CA1267826A - Process for desmearing and etching of plastics layers in holes drilled in basic material of printed circuit boards - Google Patents
Process for desmearing and etching of plastics layers in holes drilled in basic material of printed circuit boardsInfo
- Publication number
- CA1267826A CA1267826A CA000492324A CA492324A CA1267826A CA 1267826 A CA1267826 A CA 1267826A CA 000492324 A CA000492324 A CA 000492324A CA 492324 A CA492324 A CA 492324A CA 1267826 A CA1267826 A CA 1267826A
- Authority
- CA
- Canada
- Prior art keywords
- accordance
- basic material
- acid
- etching
- liter
- 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.)
- Expired - Lifetime
Links
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
- H05K3/38—Improvement of the adhesion between the insulating substrate and the metal
- H05K3/381—Improvement of the adhesion between the insulating substrate and the metal by special treatment of the substrate
-
- 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
- H05K3/0011—Working of insulating substrates or insulating layers
- H05K3/0055—After-treatment, e.g. cleaning or desmearing of holes
-
- 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
- H05K2203/07—Treatments involving liquids, e.g. plating, rinsing
- H05K2203/0779—Treatments involving liquids, e.g. plating, rinsing characterised by the specific liquids involved
- H05K2203/0786—Using an aqueous solution, e.g. for cleaning or during drilling of holes
- H05K2203/0789—Aqueous acid solution, e.g. for cleaning or etching
-
- 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
- H05K2203/12—Using specific substances
- H05K2203/125—Inorganic compounds, e.g. silver salt
-
- 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
- H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
- H05K3/18—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material
- H05K3/181—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material by electroless plating
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Manufacturing Of Printed Wiring (AREA)
- ing And Chemical Polishing (AREA)
- Chemically Coating (AREA)
- Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)
- Detergent Compositions (AREA)
Abstract
A B S T R A C T
The invention relates to a process for the reliable des-mearing and etching as well as crack-free roughening of plastic layers in holes drilled in basic material of printed circuit boards for highly adhesive metal-coating of the same with the use of sulfuric-acid solutions, characterized in that the holes are treated with a solution containing sulfuric acid and nitrate anions, the process being suitable for manufacturing printed circuit boards and/or through-plated circuit boards.
The invention relates to a process for the reliable des-mearing and etching as well as crack-free roughening of plastic layers in holes drilled in basic material of printed circuit boards for highly adhesive metal-coating of the same with the use of sulfuric-acid solutions, characterized in that the holes are treated with a solution containing sulfuric acid and nitrate anions, the process being suitable for manufacturing printed circuit boards and/or through-plated circuit boards.
Description
7~
The present invention relates to a prOGeSS for -the reliable desmearing and etching as well as roughening of plastic layers in holes drilled in basic material of printed circuit boards for adhesive metal-coating of the same.
When holes are drilled in plastic boards, e.g. glass-fiber boards impregnated with epoxy resin, the drill smears the wall of the hole since the material heats up during drilling and becomes soft.
The functional capacity of multilayer circuits of printed circuits boards in which the electrical connections between the two sides or between the different layers of inter-connections are established via feedthrough in the through-plat-ing process depends to a greater degree on whether the smearingof the plastic layers that occurs during drilling of the holes can be reliably removed.
Processes for the removal of this smearing are already known, examples being the chromic-acid or sulfuric-acid process.
But these processes work unsatisfactorily in as much as the copper that is deposited without the use of electric current adhered poorly on the walls of the holes, especially on resin~
coated zones, which leads to defectlve feedthrough as a result of poor coating.
The present invention provides a process of the type initially mentioned, which permits reliable removable of the plastic smears contained in the holes of basic boards due to the drilling, as well as crack-free roughening of the walls of the holes.
According to the present invention there is provided a process for the reliable desmearing and etching as well as crack-free rougheniny of plastic layers in holes drilled in basic mate-r~" ~
~ 267826 rial of printed circuit boards for adhesive metal-coating of the same, in which the holes are treated with a solution containing sulfuric acid and nitrate anions.
