JPH0534428B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to applying masking or the like to the surface of a synthetic resin substrate, a silicone or other ceramic substrate, or a semiconductive or insulative poorly conductive material such as a metal oxide. The present invention relates to a method of manufacturing various complex and fine metal deposition patterns by partially or selectively plating without any process, and particularly to a manufacturing method with improved manufacturing speed and efficiency.

An example of this type of plating method using electroplating is the selective electroplating method described in JP-A-55-148797. According to this publication, a cathode is provided in an electrolyte, an anode is provided in the electrolyte at a distance from the cathode, and an energy beam ( Electromagnetic radiation (e.g., laser) is applied to the area, a voltage is applied between the anode,
A prior art technique has been disclosed in which plating is performed while relatively moving the beam spot and the cathode so as to draw a predetermined plating pattern on the beam spot. However, according to this prior art, to form a 10μ wide Ni line plating with a thickness of 0.2 to 0.4μ, the argon laser is focused into a beam with a diameter of 20μ and the intensity at the spot is 2×10 ⁵ . When applying a DC plating potential of 1.5 V between the Ni evaporated cathode and anode as W/cm ² , the effective exposure time to the cathode must be 20 milliseconds, and the plating line path speed of the light source is 1 mm/sec.
(≒60mm/min). And this means that in the above laser, the diameter of the beam spot is less than half that of the above, the power intensity at the spot is quadrupled, and the beam is pulsed by a mechanical chopper.
When plated under the same conditions as above while repeatedly irradiating 0.3 millisecond light pulses, the diameter was 6 μm thick.
As is clear from the fact that it takes 1 second to make a 30μ plating spot, it is far from being fast, but rather slow, and is suitable for various electronic devices such as ICs and LSIs that the above-mentioned prior art documents apply to. It could not be applied to printed circuit boards or the like except in special cases.

Furthermore, JP-A-55-148757 discloses a step of preparing a non-photosensitive plating bath, a step of bringing the object to be plated into contact with the plating bath, and a step of locally heating the contact surface to promote plating. applying an energy beam (electromagnetic radiation such as a laser) of sufficient intensity to the contact surface, the beam spot and the object to be plated so as to draw a predetermined plating pattern on the beam spot; A prior art technique has been disclosed in which selective plating (electroless or chemical plating that does not use electricity) is performed while relatively moving the material and the material. According to the plating method of this prior art, the plating speed for the plated object on which Ni is vapor-deposited is set according to the conditions of the first prior art (plating thickness 0.2 to 0.4μ, plating width 10μ). When converted, the plating speed is approximately 0.5 to 3.6 mm/sec (≒30 to 216
It is only to say that there are cases where the speed is approximately twice as fast as that of the first prior art mentioned above.
It is thought that it cannot be applied to the intended integrated circuits, etc., except in special cases, because the plating speed is slow.

In addition, since various electronic devices and substrates such as printed boards are usually insulators or semiconductors, the first and second methods described above involve selectively plating a predetermined pattern in the metal conductive surface area. What is described in the prior art documents cannot be applied to the substrate to be plated in the present invention without some kind of ingenuity. Unless the deposited film portion is preferably selectively removed, it is not possible to fabricate a device having a conductive pattern of metal or alloy on an insulating substrate.

The present invention has been proposed in view of these points, and an object of the present invention is to provide a selective plating method that enables high-speed plating and also allows plating of insulating substrates.

In order to achieve this objective, in the present invention,
The irradiated area is activated by irradiating the substrate surface with energy spots in a predetermined pattern, and then a fluid containing a substance that will become a precipitation nucleus during chemical plating is brought into contact with the substrate surface, and then brought into contact with a chemical plating solution. By performing chemical plating in a predetermined manner, selective chemical plating of a predetermined pattern can be performed at high speed without using a mask or the like.

In the present invention, palladium, tin, etc. are used as the substance serving as the precipitation nucleus, and compounds such as chlorides of these are used as contained in a liquid or paste-like fluid. Further, the substance used for the chemical plating is generally nickel, copper, gold, or the like. That is, the present invention performs chemical plating, but instead of using an energy beam in the metal deposition stage of chemical plating, it uses an energy beam in the pretreatment stage of chemical plating, and the energy beam irradiation By making it possible to form deposition nuclei during chemical plating with high deposition efficiency and at high speed while forming a predetermined pattern, metal deposition can be performed on precipitate nuclei in a predetermined pattern at once by chemical plating. As a result, selective plating by chemical plating has become possible at high speed as a whole.

The details of the present invention will be explained below with reference to the embodiment shown in FIG. As shown in FIG. 1A, a substrate 3 to be selectively plated is set on an XY table 2 whose position is controlled by an NC device 1. Note that, as shown in FIG. 2A, for example, the substrate 3 is made by coating the surface of glass fiber 3A with epoxy resin 3B, and before setting it, it is washed with a neutral detergent and washed with water. It was washed thoroughly and then dried in an electric furnace or an open fire. A laser beam of 1.5× is focused onto the surface of the substrate 3 by a convex lens 7 to a diameter of 1 mm from a laser device 6 including a modulator.
By irradiating the surface of the substrate 3 with a laser beam 8 of 10 ³ W/cm ² , preferably in reduced pressure or vacuum or in a clean gas, an active line width of 1 mm based on the numerical value generated by the NC device 1 is generated on the surface of the substrate 3. Draw the specified stroke line.

To explain activation by energy beams including laser beams, when energy beams are locally irradiated onto the surface of polymeric substances such as synthetic resins, ceramics such as oxides, metals, etc.
A temperature rise occurs in the irradiated area, or adsorbed substances on the surface (oxides in a thin molecular layer, water, dust, oil, etc.) fly out, and an energetically or chemically clean surface appears. It can be said that the surface atoms of this cleaned outermost surface of a solid substance are in a state where the electronic structure is extremely unstable compared to the part covered with the adsorbate, so to speak. It forms a kind of excited state in which molecules and atoms are constantly trying to stick together in an attempt to resolve the state, and are in a higher energy state than the atoms below the surface. Such a locally activated state is created at a desired location by irradiation with an energy beam. FIG. 2A shows a state in which active points 3a are formed on the surface of the substrate 3 by irradiation with the laser beam 8. FIG.

Although the active points (lines) described above are not as highly active as those mentioned above, they can be exposed and formed by, for example, scraping off the surface layer of the substrate 3 with a diamond cutting tool, etc. The present invention can be applied to the following cases.

After forming the active points 3a or a line consisting of a series of active points 3a in this manner, the substrate 3 is immediately placed in an activation treatment tank 4 and immersed in a palladium chloride solution 5, as shown in FIG. 1B. 2B and 2C show the formation of palladium precipitation nuclei 9 in the concave active points 3a on the surface of the substrate 3 in the presence of the palladium chloride solution 5.

The palladium chloride solution 5 used here had the following composition.

PdCl ₂ 0.25-12.5 g / 36% HCl 2.5-125 ml / C ₃ H ₈ O ₃ 0-200 ml / C ₂ H ₅ OH base Note that the above HCl is used to dissolve PdCl ₂ in ethanol (C ₂ H ₅ OH). In addition, glycerin (C ₃ H ₈ O ₃ ) was added to increase the viscosity of the solution and to make the solution 5 wet the substrate 3, and ethanol was used as the base. This is because this has the effect of etching the substrate 3 coated with the epoxy resin, and since the heat of evaporation is small, it also has the effect of reducing the laser power. In addition, solution 5
is heated to about 50 to 60°C as necessary to reduce the active site 3a by reduction of palladium chloride.
It is preferable to make the precipitation smooth and rapid, and as the base, acetone, water, etc. can be used in addition to the above-mentioned base.

After forming the precipitation nuclei 9 as described above, as shown in FIG. After washing away the hydrochloric acid aqueous solution, the substrate 3 is coated with a copper or nickel electroless plating solution 11 as shown in FIG. 1D.
Electroless plating (chemical plating) is performed by immersing it in the liquid. In this electroless plating, as shown at D in FIG. 2, copper or nickel 14 is deposited on the precipitation core 9 made of palladium.

Here, the copper plating solution used for electroless plating in this example contains the following amount of substance in water.

Copper sulfate 7 g / Rothsiel's salt 20 g / Sodium carbonate 2 g / Sodium hydroxide 5 g / Formaldehyde 40% aqueous solution 25 ml / The Nickelmeck liquid had the following composition.

Nickel chloride 45g / Sodium hypophosphite 11g / Sodium citrate 100g / Ammonium chloride 50g / Then, as shown in Figure 1E, the substrate 3 is cleaned by flowing water through the nozzle 12 to increase the plating thickness. In such a case, electroplating is performed by immersing the substrate in electroplating liquid 13 as shown in FIG. 1F. This electroplating may be performed not only on the same metal as chemical plating, but also on different metals such as silver, gold, etc.

When performing pretreatment to form active points (lines) 3a for palladium precipitation using a laser beam as described above, if the beam scanning speed is approximately 180 m/min (3.0 m/sec) or less, the subsequent The treatment (FIG. 1B) allowed palladium to be deposited. After drawing the palladium pattern on the substrate 3, it is plated by electroless plating, but this does not pose a problem in improving efficiency. This is because electroless plating proceeds at high speed using precipitation nuclei as a stop, and plating can proceed by immersing a large number of substrates 3 in a plating bath.

Here, instead of the above palladium solution, when using a solution containing 0.04M of Pd(NH ₃ ) ₂ (NO ₂ ) ₂ in ammonia water containing ammonium nitrate and sodium nitrite at pH 8.5 and 45°C. also obtained almost the same results.

As another example, the diameter of the output beam may be
Using a CO ₂ laser of 0.6cm, output 10W, and wavelength 10.6μ,
After performing a pretreatment of irradiating a predetermined portion of the surface of the substrate 3 with the laser to form active points (lines) on the irradiated portion, a palladium solution 5 is prepared by adding 0.1% palladium chloride and 0.3% hydrogen chloride in water. As shown in FIG. 3, the palladium chloride solution 5 is poured from the outlet 15 at a flow rate of 1 c.c./sec so that a 0.1 to 1 mm liquid layer is formed on the surface of the substrate 3. When palladium is deposited on the active point (line) 3a, if the beam scanning speed is 36 cm/min or less, the predetermined portion of the surface of the substrate 3 is sufficiently activated by the laser irradiation to deposit palladium. It was possible. Therefore, the area on which palladium can be deposited per minute is 0.6×36=21.6 cm ² /min. If the beam is reduced to 0.06 cm (0.6 mm), it is possible to achieve a scanning speed of 21.6 ÷ 0.06 = 360 cm/min. If we increase the laser power by 10 times, or 100W, with the same beam diameter, the scanning speed is proportional to the laser power, so
Scanning speed is also up to 10 times faster, i.e. 3600cm/min
(36m/min), which is approximately 0.6 when converted to speed per second.
m/sec. Note that the scanning speed is also proportional to the temperature and supply amount of the palladium chloride solution.

In the above embodiment, the palladium chloride solution was supplied by dipping or flowing down onto the substrate, but it may also be sprayed from the nozzle 15' as shown in FIG. may be in the form of a paste rather than a liquid; in that case, as shown in FIG. A coating mechanism such as coating on the surface can be adopted.

FIG. 6 shows another embodiment of the present invention. In this embodiment, in order to promote the precipitation of palladium etc.,
For example, 10 from the ultrasonic generator 18 to the substrate 3
The solution 5 is brought into contact with the substrate surface while applying ultrasonic waves of ~50 kHz. According to this embodiment, the composition, supply amount, laser beam intensity, etc. of the solution 5 are the same as in the embodiment shown in FIG. About twice the precipitation rate could be obtained under these conditions. In addition, by applying ultrasonic waves to the substrate 3, the laser beam output can be reduced by 1/2.
4, the same precipitation rate could be obtained.

FIG. 7 shows another embodiment of the present invention. In this embodiment, continuous processing is performed by using a band-shaped flexible synthetic resin as the substrate 20 or by pasting the substrate on a band-shaped base material. It was made so that it could be done. In FIG. 7, a substrate 2 that has been subjected to an appropriate cleaning process is fed out from a supply reel 21.
0 is irradiated with a laser beam 8 by a laser device 6 under the relative position control of the NC device 1, and then guided by a roller 23 in an activation treatment tank 22 and immersed in a palladium compound solution 5, whereby the above-mentioned The surface is streaked with metallic palladium in a predetermined pattern.

After that, it is washed with water jetted from the nozzle 26 between the guide rollers 24 and 25 outside the tank, and then guided by the guide rollers 27 and 28 to the chemical plating tank 29.
Electroless plating is performed by immersing the nickel or copper in the electroless plating solution 11. In this case, the plating liquid 1 is placed between the ion control tank 30 and the chemical plating tank 29.
1 is circulated, and nickel or copper 3 is placed at the anode so that the concentration of nickel or copper ions is constant.
Connect 1 and electrolyze. Next, the electroplating liquid 13 of nickel, copper, gold and silver, etc. in the electroplating tank 36 is washed with water jetted from the nozzle 26 between the guide rollers 32 and 33 outside the tank, and then guided by the guide rollers 34 and 35. The chemical plating layer is connected to the cathode on the substrate 20 via the contact roller 37, and electroplating is performed. Next, the portion pulled up via the guide roller 38 is dried by hot air etc. ejected from the nozzle 39 etc., and then the take-up reel 4
Gather together by winding up to zero or other means.

In the case of a palladium chloride solution, the activation treatment solution used in this example was a solution in which 3.3 g of KCl, 2 g of PdCl ₂ , and 25 ml of 36% HCl were dissolved in 1 part of water. In addition, a solution of tin chloride was used; in this case, a solution of 25.2 g of SnCl ₂ .H ₂ O, 2.5 g of HCl, and 25 ml of 36% HCl dissolved in 1 part of water was used. Furthermore, in the case of activation treatment, when 1.5 g of AgNO ₃ was added as a sensitizer, the precipitation rate could be increased by about 20%.

In addition, the electroless plating solution containing nickel is a solution containing sodium citrate 0.2M boric acid 0.5M sodium subzincate 0.2M nickel sulfate 0.1M at pH 8 and 70℃, and containing copper. A solution containing 0.3M formaldehyde and 0.1M copper sulfate at pH 11 and 25%°C was used.

If the above-mentioned continuous processing is performed, the work can be performed automatically and labor saving becomes easy.

When carrying out the present invention, the substrates 3 and 20 include ABS, polypropylene, epoxy, polyester, phenol, polyphenylene oxide,
Synthetic resins such as polyvinyl, urethane, acrylic, silicone, glass, porcelain such as alumina, etc. can be used. Further, as the energy beam, electromagnetic waves of 100 MHz or more can be used.

As described above, according to the present invention, instead of using an energy beam at the stage of metal deposition in chemical plating, an energy beam is not used in the stage of chemical plating metal deposition, but in a stage prior to the processing stage in which chemical plating precipitation nuclei such as palladium are generated. Since an energy beam is used to form active points (lines) on predetermined portions of the surface, the processing scan is increased and the processing speed is increased until the palladium, which becomes the precipitation nucleus during chemical plating, is deposited in the predetermined pattern shape. As a result, the time required for the entire plating process can be shortened, and the insulating substrate can be selectively plated at high speed. Furthermore, according to the present invention, the amount of wear and tear during use of the nuclear deposition solution for chemical plating and the electroless plating solution for metal deposition corresponds to the amount of selective plating of a predetermined pattern, etc., so there is no waste and it is extremely economical. It is true. Furthermore, to form the active points (lines), the scraping operation of the substrate surface using a diamond cutting tool or the like as described above can be used in combination with the energy beam irradiation of the present invention.

[Brief explanation of the drawing]

Figure 1 is a process diagram showing one embodiment of the present invention, Figure 2 is a process diagram showing an embodiment of the present invention.
The figure is a diagram of the principle when implementing the method of the present invention.
6 to 6 are diagrams showing another example of how the substrate and fluid come into contact in the present invention, and FIG. 7 is a process diagram showing another embodiment of the present invention. 1...NC device, 2...XY table, 3,2
0... Substrate, 4... Activation tank, 5... Palladium chloride solution, 6... Laser device, 7... Convex lens,
8...Laser beam, 9...Precipitation nucleus, 10,1
2... Nozzle, 11... Chemical plating liquid, 13...
Electroplating liquid, 14... Nickel or copper, 18
...Ultrasonic generator.

Claims (1)

[Claims] 1. After irradiating and heating a predetermined portion of the surface of the insulating substrate that is the object to be plated with an energy beam to form active points (lines) on the irradiated portion, precipitated nuclei are formed during chemical plating. A fluid containing a substance as a compound is brought into contact with the surface of the substrate to form the active points (lines).
After depositing the substance on the active point (line) portion, and then cleaning the substrate to remove the remaining fluid, the surface of the substrate is brought into contact with a predetermined chemical plating solution to deposit the substance on the active point (line) portion. A selective plating method characterized by depositing metal by chemical plating using a substance as a core. 2. The selective plating method according to claim 1, wherein the energy beam is a laser beam. 3. The selective plating method according to claim 1, wherein the substance that becomes a precipitation nucleus during the chemical plating is palladium, and the compound of the substance is palladium chloride. 4. The selective plating method according to claim 1, wherein the fluid containing as a compound a substance that becomes a precipitation nucleus during the chemical plating is an aqueous solution containing the compound dissolved therein. 5. The selective plating method according to claim 1, wherein the fluid is a paste-like material. 6. The selective plating method according to claim 1, wherein the fluid contacts the substrate surface by flowing the fluid in a layered manner along the substrate surface. 7. The selective plating method according to claim 1, wherein the contact of the fluid to the substrate surface is performed by applying the fluid to the substrate surface in a layered manner. 8. The selective plating method according to claim 1, wherein the fluid contacts the substrate surface by spraying the fluid onto the substrate surface. 9 When bringing the fluid into contact with the surface of the substrate,
The selective plating method according to claim 1, wherein the substrate is vibrated by ultrasonic waves. 10. The selective plating method according to claim 1, wherein the insulating substrate is made of a long strip-shaped plate, and the plating is performed sequentially in the length direction. 11. The selective plating method according to claim 1, wherein the insulating substrate is made of synthetic resin. 12. The selective plating method according to claim 1, wherein the insulating substrate is porcelain. 13. The selective plating method according to claim 1, wherein the chemical plating is nickel plating. 14. The selective plating method according to claim 1, wherein the chemical plating is copper plating. 15. The selective plating method according to claim 1, wherein the irradiation of the energy beam onto a predetermined portion of the substrate surface is performed by relative numerically controlled movement of the beam and the substrate. 16. The selective plating method according to claim 1, wherein electroplating is further performed on the substrate on which metal has been deposited by the chemical plating.