CA1330020C - Process for treating the surface of polyimides to improve properties to receive metal layer - Google Patents
Process for treating the surface of polyimides to improve properties to receive metal layerInfo
- Publication number
- CA1330020C CA1330020C CA000607389A CA607389A CA1330020C CA 1330020 C CA1330020 C CA 1330020C CA 000607389 A CA000607389 A CA 000607389A CA 607389 A CA607389 A CA 607389A CA 1330020 C CA1330020 C CA 1330020C
- Authority
- CA
- Canada
- Prior art keywords
- polyimide
- transimide
- acid
- article
- polyamic acid
- 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 - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
- C08J7/12—Chemical modification
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/14—Metallic material, boron or silicon
- C23C14/20—Metallic material, boron or silicon on organic substrates
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2379/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2361/00 - C08J2377/00
- C08J2379/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
- C08J2379/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
Abstract
ABSTRACT OF THE DISCLOSURE
A process is provided for improving the surface properties of polyimide articles which contain significant amounts of transimide. The surface of the polyimide containing the transimide is first treated with a base to convert the surface layer of both the polyimides and the transimides to the polyamic salt.
Thereafter the surface layer of the converted polyamic salt is treated with an acid to convert the layer to a polyamic acid. This is followed by a cure preferably in infrared radiation at a sufficiently rapid rate to prevent the formation of any significant amounts of transimide and provide only polyimide. Following this treatment metallization is applied to the improved surface layer.
A process is provided for improving the surface properties of polyimide articles which contain significant amounts of transimide. The surface of the polyimide containing the transimide is first treated with a base to convert the surface layer of both the polyimides and the transimides to the polyamic salt.
Thereafter the surface layer of the converted polyamic salt is treated with an acid to convert the layer to a polyamic acid. This is followed by a cure preferably in infrared radiation at a sufficiently rapid rate to prevent the formation of any significant amounts of transimide and provide only polyimide. Following this treatment metallization is applied to the improved surface layer.
Description
] 133002~
A PROCESS FOR TREATING THE SURFACE
OF POLYIMIDES TO IMPROVE PROPERTIES
TO RECEIVE METAL LAYER
Background of the Invention Conventionally polyimides are prepared by curing polyamic acid to remove a water molecule and convert the polyamic acid to a polyimide structure. Typically this curiny is done at an elevated temperature in various types of ovens. In the case of films, the films are heated to cure the polyamic acid to polyimide throughout the entire body of the film and the film is then spooled or otherwise supported. With this type of bulk curing, i.e. curing over the entire body of the article, in many cases the curing process is incomplete and also the curing process will provide a mixture of end products which can include isoimides and transimides as well as polyimides. The polyimides and isoimides are essentially linear and not branched whereas the transimides are a branched structure. These reactions of curing polyamic acid (PAA) to the polyimide, isoimide and transimide structures are as follows:
,~
A PROCESS FOR TREATING THE SURFACE
OF POLYIMIDES TO IMPROVE PROPERTIES
TO RECEIVE METAL LAYER
Background of the Invention Conventionally polyimides are prepared by curing polyamic acid to remove a water molecule and convert the polyamic acid to a polyimide structure. Typically this curiny is done at an elevated temperature in various types of ovens. In the case of films, the films are heated to cure the polyamic acid to polyimide throughout the entire body of the film and the film is then spooled or otherwise supported. With this type of bulk curing, i.e. curing over the entire body of the article, in many cases the curing process is incomplete and also the curing process will provide a mixture of end products which can include isoimides and transimides as well as polyimides. The polyimides and isoimides are essentially linear and not branched whereas the transimides are a branched structure. These reactions of curing polyamic acid (PAA) to the polyimide, isoimide and transimide structures are as follows:
,~
2 133~20 PAA _ 2Hp > P~
~ 1l 10~OH
_ HO--~C--N~O~) --2H20 ~
--f N ~ N ~ 0~ ~
--2Hp >lSolMlDE
o--c~C--I ~o~ -2H20 O O
_~ N ~ O
2PAA _~H20 >TRANSIMIDE
~_0--C~C--N~O~)} --~Hp O O
~~mO ¦--~ /N~~~~J
`, r 1`~
~ 1l 10~OH
_ HO--~C--N~O~) --2H20 ~
--f N ~ N ~ 0~ ~
--2Hp >lSolMlDE
o--c~C--I ~o~ -2H20 O O
_~ N ~ O
2PAA _~H20 >TRANSIMIDE
~_0--C~C--N~O~)} --~Hp O O
~~mO ¦--~ /N~~~~J
`, r 1`~
It has been found that the non-linear nature of the transimide structure results iII a lower surface density as compared to the linear structure of the polyimide whicll provides a much higher density surface. This presence of the lower density structure of transimide in any appreciab]e amoullts wil] result in an undesirable surface conditioll Wl~i.C]l al]ows t]le penetratioll illtO the surface of moisture which can migrate therei]l via ionic solvents. The presence of the moisture will tend -to swe]l and plastlcize the polyimide film which in turIl degrades the surface properties and, in particular, may lead to tensile stresses at inner facial regions with embrittlement, delamination and stress cracking being prevalent. This can and does significantly lower the ~trength of a bond between any meta] ization or metal layer applied to the surface of the polyimide and the underlying substrate. Thus, in cases where metal is to be applied to the surface of a polyimide substrate, it is desirab].e to reduce to a minimum and preferably eliminate any low density branc1led structures such as transimides.