The process in accordance with the invention leads, in hitherto unattained fashion, to bo-th complete removal of the layer smears in the walls of ths holes and ideal microroughening of the surface of these holes.
The consequence thereof is that the metal deposited chemically and galvanically, e.g. a metal in groups I B and VIII, such as copper, after subsequent activation and reduction adheres especlally well to the walls of the holes and is superbly suit-able for the through-plating required to build up the conductive pattern.
Another important advantage is to be found in the fact that the etching rate can be lowered considerably.
The process can be applied in the generally ~nown fash-ion by the spray-on or wave-flow method, but unlike the known methods it can also be advantageously applied by the immersion method.
By preference concentrated sulfuric acid containing 92 to 98 percent H2S04 by weight is used.
An acid containing 85 percent H3PO4 by weight is used by preference as the phosphoric acid.
3~
Nitrate anions N03 are contained in the sulfuric-acid solution in the form of nitric acid and~or its salts, possible salts of the nitric acid being alkali-metal nitrates, e.g.
sodium, potassium, lithium or ammonium nitrate, or heavy-metal nitrates, e.g. chromic nitrate or ferric nitrate.
~i3.
~267~2~
The solution preferably contains the designated consti-tuents in concentrations of 9 to 17 moles/liter of sul-furic acid (d = 1.84 g/ml) corresponding to 500 to 950 ml/
liter, and 1.2 to 1.4 10 moles/liter of NO3 anions, corresponding for example to 0.1 to 120 g/l or sodium nitrate. Phosphoric acid is contained in concentrations of 0.7 to 7.4 moles/liter corresponding to 50 to 500 ml/l of H3PO4 (d = 1.71 g/ml) It is advantageous to add hydrofluoric acid and, possibly, a wetting a~ent to the solution in accordance with the in-vention, by preference a fluoridated hydrocarbon, expediently in concentrations of 0.01 g to 0.5 g/l. The addition of alkali-metal phosphates has also proved to be advantageous.
It is understood that the process in accordance with the invention is also suitable for desmearing and etching as well as roughening of the plastic layer on the surface of the basic material.
As a rule, treatment takes place at room temperatures of 20 to 45 C, by preference at 25 to 40 C and can, depending on the desired effect, take frorn 2 to 5 minu-tes, shorter or longer reaction times being possible if needed.
By varying the concentrations and reaction times it is pos-sible, for example, to superficially corrod~ a surface coating of less than 10 ~m (so-called desmearing) and etch-back a surface coating of more than 10 ~m.
A suitable basic material is, in par-ticular, glass-fiber reinforced epoxy resin, but i-t is also possible to use other common materials such as non-coated basic material, ~jey /,g /Cls <~ ~r~a~
phenolic paper, epoxy paper, p~e~h~, polysulfone, poly-imide, polyamide, polyphenylene odixe polystyrene, fluoro-carbon, polycarbonates, polyether imide or, as a coated basic material, a carrier, the surface of which has been provided with an adhesive coating which can be hardened by heat and which contains at least one material that be-longs to the group comprising modified rubber and/or ar-ti-ficial rubber and which can be oxidized and/or decomposed by suitable oxidants, or, as the basic material, a carrier whose surface is coated with a metal, copper by preference, on one or both sides.
The individual operations up to the drilling and further treatment performed in accordance with the invention such as rinsing processes, activation and metal-coating by chemical and, possibly, galvanic methods are already known in the art and, depending on the task, can be performed without major modifications by an expert.
The process in accordance with the invention is suitable ~or both the semisubtractive and subtractive tec~miques of manufacturing printed circuits.
The following examples serve to explain the process in ac cordance with the invention.
~ 67~3~ 6 EX~MPLE 1 A basic material consisting of glass-fiber reinforced epoxy resin and coated with copper on both sides is dril-led and deburred in the customary fashion.
The board is subsequently immersed in a solution consisting ~ of i 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 1 g of sodium nitrate I for 1 to 5 minutes at a temperature of 25 to 40 C.
