
• holes such as plates, in particular printed circuit boards
• the workpiece to be treated being located between a first and a second anode (preamble of claim 1).
• the two anodes were put together at a voltage that was positive with respect to the workpiece (cathode) and thus treated the workpiece from both sides at the same time.
• Practice has shown that the on the inner walls of.
• the resulting layer of perforations is thinner than the layer on the outer surfaces of the plate on both sides.
• This mismatch which should be avoided in practice as far as possible, became increasingly stronger with increasing size of the ratio "plate thickness divided by hole diameter”.
• the task or problem of the present invention is, starting from the preamble of claim 1, to make the ratio of the thickness of the material application or layer on the outer plate surfaces to the thickness of the layer on the inner walls of the perforations more favorable, ie to reduce towards 1.
• This layer will then, with a reduction in its thickness, extend "approximately to the other end of the perforation, which is opposite the anode which is inactive in this process section. If the positive voltage is now applied to the latter anode, the perforation region which is on the side becomes this anode is correspondingly more strongly provided with a layer, while the perforation area is opposite the other,
• the features of claim 2 include, for example, a range of the periodic exposure duration, without the invention being restricted to this.
• the invention is also based on the object of providing arrangements for carrying out one or more of the above-described procedural measures, with a faultless functional sequence, but with as little effort as possible.
• the arrangement according to claim 4 is initially provided. This means that only a single galvanizing rectifier and the associated changeover switch are required. If the application of a holding current is desired in order to eliminate the above-mentioned concerns regarding the interruption of the galvanizing current when the positive voltage of the rectifier is switched to the first or the second anode, an arrangement according to claim 5 with a holding current rectifier and two blocking diodes can be provided. hen. The strength of the holding current can hereby be set via the holding rectifier. The blocking diodes ensure that the electroplating current of the electroplating rectifier only ever reaches the active anode, but not the inactive anode.
• the arrangement according to claim 4 can also be supplied with a holding current by the features of claim 6.
• a holding current rectifier is not required.
• the manufacturing costs are therefore minimal.
• the additional power losses. in the resistances of the holding circuits are within acceptable limits.
• Fig. 1 shows a plate-shaped workpiece 1, in particular a printed circuit board, with perforations, e.g. Bores 2.
• perforations e.g. Bores 2.
• the diameter of the perforation 2 in relation to the thickness of the plate 1 is also shown too large for reasons of drawing.
• the ratio of the thickness of the printed circuit board to the diameter of the perforation is of the order of 8: 1 or even higher.
• the layers applied by electroplating on the outer surfaces of the workpiece 1 and on the inner walls of the perforations 2 are not shown.
• the workpiece 1 forming the cathode is located together with a first anode 3 and a second anode 4 within a bath container 5, indicated only by dash-dotted lines, for electroplating or the like.
• the bath surface is indicated by the dashed line 5 '.
• An electroplating rectifier 6 is provided outside the bath, the negative side 7 of which is connected to the workpiece (cathode) 1, while its positive side 8 is applied to the input side 9 of a changeover switch 10.
• the changeover switch 10 is placed over the desired periodic exposure period either at the connection 11 of a line 12 leading to the first anode 3, or at the connection 13 of a line 14 leading to the second anode 4.
• the periodic exposure time is understood to mean the time over which one of the anodes is connected to positive voltage. In contrast, the total exposure time is equal to the time of the entire treatment of a workpiece.
• the second anode 4 thus has a positive voltage with respect to the workpiece (cathode) 1, while the voltage of the first anode (3) without holding current rectifier 15 with respect to the workpiece (cathode) is 0 V.
• a plating current thus arises from the second anode 4 to the workpiece 1. If the changeover switch 10 is brought into contact with the contact 11, the voltage and current conditions are reversed such that the first anode 3 is now positive with respect to the workpiece 1 and the second anode 4 without a holding current rectifier 15 against the workpiece (cathode) the voltage is 0 V.
• the galvanizing current v runs from the first anode 3 to the workpiece 1.
• the periodic exposure time of each anode can be, for example, about 1 min. be.
• a holding current rectifier 15 can be provided, which is also connected on the minus side to the workpiece 1 (cathode) and leads to a line 16 on the plus side.
• the mode of operation is as follows:
• Switching means can be applied to the contacts 11 and 13 alternately with the periodic exposure times over the desired total exposure time, thereby causing the galvanic currents to change sides. Since the voltage of the holding current rectifier 15 is lower, e.g. 2 V than that e.g. 3 V voltage of the electroplating rectifier 6, the holding current can only flow via the blocking diode (decoupling diode) 17 or 18, the output side 17 'or 18' of which is not connected to the voltage of the electroplating rectifier 6. This means that in the switching position shown in FIG. 1, the holding current flows via the blocking diode 17 to the first anode 3 and from there to the workpiece 1.
• the holding current then flows via the other blocking diode 18 to the second anode 4 and from this to the workpiece 1. Also during the period when the switch 10 is switched from point 13 to point 11 or vice versa a holding current at least over the anode through which the holding current has flowed so far, possibly also during this relatively short period of time over both anodes.
• the blocking diodes be of a type that change very quickly, at least in the microsecond range, from the blocking to the conducting state.
• the strength of the holding current can be changed by setting the holding current rectifier accordingly.
• REPLACEMENT LEAF two resistors 19, 20 are provided, the size of which can be adjusted or regulated.
• the resistors 19, 20 are connected between the positive side 8 of the galvanizing rectifier 6 and the feed lines 12 and 14 to the first anode 3 and the second anode 4, respectively.
• the holding current is thus from
• Galvanizing rectifier 6 also generated.
• the holding current rectifier 15 of the embodiment according to FIG. 1 is therefore omitted. Because of the resistors 19, 20, the holding current is correspondingly smaller than the respective galvanizing current.
• the circuit described above and shown in FIG. 2 shows that a holding current always flows. There is also a certain relief of the switch 10 by the resistors.
• two electroplating rectifiers 21, 22 are provided, which are also connected to the workpiece 1 (cathode) with their minus sides 23, 24, but with their plus sides 25, 26 to the first anode 3 or the second anode 4.
• the electroplating rectifier 22 After the set exposure period has elapsed, it is ensured that in the present example the electroplating rectifier 22 now supplies the second anode 4 connected to it with a positive voltage, i.e.
• the voltage of the respective inactive anode can be kept somewhat positive compared to the voltage of the cathode in the sense that a holding current flows from this anode to the workpiece (cathode).
• a switching arrangement (not shown separately) can be connected upstream in such a way that the switch-on times of the two rectifiers 21, 22 overlap.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Manufacturing & Machinery (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Electroplating Methods And Accessories (AREA)
• Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6426109

Family Applications (1)

Country Status (4)

Families Citing this family (3)

Family Cites Families (5)

• 1991
  • 1991-02-28 DE DE19914106333 patent/DE4106333C1/de not_active Expired - Lifetime
• 1992
  • 1992-02-26 EP EP19920905629 patent/EP0573511A1/de not_active Ceased
  • 1992-02-26 WO PCT/DE1992/000162 patent/WO1992015726A1/de not_active Ceased
  • 1992-02-26 CA CA002105078A patent/CA2105078A1/en not_active Abandoned

Non-Patent Citations (1)

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