While the prior art has recognized the desirability to increase certain surface properties of polyimides, nevertheless, none have suggested a process for improving the surface properties for the reception of metal OL IlletaliZat.iOlI Oll the surface thereof.
For example, U.S. Patent 3,36],589 teaches a treatment of the surface of a polyimide with a base for the purpose of improving the adhesion of the polyimide to orgal~ic adhesives which may be applied thereto. This process is also taught in U.S. Patent 3,505,168.
U.S. Patent 4,440,643 teaches a process of applying a coating of polyamic acid onto the surface of an existing polyimide and curing the added polyamic acid to provide an essentially dual layer polyimide structure. The followil~g ll.S. patents suggest various polyimide materials and various types of surface treatments for various purposes; 3,179,633, 3,416,994, 4,623,563, 4,731,287, 4,543,295, 3,770,573, 3,770,528, re. 29,134 also the following IBM
Technical Disclosure Bulletins suggest various curing processes for polyimides.
Volume 28, No. 6; dated Nov. 1985 pages 2646 and 2647;
Volume 24, No. 10; dated March, 1982, page 5110.
However, none of these patents or articles teach or suggest a method of improving the surface of an existing polyimide for the reception of a metal layer thereon.
1~
4 1330~20 Summary of the Invention According to the present invention, a process for improving the surface of a polyimide article which contains significant amounts of transimide is provided. In this process, the surface layer is treated Wit}l a base to convert the polyimide and transimid~ to polyamic acid sa].ts. This is followed by a treatment of the polyamic acid salts so formed on the surface with an acid which will convert the polyamic acid salts to polyamic acid.
Following this treatment, the polyamic acid is cured sufficiently rapidly to form ].inear polyimides only and prevent the formation of any significant amount of transimide. This preferably is done by infrared radiation.
Deæ_ription of the Preferred Embodiment It has been found that many types of commercially available polyimides, including polyimide films, have significant amounts of transimides present as well as smaller amounts of isoimides along with the desirable polyimide structure. For example, ~ Kapton polyimide films so].d by E.I. DuPont Co. have been analyzed and shown to have as m~lch as 20% transimide present as well as approximately 1% of isoi.mide. As indicated above, the transimide is a lower density structure than the polyimide and the isoimide due to its nonlinear ~ranched nature as opposed to the linear nature of the polyimides and isoimides. As noted above, this can result in significantly degraded surface properties of the polyimide article especially with respect to the adhesion of metal or metalization layers thereon. While the reason for the presence of the transimide is not completely understood, it is believed that it is probably related to the relative slowness of the bulk cure. Formation of linear polyimide from the polyamic acid is the preferred reaction if the reaction rate is sufficiently rapid to convert the polyamic acid to polyimide. This reaction is as follows:
1~, 133~20 P~ --2Hp > Pl H O O OH
I 1~ U/
~ H ~C--N~O~) --2HP ~
U 1l I ~N~ ~ N~O~ _ However, if the reaction rate i8 sufficiently slow the competing reaction in which transimide is formed from polyamic acid may take place forming an appreciable amount of the transimide.