. .
! After dripping off, rinsing, subsequen~ alkaline cleansing, I treatment with a solution of hydrochloric acid and ammonium fluoride as well as further, customary follow-up treat~
ment, it is activated and chemically plated with a copper coating of 0.2 ~m or 3 ~m in thickness.
The copper cQating is free of pores and features excellent adhesion, is capable of being soldered (solder-resistance test 3 x 5 sec. at 260 C). The desmearing ~etching rate) in this connection is greater than 10 ~m (e-tch-back).
~6782~
l Similar to Example 1 a board is treated with a solution con-sisting of `, 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 10 g of sodium nitrate.
The copper deposit displays the same outstanding properties as those described in Example 1.
1~ 6 Similar to Example 1 a board is treated with a solution consisting of 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 10 g of potassium nitrate.
The copper deposit displays the same outstanding properties as those described in Example 1.
~267~3Zfi Similar to Example 1 a board is treated with a solution consisting of 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 10 g of ammonium nitrate The copper deposit displays the same outstanding properties as those described in Example 1.
- 12~i7~3;26 o Similar to Example 1 a board is treated with a solution consisting of 850 ml of suluric acid (96 percent by weight) 150 ml o phosphoric acid (85 percent by weight) 10 g of chromic ni-trate The copper deposit displays the same outstanding p.roperties as those described in Example 1.
- 12 ~
1 2 F;t7R2~
EX~MPLE 6 Similar to Example 1 a board is treated with a solution consisting of 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 1 g of sodium nitrate 0.05 g of wetting agent (fluorocarbon).
The copper deposit displays the same outstanding properties as those described in Example 1.
~26~78~:6 EXAMPLE_7 The processes descri~ed in Examples 1 to 6 are repeated with an immersion time of 20 to 60 seconds.
This results in a desmearing (etching rate) of less than 10 ~m, and the copper deposits display the same outstanding properties as those described in Example 1.
The basic material made of glass-fiber reinforced epoxy resin and coated with copper on both sides is drilled and deburred in the customary fashion.
The board is subsequently immersed in a solution con-sisting of 1000 ml of sulfuric acid (96 percent by weight) 1 g of sodium nitrate for 20 to 60 seconds at a temperature of 25 to 40 C.
After dripping off, rinsing, subsequent alkaline cleansing, treatment with a solution of hydrochloric acid and ammonium bifluoride as well as further, customary follow-up treat-ment, it is activated and chemically plated with a copper coating of 0.2 ~m or 3 ~m in thickness.
The copper coating is free of pores and displays excellent adhesion, is capable of being soldered (solder-resistance test 3 x S sec at 260 C~. The desmearing (etchin~ rate) is this connection is greater than 10 ~m 5etch-back).
~LZ~;78Z6 o Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid ~96 percent by weight) 10 g of sodium nitrate.
The copper deposit displays the same outstanding properties as those described in Example 8~
- ~678Z~
EXA~IPLE 10 Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid (96 percent by weight) 10 g of potassium nitrate.
The copper deposit displays the same outstanding properties as those described .in Example 8.
~7 -, ~L2~32~à
Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid (96 percent by weight) 10 g of ammonium nitrate.
The copper deposit displays the same outstanding properties as those describedin Example 8.
~26~1~3Z~;
Similar to Example 8 a board is treated with a solution consisting of 1300 ml of sulfuric acid (96 percen-t by weight) 10 g of chromic nitrate.
The copper deposit displays the same outstanding properties as those described in Example 8.
~. .
r ~ 782~E;
EXAMP~E 13 Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid ~96 percent by weight) 1 g of chromic nitrate.
The copper deposit displays the same outstanding properties as those described in Example 8.
.
82~i i~
Similar to Example 8 a board is treated wi-th a solution consisting of 1000 ml of sulruric acid (96 percent by weight~
1 g of potassium nitrate 0.05 g of wetting agent (fluorocarbon) The copper deposit displays the same outstanding properties as those described in Example 8.
`: :
~ - 21 -:
The present invention relates to a prOGeSS for -the reliable desmearing and etching as well as roughening of plastic layers in holes drilled in basic material of printed circuit boards for adhesive metal-coating of the same.
When holes are drilled in plastic boards, e.g. glass-fiber boards impregnated with epoxy resin, the drill smears the wall of the hole since the material heats up during drilling and becomes soft.
The functional capacity of multilayer circuits of printed circuits boards in which the electrical connections between the two sides or between the different layers of inter-connections are established via feedthrough in the through-plat-ing process depends to a greater degree on whether the smearingof the plastic layers that occurs during drilling of the holes can be reliably removed.
Processes for the removal of this smearing are already known, examples being the chromic-acid or sulfuric-acid process.
But these processes work unsatisfactorily in as much as the copper that is deposited without the use of electric current adhered poorly on the walls of the holes, especially on resin~
coated zones, which leads to defectlve feedthrough as a result of poor coating.
The present invention provides a process of the type initially mentioned, which permits reliable removable of the plastic smears contained in the holes of basic boards due to the drilling, as well as crack-free roughening of the walls of the holes.
According to the present invention there is provided a process for the reliable desmearing and etching as well as crack-free rougheniny of plastic layers in holes drilled in basic mate-r~" ~
~ 267826 rial of printed circuit boards for adhesive metal-coating of the same, in which the holes are treated with a solution containing sulfuric acid and nitrate anions.
The process in accordance with the invention leads, in hitherto unattained fashion, to bo-th complete removal of the layer smears in the walls of ths holes and ideal microroughening of the surface of these holes.
The consequence thereof is that the metal deposited chemically and galvanically, e.g. a metal in groups I B and VIII, such as copper, after subsequent activation and reduction adheres especlally well to the walls of the holes and is superbly suit-able for the through-plating required to build up the conductive pattern.
Another important advantage is to be found in the fact that the etching rate can be lowered considerably.
The process can be applied in the generally ~nown fash-ion by the spray-on or wave-flow method, but unlike the known methods it can also be advantageously applied by the immersion method.
By preference concentrated sulfuric acid containing 92 to 98 percent H2S04 by weight is used.
An acid containing 85 percent H3PO4 by weight is used by preference as the phosphoric acid.
3~
Nitrate anions N03 are contained in the sulfuric-acid solution in the form of nitric acid and~or its salts, possible salts of the nitric acid being alkali-metal nitrates, e.g.
sodium, potassium, lithium or ammonium nitrate, or heavy-metal nitrates, e.g. chromic nitrate or ferric nitrate.
~i3.
~267~2~
The solution preferably contains the designated consti-tuents in concentrations of 9 to 17 moles/liter of sul-furic acid (d = 1.84 g/ml) corresponding to 500 to 950 ml/
liter, and 1.2 to 1.4 10 moles/liter of NO3 anions, corresponding for example to 0.1 to 120 g/l or sodium nitrate. Phosphoric acid is contained in concentrations of 0.7 to 7.4 moles/liter corresponding to 50 to 500 ml/l of H3PO4 (d = 1.71 g/ml) It is advantageous to add hydrofluoric acid and, possibly, a wetting a~ent to the solution in accordance with the in-vention, by preference a fluoridated hydrocarbon, expediently in concentrations of 0.01 g to 0.5 g/l. The addition of alkali-metal phosphates has also proved to be advantageous.
It is understood that the process in accordance with the invention is also suitable for desmearing and etching as well as roughening of the plastic layer on the surface of the basic material.
As a rule, treatment takes place at room temperatures of 20 to 45 C, by preference at 25 to 40 C and can, depending on the desired effect, take frorn 2 to 5 minu-tes, shorter or longer reaction times being possible if needed.
By varying the concentrations and reaction times it is pos-sible, for example, to superficially corrod~ a surface coating of less than 10 ~m (so-called desmearing) and etch-back a surface coating of more than 10 ~m.
A suitable basic material is, in par-ticular, glass-fiber reinforced epoxy resin, but i-t is also possible to use other common materials such as non-coated basic material, ~jey /,g /Cls <~ ~r~a~
phenolic paper, epoxy paper, p~e~h~, polysulfone, poly-imide, polyamide, polyphenylene odixe polystyrene, fluoro-carbon, polycarbonates, polyether imide or, as a coated basic material, a carrier, the surface of which has been provided with an adhesive coating which can be hardened by heat and which contains at least one material that be-longs to the group comprising modified rubber and/or ar-ti-ficial rubber and which can be oxidized and/or decomposed by suitable oxidants, or, as the basic material, a carrier whose surface is coated with a metal, copper by preference, on one or both sides.
The individual operations up to the drilling and further treatment performed in accordance with the invention such as rinsing processes, activation and metal-coating by chemical and, possibly, galvanic methods are already known in the art and, depending on the task, can be performed without major modifications by an expert.
The process in accordance with the invention is suitable ~or both the semisubtractive and subtractive tec~miques of manufacturing printed circuits.
The following examples serve to explain the process in ac cordance with the invention.
~ 67~3~ 6 EX~MPLE 1 A basic material consisting of glass-fiber reinforced epoxy resin and coated with copper on both sides is dril-led and deburred in the customary fashion.
The board is subsequently immersed in a solution consisting ~ of i 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 1 g of sodium nitrate I for 1 to 5 minutes at a temperature of 25 to 40 C.
. .
! After dripping off, rinsing, subsequen~ alkaline cleansing, I treatment with a solution of hydrochloric acid and ammonium fluoride as well as further, customary follow-up treat~
ment, it is activated and chemically plated with a copper coating of 0.2 ~m or 3 ~m in thickness.
The copper cQating is free of pores and features excellent adhesion, is capable of being soldered (solder-resistance test 3 x 5 sec. at 260 C). The desmearing ~etching rate) in this connection is greater than 10 ~m (e-tch-back).
~6782~
l Similar to Example 1 a board is treated with a solution con-sisting of `, 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 10 g of sodium nitrate.
The copper deposit displays the same outstanding properties as those described in Example 1.
1~ 6 Similar to Example 1 a board is treated with a solution consisting of 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 10 g of potassium nitrate.
The copper deposit displays the same outstanding properties as those described in Example 1.
~267~3Zfi Similar to Example 1 a board is treated with a solution consisting of 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 10 g of ammonium nitrate The copper deposit displays the same outstanding properties as those described in Example 1.
- 12~i7~3;26 o Similar to Example 1 a board is treated with a solution consisting of 850 ml of suluric acid (96 percent by weight) 150 ml o phosphoric acid (85 percent by weight) 10 g of chromic ni-trate The copper deposit displays the same outstanding p.roperties as those described in Example 1.
- 12 ~
1 2 F;t7R2~
EX~MPLE 6 Similar to Example 1 a board is treated with a solution consisting of 850 ml of sulfuric acid (96 percent by weight) 150 ml of phosphoric acid (85 percent by weight) 1 g of sodium nitrate 0.05 g of wetting agent (fluorocarbon).
The copper deposit displays the same outstanding properties as those described in Example 1.
~26~78~:6 EXAMPLE_7 The processes descri~ed in Examples 1 to 6 are repeated with an immersion time of 20 to 60 seconds.
This results in a desmearing (etching rate) of less than 10 ~m, and the copper deposits display the same outstanding properties as those described in Example 1.
The basic material made of glass-fiber reinforced epoxy resin and coated with copper on both sides is drilled and deburred in the customary fashion.
The board is subsequently immersed in a solution con-sisting of 1000 ml of sulfuric acid (96 percent by weight) 1 g of sodium nitrate for 20 to 60 seconds at a temperature of 25 to 40 C.
After dripping off, rinsing, subsequent alkaline cleansing, treatment with a solution of hydrochloric acid and ammonium bifluoride as well as further, customary follow-up treat-ment, it is activated and chemically plated with a copper coating of 0.2 ~m or 3 ~m in thickness.
The copper coating is free of pores and displays excellent adhesion, is capable of being soldered (solder-resistance test 3 x S sec at 260 C~. The desmearing (etchin~ rate) is this connection is greater than 10 ~m 5etch-back).
~LZ~;78Z6 o Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid ~96 percent by weight) 10 g of sodium nitrate.
The copper deposit displays the same outstanding properties as those described in Example 8~
- ~678Z~
EXA~IPLE 10 Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid (96 percent by weight) 10 g of potassium nitrate.
The copper deposit displays the same outstanding properties as those described .in Example 8.
~7 -, ~L2~32~à
Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid (96 percent by weight) 10 g of ammonium nitrate.
The copper deposit displays the same outstanding properties as those describedin Example 8.
~26~1~3Z~;
Similar to Example 8 a board is treated with a solution consisting of 1300 ml of sulfuric acid (96 percen-t by weight) 10 g of chromic nitrate.
The copper deposit displays the same outstanding properties as those described in Example 8.
~. .
r ~ 782~E;
EXAMP~E 13 Similar to Example 8 a board is treated with a solution consisting of 1000 ml of sulfuric acid ~96 percent by weight) 1 g of chromic nitrate.
The copper deposit displays the same outstanding properties as those described in Example 8.
.
82~i i~
Similar to Example 8 a board is treated wi-th a solution consisting of 1000 ml of sulruric acid (96 percent by weight~
1 g of potassium nitrate 0.05 g of wetting agent (fluorocarbon) The copper deposit displays the same outstanding properties as those described in Example 8.
`: :
~ - 21 -:
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the reliable besmearing and etching as well as crack free roughening of plastic layers in holes drilled in basic material of printed circuit boards for adhesive metal-coating of the same, in which the holes are treated with a solution containing sulfuric acid and nitrate anions.
2. A process in accordance with claim 1, in which the nitrate anions are formed with at least one of nitric acid and the salts of nitric acid.
3. A process in accordance with claim 1, in which con-centrated sulfuric acid containing 92 to 98%H2SO4 by weight is involved.
4. A process in accordance with claim 1, in which the solution contains 9 to 17 moles/liter of sulfuric acid and 1.2 to 1.4 10-3 moles/liter of nitrate anions.
5. A process in accordance with claim 1, in which the solution additionally contains at least one of phosphoric acid and hydrofluoric acid.
6. A process in accordance with claim 5, in which the solution contains 0.7-7.4 moles/liter of phosphoric acid with 85 percent H3PO4 by weight.
7. A process in accordance with claim 1, in which a wetting agent is present.
8. A process in accordance with claim 7, in which the wetting agent is a fluoridated hydrocarbon.
9. A process in accordance with claim 7 or 8, in which a wetting agent is present in concentrations of 0.01 to 0.5 g/liter.
10. A process in accordance with claim 1, in which treatment takes place at temperatures of 20 to 45°C.
11. A process in accordance with claim 1, in which treatment takes place at temperatures of 25 to 40°C.
12. A process in accordance with claim 1, 2 or 3, in which the basic material used is glass-fiber reinforced epoxy resin, phenolic paper, epoxy paper, polysulfone, polyimide, polyamide, polyphenylene oxide polystyrene, fluorocarbon, poly-carbonates or polyether imide.
13. A process in accordance with claim 1, in which a non-coated or coated basic material is used.
14. A process in accordance with claim 13, in which the coated basic material to be used is a carrier whose surface has been provided with an adhesive coating which can be hardened by heat and which contains at least one material that belongs to the group comprising modified rubber and artificial rubber and which can be oxidized or decomposed or both by appropriate oxidants.
15. A process in accordance with claim 1, in which the basic material to be used is a carrier whose surface is plated with a metal on one or both sides.
16. A process in accordance with claim 1, in which after completion of etching the basic material is activated, reduced and metal-coated.
17. A process in accordance with claim 15, in which the metal is copper.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19843437084 DE3437084A1 (en) | 1984-10-05 | 1984-10-05 | METHOD FOR ETCHING AND REMOVING PLASTIC LAYERS IN BORES OF BASE MATERIAL FOR CIRCUIT BOARDS |
| DEP3437084.6 | 1984-10-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1267826A true CA1267826A (en) | 1990-04-17 |
Family
ID=6247502
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000492324A Expired - Lifetime CA1267826A (en) | 1984-10-05 | 1985-10-04 | Process for desmearing and etching of plastics layers in holes drilled in basic material of printed circuit boards |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0183925B1 (en) |
| JP (1) | JPS6190497A (en) |
| CN (1) | CN1003974B (en) |
| AT (1) | ATA288085A (en) |
| CA (1) | CA1267826A (en) |
| DE (2) | DE3437084A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CS270372B1 (en) * | 1987-12-09 | 1990-06-13 | Sulc Jiri | Method of thin hydrophilic layers formation on surface of articles of non-hydrophilic methacrylic and acrylic polymers |
| US4959121A (en) * | 1990-01-05 | 1990-09-25 | General Electric Company | Method for treating a polyimide surface for subsequent plating thereon |
| US5180639A (en) * | 1990-10-26 | 1993-01-19 | General Electric Company | Method of preparing polymer surfaces for subsequent plating thereon and improved metal-plated plastic articles made therefrom |
| CN100398238C (en) * | 2003-06-06 | 2008-07-02 | 住友电气工业株式会社 | Drilled porous resin base material, and method of manufacturing porous resin base material with conductive drilled inner wall surface |
| TWI252721B (en) | 2004-09-10 | 2006-04-01 | Nan Ya Printed Circuit Board C | Method of manufacturing double-sided printed circuit board |
| DE102005051632B4 (en) * | 2005-10-28 | 2009-02-19 | Enthone Inc., West Haven | Process for pickling non-conductive substrate surfaces and for metallizing plastic surfaces |
| CN101638802B (en) * | 2008-07-28 | 2011-05-18 | 比亚迪股份有限公司 | Pre-plating correction liquid and pre-plating treatment method for circuit board |
| CN111748806B (en) * | 2020-07-21 | 2022-08-23 | 江苏悦锌达新材料有限公司 | Roughening liquid for polyphenylene sulfide and composite material thereof, preparation method and use method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1209844B (en) * | 1958-10-08 | 1966-01-27 | Telefunken Patent | Solution for matt etching of semiconductor bodies |
| GB1139441A (en) * | 1965-02-18 | 1969-01-08 | Pernix Enthone | Improvements in metal bondable plastics |
| US3523874A (en) * | 1967-03-16 | 1970-08-11 | Hooker Chemical Corp | Metal coating of aromatic polymers |
| JPS5481127A (en) * | 1977-12-13 | 1979-06-28 | Toshiba Corp | Method of forming chemical plating foundation |
-
1984
- 1984-10-05 DE DE19843437084 patent/DE3437084A1/en not_active Withdrawn
-
1985
- 1985-09-07 EP EP85111347A patent/EP0183925B1/en not_active Expired - Lifetime
- 1985-09-07 DE DE8585111347T patent/DE3577887D1/en not_active Expired - Lifetime
- 1985-10-04 CN CN85108628.4A patent/CN1003974B/en not_active Expired
- 1985-10-04 JP JP60220496A patent/JPS6190497A/en active Granted
- 1985-10-04 AT AT0288085A patent/ATA288085A/en not_active Application Discontinuation
- 1985-10-04 CA CA000492324A patent/CA1267826A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0183925A3 (en) | 1987-09-23 |
| EP0183925A2 (en) | 1986-06-11 |
| DE3577887D1 (en) | 1990-06-28 |
| CN1003974B (en) | 1989-04-19 |
| EP0183925B1 (en) | 1990-05-23 |
| ATA288085A (en) | 1993-07-15 |
| DE3437084A1 (en) | 1986-04-10 |
| JPS6190497A (en) | 1986-05-08 |
| JPH0317391B2 (en) | 1991-03-07 |
| CN85108628A (en) | 1986-06-10 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |