JP2001200370A - Method for forming plating on high polymer forming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming plating on a high polymer forming material by which the adhesion between the high polymer forming material and the plating film is improved. SOLUTION: A high polymer material obtained by filling a high polymer material with an inorganic filler is irradiated with a laser of high fluence as a first stage, and the irradiated part is irradiated with a laser of low fluence as a second stage to increase its surface roughness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating method for applying electroless and electrolytic plating after irradiating a polymer molding material, for example, a substrate or a package of electronic parts with a laser, and more particularly to a polymer molding material. The present invention relates to a method for forming a plating of a polymer molding material for improving the adhesion between a metal and a plating film.

[0002]

2. Description of the Related Art In general, a molded article made of a polymer material is subjected to electroless plating after the surface is roughened by a chemical and Pd is adsorbed. However, Pd
Since it is difficult to adsorb only the tin-palladium compound, it is necessary to reduce it after adsorbing the tin palladium compound.

However, since surface roughening by chemicals cannot be performed selectively, when plating only a specific portion, it is necessary to first perform plating and exposure and development processing with a photoresist after plating the entire surface. there were. For this reason,
There has been a demand for a method of easily forming a plating on the surface of a polymer molded article.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 4-183873, there has been proposed a method of irradiating a molded article made of a polymer material with an ultraviolet laser so that plating can be performed on a specific portion.

According to this method, a molded article made of a polymer material is irradiated with an ultraviolet laser, and the molded article is immersed in an aqueous solution of Pd colloid. It is possible. That is, only the irradiated area is positively charged by the irradiation of the ultraviolet laser, so that when immersed in an anionic Pd colloid aqueous solution,
The Pd colloid can be easily attached only to the irradiation area. By including a reducing agent in the aqueous Pd colloid solution, it is possible to precipitate only Pd which serves as a catalyst for electroless plating.

[0006]

However, at present, the above-described method using laser irradiation has not been adopted because of the following problems.

That is, when a laser is irradiated at a high fluence, only the area around the irradiation area (specific portion) is charged. Therefore, it is necessary to perform the process at a low fluence. However, the amount of charge becomes insufficient, and the Pd colloid becomes insufficient. Does not adhere. In addition, it becomes necessary to irradiate a considerable number of lasers, which deteriorates workability. Specifically, the laser is set to 0.05 J / cm
^When irradiation is performed at a low fluence of ² / pulse, the number of irradiations must be 1,000 times in order to obtain a sufficient charge amount.

[0008] In particular, when the laser beam is irradiated at a low fluence, the surface roughness of the irradiated area becomes small, and the formed plating film is easily peeled off.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method for forming a plating of a polymer molding material in which the adhesion between the polymer molding material and a plating film is improved.

[0010]

In order to achieve the above object, a method for forming a plating of a polymer molding material according to the present invention comprises:
This is a plating method for a polymer molding material in which a polymer molding material in which a polymer material is filled with an inorganic filler is irradiated with a laser, and the irradiated portion is plated. As a first step, a high fluence laser is applied to the irradiated portion. Irradiation is performed, and as a second stage, a low fluence laser is applied to the irradiated portion to increase the surface roughness.

[0011] Then, the plating is performed by irradiating a laser to a polymer molding material in which a polymer material is filled with an inorganic filler to generate a positive surface potential at an irradiated portion, and then depositing a catalyst for electroless plating at the irradiated portion. Then, the polymer molding material is immersed in an electroless plating solution to perform electroless plating, and the plating is performed by irradiating a polymer molding material in which a polymer material is filled with an inorganic filler with laser. After imparting conductivity to the part
This is electrolytic plating performed by immersing a polymer molding material in an electrolytic plating solution.

And a laser having a wavelength of 600 nm or less, and a high fluence of 0.2 to 2.0 J / cm.
Preferably, the fluence is ² and the low fluence is less than half of the high fluence.

As described above, as a first step, the surface of a polymer molding material in which a polymer material is filled with an inorganic filler is irradiated with a high fluence laser, and as a second step, a low fluence laser is applied to the irradiated portion. Since the surface roughness can be increased by irradiation, the peel strength value is improved, and the adhesion between the polymer molding material and the plating film is improved.

For this reason, the plating film is not easily peeled off, and the share strength of components is reduced in SMT mounting (surface mounting), and the D / B share strength is reduced in COB mounting. Such a problem can be solved.

Further, using a package of a substrate or an electronic component as a polymer molding material, a conductive pattern on the substrate or the package can be formed by electroless plating or electrolytic plating.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for forming a plating of a polymer molded material according to the present invention will be described below.

FIG. 1 is a diagram showing the relationship between the peel strength of the plating film and the fluence of the laser. FIG. 2 (a) shows the LCP as a polymer material to which a glass filler as an inorganic filler is added. 2 (b) to 2 (d) are cross-sectional views of a polymer molded material having a surface patterned by laser irradiation, and FIG. FIG. 3 is a cross-sectional view of a polymer molding material having a shape envelope with increased surface roughness by irradiating a high fluence laser to an irradiation part as one step and irradiating a low fluence laser to the irradiation part as a second step. .

In the method of performing electroless plating after laser irradiation, an inorganic filler is mixed into a polymer material to form unevenness on the surface by utilizing a difference in processing threshold value between the inorganic material and the polymer material. There is a method in which the adhesion between the plating films is enhanced. In this plating method, for example, LCP (Liquid Crystal) to which 30% of a glass filler having a diameter of 10 μm is added as an inorganic filler is used.
(Polymer: liquid crystal polymer) has a peel strength of 4 to 5 N / cm by a peel strength test.

It is still weaker than a method of forming a plating on LCP by a roughening method using a normal chemical (eg, an aqueous solution of potassium hydroxide). This leads to, for example, a decrease in the share strength of components such as a resistor and a capacitor in SMT mounting (surface mounting) and a decrease in D / B share strength in COB mounting.

The method of forming a plating of a polymer molding material according to the present invention comprises irradiating a laser to a polymer molding material in which a polymer material is filled with an inorganic filler, and plating the irradiated portion. A laser having a wavelength of 600 nm or less as a first step;
After irradiating the irradiated part with a fluence (high fluence) of / cm ² , as a second step, the irradiated part is irradiated with a fluence (low fluence) of half or less of the irradiated part to increase the surface roughness.

As described above, as a first step, a high fluence laser is applied to the surface of a polymer molding material in which a polymer material is filled with an inorganic filler, and as a second step, a low fluence laser is applied to the irradiated portion. Irradiation can increase the surface roughness, thus improving the peel strength value, improving the adhesion between the polymer molding material and the plating film, and preventing the plating film from being easily peeled off. (Surface mount)
Thus, it is possible to prevent the share strength of the component from being reduced and the share strength of the D / B from being reduced by COB mounting.

The plating is applied to the polymer material by 10 to 5 times.
After irradiating a laser having a wavelength of 600 nm or less to a polymer molding material filled with 0% of the inorganic filler to generate a positive surface potential at the irradiated portion, the polymer molding material is anionic Pd compound or Pd colloid. Is immersed in an aqueous solution containing Pd to precipitate only Pd, which serves as a catalyst for electroless plating, on the irradiated portion, and then immersed in a polymer molding material in an electroless plating solution. However, 1
Electrolytic plating is performed by irradiating a polymer molding material filled with 0 to 50% of an inorganic filler with a laser having a wavelength of 600 nm or less to impart conductivity to an irradiated portion, and then immersing the polymer molding material in an electrolytic plating solution. It is.

In this case, the polymer material is a liquid crystal polymer (L
CP: Liquid Crystal Polymer
r) etc. are used. Examples of the inorganic filler include a glass filler, ceramic particles, and the like.
20 μm, fiber length of 10 μm or more, or
When the particles are 0.5 to 20 μm in particle size and the amount added to the polymer material is 10 to 50% by weight, scattering of debris can be further suppressed.

As the laser, an excimer laser (wavelength λ = 193, 248, 308, 351 nm), Y
As long as the wavelength of the second harmonic of the AG (wavelength λ = 532 nm), the third harmonic of the YAG (wavelength λ = 355 nm), or the like is 600 nm or less, it can be used.

When the total input energy of the laser is 10 to 500 J / cm ² , in the case of electroless plating, the charged state of the laser irradiation area can be set to a state suitable for precipitating a noble metal. Alternatively, in the case of electrolytic plating, it is possible to make the conductivity of the laser irradiation area suitable for forming an electrolytic plating film.

The inventor of the present invention filled a polymer material with 10 to 50% of an inorganic filler, injection-molded this material, irradiated a polymer having a wavelength of 600 nm or less on the obtained polymer molded material, and irradiated the irradiated portion with the laser. After generating a positive surface potential, immersing it in an aqueous solution containing an anionic Pd compound or Pd colloid, and then performing electroless plating,
In a plating method of irradiating a laser having a wavelength of 600 nm or less to a polymer molding material filled with 50% or less of an inorganic filler to impart conductivity to an irradiated portion, and directly performing electrolytic plating, the polymer molding material and a plating interlayer We have obtained new knowledge from experiments that there is a correlation between the surface roughness and the surface roughness, and that the surface roughness is related to the fluence.

The relationship between the fluence and the peel strength value is as shown in FIG. 1, and the relationship between each fluence and the surface roughness at that time is as shown in FIGS. 2 (b) to 2 (d).

In FIG. 1, a region is a region where the peel strength value increases with an increase in the fluence above the minimum fluence H required for plating, and a region is a region where the peel strength decreases with an increase in the fluence. is there. In FIG. 1, the input energy amount is constant at each fluence.

FIG. 2A shows LC as a polymer material.
A polymer molding material 31 obtained by adding a glass filler 21 as an inorganic filler to P (Liquid Crystal Polymer: liquid crystal polymer) 11 and injection molding the material, and a surface 31A of the polymer molding material 31
Does not have a pattern formed by laser irradiation (in the case of fluence 0 in FIG. 1),
A is smooth, and no irregularities appear on its surface shape envelope A.

FIG. 2B shows a pattern formed by irradiating the surface (irradiation portion) 31A of the polymer molding material 31 with a laser at a fluence of 0.1 J / cm ² . The unevenness 11B of the LCP 11 and the unevenness 21B due to the glass filler 21 are generated on the surface 31A, and the unevenness appears on the surface shape envelope B, and the surface roughness appears.

FIG. 2 (c) shows a pattern formed by irradiating the surface (irradiation part) 31A of the polymer molding material 31 with a laser at a fluence of 0.2 J / cm ² . The unevenness 11B of the LCP 11 and the unevenness 21B due to the glass filler 21 are larger on the surface 31A than in the case of FIG. 2B, and the unevenness appears on the surface shape envelope c. Has appeared.

FIG. 2D shows a pattern formed by irradiating the surface (irradiation part) 31A of the polymer molding material 31 with a laser at a fluence of 0.6 J / cm ² . On the surface 31A, the surface of the LCP 11 is smoothed, and irregularities 21B due to the glass filler 21 are generated, and the surface shape envelope d has the surface roughness of only the irregularities 21B.

That is, the fluence of the laser for irradiating the surface (irradiation part) 31A of the polymer molding material 31 is 0.1 J
/ Cm ² , 0.2 J / cm ² , the surface roughness increases as shown in FIG. 2 (b) and FIG. 2 (c). The adhesion of the plating film increases.

However, if the fluence is sufficiently larger than the ablation threshold of the polymer material LCP11, the irregularities 21B due to the glass filler 21 become large as shown in FIG. The surface of the LCP 11 on the surface 31A of the molding material 31 is smoothed, and the adhesion of the plating film during plating is reduced.

From this, it can be seen that the fluence is 0.2 to
Peel (peeling) strength of 4 to 5 N / c at 0.3 J / cm ²
m, which indicates that it is difficult to improve the adhesion of the plating film during plating even if the fluence is increased.

Therefore, the surface 31A of the polymer molding material 31
As a first step, the surface (irradiation part) 31A of the polymer molding material 31 is irradiated with a laser at a fluence (high fluence) of 0.6 J / cm ² to form a shape envelope shown in FIG. The second step is to make a polymer molding material 31
The surface (irradiation portion) 31A having the shape envelope d was irradiated with a laser at a fluence (low fluence) of 0.2 J / cm ² to obtain a shape envelope E shown in FIG.

That is, as a first step, the surface (irradiation portion) 31A of the polymer molding material 31 is irradiated with a high fluence laser, and as a second step, a low fluence laser is irradiated, whereby the shape shown in FIG. As shown in FIG. 2 (c), a portion 11C smoothed by high fluence laser irradiation by low fluence laser irradiation is shown in FIG. The surface roughness can be increased because the shape is roughened by the size of the envelope c.

By using the plating method for a polymer molding material according to the present invention, a substrate as a polymer molding material,
It becomes possible to form a conductive pattern in a package of an electronic component by electroless plating or electrolytic plating.

[0039]

As described above, according to the method for forming a plating of a polymer molded material according to the present invention, as a first step,
In order to increase the surface roughness by irradiating the high-fluence laser to the surface of the polymer molding material in which the polymer material is filled with the inorganic filler, and irradiating the irradiation part with the low-fluence laser in the second stage , The peel strength value is improved,
The adhesion between the polymer molding material and the plating film is improved.

For this reason, the plating film is not easily peeled off, and the share strength of components is reduced by SMT mounting (surface mounting), and the share strength of D / B is reduced by COB mounting. Such a problem can be solved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a peel strength value of a plating film and a fluence of a laser.

FIG. 2A is a cross-sectional view of a polymer molding material obtained by adding a glass filler as an inorganic filler to LCP as a polymer material and injection molding this material. (B)
(D) is a cross-sectional view of a polymer molded material whose surface is patterned by laser irradiation.

FIG. 3 shows a polymer molding material having a shape envelope having a surface roughness increased by irradiating a high fluence laser to an irradiation part as a first step and irradiating a low fluence laser to a irradiation part as a second step. FIG.

[Explanation of symbols]

 11 LCP (polymer material) 11B unevenness 11C smoothed portion 21 glass filler (inorganic filler) 21B unevenness 31 polymer molding material 31A surface b surface shape envelope b surface shape envelope c surface shape envelope d surface shape envelope Wire E Surface shape envelope

Continued on the front page F term (reference) 4F073 AA01 AA06 BA23 BA47 CA53 4K022 AA26 AA42 AA51 BA35 CA02 CA06 CA08 CA12 CA21 DA01 4K024 AB01 AB08 BA12 BB09 BB11 DA06 DA07 FA01 GA01

Claims (5)

[Claims] 1. A method for forming a plating of a polymer molding material, comprising irradiating a laser to a polymer molding material in which a polymer material is filled with an inorganic filler, and plating the irradiated portion. Irradiating the laser with a high fluence to the laser, and as a second step, irradiating the laser with a low fluence to the irradiation section to increase the surface roughness. 2. The method according to claim 1, wherein the plating irradiates the laser to the polymer molding material in which the polymer material is filled with the inorganic filler, and generates a positive surface potential at the irradiation unit. The method for forming a plating of a polymer molded material according to claim 1, wherein the electroless plating is performed by precipitating a catalyst for the electroless plating and thereafter immersing the polymer molded material in an electroless plating solution. 3. The plating is performed by irradiating the laser to the polymer molding material in which the polymer material is filled with the inorganic filler, and imparting conductivity to the irradiated portion. 2. The method for forming a plating of a polymer molded material according to claim 1, wherein the plating is electrolytic plating performed by immersion in a plating solution. 4. The laser according to claim 1, wherein the laser has a wavelength of 600 nm or less, and the high fluence is 0.2 to 2.0 J / c.
4. The method according to claim 1, wherein the fluence is m ² and the low fluence is less than half of the high fluence. 5. The method according to claim 1, wherein the polymer molding is a package of a substrate and an electronic component.