This reaction in which transimide if formed from polyamic acid is as follows:
2r~A _3~p >ll~NSlMlDe ~N~o~¦ -lUp 3 {~
:~ In any event whatever the rea~30n for the presence of the transimide in the article, it does have an adverse effect on the surface of the article Witll respect to metal coatings applied thereto. The process of this invention removes the transimide 6 13~0~20 present in polyimide articles by converting the surface layer of both the transimide and the polyimide back to polyamic acid and thereafter curing the t]lUS converted surface layer sufficiently rapidly so that no significant transimide is formed but while forming only the more dense linear polyimide structure.
Broadly, the proces~ comprises the treating of the surface layer of an article of polyimide with a base to convert the surface layer of the polyimide and transimide to polyamic acid salts. Of course, any isoimide present will also be then converted to polyamic acid salts. Thereafter the polyamic acid salts are treated with an acid to convert the polyamic acid salts to polyamic acid. Following this, the surface layer of polyamic acid is cured sufficiently rapidly to form only polyimide and not to form any appreciable amounts of transimide. This cure preferably i8 an infrared cure with the infrared radiation being in the range of 1-3 microns.
While the particular base and acids used are not critical, it is preferred that the base be either alkali metal hydroxides or alkaline metal hydroxides and more preferably an alkali metal hydroxide and specifically sodium hydroxide has been found to work very effectively. Similarly, any acid can be used although it is preferred that a weak acid SUC]l as an organic acid be used and more preferably acetic acid has been found to work quite well. The reactions converting both the polyimides and the transimide to polyamic acid salts and thereafter to polyamic acid and then the curing of the polyamic acid surface layer to a polyimide are shown below:
, ., 1330~20 ~N ~ N~O~)~
~¦~N~OH
~H 1l o ~ N--Cc~xr--o-~N
~¦HOAc(Acedc Acid~
,~ ~ N--C~,,C--OH
HO--C ~C--N~O~ _ ¦ ~(IR Cul~) J~--2Hp __ N ~ N~O~ _ O O
¦~HO--C ~C~ N~O~) ~lc~ f=o J
~C
~iN-OH
1330~2~
--~N--C~C--O- "N-O O
_~C~ C--N~ 0~--O O
~IHOAC
_ ¦ _O--C~ C_ N~O ~ _ O O
{~HO--C~C--N~O~_ O O
¦ ~UIR Cure~
2--~N ~ N~O
L~
9 1330~20 A specific preferred process was performed as follows. A 2 mil thick H Kapton strip (Kapton is a trademark of E.I. DuPont for a polyimide which is a condensation product of pyromellitic dianhydride and oxydianiline) was treated in a .8M NaOH spray for two minutes at 50C, the spray being at 15-20 psi. This was followed by deionized water rinse at room temperature. (It is believed that this step converts both the polyimide and the transimide to polyamic acid salts.) This was followed by a two minute dip in 10% acetic acid at room temperature followed by a five minute deionized water soak which was followed by a one minute deionized water spray rinse at room temperature. (It is believed that this step converts the polyamic acid salts to polyamic acid.) The surface layer was then cured in an infrared curing oven for four minutes using a tungsten quartz source providing infrared radiation at 1-3 microns wave length. At this point, the process of converting the transimide to polyimide has been completed. The surface is now ready for metalization.
In order to test the effectiveness of the surface treatment, twenty samples of a Kapton strip were treated according to this method and had metalization applied to the surface thereof, and twenty samples of an untreated as received Kapton strip also had metallization applied to the surface thereof. The metalization in both cases was as follows. Sheets of Kapton material were preheated for six minutes at 50% power in a Leybold-Heraus vacuum furnace to about 200C. This was followed by an 02plasma discharge surface treatment for one mimlte at 200 Watts at a flow of 490 sccm flow of 0~. The chromium and copper were sputtered on in a conventional manner in which a layer of about 250 angstroms thick of chromium was first applied followed by a layer about 3,000 angstroms thick of copper. Following this, a copper plate was put on over the layer of the chromium and copper; this was done in a conventional way utilizing a 10% H2SO~ solution at room temperature for one minute which solution contained 200 grams per liter of H2SO~, 20 grams per liter of copper sulphate and 50 parts per million of chlorine, to provide a copper plate on top of the seed layer of chromium and copper. The sample was left in the bath for fourteen minutes at 27C which resulted in a 0.3 mil thick layer of copper.
