GB2057774A - Manufacture of printed circuits - Google Patents
Manufacture of printed circuits Download PDFInfo
- Publication number
- GB2057774A GB2057774A GB8025868A GB8025868A GB2057774A GB 2057774 A GB2057774 A GB 2057774A GB 8025868 A GB8025868 A GB 8025868A GB 8025868 A GB8025868 A GB 8025868A GB 2057774 A GB2057774 A GB 2057774A
- Authority
- GB
- United Kingdom
- Prior art keywords
- copper
- conductors
- process according
- action
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 13
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 42
- 229910052802 copper Inorganic materials 0.000 claims abstract description 42
- 239000010949 copper Substances 0.000 claims abstract description 42
- 239000004020 conductor Substances 0.000 claims abstract description 28
- 239000000126 substance Substances 0.000 claims abstract description 22
- 230000009471 action Effects 0.000 claims abstract description 18
- 239000000463 material Substances 0.000 claims abstract description 13
- 239000000758 substrate Substances 0.000 claims abstract description 13
- 238000003475 lamination Methods 0.000 claims abstract description 9
- 230000002829 reductive effect Effects 0.000 claims abstract description 7
- 238000005476 soldering Methods 0.000 claims abstract description 7
- 239000002904 solvent Substances 0.000 claims abstract description 6
- 238000004080 punching Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 37
- 230000008569 process Effects 0.000 claims description 31
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 18
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims description 12
- 238000005530 etching Methods 0.000 claims description 11
- 239000004922 lacquer Substances 0.000 claims description 11
- 229910000978 Pb alloy Inorganic materials 0.000 claims description 8
- 229910001128 Sn alloy Inorganic materials 0.000 claims description 8
- 230000002378 acidificating effect Effects 0.000 claims description 8
- 238000007650 screen-printing Methods 0.000 claims description 8
- 239000003513 alkali Substances 0.000 claims description 6
- 238000000151 deposition Methods 0.000 claims description 5
- 230000008021 deposition Effects 0.000 claims description 5
- 238000007639 printing Methods 0.000 claims description 5
- 239000004160 Ammonium persulphate Substances 0.000 claims description 4
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 claims description 4
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims description 4
- 235000019395 ammonium persulphate Nutrition 0.000 claims description 4
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims description 4
- 229940065287 selenium compound Drugs 0.000 claims description 4
- 150000003343 selenium compounds Chemical class 0.000 claims description 4
- UKLNMMHNWFDKNT-UHFFFAOYSA-M sodium chlorite Chemical compound [Na+].[O-]Cl=O UKLNMMHNWFDKNT-UHFFFAOYSA-M 0.000 claims description 4
- 229960002218 sodium chlorite Drugs 0.000 claims description 4
- 239000000470 constituent Substances 0.000 claims description 3
- 150000001879 copper Chemical class 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- 239000003381 stabilizer Substances 0.000 claims description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 2
- 239000000155 melt Substances 0.000 claims description 2
- PSGAAPLEWMOORI-PEINSRQWSA-N medroxyprogesterone acetate Chemical compound C([C@@]12C)CC(=O)C=C1[C@@H](C)C[C@@H]1[C@@H]2CC[C@]2(C)[C@@](OC(C)=O)(C(C)=O)CC[C@H]21 PSGAAPLEWMOORI-PEINSRQWSA-N 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 20
- 239000010410 layer Substances 0.000 description 6
- ICSNLGPSRYBMBD-UHFFFAOYSA-N 2-aminopyridine Chemical compound NC1=CC=CC=N1 ICSNLGPSRYBMBD-UHFFFAOYSA-N 0.000 description 4
- 239000002585 base Substances 0.000 description 4
- 239000003822 epoxy resin Substances 0.000 description 4
- 229920000647 polyepoxide Polymers 0.000 description 4
- 229910000679 solder Inorganic materials 0.000 description 4
- 238000005238 degreasing Methods 0.000 description 3
- VDMJCVUEUHKGOY-JXMROGBWSA-N (1e)-4-fluoro-n-hydroxybenzenecarboximidoyl chloride Chemical compound O\N=C(\Cl)C1=CC=C(F)C=C1 VDMJCVUEUHKGOY-JXMROGBWSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- KXZJHVJKXJLBKO-UHFFFAOYSA-N chembl1408157 Chemical group N=1C2=CC=CC=C2C(C(=O)O)=CC=1C1=CC=C(O)C=C1 KXZJHVJKXJLBKO-UHFFFAOYSA-N 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- RFLFDJSIZCCYIP-UHFFFAOYSA-L palladium(2+);sulfate Chemical compound [Pd+2].[O-]S([O-])(=O)=O RFLFDJSIZCCYIP-UHFFFAOYSA-L 0.000 description 2
- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Chemical compound [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 description 2
- 239000001117 sulphuric acid Substances 0.000 description 2
- 235000011149 sulphuric acid Nutrition 0.000 description 2
- FQRJWIRWWRZJAD-UHFFFAOYSA-N C(C)N(CC)B.[Na] Chemical compound C(C)N(CC)B.[Na] FQRJWIRWWRZJAD-UHFFFAOYSA-N 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 238000005234 chemical deposition Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- 229910000366 copper(II) sulfate Inorganic materials 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 150000003959 diselenides Chemical class 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000006864 oxidative decomposition reaction Methods 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- KYEKHFSRAXRJBR-UHFFFAOYSA-M potassium;selenocyanate Chemical compound [K+].[Se-]C#N KYEKHFSRAXRJBR-UHFFFAOYSA-M 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- CRDYSYOERSZTHZ-UHFFFAOYSA-N selenocyanic acid Chemical class [SeH]C#N CRDYSYOERSZTHZ-UHFFFAOYSA-N 0.000 description 1
- MNWBNISUBARLIT-UHFFFAOYSA-N sodium cyanide Chemical compound [Na+].N#[C-] MNWBNISUBARLIT-UHFFFAOYSA-N 0.000 description 1
- -1 sodium diethylaminofurane Chemical compound 0.000 description 1
Classifications
-
- 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
-
- 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
- H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
- H05K3/06—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed chemically or electrolytically, e.g. by photo-etch process
- H05K3/061—Etching masks
-
- 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
- H05K3/425—Plated through-holes or plated via connections characterised by the sequence of steps for plating the through-holes or via connections in relation to the conductive pattern
- H05K3/428—Plated through-holes or plated via connections characterised by the sequence of steps for plating the through-holes or via connections in relation to the conductive pattern initial plating of through-holes in substrates having a metal pattern
-
- 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
- H05K2203/05—Patterning and lithography; Masks; Details of resist
- H05K2203/0502—Patterning and lithography
- H05K2203/0542—Continuous temporary metal layer over metal pattern
-
- 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
- H05K2203/14—Related to the order of processing steps
- H05K2203/1423—Applying catalyst before etching, e.g. plating catalyst in holes before etching circuit
-
- 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
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/3452—Solder masks
Abstract
After boring or punching, copper- laminated substrate material is brushed, degreased, etched lightly, activated and reduced, and then printed, with an etch resist which covers the pattern desired for the printed conductors, the exposed copper lamination is etched away and then the etch resist is removed by means of a solvent to bare the conductors, at least the boreholes and soldering eyes of the pattern being then provided with a layer of copper by the action of a chemical copper bath. In one variant, the entire surface of the pattern of printed conductors is provided with amen a layer of copper by the action of the chemical copper bath. Objectives include improved through-connections and production of circuits having closely spaced and narrow conductors with optimal electrical characteristics.
Description
SPECIFICATION
Manufacture of printed circuits
The invention relates to the manufacture of printed circuits using copper-laminated substrate material which is provided with through-holes.
Various processes for the manufacture of printed circuits have already been proposed but these have certain disadvantages.
Difficulties are encountered in the manufacture of reliable through-connexions for interconnecting printed circuits on opposite sides of a board.
A disadvantage of the co-called subtractive technique, in which an entire surface of a base material is covered with a, say copper, lamination which is then selectively etched away to produce a desired pattern of conductors, is, for example, that large quantities of the lamination on the base material have to be removed to form the conductive pattern. At the same time, as a result of the etching under-cutting the conductors of the pattern the known impairments of such under-cutting become all the more serious the narrower the conductive paths and the distances between them. These phenomena therefore preclude further miniaturisation of circuits produced by the subtractive technique.
A disadvantage of the co-called additive technique, in which conductive material is applied to only these parts of a surface of a base material, which form part of the pattern which the conductors of the printed circuit are required to have, is that the base material used must be coated with an adhesion-imparting agent. The adhesion-imparting agent forms, after chemical dissolution and activation have been carried out, the base for selectively applied, chemically deposited, copper as the conductive material, and, after the wet treatment, has distinctly poorer electrical insulation characteristics as compared with epoxy resin, for example, as a result of which, similarly, narrow limits are placed on the use of this technique for producing miniaturised circuits.
A further disadvantage of the known processes is that to form the patterns of conductors and the conductive connections between them and the boreholes and through-connexions considerable quantities of copper bath solution are required.
An object of the present invention is therefore to provide an improved process for the manufacture of printed circuits. A process according to the present invention may avoid certain disadvantages of the known processes and render possible the manufacture of printed circuits with very closely spaced narrow conductors with optimal electrical characteristics using very small quantities of copper bath solution.
According to the present invention thee is provided a process for the manufacture of printed circuits using copper-laminated substrate material which after boring or punching, is brushed, degreased, etched lightly, activated and reduced, and then printed, with an etch resist which covers the pattern desired for the printed conductors, the exposed copper lamination is etched away and then the etch resist is removed by means of a solvent to bare the conductors, at least the boreholes and soldering eyes of the pattern being then provided with a layer of copper by the action of a chemical copper bath.
Embodiments of the invention may include any of the following features: the entire surface of the pattern of printed conductors may be provided with a layer of copper by the action of the chemical copper bath; the copper lamination may be etched away by means of an acidic etching solution, advantageously an acidic ammonium persulphate solution, or an alkaline etching solution, advantageously an ammoniacal solution of sodium chlorite;
the etch resist may be an alkali-soluble silk screen printing ink and may be removed by means of a 3 to 5% sodium hydroxide solution or an organic solvent, advantageously methylene chloride;
the solder-blocking lacquer used may be used to limit deposition of a lead/tin alloy to the boreholes and soldering eyes after the layer of copper has been deposited;
a stabilised chemical copper bath may be used;;
the chemical copper bath used may contain as the essential constituents a copper salt, a complex former, formaldehyde, as well as an alkali cyanide and optionally a selenium compound as stabilisers; and the lead/tin alloy may be applied in the form of a melt by the action of very hot air or by reductive deposition from a chemical tin bath.
A process according to the invention renders possible the manufacture of high-quality miniaturised circuits, using positive silk screen printing. The process produces fine conductors of a quality that can otherwise be obtained only be using photo-graphic printing; although photographic printing could be used instead of silk screen printing. The process furthermore has the great advantage that, starting from a copper-laminated substrate material, it is possible to produce the conductors having a width of less than 100 ym with excellent insulation and surface resistance properties.
A further important advantage is the saving of chemical copper bath solution, which is of special economic significance.
Also of commercial importance is that by contrast with the additive technique, it is possible to dispense with an adhesive-coated or nuclear-catalysed substrate material so that the high performance requirements of the adhesive coating and the oxidative decomposition of the adhesive layer by means of chromosulphuric acid are not required. A process according to the invention thus has an especially low pollution effect.
A suitable substrate material is, for example, phenol resin-bonded paper, epoxy resin paper, and especially glass-fibre-reinforced epoxy resin.
The process according to the invention is carried out, for example, after boring or punching, by brushing the plates in the usual manner followed by alkaline degreasing. The surface is then etched lightly, to remove about 5 ym, which can be effected by the action of approximately 10% sodium persulphate solution at 28-32 C. After pickling, for example, with 10% sulphuric acid, the surface is then activated by means of an activator, preferably an aqueous alkaline solution of a palladium complex, especially palladium sulphate with 2-aminopyridine, wherein attention is to be paid to a high covering density especially on the borehole wails so as to ensure activation even after the later etching operation.Reduction is then carried out by the action of a reducing agent, for example sodium diethylaminoborane, and the surface is aftertreated in the usual manner.
The desired wiring pattern is then positively applied thereto in accordance with the invention by silk-screen or photographic printing, which is effected by means of an etch resist, advantageously an alkali-soluble silk-screen printing ink, which covers the pattern required for the conductors, after which the exposed areas of the copper lamination are etched away, which can be carried out by the action either of an acidic etching solution, for example an acidic ammonium persulphate solution, or of an alkaline etching solution, for example an ammoniacal sodium chlorite solution. Subsequent thorough rinsing of the boreholes or punched holes must follow the etching.
After removing the etch resist by means of a solvent, for example by means of a 3 to 5% sodium hydroxide solution, or an organic solvent, such as methylene chloride, according to one form of process in accordance with the invention, a lacquer layer is then applied, leaving the bore-holes uncovered, for which prupose a solder-blocking lacquer is especially suitable, this being applied as a mask print. After customary alkaline degreasing, chemical deposition of metal into the boreholes is then carried out to a layer thickness of preferably 15 to 25 gm, this advantageously being effected with a stabilised chemical copper bath preferably containing, as the essential constituents, a copper salt, a complex former, formaldehyde, as well as an alkali cyanide and optionally a selenium compound as stabilisers.
Finally there is applied to the boreholes and solder eyes a lead/tin alloy, advantageously in a hot air process by the action of very hot air, giving a purely eutectic solder which, even after accelerated ageing, is satisfactorily solderable.
In accordance with another form of process according to the invention, after removing the etch resist the surface of the entire pattern of conductors is copper-plated by the action of the above-described chemical copper bath, then the solder-blocking lacquer is applied leaving the boreholes and solder eyes uncovered, and finally-if desired-hot-air tinning as mentioned above may be carried out.
A chemical copper bath of the above-described composition is particularly suitable for carrying out a process according to the invention. A suitable alkali cyanide is sodium cyanide used in concentrations of 15 to 30 mg/litre.
Suitable selenium compounds are the organic, inorganic and organic/inorganic monoselenides and diselenides and, of these, especially alkali selenocyanates, such as potassium selenocyanate, which are used in concentrations of, preferably, 0.1 to 0.3 mg/litre of bath liquid.
The following Example serves to illustrate the invention.
EXAMPLE
A substrate of glass-fibre-reinforced epoxy resin which is copper-laminated on both sides is bored or pierced in the usual manner, mechanically cleaned (deburred), and degreased by means of alkali at approximately 80QC with a treatment time of about 7 minutes. The substrate is then etched lightly (to remove approximately 5 !lem) by the action of a 10% sodium persulphate solution at a temperature of approximately 28 to 32 C for a period of 3 minutes.
The substrate is subsequently pickled with sulphuric acid with a content of 10% by weight at room temperature and then activated with an aqueous alkaline solution of palladium sulphate in 2-amino-pyridine, whereupon it is reduced using sodium diethylaminofurane as reducing agent, then rinsed and dried.
The conductive pattern is then printed positively by silk-screen printing using an alkali-soluble silk-screen printing ink. The printing can alternatively be carried out by the photographic method, advantageously using an alkali-soluble liquid resist. The exposed areas of copper are then etched away, which may be effected by the action of an acidic etching solution, such as an acidic ammonium persulphate solution, or an alkaline etching solution, such as an ammoniacal solution of sodium chlorite.
The removal of the silk-screen printing ink or other resist is then effected by treating with a solvent, such as a 3 to 5% sodium hydroxide solution or methylene chloride, after which the substrate is thoroughly rinsed and dried. Thereafter, a solder-blocking lacquer in accordance with the negative process is then applied, with subsequent alkaline degreasing.The boreholes and solder eyes are subsequently copper-plated by means of a stabilised chemical copper bath of the following composition:
10 g/l of copper sulphate CuS04. 5H2O 30 g/l of ehtylenediaminetetraacetic acid
20 g/I of sodium hydroxide NaOH
0.025 g/l of sodium cyanide NaCN
0.001 g/l of potassium selenocyanate KSeCN
4 ml of formaldehyde, 37%
The copper deposition is effected at a temperature of 65 C and a treatment time of 20 hours at an average deposition speed of 1.5 itm/hour. If desired, a selective hot-air tinning (a socalled HOT-AIR-LEVELLING process) can then finally be carried out.
Alternatively, the solder-blocking lacquer can be applied after the copper-plating, using the chemical copper bath has been applied to the entire pattern of conductors whereupon finally, if desired, selective hot-air tinning is carried out.
The result of this process is a pattern of conductors having a layer thickness of approximately 30 ,um with electrical resistivity between conductors of the pattern of at least 1 . 10122,
Claims (12)
1. A process for the manufacture of printed circuits in which copper-laminated substrate material which, after boring or punching, is brushed, degreased, etched lightly, activated and reduced, and then printed, with an etch resist which covers the pattern desired for the printed conductors, the exposed copper lamination is etched away and then the etch resist is removed by means of a solvent to bare the conductors, at least the boreholes and soldering eyes of the pattern being then provided with a layer of copper by the action of a chemical copper bath.
2. A process according to claim 1, wherein the entire surface of the pattern of printed conductors is provided with a layer of copper by the action of the chemical copper bath.
3. A process according to claim 1 or 2, wherein after the layer of copper has been deposited by the action of the chemical copper bath the boreholes and soldering eyes are coated with a lead/tin alloy using a lacquer to prevent the lead/tin alloy being deposited on other parts of the pattern of conductors.
4. A process according to claim 1, 2 or 3, wherein the etch resist is applied using an alkalisoluble silk screen printing ink.
5. A process according to any preceding claim, characterised in that the copper lamination is etched away by means of an acidic etching solution, advantageously an acidic ammonium persulphate solution, or an alkaline etching solution, advantageously an ammoniacal solution of sodium chlorite.
6. A process according to claim 4, characterised in that the etch resist is removed by means of a 3 to 5% sodium hydroxide solution or an organic solvent, advantageously methylene chloride.
7. A process according to claim 3 characterised in that the lacquer used is a solder-blocking lacquer.
8. A process according to any preceding claim, characterised in that a stabilised chemical copper bath is used.
9. A process according to claim 8, characterised in that the chemical copper bath used contains as the essential constituents, a copper salt, a complex former, formaldehyde, as well as an alkali cyanide and optionally a selenium compound as stabilisers.
10. A process according to claim 3, characterised in that the lead/tin alloy is applied in the form of a melt by the action of very hot air or by reductive deposition from a chemical tin bath.
11. A process for the manufacture of printed circuits according to claim 1 and substantially as described herein.
12. A process for the manufacture of printed circuits using copper-laminated substrate material which, in the usual manner, after boring or punching, is brushed, degreased, etched slightly, activated and reduced, characterised in that the substrate material prepared in such a manner is printed, preferably by the positive process, advantageously using an alkali-soluble silkscreen printing ink, with an etch resist which covers the desired series of conductors, whereupon first of all the copper lamination is etched away and then the etch resist is removed by means of a solvent to bare the conductors, that then either first of all the lacquer layer is applied, leaving the boreholes and soldering eyes uncovered, and these are then, to produce a conductive connection between the conductors and bpreholes, provided with a layer of copper by the action of a chemical copper bath and subsequently, if desired, covered with a lead/tin alloy, or first of all the entire surface is coated with a layer of copper by the action of a chemical copper bath, then the lacquer layer is applied, leaving the boreholes and soldering eyes uncovered, and these are subsequently, if desired, provided with a covering of lead/tin alloy.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792932536 DE2932536A1 (en) | 1979-08-09 | 1979-08-09 | METHOD FOR PRODUCING PRINTED CIRCUITS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2057774A true GB2057774A (en) | 1981-04-01 |
| GB2057774B GB2057774B (en) | 1983-09-07 |
Family
ID=6078196
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8025868A Expired GB2057774B (en) | 1979-08-09 | 1980-08-08 | Manufacture of printed circuits |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5629395A (en) |
| CA (1) | CA1152226A (en) |
| CH (1) | CH647372A5 (en) |
| DE (1) | DE2932536A1 (en) |
| FR (1) | FR2463569B1 (en) |
| GB (1) | GB2057774B (en) |
| IE (1) | IE49971B1 (en) |
| IT (1) | IT1131716B (en) |
| NL (1) | NL8003939A (en) |
| SE (1) | SE454476B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0090900A1 (en) * | 1982-04-05 | 1983-10-12 | Kanto Kasei Co., Ltd. | Process of manufacturing printed wiring boards and printed wiring boards manufactured by the same |
| EP0658075A1 (en) * | 1993-12-06 | 1995-06-14 | ENTHONE-OMI, Inc. | Method for manufacture of printed circuit boards |
| EP0762814A1 (en) * | 1995-08-22 | 1997-03-12 | Macdermid Incorporated | Method for the manufacture of printed circuit boards |
| US5665525A (en) * | 1990-10-30 | 1997-09-09 | Nokia Mobile Phones Ltd. | Method for producing printed circuit boards |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1378154A (en) * | 1962-09-24 | 1964-11-13 | North American Aviation Inc | Electrical interconnections for printed circuit boards |
| US3269861A (en) * | 1963-06-21 | 1966-08-30 | Day Company | Method for electroless copper plating |
| DE1690224B1 (en) * | 1967-08-29 | 1971-03-25 | Standard Elek K Lorenz Ag | BATHROOM FOR ELECTRONIC COPPER PLATING OF PLASTIC PANELS |
| FR2128355A1 (en) * | 1971-03-01 | 1972-10-20 | Fernseh Gmbh | |
| JPS5489276A (en) * | 1977-12-27 | 1979-07-16 | Fujitsu Ltd | Method of producing printed board |
-
1979
- 1979-08-09 DE DE19792932536 patent/DE2932536A1/en not_active Withdrawn
-
1980
- 1980-07-08 NL NL8003939A patent/NL8003939A/en not_active Application Discontinuation
- 1980-07-17 CH CH5489/80A patent/CH647372A5/en not_active IP Right Cessation
- 1980-07-18 IT IT23530/80A patent/IT1131716B/en active
- 1980-07-29 SE SE8005443A patent/SE454476B/en not_active IP Right Cessation
- 1980-08-07 FR FR8017460A patent/FR2463569B1/en not_active Expired
- 1980-08-08 CA CA000357874A patent/CA1152226A/en not_active Expired
- 1980-08-08 GB GB8025868A patent/GB2057774B/en not_active Expired
- 1980-08-08 JP JP10841080A patent/JPS5629395A/en active Pending
- 1980-08-08 IE IE1669/80A patent/IE49971B1/en unknown
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0090900A1 (en) * | 1982-04-05 | 1983-10-12 | Kanto Kasei Co., Ltd. | Process of manufacturing printed wiring boards and printed wiring boards manufactured by the same |
| US5665525A (en) * | 1990-10-30 | 1997-09-09 | Nokia Mobile Phones Ltd. | Method for producing printed circuit boards |
| EP0658075A1 (en) * | 1993-12-06 | 1995-06-14 | ENTHONE-OMI, Inc. | Method for manufacture of printed circuit boards |
| EP0762814A1 (en) * | 1995-08-22 | 1997-03-12 | Macdermid Incorporated | Method for the manufacture of printed circuit boards |
Also Published As
| Publication number | Publication date |
|---|---|
| NL8003939A (en) | 1981-02-11 |
| IE801669L (en) | 1981-02-09 |
| FR2463569A1 (en) | 1981-02-20 |
| IT8023530A0 (en) | 1980-07-18 |
| IE49971B1 (en) | 1986-01-22 |
| FR2463569B1 (en) | 1985-09-20 |
| GB2057774B (en) | 1983-09-07 |
| JPS5629395A (en) | 1981-03-24 |
| SE454476B (en) | 1988-05-02 |
| CA1152226A (en) | 1983-08-16 |
| IT1131716B (en) | 1986-06-25 |
| SE8005443L (en) | 1981-02-10 |
| CH647372A5 (en) | 1985-01-15 |
| DE2932536A1 (en) | 1981-02-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |