DE1790293A1 - METHOD OF MANUFACTURING BASE MATERIALS FOR PRINTED CIRCUITS - Google Patents

Description

PhötQOireuits Corporation, (ilen öove, jtfew York ^ USA

Process for making tan ßäsismaterialien for

printed circuits

The Irflndung tsezleht SiOH to a process for tellurium Prod van BaMsmaterialien en printed circuit $ consisting Au0 a! Carrier aus'isolierendem'Material, an adhesion-promoting intermediate layer and a metal base layer is not fully extended barren located partially out *

Wiring from printed retainers has largely grown in practice. In the simplest case Until now there are such printed circuits as well as printed circuit boards from lifiterpUgenj like Kupfeffalie o * the like *, which on a Insulation material firmly applied aindi, PUr complicated Wiring has proven to be useful, such Arrange conductor tracks on both sides of an insulating plate / and & n Conductor tracks corresponding to predetermined points, through the insulation * with each other ^ u It is particularly advantageous here to connect the wall

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^ Openings within the Isolieriiia.t © rials

by means of the combination of a metal separation strip that can be reached with and without atrial separation "along the" at least as much punched or drilled holes, so that a direct connection of a pus on one side with a conductor on the other side can be seen ^ e of the "Iöoiiermaterials Bianergesteil is. i) @rartigg metaüi * - siörte itsönwaiiäüngen have proven siön nioiit only as extremely reliable * electrical connections »söMerr. simultaneously cause of iiöverbindurigen to AfisöhluBeiiten of Bauelemtiit mi of ^ · lind same "The reason for this is seen in co» Sioen the Zwiäohinrauiii between iii © tailiii @ rt © r iiOöhwand and diesis liöciL eingösteokten wire fully with solder gu fill a significant improvement that able * For this reason one is in niuirgr with also übergegättgenj mgtaliislerte IiööhwaMuiigtn with printed circuitry veriusglagni which only on one side of the e an i © it © rit4gmuster

is can ßüÄL en Herstellen- van circuit boards without metallized hole wall ung Above all, the so-called Jj ¹ OJlienkupfernteverfahren verwetidit wirdetu S ¹ Ur ^ n this Virxahr a base material used on a _t the Isolierstöffplatt ©, for example, of a modified Phenolpäpierlam-Lnate

"" ^> üsmo> ^ 30883 3/0961 "" ■.

1730293

and which carries a copper foil of e.g. 35 / U thickness « Is a circuit board required for the circuit that should be equipped with conductor tracks on both sides, an insulating plate is used as the base material, which are provided with a copper foil layer on both sides is. As J'olienmaterial has become quite general Electrolyte copper foil prevailed in practice. These is deposited, for example, on drums using electroplating methods known per se, drawn off from them, oxidized on one side and by means of a thermosetting Adhesive connected to the surface of the insulating material. The lamination process can expediently be carried out with the actual Manufacturing process for the phenolic paper laminate will.

Ji ¹ Ur, the actual manufacturing of the printed circuit is provided in such a manner, the copper surface of the Basismaxerials Γ described above with an etch-resistant layer, that all genes surface areas corresponding to the desired conductor patterns are covered. This can be done in offset printing, screen printing, photographic printing or another printing process.

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The protective layer is removed in a flowing manner, §§ that each unat? $ en: tfplienbez.irkß, the äem iewünsghtp. ! jje.ite, rz.ugp - sample correspond to ^ lie free. Under certain circumstances tji has jgs, augJi as? y? eei £ mäiig eri / en, niit l

peMoht WOlwork m _? the so-called JLQiibe, | i || istigfiid§ possesses and that he · naeii 4 © iB Jitf learns? iu needs to be, with ^ tstandardr- | g! itfr |) the ratio is fisheii of the ladderiip ^ Kussferölierfl ^che and . der isolierstQffpbgriig.c.he 30 to 40 ^ · Ϊ ^ θ-S means 1 day 6Q big ^ Qf _{9 of} the copper must be used. Yes@,. is Je <l8 (? Ji iß economically very naphteiiigi dp e§§ieh bgi for the production of the] | as, iisniaterials ¥ fi? vyend§t§n K folie ma. a high quality Pradufct hand§it _? 4θΡ fffi P.Qren is required, and special care is required in the manufacture "in order to ensure a good delivery.

To make! Printed circuit boards! Which such circuits carry on both sides is assumed from material clad with copper foil on both sides _? where • the reject rate npch that may occur is greater.

2um ^ create metallized associated βψ Lfit connected ijochwandungen is besides einim Itzypr-gang also

BATH ORIGINAL

electroless and galvanic metal separation is used. For this purpose, the copper-clad base material plate is first provided with the holes to be metallized, the hole walls are then for example by treatment activated with silver nitrate solutions or with tin and metal ions for electroless metal deposition and in an electroless metal plating bath, for example Hickel or preferably Kupier brought. There forms a * thin, electrically conductive metal layer on the hole walls, which is electrically connected to the copper foil is. A protective layer is then applied in a printing process applied, which only leaves those areas free that correspond to the desired conductor pattern. Then will first a galvanic metal layer corresponding to the desired metal layer thickness on the JJoek walls, preferably a copper layer, applied and this subsequently again covered galvanically with an etch-proof protective layer. Among other things, silver, Tin-lead or gold can be used. Then the printed protective layer is removed and the one underneath lying, thick foil copper that does not correspond to the desired conductor pattern is etched away. Here, too, is the high one The amount of copper to be removed is economically disadvantageous. This production of printed circuits is also relatively complex and actually only then

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justify if the manufacturing price of each Printed circuit boards are relatively small compared to the cost of the device for which they are used.

Especially recently, circuit boards have been using metallized perforated walls are also used for cheaper consumer goods in a variety of ways. Jjies & r! is mainly due to the strong tendency to reduce the size of electrical devices of all kinds and inevitably given. Particularly for consumer goods, such as radio and television sets, it is essential to be able to to resort to soldering processes, such as dip or drag soldering. If this is the case with the usual printed circuit boards without metaiii ized hole walls are used, so not only a very precise solder joint control is required, but a large number of so-called "cold" or otherwise defective soldering points must also be re-soldered. A disproportionately high personnel wall is required for this required, which necessarily affects the economy has an unfavorable effect. Another handicap at the use of the previously known circuit boards is that it is indispensable in the manufacturing process that lOlienkupfer in the area of the conductor tracks by a j To reinforce a layer that corresponds to that which must be minimally required within a perforation · This leads

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BADORlGfNAL

dgr- fer ^ ending γοη ladder lines that are uselessly thick have rschicht. Next, it has been found to be practical ögliQii e / r ^ iesen, much thinner JiOlien, so such IQ u Picke to produce enough pore-free and

safe to use. Particular difficulties occur above all, such thin, surfaces? u ~

Up. dip oneself from the high pra ^ entsats used or, i; egguätgfnderi Eliminate uncleaned properties which result in swabs, mjrae already mistaken by uncovered ones JassiSBi & tfcrial »al ^ s» for example phenolic paper plates to go out and this only to the desired leader jsügsi! corresponding.-surface districts with a metal? preferably a copper layer, to be seen.

In. disbßm gusaiaihenhang was beaten, initially the Phenolic paper surface to be carefully cleaned and iawar ^ wake-up using a mechanical Process, like Abbürs.teii q, like, around 'Urennmittelreste safe to remove. Then the purified and yqr ~ texlhafterweiire roughened surface by working " suitable solutions for electroless metal deposition adjusted. For example, the use of

B -

Tin salt and precious metal alloys as. expedient- ■. ■ proven. Subsequently, the entire insulating material or surface is coated with a thin metal layer, preferably a copper layer, deposited from a bath that works without an external current supply. If the phenolic paper plate has already been provided with.! ». Ο before your printed, which only the desired conductor pattern; enu talks, and subsequently .in this loading ^ circuses in _known:, a correspondingly thick electrodeposited metal layer deposited. The protective layer is then removed and the thin, original copper foil is etched away Adhesion between base material and copper conductors. In order to remedy this technical part, it was proposed to provide the surface of the Xs oil material with an adhesive and finally to subject the circuit board equipped with the electrodeposited conductor tracks to a heat curing and pressing process. Such curing processes are not only very complex, they are

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_{BATHROOM 0R} GINAL}

also require precise work sequence monitoring and thus go beyond the scope of what is usually used by printed circuit board manufacturers work steps to be carried out far beyond.

It is also necessary to use the original, de-energized deposited "metal layer with a galvanic protective layer to be provided, if not extraordinary and cost-increasing Care in handling the semi-finished products All this leads to a complication and deterioration of the economy and had the consequence that such proceedings were opposed the Poli-eriätzverfahren were not able to enforce.

Of the. The invention is based on the object of improving the adhesive strength between conductor tracks produced by metal deposition and to increase a carrier material, the used Base material should be designed so that both with electroless metal deposition alone as well as together with a galvanic deposition of printed circuits of printed circuit boards with and onne metallized hole walls • are easy and economical to manufacture.

This object is achieved according to the invention .achieved." that one on the surface of the (embossing a

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at least one, oxidizable by oxidizing agents, ' thermosetting modified rubber or synthetic rubber (rubber) containing layer evenly distributed Applied that the applied layer is heated at least partially hardens and that at least one partially hardened layer prior to electroless or electroless and galvanic metal deposition at least in the areas to be metallized with an oxidizing agent, preferably with a chromium sulfuric acid or , Permanganate solution treated.

Corresponding studies have shown that 'it is in it is advantageously possible to firmly connect applied copper layers with insulating material surfaces, without there being too much heat for a preprint requirement. The base material used to manufacture Printed circuit boards can be handled in a simple manner. It has been found to be advantageous to use a hardening process and to coordinate the oxidation process and the To cancel the hardening process before a state is reached, in which the oxidizing agent used can no longer or only very slowly become effective. Because of a number of Attempts could prove that an adaptation the oxidation process to the hardening process is possible within wide limits and with great tolerance. The heat process

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O -: ^ _ BADORtGfNAL

can be brought to full hardening up to hae,. however, if the over-hardened gate is to be broken off, "

As, suitable. Adhesive layers are used which contain ... "a (naturally occurring) rubber or synthetic rubber that is oxidizable and degradable;" where this component is finely distributed in the adhesive layer or at least on the surface of the same in a zone, brewable substances are, for example, types of rubber, for example nitrile rubber, butadiene styrene miscopolymers, butyl rubber, polybutylene, neoprene, Buna M, polyvinyl acetal resins, silicone rubber, acrylonitrile butadiene -Kaiitschuk, synthetic resins containing carboxyl radicals, modified polyamides and products thereof modified with phenolic resins, epoxy resins and other suitable resins and plastics.

As an oxidizing and degrading agent, for example Chromium sulphurous acid or, respectively, permanganate solutions as special suitably highlighted .. ".... '

in the following, the _xi is only intended to elix the .inventive; <...; ·. Baaismaterials are shown in more detail using an example;:. ,,

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BAO

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Example I.

B & si © mat © rial diejit eiäe tiartjÄfl & rglitzer d.ef fei i »p sä piöfeg, jjiee # P |. & tf # ·»? ii »4

with eiiies alfcäli ^ siiea HeiÄifS3?, iW) ö. ftilfft fsf »

resinous B.

* ii

BüllöslioheB Plieüol

dehyde resin 11

K & £ i6 «Möiit f-jg £ # · # &# &, All $ gffijP

308113/0111 '

BATH

Resin mixture G

Butadiene acrylonitrile rubber

15 g

Chlorinated rubber
Visc. 10 cps 20 g Diacetone alcohol 75 g Mtromethane 70 g ulloslich.es' phenolic
formaldehyde resin 10 g Ethanol 10 g Fine, urgent SiOp 7 g Xylene 50 g

The application can be carried out in a known manner, for example by means of olxen lacquering machines, flaw lacquering machines or by the hissing process. Depending on the selected Äufbrin _c art, the viscosity must be adjusted accordingly, v / ill be, for example, an order selected by WalzenlacKiermaschxnen, a viscosity of about 10 is appropriate OOÜGPS} for the dipping method, however, are advantageous values between 500 and 1000 GPb. Adjustment is made by adding a solvent or filler, such as SiOp.

Pure the present. Example should be used roller application, and with an attitude that is a l'roekenso

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- 14 ORIGINAL BATHROOM

thickness of 20 to 30 / rev, im ach. the accompanying light task will be this hardened. This can be done in the IR oven or in the Frischlux't circulation oven happen. A circulating oven with a fresh air supply is used for the present example. ■

The resin mixture used is that according to formula B, adjusted to a viscosity of 700 cps. The application is carried out by dipping, the speed at which the plates are pulled out (vertically) being, for example, 6 m per hour. The hardening of the air pre-dried plates are in the fresh air - convection oven at 15O ⁰ G for 4 hours. i) The cooled plates have a practically unlimited shelf life and can be stored and serve as one of the basic materials.

Example II

A phenol-formaldehyde paper press laminate is again used as the starting material; A resin mixture D is used for coating in the thawing process

Methyl ethyl ketone Oil solve acetate in nitrile rubber, liquid Juitrile rubber in chunks

.- ;. . ι, -).:. Oleoluble phenolic resin, thermosetting bar

Epoxy resin (ü / pochlorhydrin ^j derivative mg) _

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2375 g 590 g 350 g 350 g 400 g

- 15-

BATH

17S0293

300 g 1830 g

ität © ea £ 00 ßps »toei 2k? U ·

± u-

O fäp ^ i / 2 ötuaatten

XL * ^ .gdöGii with sea WQQ ■ $. SiQp uild siaer

t äie eiue Yisitösitat v © ii a-ßa 12 000 ops i des? Order ai with a W

Example IY

wi # Sgpiel II, jjgdjööji with, eiüem & ö4! fixed

() KuaMtkarM & ua BestjiiiGhten eggs

i being the. Viscosity to about 550 <3 ps list and the order ± m TaüßiiyerfaiireS: i with an Afggt ßßa tfli'pro ütünde takes place * j) as

he-followed by warming up. to l ^ Ü ^ ü for 4Ö minutes »

For example, naeji - one of the basic materials produced in the first place becomes part of the basic material

'AL

firmly adhering metal layer initially, at least in the to metallizing areas, a suitable oxidation or Exposed to mining agents. ^ .B. Chromosulfuric acid baths and / or P eranganatiö solutions have been proven. For example, a bath with the following composition can be used for this purpose:

Bath a

Potassium dichromate 57 g

Water 500 ml

conc. Sulfuric acid 500 ml.

If prepared base material according to example ^ IV is used, so is the exposure time, for example at room temperature 30 minutes.

It is then rinsed in water, and it will be the chromium-acid residues, for example by means of a weakly acidic, atriumsulfitlösung 5 $ B or a 5 to 10 $ ie ⁺⁺ salt solution such as ferrous sulfate solution and then rinsing with water removed. The coated carrier plate provided with micropores or the base material can be stored for practically unlimited periods if it is briefly rinsed in HGl, 10 $ or another suitable acid before further treatment after longer storage. . .

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BADORJQfNAL

Should follow the entire surface of the base material plate Example IV are coated with a metal layer, so this is done in a manner known per se, for example by the action of stabilized silo salt solutions from Palladium salt solutions activated for electroless metal deposition. The surface is also expediently known Way, first exposed to a bath that contains tin ions. Then the activated base material is then plate exposed to an electroless metal-depositing bath, For example, one to deposit the Iiekel or copper able. ■. .

Instead of the material plate according to Example IV, a those according to one of the other examples can be used. Ehenso can be used to oxidize and create the micropores differently composed chromic acid solution is used be like for example

Bath b

^: iSodium dichromate 120 g

conc. Sulfuric acid 600 hlL Water 500 ml

or a permangealate solution of the appropriate concentration x> the other suitable oxidizing and building agent. The duration of this period depends on the type of the coating material and its hardness and can

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BATH ORIGINAL

for any desired combination in a simple manner Attempt to be set.

Example V

describes the making of one the whole surface of the Base material covering copper coating, this is a according to Example IV or in another manner described Prepared base material equipped with micropores is initially exposed to a solution such as

100 G Tin (II) chloride 35 ml hydrochloric acid 1000 ml water

contains.

After rinsing, the surface is then exposed to a bath, that for example

1 S. Palladium chloride 40 ml ■ hydrochloric acid 1000 ml water

consists.

After careful rinsing, the base material surface is

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exposed to a suitable copper plating bath. To have excellent adhesion between the copper film and the Ensure subsurface and to avoid that at later Visual vibration or bending loads hover in the Copper film, it has been found to be expedient and advantageous proven to ensure that the electroless deposited Metal layer has good ductility «In addition has shown from corresponding studies that it is possible by using certain copper deposition baths, to make a metal layer that has great unity and · permitted due to their structure and nature Your other, firmly adhering, currentless or galvanically produced Metal layers to be deposited «Baths of suitable composition contain a complexing agent for the Cu (II) Ions a complexing agent for GU (I) ions in small quantities as well as the other usual ingredients, ii a well-suited one Bath solution consists, for example, of

50 g per liter of Cu ₂ SO ₄ . 5H ₂ O 150 g per liter of Rochelle salt

1 ml wetting agent
30 mg per liter of sodium cyanide 15 ml per liter of formaldehyde (37%)

Sodium hydroxide in an amount giving a pH of 13 "~ b .. ■ - ■ · -., ·. _: .

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This bath provides a ductile, smooth, shiny finish Copper deposit in a layer thickness of about 3 / U in 45 minutes or 6 / rev in 1 1/2 hours.

It has been shown that such changes are extraordinary are storable. You can simply activate it in, for example sulfuric acid, even after prolonged storage for applying another, currentless or galvanic deposited coating are prepared. In addition, such layers not only have a very high adhesive strength but are also largely free of pores, since electroless depositions take place depending on the direction. Approximately At the beginning of the deposition process, pore-shaped islands are formed due to activation imperfections become in the further course of the electroless metal deposition process automatically filled. In this way, such metal foils differ fundamentally from those produced by electroplating. Because of the inevitable pores in the latter " education as well as the extraordinary difficulties in the production of very thin electrodeposited foils and when applying them to a support, it has heretofore been practically impossible to use a thin one, for example 10 / sx & rken Xupferfölie provided base material. The practically pore-free copper foil of small thickness is highly ductile, adheres extremely firmly to the

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reason and allows it to be stuck on it without difficulty Adhesive, further metal layers to be deposited.

In this context it should be pointed out that Electroless and galvanic metal deposition carried out separately or can also be combined, for example a metal layer of the desired thickness partly by deposition from an electroless bath and partly by electrodeposition can be produced. This can be particularly advantageous when the finished conductor run is made Metals of different kinds should consist of, for example, 20 / U copper, 8 / U IM ick el and 2, u gold.

jpür activating the hole walls has proven to be special A bath solution proved to be advantageous, which consists of an aqueous Solution of tin and palladium ions and from 0.1 to Contains 5 $ methyl ethyl ketone. This same solution can also to activate before applying the first thin copper foil be used successfully. ·

For example, to produce a printed circuit board on both sides with a printed circuit board, the base material According to the type of product described in Example V, according to one of the known printing processes or in another

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© AD ORIQINAi

Way provided with a mask that only those Leaves areas free that correspond to the desired ladder lines. The layer masked in this way is then de-energized Metal, for example copper, exposed to the deposition bath and left in this until deposition is sufficient Thickness is reached. The mask is then removed in the usual manner and. the base material located on the copper foil by brief treatment with ammonium persulfate or removed with another suitable solvent. This is done extremely quickly and economically because the Base material foil made of a copper-clad compared to the usual Base materials, an extremely thin layer of copper is made.

This procedure is intended to be more precise in your example below are set out:

Example VI

An example according to Example V is prepared based material as a starting material, _and with a K 5 / U and a pferfilmstärke both sides of, for example fully covering copper film.

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BATH

To produce a printed circuit board with a printed circuit on both sides, a mask is first printed on both sides of the base material, in this example by means of screen printing. A composition is used as the paint which, on the one hand, has good resistance to the other bath fluids used, but on the other hand can be easily removed using a suitable solvent. Such printing inks are available in large numbers. Their resistance is expediently improved by a hardening process, for example by heat drying. The base material plate provided with the mask imprint in this way is then briefly cleaned, for example in an alkaline solution, and after rinsing with water, the copper surface is reactivated , for example in sulfuric acid (10fo). The piaute is then placed in a ductile metal, for example such a bath that deposits copper without an external power supply, and left therein until a copper layer of the desired thickness has been built up in the areas corresponding to the circuit pattern. A particularly useful bath consists _t for example from a bath solution according to the following composition:

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ORlGlNAt.

Copper sulfate formaldehyde

0.002 mol / liter to 0.15 mol / liter

0.05

3.5

Complexing agent for

Copper (II) ions 0.001 »" "0.25" "

Complexing agent for

Copper (I) ions 0.00005 "" "0.09" "

Alkali hydroxide to adjust the pH between 10 and 14 Such a bath consists for example of bath d

15 g / l

GuSO

5H ₂ O

Rochelle salt 45 g / l

sodium cyanide 0.7 g / l

HGHO (37/0 10 ml / 1

Sodium hydroxide to achieve a pH of 13.5.

A bath of the following composition is also very suitable
Bath e

GuSO ₄ . 5H ₂ O 5 g / l - trisodium nitrilotri-
acetate ($ 40) 23 ml / 1 (xlyconitrile 12th mg / 1 2-mercaptobezothiazole 0 , 08 mg / 1 HGHO ($ 37) 10 ml / 1 Wetting agents 2 g / l Sodium hydroxide. 2 , 1 g / l

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JBAD ORIGINAL

179Q293

". 5H ₂ O; ·. 10 g / l

ethyl ethyl en-

diämihtriacetat. (4-lfo) 15 ml / l

aerosol hydroxide 2 g / l i 55 / Ü- Mofce IHsrmsldehyd ($ 37) 6th mlA ihiödiäthanöi O ₁ i0Ö0Ö15 ml / 1 NätriümcyaMtf ^: 10 mg / 1 ■ * rt means 1 g / l Mm Baäer liiferfi höcligläiizeiide express earth defili ch copper deprecated hints of hype 15 'S-feii ilea.

If the viiiiiäöHte metal ocliieiitslär & e eert-calibrated, When the Mkske dye is dissolved, the fare is carefully rinsed üM: "B-ebeispielä'vie ± se iit ein fassertauoniacic überzögeii, üäi EörfööiÖn zti feriäeiäeri.

Seispiei TΪΙ

itelit represents a different 'Inventor _ö agem &ße'Veranrensweisö; Over at Wirä, the metal that forms the daö ijeitefiiruoter alls chi hurries galvanically ätifgefeküti 2ünaeiist -iiil'ifä: | ^: iie in Beiäpiei Yl also a lasfce äüfgeördbiit ^ which merely, öties deiii

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iie ± t # 3? iiiiisiii ?. eligible districts fell to MJt; Scjdämi is the smoothness in lift gslvanisöiiäe Met ^ läb ^ tieidüngsb'äd; .at: - spielsweiäe in a f ^ rbp1iä |) iist ^::: Kü [pferbad feingöb ^ äoHt ^, whereby the electrical iiiäönlilß from the Mnhahgig to disr. thin. Ölie deä Basisiaateriäls takes place. According to the appropriate nisierzext> bliäpieisweiäS nacii oa.4-5 'Mniiteii f iir.

35 / ti Öü is the flatte iespült ^ UIID hköH d§iii, J; rtt || r '| ien _LOER; ; i? ärbe ufid döffi liHsöfi des. £ # 1 ropes. deti Eeiterzuggeh frÄi iiegjsidi dlii Bäsiäläte ^; rlMiIüpfe ^; rä.fiiit hurry ^; r Söiltit ^ BiiiÖiit Gege. ......

öä vetäe'iiln; . . .., - .. ... .- .... ..-, ■ <

ifliBi the 'HSi iteiiülig t <M i, eitärpiättiii dit iStäi teü 1.8öHwiiidiifi | ln iititär fer ^ endüni etii ifi de'ii Jiiä |) fglSH ti "" üüd fli ßeSciirie'Böniii terfaiireliääöiirittl: Mierb'li lird "ZtiimMiäl the SäöiiSäteriäi der Irtj'iiö UiU fiif d'i§ Jiiäßie'li TI tiiid tii beiÖÖrieBin Mrdi ^ Mt aiii iBBM ^ rä aüMä MtBH- MMMit ^ Sileiiliil dere'ri'fäiidHiiiieii MetäÜiÜIrt iüia / 8 isdefüsalen z tli ± ^{e; rb} cgr ^ iigeli #if biiältt sgitiü zÜisöitiger liSitörliiältifl ciieiiin Idliöni SbdäMii ferae til IiI "d§ii BBcMiingin verüBiÖS iiöisffiateriii | iiatti I Blim ^ ^ iöil iiäe"te'r- * littlis eliief 'mNm- and' iaiiittitaiiiSniii Mlüiiiitidln Iiöätilif "" iI Uk the i, BöH # ifidüngeit for dil itfBifeiOMllgiallltii Mi ätti ^ ilrin; MiÖiiiilBeiid IiM ^ fie iii "dSn ^: Mi-

-02

iöiiäi / öiit

play VI and. VlI described, printed the mask and on Proceed as stated there, but in each case a currentless metal bar, possibly less Thickness, must be made.

Finally, "investigations have shown that the 'finished, printed circuit board exposed to an acid bath for a short time before applying corrosion protection so are all those still remaining from previous procedural steps to remove courtship rests.

Έ after another Äus Ausführungsforin of the invention is in the production of circuit boards from a base material in the manner of the materials described in Examples I and II suitable surface layer is provided. This base material is first covered with a mask that is resistant to the oxidation and build-up bath and the baths of the activation process for electroless metal deposition, which only leaves the surface areas corresponding to the later conductor pattern exposed Highly etch-resistant printing inks have proven »To improve their resistance, you can

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BATH

be expedient, this by a warm process. to .harden « '■ - ·, the mother plates are to be metallized with. iocn wall s ■ -: .-. are provided, the corresponding IiOßimugep. ■■ _ ■■ · ... ■■ either before or · after applying this.-Ms ^ rather-; ...

represents. . . ■ -'.... ·., -, .. ■■■ . · ■ ■■ ■ ■ - · ... -

Then the exposed base material © The surface is exposed to the, ■ Oxidation and transfer agent, De for example a permanganate solution, for a .. time _f . which is sufficient to produce sufficient oxidation; ei güf uhr en -wa &. -. '.. to form micropores. The plate surface is then activated after rinsing, for example exposed to a solution containing tin and noble metal ions. The solution containing the noble metal ions expediently contains a small percentage, up to 5%, of MEK. The mask paint is removed after rinsing. It has proven particularly advantageous to use mask paints that can be removed in alkaline isä & ungeu . The base material plate pretreated in this way is then exposed to a suitable electroless metal plating bath for a time which is sufficient to build up a layer of the desired thickness.

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BATH ORIGINAL

The electroless baths described in the preceding examples can be used particularly advantageously. , _; In the final section, the panels are carefully rinsed and, if necessary, provided with corrosion protection after further cleaning and neutralizing baths. A water-immersed lacquer or a spray-applied tin layer or roller tin plating can serve as such. -

This one according to the invention has proven to be particularly advantageous Execution that between, the ladders no remnants of Substances from the activation cycle may be present, the. about without careful cleaning to deterioration the surface resistance could be the cause.

On the other hand, it may be procedurally simpler under certain circumstances be to start from a base material like the one Example III corresponds. This base material has a surface layer that has already been treated with the oxidizing and degrading agent. For further processing into printed circuit boards there are two process variants, one of which is first applied the mask and then proceed as in that for base material according to the type of examples I and II given method example carried out.

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309833/0951

BAO

However, the entire unmasked surface can also be used initially. _{; i}

activated for electroless metal deposition and only _; f.

then the mask can be printed on. Apart from this difference, as for the first, ... variant is indicated _t . . ,

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30983 3/09 5 1

BATH ORIGINAL

Claims (13)

, .31 - Expectations Process for the production of egg ü printedοc & altungeh, ordering from a 'questioner made of insulating material, an adhesion-promoting intermediate layer and one, if necessary, in whole or in part - · ■ · metal green layer on it, thereby g e k e η η ζ ei c h η e t that one is on the surface of the carrier one at least one by oxidizing agents layer containing oxidizable, thermosetting modified rubber or synthetic rubber (rubber) evenly distributed appXxziertj that the applied layer is passed through Heating at least partially cures and that the at least partially hardened layer before the electroless or electroless and galvanic metal deposition at least in the areas to be metallized with an oxidizing agent, preferably with a chromosulfuric acid or permanganate solution. 2. The method according to -.Anspruch 1, characterized in that the Metallgrundscnicht initially provided with a cover mask which merely correspond to the desired line pattern . Leaves districts free, then the masked one Surface an electroless metal, preferably ductile 309833/0951 Is exposed to a copper-plating bath for a time sufficient for the desired conductor thickness, a then the cover mask, and either z or, in a subsequent operation, the thin, Metal layer located between the conductor tracks. removed, preferably etched away. 3. The method according to claim 1 and 2, characterized in that that the metal surface is first covered with a cover layer is provided, which is only the desired Leaves the corresponding districts free, then the unmasked surface is reinforced by means of a galvanic process, then the mask layer removed and either at the same time or afterwards that of. original thin 'that was covered by the mask Metal layer degraded is preferably etched away. 4 »Method according to claims 1 to 3, for the production of printed circuits with metallized perforated or breakthrough walls, characterized in that" the base material plate is placed before or after the application of the layer of varnish, ¹ but in any case before it is inserted into the Conductor lines used metallization bath is brought, provided with the appropriate holes or Durohbrbruch and exposed to a -customary activation treatment 309833/0 9 51 BATH 5- i method according to claim 1 to 4, characterized in ", 'da® - the coated' substrate surface according to the corresponding Heat treatment is provided with a cover layer, which only corresponds to the desired conductor pattern leaves corresponding areas free, then the surface masked in this way for the corresponding period of time exposed to an oxidizing agent and then an activation process for electroless metal deposition is subjected to finally after the! remove the covering layer to be baked in an electroless metal plating bath for such a period of time that darm the desired conductor tracks in the appropriate thickness applied. ■ 6. The method according to claim 1 to 5, characterized in that that the surface that has been exposed to the oxidizing agent is printed with a fine mask, the only 3rd Leaving districts free which correspond to the desired pattern of conductors, the districts left free then for the electroless metal deposition activated and then after removing the mask layer, put the conductor tracks in an electroless metal separating bath built up weruen. - 34 - 3 0 9833/0951 BATH ORIGINAL 7. The method according to claims 1 to 6, characterized in that the oxidized surface layer, they are used for separation from non-current baths' has been activated, is provided with a mask that corresponds only to the desired conductor pattern leaves the districts free, then the ladder tracks in an electroless deposition bath and the cover mask can be removed if desired. ^! . "> 8. The method according to claims 5 to 7, for the production of printed circuits with metallized hole or Durchbruc! Walls, characterized in that the activation for the electroless deposition in the ^r time sequence at a suitable point before introduction into the electrolessly separating bath and after making the holes bsaw. Breakthroughs occurred Process according to claim 5, characterized in that an aqueous solution is used for activation which, in addition to tin and palladium ions, contains a small amount of an organic solvent, preferably methyl ethyl ketone in a concentration of 0.1 to 5%. 10. The method according to claims 6 to 9 or at least one of them, characterized in that the currentless meter R ₁ ^ -m 0> £ 3 0 9 8 3 3/0 9 5 1 BATH tall ^ separating bath is a copper bath that is next to one Reducing agents and other suitable ingredients both , Gupri and Gupro ion complexing agents. 11 »Method according to claim 10, characterized in that the electroless copper separating bath is water-soluble € yanid, i preferably in a concentration of 0.004 to Contains 0.025 mol / l. 12. The method according to claims 1 to 11, characterized in that that the surface exposed to the oxidizing agent is then exposed to a bath, the best of which is still present after washing the surface neutralized or converted into a washable form. 13. The method according to claims 1 to 12, characterized in that that the covered with the built-up conductor tracks from the mask layer and possibly from a thin one The metal layer between the conductors was exposed to an acid bath after rinsing again rinsed and finally in a known manner by means of a suitable water immersion paint ; a protective layer is provided. 30 983 3/09 51 Bfi®