In order to prepare the various samples from the two large ,~
133~20 sheets of plated metal, one sheet being on the untreated substrate and the other on the treated substrate according to this process, standard substractive etching processes were performed to create 30 mil wide lines separated by 30 mil wide spaces which lines would be suitable for peel testing for shear strength. The plated substrates were subjected to selected etch in a solution o~ 564 grams per 2~0 milliliter of ferric chloride at 30 to etch the copper followed by a standard substractive chrome etching in a solution of 62 grams per liter of KMnO4 and 40 grams per liter of NaOH at 40C followed by a dilute oxalic acid rinse. This resulted in two sheets of material having 30 mil Cr/Cu lines separated by 30 mil spaces thereon. Each of the sheets were then cut into 20 test pieces and peel tested on an Instrom tensile testing machine using the standard 90 peel test. The results of the 20 tests on each of the treated and untreated samples are as shown in Table I below:
, . . .
11 133~020 TABLE_ I
Un t re~ted ~ ~t ~ ~
( gm/mm ) th i s I nve nt i on ~ gm/mm ) 1. 23.6 1. 56.3 2. 22.9 2. 58.2 3. 24.6 3. 57.2 4. 23.3 4. 57.3 5. 24.2 5. 57.5 6. 22.1 6. 58.1 7. 25.4 7. 56.8 8. 23.8 8. 56.2 9. 23.7 9 _ 57.9 10. 24.0 10. 58.1 11. 23.2 1 11. 57.6 12. 24.6 12. 55.9 13. 24.9 13. 56.8 1~. 23.1 14. 57.4 15. 25.1 15. 57.8 16 23.6 16. 57.8 17. 23.7 17. 56.1 18. 23.8 18. 58.0 19. 23.5 19. 56.0 20. 23.0 20. 56.2 Avg 23 ~ ~-/............... Avg. 57.2 gm/mm v,~';;
As can be seen all of the samples on the substrate treated according to this invention had slgnificantly better peel strength than any of the samples on an the untreated substrate. lndeed the average peel strength of the samples on the substrate treated according to this invention as compared to one that is untreated showed a peel strength over twice as great.
While the invention has been described to some degree of particularity, various adaptations and modifications can be made without departing from the scope of the invention as defined in the appended claims.
While the prior art has recognized the desirability to increase certain surface properties of polyimides, nevertheless, none have suggested a process for improving the surface properties for the reception of metal OL IlletaliZat.iOlI Oll the surface thereof.
For example, U.S. Patent 3,36],589 teaches a treatment of the surface of a polyimide with a base for the purpose of improving the adhesion of the polyimide to orgal~ic adhesives which may be applied thereto. This process is also taught in U.S. Patent 3,505,168.
U.S. Patent 4,440,643 teaches a process of applying a coating of polyamic acid onto the surface of an existing polyimide and curing the added polyamic acid to provide an essentially dual layer polyimide structure. The followil~g ll.S. patents suggest various polyimide materials and various types of surface treatments for various purposes; 3,179,633, 3,416,994, 4,623,563, 4,731,287, 4,543,295, 3,770,573, 3,770,528, re. 29,134 also the following IBM
Technical Disclosure Bulletins suggest various curing processes for polyimides.
Volume 28, No. 6; dated Nov. 1985 pages 2646 and 2647;
Volume 24, No. 10; dated March, 1982, page 5110.
However, none of these patents or articles teach or suggest a method of improving the surface of an existing polyimide for the reception of a metal layer thereon.
1~
4 1330~20 Summary of the Invention According to the present invention, a process for improving the surface of a polyimide article which contains significant amounts of transimide is provided. In this process, the surface layer is treated Wit}l a base to convert the polyimide and transimid~ to polyamic acid sa].ts. This is followed by a treatment of the polyamic acid salts so formed on the surface with an acid which will convert the polyamic acid salts to polyamic acid.
Following this treatment, the polyamic acid is cured sufficiently rapidly to form ].inear polyimides only and prevent the formation of any significant amount of transimide. This preferably is done by infrared radiation.
Deæ_ription of the Preferred Embodiment It has been found that many types of commercially available polyimides, including polyimide films, have significant amounts of transimides present as well as smaller amounts of isoimides along with the desirable polyimide structure. For example, ~ Kapton polyimide films so].d by E.I. DuPont Co. have been analyzed and shown to have as m~lch as 20% transimide present as well as approximately 1% of isoi.mide. As indicated above, the transimide is a lower density structure than the polyimide and the isoimide due to its nonlinear ~ranched nature as opposed to the linear nature of the polyimides and isoimides. As noted above, this can result in significantly degraded surface properties of the polyimide article especially with respect to the adhesion of metal or metalization layers thereon. While the reason for the presence of the transimide is not completely understood, it is believed that it is probably related to the relative slowness of the bulk cure. Formation of linear polyimide from the polyamic acid is the preferred reaction if the reaction rate is sufficiently rapid to convert the polyamic acid to polyimide. This reaction is as follows:
1~, 133~20 P~ --2Hp > Pl H O O OH
I 1~ U/
~ H ~C--N~O~) --2HP ~
U 1l I ~N~ ~ N~O~ _ However, if the reaction rate i8 sufficiently slow the competing reaction in which transimide is formed from polyamic acid may take place forming an appreciable amount of the transimide.
This reaction in which transimide if formed from polyamic acid is as follows:
2r~A _3~p >ll~NSlMlDe ~N~o~¦ -lUp 3 {~
:~ In any event whatever the rea~30n for the presence of the transimide in the article, it does have an adverse effect on the surface of the article Witll respect to metal coatings applied thereto. The process of this invention removes the transimide 6 13~0~20 present in polyimide articles by converting the surface layer of both the transimide and the polyimide back to polyamic acid and thereafter curing the t]lUS converted surface layer sufficiently rapidly so that no significant transimide is formed but while forming only the more dense linear polyimide structure.
Broadly, the proces~ comprises the treating of the surface layer of an article of polyimide with a base to convert the surface layer of the polyimide and transimide to polyamic acid salts. Of course, any isoimide present will also be then converted to polyamic acid salts. Thereafter the polyamic acid salts are treated with an acid to convert the polyamic acid salts to polyamic acid. Following this, the surface layer of polyamic acid is cured sufficiently rapidly to form only polyimide and not to form any appreciable amounts of transimide. This cure preferably i8 an infrared cure with the infrared radiation being in the range of 1-3 microns.
While the particular base and acids used are not critical, it is preferred that the base be either alkali metal hydroxides or alkaline metal hydroxides and more preferably an alkali metal hydroxide and specifically sodium hydroxide has been found to work very effectively. Similarly, any acid can be used although it is preferred that a weak acid SUC]l as an organic acid be used and more preferably acetic acid has been found to work quite well. The reactions converting both the polyimides and the transimide to polyamic acid salts and thereafter to polyamic acid and then the curing of the polyamic acid surface layer to a polyimide are shown below:
, ., 1330~20 ~N ~ N~O~)~
~¦~N~OH
~H 1l o ~ N--Cc~xr--o-~N
~¦HOAc(Acedc Acid~
,~ ~ N--C~,,C--OH
HO--C ~C--N~O~ _ ¦ ~(IR Cul~) J~--2Hp __ N ~ N~O~ _ O O
¦~HO--C ~C~ N~O~) ~lc~ f=o J
~C
~iN-OH
1330~2~
--~N--C~C--O- "N-O O
_~C~ C--N~ 0~--O O
~IHOAC
_ ¦ _O--C~ C_ N~O ~ _ O O
{~HO--C~C--N~O~_ O O
¦ ~UIR Cure~
2--~N ~ N~O
L~
9 1330~20 A specific preferred process was performed as follows. A 2 mil thick H Kapton strip (Kapton is a trademark of E.I. DuPont for a polyimide which is a condensation product of pyromellitic dianhydride and oxydianiline) was treated in a .8M NaOH spray for two minutes at 50C, the spray being at 15-20 psi. This was followed by deionized water rinse at room temperature. (It is believed that this step converts both the polyimide and the transimide to polyamic acid salts.) This was followed by a two minute dip in 10% acetic acid at room temperature followed by a five minute deionized water soak which was followed by a one minute deionized water spray rinse at room temperature. (It is believed that this step converts the polyamic acid salts to polyamic acid.) The surface layer was then cured in an infrared curing oven for four minutes using a tungsten quartz source providing infrared radiation at 1-3 microns wave length. At this point, the process of converting the transimide to polyimide has been completed. The surface is now ready for metalization.
In order to test the effectiveness of the surface treatment, twenty samples of a Kapton strip were treated according to this method and had metalization applied to the surface thereof, and twenty samples of an untreated as received Kapton strip also had metallization applied to the surface thereof. The metalization in both cases was as follows. Sheets of Kapton material were preheated for six minutes at 50% power in a Leybold-Heraus vacuum furnace to about 200C. This was followed by an 02plasma discharge surface treatment for one mimlte at 200 Watts at a flow of 490 sccm flow of 0~. The chromium and copper were sputtered on in a conventional manner in which a layer of about 250 angstroms thick of chromium was first applied followed by a layer about 3,000 angstroms thick of copper. Following this, a copper plate was put on over the layer of the chromium and copper; this was done in a conventional way utilizing a 10% H2SO~ solution at room temperature for one minute which solution contained 200 grams per liter of H2SO~, 20 grams per liter of copper sulphate and 50 parts per million of chlorine, to provide a copper plate on top of the seed layer of chromium and copper. The sample was left in the bath for fourteen minutes at 27C which resulted in a 0.3 mil thick layer of copper.
In order to prepare the various samples from the two large ,~
133~20 sheets of plated metal, one sheet being on the untreated substrate and the other on the treated substrate according to this process, standard substractive etching processes were performed to create 30 mil wide lines separated by 30 mil wide spaces which lines would be suitable for peel testing for shear strength. The plated substrates were subjected to selected etch in a solution o~ 564 grams per 2~0 milliliter of ferric chloride at 30 to etch the copper followed by a standard substractive chrome etching in a solution of 62 grams per liter of KMnO4 and 40 grams per liter of NaOH at 40C followed by a dilute oxalic acid rinse. This resulted in two sheets of material having 30 mil Cr/Cu lines separated by 30 mil spaces thereon. Each of the sheets were then cut into 20 test pieces and peel tested on an Instrom tensile testing machine using the standard 90 peel test. The results of the 20 tests on each of the treated and untreated samples are as shown in Table I below:
, . . .
11 133~020 TABLE_ I
Un t re~ted ~ ~t ~ ~
( gm/mm ) th i s I nve nt i on ~ gm/mm ) 1. 23.6 1. 56.3 2. 22.9 2. 58.2 3. 24.6 3. 57.2 4. 23.3 4. 57.3 5. 24.2 5. 57.5 6. 22.1 6. 58.1 7. 25.4 7. 56.8 8. 23.8 8. 56.2 9. 23.7 9 _ 57.9 10. 24.0 10. 58.1 11. 23.2 1 11. 57.6 12. 24.6 12. 55.9 13. 24.9 13. 56.8 1~. 23.1 14. 57.4 15. 25.1 15. 57.8 16 23.6 16. 57.8 17. 23.7 17. 56.1 18. 23.8 18. 58.0 19. 23.5 19. 56.0 20. 23.0 20. 56.2 Avg 23 ~ ~-/............... Avg. 57.2 gm/mm v,~';;
As can be seen all of the samples on the substrate treated according to this invention had slgnificantly better peel strength than any of the samples on an the untreated substrate. lndeed the average peel strength of the samples on the substrate treated according to this invention as compared to one that is untreated showed a peel strength over twice as great.
While the invention has been described to some degree of particularity, various adaptations and modifications can be made without departing from the scope of the invention as defined in the appended claims.
Claims (17)
1. A process for improving the surface properties of a polyimide article for the reception of a metal film and wherein said polyimide article has substantial amounts of transimide present, said process comprising, in the order listed, the steps of:
treating the surface of the article with a base to convert the surface layer of the polyimide and transimide to polyamic acid salts, thereafter treating the surface with an acid to convert the polyamic acid salts to polyamic acid, and thereafter curing the surface layer of polya?
mic acid sufficiently rapidly to form a polyimide surface substantially free of transimide, whereby the surface properties of the article for the reception of a metal layer are improved.
treating the surface of the article with a base to convert the surface layer of the polyimide and transimide to polyamic acid salts, thereafter treating the surface with an acid to convert the polyamic acid salts to polyamic acid, and thereafter curing the surface layer of polya?
mic acid sufficiently rapidly to form a polyimide surface substantially free of transimide, whereby the surface properties of the article for the reception of a metal layer are improved.
2. The invention as defined in Claim 1 wherein the base is selected from alkali metal hydroxides and alkaline metal hydroxides.
3. The invention as defined in Claim 1 wherein the base is an alkali metal hydroxide.
4. The invention as defined in Claim 3 wherein the base is sodium hydroxide.
5. The invention as defined in Claim 1 wherein the acid is an organic acid.
6. The invention as defined in Claim 5 wherein the acid is acetic acid.
7. The invention as defined in Claim 1 wherein the curing step is performed by infrared radiation treatment of the surface.
8. The invention as defined in Claim 7 wherein the infrared radiation is in the wave length of one to three microns.
9. A process for improving the adhesion of metals to the surface of a polyimide article wherein said polyimide article has substantial amounts of transimide present, said process comprising, in the order listed, the steps of:
treating the surface of the article with a base to convert the surface layer of the polyimide and transimide to polyamic acid salts to polyamic acid, thereafter curing the surface layer with polyamic acid sufficiently rapidly to form a polyimide surface substantially free of transimide, and thereafter applying a metallization layer to the surface of the article, whereby the adhesion of the metal to the surface of the article is improved.
treating the surface of the article with a base to convert the surface layer of the polyimide and transimide to polyamic acid salts to polyamic acid, thereafter curing the surface layer with polyamic acid sufficiently rapidly to form a polyimide surface substantially free of transimide, and thereafter applying a metallization layer to the surface of the article, whereby the adhesion of the metal to the surface of the article is improved.
10. The invention as defined in Claim 9 wherein the base is selected from alkali metal hydroxides and alkaline metal hydroxides.
11. The invention as defined in Claim 9 wherein the base is an alkali metal hydroxide.
12. The invention as defined in Claim 11 wherein the base is sodium hydroxide.
13. The invention as defined in Claim 9 wherein the acid is an organic acid.
14 14. The invention as defined in Claim 13 wherein the acid is acetic acid.
15. The invention as defined in Claim 9 wherein the curing step is performed by infrared radiation treatment of the surface.
16. The invention as defined in Claim 15 wherein the infrared radiation is in the wave length of one to three microns.
17. The invention as defined in Claims 9, 10, 11, 12, 13, 14, 15 or 16 wherein the metal is a composite layer of Cr and Cu.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/275,825 US4931310A (en) | 1988-11-25 | 1988-11-25 | Process for treating the surface of polyimides to improve properties to receive metal layer |
| US07/275,825 | 1989-11-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1330020C true CA1330020C (en) | 1994-06-07 |
Family
ID=23053955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000607389A Expired - Fee Related CA1330020C (en) | 1988-11-25 | 1989-08-02 | Process for treating the surface of polyimides to improve properties to receive metal layer |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4931310A (en) |
| EP (1) | EP0370269B1 (en) |
| JP (1) | JPH02173129A (en) |
| CA (1) | CA1330020C (en) |
| DE (1) | DE68921849T2 (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5135779A (en) * | 1988-12-23 | 1992-08-04 | International Business Machines Corporation | Method for conditioning an organic polymeric material |
| US5187241A (en) * | 1990-05-15 | 1993-02-16 | International Business Machines Corporation | Isoimide modifications of a polyimide and reaction thereof with nucleophiles |
| JPH0427472A (en) * | 1990-05-21 | 1992-01-30 | Nippon Parkerizing Co Ltd | Washing method for resin molding |
| US5178914A (en) * | 1990-10-30 | 1993-01-12 | International Business Machines Corp. | Means of seeding and metallizing polymide |
| US5151304A (en) * | 1991-01-22 | 1992-09-29 | International Business Machines Corporation | Structure and method for enhancing adhesion to a polyimide surface |
| US5248760A (en) * | 1991-01-25 | 1993-09-28 | Unc At Charlotte | Chemically cured low temperature polyimides |
| US5156710A (en) * | 1991-05-06 | 1992-10-20 | International Business Machines Corporation | Method of laminating polyimide to thin sheet metal |
| US5427848A (en) * | 1991-05-06 | 1995-06-27 | International Business Machines Corporation | Stress balanced composite laminate material |
| US5183692A (en) * | 1991-07-01 | 1993-02-02 | Motorola, Inc. | Polyimide coating having electroless metal plate |
| US5290597A (en) * | 1992-04-27 | 1994-03-01 | General Electric Company | Method of treating halogenated polyimide substrates for increasing adhesion of metal layer thereon |
| EP0949277A3 (en) * | 1995-06-22 | 2000-12-27 | Yuri Gudimenko | Surface modification of polymers and carbon-based materials |
| US6171714B1 (en) | 1996-04-18 | 2001-01-09 | Gould Electronics Inc. | Adhesiveless flexible laminate and process for making adhesiveless flexible laminate |
| KR100383399B1 (en) * | 2001-02-28 | 2003-05-12 | 이걸주 | Portable vacuum packing machine |
| JP2006028484A (en) * | 2004-06-18 | 2006-02-02 | Mec Kk | Resin surface treatment agent and resin surface treatment method |
| WO2022033906A1 (en) | 2020-08-11 | 2022-02-17 | Basf Se | Use of strobilurin type compounds for combating phytopathogenic fungi containing an amino acid substitution f129l in the mitochondrial cytochrome b protein conferring resistance to qo inhibitors viii |
| EP3970494A1 (en) | 2020-09-21 | 2022-03-23 | Basf Se | Use of strobilurin type compounds for combating phytopathogenic fungi containing an amino acid substitution f129l in the mitochondrial cytochrome b protein conferring resistance to qo inhibitors viii |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US29134A (en) * | 1860-07-17 | Improvement in seed-planters | ||
| US3179633A (en) * | 1962-01-26 | 1965-04-20 | Du Pont | Aromatic polyimides from meta-phenylene diamine and para-phenylene diamine |
| US3505168A (en) * | 1964-09-04 | 1970-04-07 | Du Pont | Heat-sealable laminar structures of polyimides and methods of laminating |
| US3361589A (en) * | 1964-10-05 | 1968-01-02 | Du Pont | Process for treating polyimide surface with basic compounds, and polyimide surface having thin layer of polyamide acid |
| US3416994A (en) * | 1967-01-12 | 1968-12-17 | Du Pont | Cross-linked polyimide |
| US3770573A (en) * | 1971-06-08 | 1973-11-06 | Du Pont | Interdiffusionally bonded structures of polyimide polymeric material |
| US3770528A (en) * | 1971-09-29 | 1973-11-06 | Martin Processing Co Inc | Method for the surface treatment of polyimide materials |
| CA1053994A (en) * | 1974-07-03 | 1979-05-08 | Amp Incorporated | Sensitization of polyimide polymer for electroless metal deposition |
| US4543295A (en) * | 1980-09-22 | 1985-09-24 | The United States Of America As Represented By The Director Of The National Aeronautics And Space Administration | High temperature polyimide film laminates and process for preparation thereof |
| US4424095A (en) * | 1981-01-12 | 1984-01-03 | Kollmorgen Technologies Corporation | Radiation stress relieving of polymer articles |
| JPS57209608A (en) * | 1981-06-22 | 1982-12-23 | Ube Ind Ltd | Preparation of composite polyimide separation film |
| JPS60206639A (en) * | 1984-03-31 | 1985-10-18 | 日東電工株式会社 | Manufacture of polyimide-metallic foil composite film |
| US4668755A (en) * | 1984-08-10 | 1987-05-26 | General Electric Company | High molecular weight siloxane polyimides, intermediates therefor, and methods for their preparation and use |
| US4775449A (en) * | 1986-12-29 | 1988-10-04 | General Electric Company | Treatment of a polyimide surface to improve the adhesion of metal deposited thereon |
| US4842946A (en) * | 1987-09-28 | 1989-06-27 | General Electric Company | Method for treating a polyimide surface to improve the adhesion of metal deposited thereon, and articles produced thereby |
-
1988
- 1988-11-25 US US07/275,825 patent/US4931310A/en not_active Expired - Fee Related
-
1989
- 1989-08-02 CA CA000607389A patent/CA1330020C/en not_active Expired - Fee Related
- 1989-10-25 JP JP1276204A patent/JPH02173129A/en active Granted
- 1989-10-28 DE DE68921849T patent/DE68921849T2/en not_active Expired - Fee Related
- 1989-10-28 EP EP89120067A patent/EP0370269B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4931310A (en) | 1990-06-05 |
| JPH02173129A (en) | 1990-07-04 |
| EP0370269A3 (en) | 1991-09-25 |
| JPH0559136B2 (en) | 1993-08-30 |
| EP0370269B1 (en) | 1995-03-22 |
| DE68921849T2 (en) | 1995-10-12 |
| DE68921849D1 (en) | 1995-04-27 |
| EP0370269A2 (en) | 1990-05-30 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |