TWI511630B - High temperature resistance and high reflectivity for printed circuit boards covered with protective film - Google Patents

Description

Covering protective film for printed circuit boards with high temperature resistance and high reflectivity

The invention relates to a cover protection film for a printed circuit board, in particular to a cover protection film for a printed circuit board having high temperature resistance and high reflectivity.

In order to achieve a specific light transmission and light distribution effect, the light source module of the prior art electronic product needs to be used by a secondary optical component. However, when the light generated by the light source component of the light source module passes through the secondary optical component, light loss such as light absorption and light scattering occurs, and the light is wasted and cannot be effectively utilized, and the overall electronic product is also affected. The light-emitting efficiency and the light color rendering property; in addition, after the light generated by the light source component of the light source module passes through the secondary optical component, the light-emitting intensity is attenuated as the transmission distance increases, and the light source of the light source module needs to be improved. The luminous intensity to ensure the light output efficiency of electronic products. For example, in the backlight module of the display, the surface light source and the uniform light effect can be achieved through the light guide plate, but the light absorption and light scattering of the light guide plate cause light loss.

Referring to FIG. 10, in order to reduce the light loss caused by the secondary optical component, the prior art provides a printed circuit board having a reflective ink layer for use in a light source component of a light source module of an electronic product, the reflective ink layer 81 being The ink is printed on one surface of the printed circuit board 82, and the light source element 83 of the light source module is adhered via the surface (SMT, Surface Mount) The process is disposed on the surface; the scattered light of the light source element 83 of the light source module toward the surface of the printed circuit board 82 can be reflected by the reflective ink layer 81 and proceed toward the direction away from the printed circuit board 82, thereby lifting Light output efficiency and light color rendering of electronic products.

However, the prior art reflective ink layer 81 has the following disadvantages:

1. After the surface of the light source component 83 is adhered, since the operating temperature of the surface adhesion process is between 160 and 320 ° C, the reflective ink layer 81 formed by ink printing will yellow, thereby reducing the reflective ink. The reflectivity of the layer (Reflection).

2. When the thickness of the reflective layer formed by printing is increased to increase the reflectance thereof, after the thickness of the printed reflective layer is thickened, the ink is formed in the cutting process and the printed circuit without using the substrate to support the reflective layer. When the plate is flexed (when the R angle is less than 0.5 mm), the reflective layer is prone to brittle fracture.

In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a cover protective film for a printed circuit board having high temperature resistance and high reflectivity, which does not cause yellowing after the surface adhesion process, and still has high reflectance, and It has less structural strength and is less prone to brittle fracture.

In order to achieve the foregoing object, the technical means adopted by the present invention is to cover the protective film for a printed circuit board having high temperature resistance and high reflectivity, comprising: a high temperature resistant polymer film having a thickness of 2 to 125 Between micrometers (μm), the melting point is greater than 260 ° C, and has two sides; a highly reflective polymer composite layer is disposed on one side of the high temperature resistant polymer film, the thickness of which is between 2 and 30 microns Between, which contains a first reflective coloring material, the first reflective coloring material has a refractive index greater than 1; an adhesive layer disposed on the other side of the high-temperature resistant polymer composite layer, the thickness of which is The light-resistant polymer film has an absorption rate of less than 35% in a wavelength range of greater than 89% for the entire protective cover film for a printed circuit board having high temperature resistance and high reflectance.

According to the present invention, the high temperature resistance refers to a surface adhesion process capable of passing a process temperature of between 160 and 320 and a process time of 10 to 180 seconds without causing yellowing and delamination.

According to the invention, the high reflectivity is in the wavelength range from 415 to 700 nm and the reflectance is between 89% and 100%. Preferably, in the wavelength range of 415 to 700 nm, the overall coverage of the cover film for the high temperature resistance and high reflectivity of the printed circuit board is between 89% and 100%.

Based on the above, the use of the highly reflective polymer composite layer containing the first reflective colorant improves the ratio of the light of the light source component to the high-reflection polymer composite layer, and reduces the light-transmitting high-reflection polymer composite of the light source component. The ratio of the material layer; the use of a high-temperature resistant polymer film having an absorption ratio of 35% or less by using a high-reflectivity-resistant and high-reflectance printed circuit board covering a protective film with a reflectance of more than 89% as a whole When the transmitted light of the band is absorbed and the multiple reflections are performed, the overall light output intensity of the electronic product can be increased, the power of the light source component of the electronic product can be reduced, and the light color rendering property of the electronic product can be improved. Wherein, the melting point of the high temperature resistant polymer film is greater than 260 ° C, thereby the present invention Covering protective film for printed circuit boards with high temperature resistance and high reflectivity can have the advantages of no yellowing and delamination after the surface adhesion process.

In addition, by providing the high-temperature resistant polymer film, the high-reflection polymer composite material layer can be supported, so that the printed circuit board with high temperature resistance and high reflectivity is covered by the protective film for the flexing or cutting process. In the case of high temperature resistance and high reflectivity, the cover film for the printed circuit board is less prone to brittle cracking.

In addition, by making the thickness of the adhesive layer between 10 and 75 microns, it is possible to achieve the effect of covering the line gap on the printed circuit board.

Preferably, the high-reflection polymer composite layer has a thickness tolerance of +2/-2 micrometers, which has good thickness uniformity, and can further enhance the light for the reflective ink of the prior art. Reflection uniformity.

Preferably, the adhesive layer comprises a second reflective coloring material, and the high temperature resistant polymer film comprises a third reflective coloring material.

Preferably, the second reflective pigment has a refractive index greater than 1, and the third reflective pigment has a refractive index greater than 1.

Preferably, the first reflective colorant accounts for 20 to 70 volume percent of the entire high reflection polymer composite material layer, and the second reflective color pigment accounts for 10 to 50 volume percent of the entire adhesive layer, the third reflective color. The material accounts for 1 to 20% by volume of the entire high temperature resistant polymer film.

Preferably, the first reflective colorant comprises at least one selected from the group consisting of titanium dioxide, barium sulfate, strontium sulfate, aluminum oxide, and zirconia. (zirconium dioxide), zinc oxide, magnesium oxide, calcium oxide, boron nitride, aluminum nitride, calcium carbonate, hydrogen a substance in a group consisting of aluminum hydroxide and magnesium hydroxide.

Preferably, the second reflective colorant comprises at least one selected from the group consisting of titanium dioxide, barium sulfate, barium sulfate, aluminum oxide, zirconium oxide, zinc oxide, magnesium oxide, calcium oxide, boron nitride, aluminum nitride, calcium carbonate. a substance in a group consisting of aluminum hydroxide and magnesium hydroxide.

Preferably, the third reflective colorant comprises at least one selected from the group consisting of titanium dioxide, barium sulfate, barium sulfate, aluminum oxide, zirconium oxide, zinc oxide, magnesium oxide, calcium oxide, boron nitride, aluminum nitride, calcium carbonate. a substance in a group consisting of aluminum hydroxide and magnesium hydroxide.

According to the present invention, the cover protective film for a printed circuit board having high temperature resistance and high reflectivity has the characteristics of not having yellowing after surface adhesion process and having high reflectivity, and having better structural strength, and also having The characteristics of low thickness can meet the trend of thin industry. Preferably, the high temperature resistant polymer film has a thickness of between 6 and 25 microns, the high reflective polymer composite layer has a thickness of between 6 and 20 microns, and the adhesive layer has a thickness of between 10 and 35 Between microns. More preferably, the high temperature resistant polymer film has a thickness of between 6 and 12 microns.

According to the invention, the highly reflective polymer composite layer comprises a first reactive functional resin and a first crosslinking agent. The reactive functional group of the first reactive functional resin comprises at least one selected from the group consisting of a carboxy group, an amine group, and an epoxy group. Group), a functional group in a group consisting of a hydroxy group and a double bond. The first crosslinking agent is an aromatic compound or an aliphatic compound containing two or more crosslinking reactive functional groups, and the crosslinking reactive functional group of the first crosslinking agent comprises at least one selected from the group consisting of a carboxyl group (carboxyl) Group), an anhydride group, an amine group, a hydroxyl group, an epoxy group, an isocyanate group, and a double bond.

According to the present invention, the adhesive layer comprises a second reactive functional resin and a second crosslinking agent, and the reactive functional group of the second reactive functional resin comprises at least one selected from the group consisting of a carboxyl group. a functional group in the group consisting of an amine group, an epoxy group, and a hydroxyl group. The second crosslinking agent is an aromatic compound or an aliphatic compound containing two or more crosslinking reactive functional groups, and the crosslinking reactive functional group of the second crosslinking agent comprises at least one selected from the group consisting of a carboxyl group and an acid anhydride. a functional group in the group consisting of an amine group, a hydroxyl group, an epoxy group, and an isocyanate group.

Preferably, the high temperature resistant polymer film comprises at least one selected from the group consisting of polyphenylene sulfide, polyethylene naphthalate, and poly(ether ether ketone). A polymer film in a group formed.

According to the present invention, the cover protective film for a printed circuit board having high temperature resistance and high reflectivity may include a release layer disposed on a side of the adhesive layer away from the high temperature resistant polymer film. The release layer comprises a plastic release film or a release paper release profile, but is not limited thereto.

According to the present invention, the cover film for the high temperature resistance and high reflectivity of the printed circuit board can be simultaneously applied to the hard circuit board and the soft type. Circuit board.

10, 10A‧‧‧ Covered protective film for printed circuit boards

11, 11A‧‧‧High temperature resistant polymer film

12‧‧‧High-reflection polymer composite layer

13, 13A‧‧‧ adhesive layer

20, 20A‧‧‧ Printed circuit board

30, 30A‧‧‧ first sample

40, 40A‧‧‧Light source components

50‧‧‧Printed circuit board

60‧‧‧Reflective ink layer

70‧‧‧Light source components

81‧‧‧Reflective ink layer

82‧‧‧Printed circuit board

83‧‧‧Light source components

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional side elevational view of a cover protective film for a printed circuit board having high temperature resistance and high reflectance according to the present invention.

2 is a cross-sectional side elevational view showing the reflectance detection of a printed circuit board with high temperature resistance and high reflectance according to Embodiments 1 to 11 of the present invention, which is attached to a printed circuit board.

Fig. 3 is a partial cross-sectional side elevational view showing the surface adhesion process of the printed circuit board with high temperature resistance and high reflectance according to Examples 4 to 11 of the present invention.

4 is a reflection spectrum diagram of a cover protective film for a printed circuit board having high temperature resistance and high reflectance according to Examples 4 to 7 of the present invention. In the figure, the symbol "" is used to indicate the embodiment 4, the symbol "●" is used to indicate the embodiment 5, the symbol "▲" is used to indicate the embodiment 6, and the symbol "▼" is used to indicate the embodiment 7.

5 is an absorption spectrum diagram of a high temperature resistant polymer film for a protective film for a printed circuit board having high temperature resistance and high reflectance according to Examples 4 to 6 and Examples 8 to 11 of the present invention. In the figure, the symbol "●" indicates the embodiment 8 using 50 micron PET, the symbol "■" indicates the embodiment 9 using 125 micron PET, the symbol "◆" indicates the embodiment 10 using the 50 micron PPS, and the symbol "▲". Examples 4 through 6 using the 12.5 micron polyimide designation and "▼" are used to indicate Example 11 using 12.5 micron PEEK.

Fig. 6 is a reflection spectrum diagram of a high temperature resistant polymer film for a protective film for a printed circuit board having high temperature resistance and high reflectance according to Example 6 and Example 11 of the present invention. In the figure, the symbol "" is used to indicate the embodiment 11 and is symbolized. "▲" indicates Example 6.

Fig. 7 is a reflection spectrum diagram of a high temperature resistant polymer film for a protective film for a printed circuit board having high temperature resistance and high reflectance according to Examples 8 to 10 of the present invention. In the figure, the symbol "" is used to designate the embodiment 10, the symbol "▲" is used to indicate the embodiment 8, and the symbol "●" is used to indicate the embodiment 9.

Figure 8 is a partially cross-sectional side elevational view showing a printed circuit board having a reflective ink layer of Comparative Example 1 of the present invention.

Fig. 9 is a reflection spectrum diagram of a printed circuit board having a reflective ink layer of Comparative Examples 1 and 2 of the present invention. In the figure, the control example 1 before the heat resistance test is indicated by the symbol "▲", the symbol "▼" indicates the control example after the heat resistance test, the symbol "■" indicates the control example 2 before the heat resistance test, and the symbol "●" indicates Comparative Example 2 after heat resistance test.

Figure 10 is a partial cross-sectional side elevational view of a prior art printed circuit board having a reflective ink layer.

Example 1

Referring to FIG. 1 , in the embodiment, the cover protection film 10 for a printed circuit board having high temperature resistance and high reflectivity comprises a high temperature resistant polymer film 11 and a high reflection polymer composite. The material layer 12, an adhesive layer 13 and a release layer. The high-temperature resistant polymer film 11 has two corresponding side surfaces, and the high-reflection polymer composite material layer 12 and the adhesive layer 13 are respectively disposed on two sides of the high-temperature resistant polymer film 11, and the release layer is disposed on the side The adhesive layer 13 is away from one side of the high temperature resistant polymer film 11.

In the present embodiment, the method for manufacturing the cover protective film 10 for a printed circuit board having high temperature resistance and high reflectivity comprises: providing the high temperature resistant polymer film 11; and providing the high reflective polymer composite material layer 12 One side of the high temperature resistant polymer film 11 comprises: first mixing a first reactive functional resin, a first crosslinking agent and a catalyst to form a first mixed solution; and using a first reflective coloring material Forming a pre-high-reflection polymer composite solution by dispersing in the first mixed solution by physical dispersion technology; coating the pre-high-reflection polymer composite solution on the high-temperature resistant polymer film by surface coating technology Forming a pre-high-reflection polymer composite layer 12 on one side; heating the pre-high-reflection polymer composite layer 12 to crosslink the first reactive functional resin and the first crosslinking agent And forming the high-reflection polymer composite layer 12; the adhesive layer 13 is disposed on a side of the high-temperature resistant polymer film 11 away from the high-reflection polymer composite layer 12, comprising: first The two reactive functional resin and a second crosslinking agent are mixed to form a second mixed solution; a second reflective color is dispersed in the second mixed solution by a physical dispersion technique to form an adhesive; Surface coating technology coating the adhesive on one side of the high temperature resistant polymer film to form the adhesive layer 13; and attaching the release layer to the adhesive layer 13 away from the high temperature resistant polymer film 11 On the side surface, the high temperature resistant polymer film 11 is a polyimide film having a thickness of 12.5 micrometers and a melting point of more than 260 °C. The first reactive functional resin is a polyester-polyol copolymer having a hydroxy group. The first crosslinking agent is a polyisocyanate (HDI polyisocyanate), and the first reflective pigment is a titanium dioxide (TiO ₂ ) powder having a refractive index greater than 1, and the highly reflective polymer composite layer The thickness of 12 is 20 μm, and the titanium dioxide powder contained in the highly reflective polymer composite layer 12 is 20% by volume (vol%). The second reactive functional resin is an epoxy group having an epoxy group, and the second crosslinking agent is a diamine having two amine groups, the second reflective The colorant is a calcium carbonate powder having a refractive index greater than 1, and the adhesive layer 13 can have a thickness of about 25 microns, such as a difference of plus or minus 2 micrometers in the relevant process, and between 23 micrometers and 27 micrometers. The thickness. The thickness of the adhesive layer 13 used in the embodiment is 25 micrometers, and the calcium carbonate powder contained in the adhesive layer 13 is 10 volume percent, and the release layer can be a plastic release film or a release paper release profile. . In the present embodiment, a release paper is used as the release layer.

Referring to FIG. 1 and FIG. 2, in the embodiment, the printed circuit board with high temperature resistance and high reflectivity is peeled off from the release layer of the cover protective film 10 to obtain a peeling release layer. The printed circuit board for high temperature resistance and high reflectivity is covered with the protective film 10, and then the printed circuit board with high temperature resistance and high reflectivity after peeling off the release layer is subjected to a pressing process by the cover protective film 10, and the adhesive film is passed through the adhesive. The layer 13 is attached to one side of a printed circuit board 20, and then subjected to a thermal curing process to cure the adhesive layer 13 by cross-linking reaction to obtain a first sample 30, which is reflected by the first sample 30. Rate detection.

In the present embodiment, the reflectivity detection is performed by using a Hitachi U-4100 spectrometer (Hitachi U-4100 spectrometer), and the standard test piece used is Hitachi original barium sulfate standard. The sheet (reflectance is 100%), and the reflectance detection value is 550 nm at a wavelength, and the reflectance of the entire cover protective film for the printed circuit board having high temperature resistance and high reflectance is measured relative to the standard sheet. Compare values. The test results are shown in Table 1.

Example 2

This embodiment is the same as Embodiment 1, except that the titanium dioxide powder as the first reflective coloring material in the highly reflective polymer composite material layer is 30% by volume. The test results of this example are shown in Table 1.

Example 3

This embodiment is the same as Embodiment 1, except that the titanium dioxide powder as the first reflective coloring material in the highly reflective polymer composite material layer is 60% by volume. The test results of this example are shown in Table 1.

Example 4

Referring to FIG. 3, this embodiment is similar to Embodiment 1, except that the thickness of the highly reflective polymer composite material layer 12 covering the protective film 10A for the printed circuit board having high temperature resistance and high reflectivity is different. It is 13 microns. In the embodiment, the reflectance detection is performed at a wavelength of 400 to 700 nm, and the printing with high temperature resistance and high reflectance is measured. The board covers the overall reflectivity of the protective film.

In addition, referring to FIG. 3, in the embodiment, the high temperature detection is performed, and the first sample 30A is subjected to a surface adhesion process so that a light source component 40A and the adhesive layer 13A are located on the printed circuit board. On the same side of 20A. The surface adhesion process has a process temperature of 300 ° C and a process time of 30 seconds.

In addition, in the present embodiment, the high-temperature resistant polymer film 11A is subjected to absorption measurement by a Hitachi U-4100 spectrometer (Hitachi U-4100 spectrometer), and the high temperature resistant polymer film 11A of the present embodiment is a polyaluminum. Amine film.

In addition, in the present embodiment, according to the Japanese Industrial Standard (JIS) JIS-K7105 specification, the cover protective film for a printed circuit board having high temperature resistance and high reflectance is tested after being subjected to high temperature resistance at 300 ° C. Whether it is yellow or not, and according to the NBS color difference unit of CIE 1976 (Lab) and the perceived color difference, the △E value is less than 1.5 for a slight to slight perceived chromatic aberration.

The test results of this example are shown in Table 2, Figure 4 and Figure 5.

Example 5

This embodiment is similar to Embodiment 4 except that the thickness of the highly reflective polymer composite layer is 20 μm. The test results of this example are shown in Table 2, Figure 4 and Figure 5.

Example 6

This embodiment is similar to Embodiment 4 except that the thickness of the highly reflective polymer composite layer is 29 μm. The test results of this example are shown in Table 2 and Figures 4 to 6.

Example 7

This embodiment is similar to Embodiment 4 except that the thickness of the highly reflective polymer composite layer is 32 μm. The test results of this example are shown in Table 2, Figure 4 and Figure 5.

Example 8

This embodiment is similar to Embodiment 4, and the difference is that the high temperature resistant polymer film is polyethylene terephthalate (polyethylene). Terephthalate, PET) film, the polyethylene terephthalate film has a thickness of 50 μm, and the high-reflection polymer composite layer has a thickness of 29 μm. The test results of this example are shown in Table 3, Figure 5 and Figure 7.

Example 9

This embodiment is the same as Embodiment 8, except that the polyethylene terephthalate film as a high temperature resistant polymer film has a thickness of 125 μm. The test results of this example are shown in Table 3, Figure 5 and Figure 7.

Example 10

This embodiment is the same as Embodiment 1, except that the high temperature resistant polymer film is poly(p-phenylene sulfide). PPS), the polyphenylene sulfide film has a thickness of 50 μm and a melting point of more than 260 °C. The highly reflective polymer composite layer has a thickness of 29 microns. The adhesive layer is formed by directly applying the second mixed solution as the adhesive solution, and coating the adhesive on one side of the high temperature resistant polymer film by wet coating, and the adhesive layer is contained therein. The second reflective colorant is 0 volume percent, that is, the adhesive layer does not contain the second reflective colorant.

In the embodiment, the reflectance detection is performed in a wavelength range of 400 to 700 nm, and the reflectivity of the cover protective film for the printed circuit board having high temperature resistance and high reflectivity is measured. In this embodiment, the polyphenylene sulfide film is also subjected to the reflectance detection. Further, in the present example, the high temperature resistance test as described in Example 4 was also carried out, and the polyphenylene sulfide film was also subjected to the absorption rate detection as described in Example 4. The test results of this example are shown in Table 4, Figure 5 and Figure 7.

Example 11

This embodiment is similar to the embodiment 10 except that the high temperature resistant polymer film is a poly(ether ether ketone) (PEEK) film having a melting point of more than 260 ° C. The test results of this example are shown in Table 4, Figure 5 and Figure 6.

Comparative Example 1

Referring to FIG. 8 , a printed circuit board having a reflective ink layer is provided on one side of a printed circuit board 50 by ink (crown ink, model T-75) to form a reflective ink. Layer 60.

In this comparative example, the printed circuit board having the reflective ink layer was directly subjected to reflectance detection. The printed circuit board having the reflective ink layer is further subjected to high temperature detection: a light source component 70 and the reflective ink layer 60 are disposed on the same side of the printed circuit board 50 (as shown in FIG. 8) through the surface adhesion process. After the high-temperature detection of the printed circuit board having the reflective ink layer, the reflectance detection was performed again, and the yellowing was detected by JIS-K7105.

In the comparative example, the reflectance is detected, and the incident light is visible light, and the wavelength thereof is between 415 and 700 nm. The surface adhesion process has a process temperature of 288 ° C and a process time of 10 seconds. The test results of this comparative example are shown in Fig. 9 and Table 5.

Comparative Example 2

The difference between this comparative example and Comparative Example 1 is that the oil used The ink is a solar ink and its model number is PSR-4000. The test results of this comparative example are shown in Fig. 9 and Table 5.

As shown in Fig. 9, before the high temperature resistance test, the highest reflectances of Comparative Examples 1 and 2 were 80% or less in the wavelength range of 415 to 700 nm. After the high temperature resistance test, the highest reflectance of Comparative Examples 1 and 2 fell below 77% in the band of 415 to 700 nm. As shown in Table 5, after the high temperature resistance test, the ΔE values of Comparative Examples 1 and 2 were 3.8 and 2.6, respectively, and all of them were greater than 1.5, and yellowing was observed in Comparative Examples 1 and 2; it was inferred that after high temperature detection Since the yellowing of Comparative Examples 1 and 2 caused yellowing, the reflectance was lowered.

It can be seen from Tables 1 to 5 and Figures 4 to 7 and that the printed circuit boards with high temperature resistance and high reflectivity of Examples 1 to 3 and Examples 5 to 11 are covered with protective film when the wavelength is 550 nm. The reflectances were all above 89%, and the reflectance of the printed circuit board having the reflective ink layer of Comparative Examples 1 and 2 was less than 80%, and the printed circuit boards having high temperature resistance and high reflectance of Examples 1 to 11 were used. The cover protective film has better reflectance than the printed circuit board having the reflective ink layer of Comparative Examples 1 and 2. After the high temperature resistance test, the ΔE values of the cover protective film for the high temperature resistant and high reflectance printed circuit boards of Examples 4 to 11 were less than 1.5, and no yellowing occurred. And the thickness of the reflective ink layer of Comparative Examples 1 and 2 has a tolerance of +15/-15 μm, and the thickness of the highly reflective polymer composite layer of Examples 1 to 11 has a tolerance of +2/-2 μm, showing a comparison. The thickness uniformity of the reflective ink layers of Examples 1 and 2 was inferior to those of Examples 1 to 11, and Examples 1 to 11 had better thickness uniformity than Comparative Examples 1 and 2.

As shown in Table 1, the high-reflection polymer composite material for the printed circuit board with high temperature resistance and high reflectance of Example 1 is covered with a protective film. When the content of the titanium dioxide powder contained in the layer is 20% by volume, and the wavelength of the incident light is 550 nm, the coverage of the protective film for the printed circuit board with high temperature resistance and high reflectance of Example 1 is 89. % or more, and the content of the titanium dioxide powder contained in the high-reflection polymer composite material layer for the printed circuit board with high temperature resistance and high reflectance of Examples 2 and 3 is higher than that of the first embodiment, respectively 30 And 60% by volume, but when the wavelength of the incident light is 550 nm, the reflectance of the cover protective film for the high temperature resistant and high reflectance printed circuit boards of Examples 2 and 3 is higher than that of the first embodiment and the high temperature resistance of the embodiment 1 The high-reflectivity printed circuit board is relatively close to the protective film, which is 90.2% and 90.5 or more respectively. It can be seen that when the content of the titanium dioxide powder contained in the highly reflective polymer composite layer is 20% by volume, the reflectance is Can reach more than 89%.

As shown in Table 2 and FIG. 4, the cover protective film for the high temperature resistant and high reflectance printed circuit board of Example 4 has a reflectance of 89% or more at a wavelength of 420 to 495 nm; The coverage protective film for the printed circuit board with high temperature resistance and high reflectance of Example 5 has a reflectance of 89% or more, and the high temperature resistance of the embodiment 6 is 620 to 700 nm. And the high-reflectance printed circuit board has a reflectance of 89% or more for the cover film; in the band of 415 to 700 nm, the cover film for the high temperature and high reflectance of the printed circuit board of Embodiment 7 has 89 The reflectance of % or more, and the thickness of the highly reflective polymer composite layers of Examples 4 to 7 are 13 μm, 20 μm, 29 μm, and 32 μm, respectively, and the high temperature resistant polymer films of Examples 4 to 7 are A polyimide film having a thickness of 12.5 microns.

As shown in Figure 5, when the incident light has a wavelength between 415 and 520 In the band of nanometers, the absorption rate of the 12.5 micron thick polyimide film is 35% or more.

It can be seen that in the band of 420 to 495 nm, a cover film with a high temperature and high reflectance of a film having a high temperature and high reflectance of 12.5 μm thick has a reflectance of 89% or more. : The thickness of the highly reflective polymer composite layer needs to be 30 microns or more. It can be further inferred that when a high-reflection polymer composite material layer covering a protective film with a high temperature resistance and a high reflectivity has a thickness of 30 μm or less, the high temperature resistance is in the range of 415 to 700 nm. And the high reflectance of the printed circuit board for the printed circuit board has a reflectance of 89% or more. The absorption rate of the high temperature resistant polymer film needs to be 35% or less.

As shown in Table 3, FIG. 5 and FIG. 7, the thickness of the high temperature resistant polymer film of Example 8 was 50 μm, and the thickness of the high temperature resistant polymer film of Example 9 was 125 μm. In the wavelength range of 330 to 700 nm, the high temperature resistant and high reflectance printed circuit board of Example 8 has an absorption rate of 35% or less for the high temperature resistant polymer film covering the protective film, and the high temperature resistance of the embodiment 9 is high. The high-reflectance printed circuit board has an absorption rate of a high-temperature resistant polymer film covering the protective film of 35% or less. And in the wavelength range of 330 to 700 nm, the reflectance of the covered protective film for the high temperature resistant and high reflectance printed circuit boards of Examples 8 and 9 is 89% or more; the thickness difference of the high temperature resistant polymer film is not displayed. The reflectance of the cover protective film for the printed circuit board having high temperature resistance and high reflectance of Examples 8 and 9 is affected.

Referring to Table 3, Table 4 and FIG. 5, the high temperature resistant polymer film of Example 8 is a 50 μm thick polyethylene terephthalate film, and the high temperature resistant polymer film of Example 10 is 50 μm. Thick polyphenylene sulfide film, In the band of 415 to 700 nm, the absorption rate of both is less than 35%. Referring to Table 3 in Fig. 7, in the wavelength range of 415 to 700 nm, the reflective films of the high temperature resistant and high reflectance printed circuit boards of Examples 8 and 10 have a reflectance of 89% or more. After the heat resistance test (surface adhesion, 300 ° C / 30 seconds), it was found that the polyethylene terephthalate film of Example 8 was insufficient in temperature resistance and the heat expansion and contraction were too large, thereby making the highly reflective polymer Debonding between the composite material layer and the polyethylene terephthalate film, between the polyethylene terephthalate film and the adhesive layer or between the adhesive layer and the printed circuit board (de- Lamination), and the polyphenylene sulfide film of Example 10 did not undergo delamination, and it was found that the melting point of the polyethylene terephthalate film was less than 260 ° C, and the polyphenylene sulfide film was obtained. The melting point is greater than 260 ° C; this can prove that when the melting point of the high temperature resistant polymer film is greater than 260 ° C, the cover film with high temperature resistance and high reflectivity can cover the surface of the protective film without delamination.

Referring to Tables 2 and 4, the high temperature resistant polymer film of Example 6 is a 12.5 micron polyimide film, and the high temperature resistant polymer film of Example 11 is a 12.5 micron polyether ether ketone film. The melting point of the quinone imine film is less than 260 ° C, and the melting point of the polyetheretherketone film is greater than 260 ° C. After the high temperature resistance test, the cover film of the high temperature resistant and high reflectance printed circuit boards of Examples 6 and 11 did not delaminate. However, please refer to Table 2, Figure 5 and Figure 6. In the band of 415 to 520 nm, the absorption rate of the high temperature resistant polymer film of Example 6 is more than 35%, and the band of 415 is less than 420 nm. The reflectance of the covered protective film for the printed circuit board with high temperature resistance and high reflectance of Example 6 is less than 89%, that is, in the band of 415 to 700 nm, the reflectance is not completely 89% or more; See Table 4, As shown in FIG. 5 and FIG. 6, the absorption rate of the high temperature resistant polymer film of Example 11 is 35% or less in the wavelength range of 415 to 700 nm, and the printed circuit board having high temperature resistance and high reflectance of Example 11 is obtained. The reflectance of the covered protective film is 89% or more.

Referring to Tables 1 to 4, the adhesive layers of Examples 1 to 8 all contain 10 volume percent of the second reflective colorant, and the adhesive layers of Examples 10 and 11 are not. Taking the wavelength of 550 nm as an example, the reflectance of the covered protective film for the high temperature resistant and high reflectance printed circuit boards of Examples 1 to 3 and Examples 5 to 8 is greater than 89%, and Examples 10 and 11 The reflectance of the cover protective film for a printed circuit board having high temperature resistance and high reflectance is also greater than 89%, and the reflectances of Examples 1 to 3 and Examples 5 to 8 are shown to be relatively close to those of Embodiment 10 and Embodiment 11. rate. Therefore, by using the second reflective colorant, the reflectance of the cover protective film for a printed circuit board having high temperature resistance and high reflectance of the present invention can be increased.

Based on the above, it was confirmed by reflectance detection and high temperature resistance detection that Examples 1 to 3 and Examples 5 to 11 had better reflectance and high temperature resistance than Comparative Examples 1 and 2; Comparison between 1 to 3 and Examples 5 to 11 confirmed that the high temperature resistant polymer film having a melting point of 260 ° C or higher and having an absorption ratio of 35% or less in a wavelength range of 415 to 700 nm and containing the first reflection The use of the high-reflection polymer composite material layer of the color material is such that the cover film for the printed circuit board with high temperature resistance and high reflectivity of the present invention has a wavelength of 415 to 700 nm, and has a purity of 89% or more. The reflectivity and the surface adhesion process (process temperature of 300 ° C, process time of 30 seconds) without the advantages of yellowing and delamination, can increase the overall light output of electronic products, reduce the source of electronic products.

10‧‧‧ Covered protective film for printed circuit boards

11‧‧‧High temperature resistant polymer film

12‧‧‧High-reflection polymer composite layer

13‧‧‧Adhesive layer

Claims (16)

A cover protection film for a printed circuit board having high temperature resistance and high reflectivity, comprising: a high temperature resistant polymer film having a thickness of between 2 and 125 microns, a melting point of greater than 260 ° C, and having two sides Wherein the high temperature resistant polymer film comprises at least one compound selected from the group consisting of polyimide, polyphenylene sulfide, polyethylene terephthalate and polyetheretherketone; The reflective polymer composite layer is disposed on one side of the high temperature resistant polymer film and has a thickness of between 2 and 30 micrometers, and includes a first reflective colorant, and the refractive index of the first reflective colorant More than 1, and the first reflective colorant accounts for more than 20% by volume of the entire high-reflection polymer composite layer; an adhesive layer is disposed on the other side of the high-temperature resistant polymer film away from the high-reflection polymer layer The thickness thereof is between 10 and 75 micrometers; wherein the absorption of the high temperature resistant polymer film is greater than 89% in the overall coverage of the protective film for the printed circuit board having high temperature resistance and high reflectivity. The rate is less than 35%. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 1, wherein the adhesive layer comprises a second reflective colorant. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 2, wherein the second reflective colorant has a refractive index greater than 1. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 1, wherein the high temperature resistant polymer film comprises a first Three reflective pigments. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 4, wherein the third reflective colorant has a refractive index greater than 1. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to any one of claims 1 to 5, wherein the first reflective colorant accounts for 20 of the high reflective polymer composite material layer as a whole 70 volume percent. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 2 or 3, wherein the second reflective colorant accounts for 10 to 50% by volume of the entire adhesive layer. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 4 or 5, wherein the third reflective colorant accounts for 1 to 20% by volume of the entire high temperature resistant polymer film. The cover protective film for a printed circuit board having high temperature resistance and high reflectance according to any one of claims 1 to 5, wherein the high temperature resistant polymer film has a thickness of between 12.5 and 125 μm. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to any one of claims 1 to 5, wherein the high-reflection polymer composite layer has a thickness of between 6 and 20 μm. The cover protective film for a printed circuit board having high temperature resistance and high reflectance according to any one of claims 1 to 5, wherein the adhesive layer has a thickness of between 10 and 35 μm. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to any one of claims 1 to 5, wherein the highly reflective polymer composite layer comprises a first reactive functional resin. The first anti The functional functional resin comprises at least one reactive functional group selected from the group consisting of a carboxyl group, an amine group, an epoxy group, a hydroxyl group, and a double bond. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 12, wherein the high-reflection polymer composite layer comprises a first crosslinking agent, and the first crosslinking agent is selected from the group consisting of a crosslinking reactive functional group of the first crosslinking agent in a group consisting of an aromatic compound containing two or more crosslinking reactive functional groups and an aliphatic compound containing two or more crosslinking reactive functional groups It is selected from the group consisting of a carboxyl group, an acid anhydride, an amine group, a hydroxyl group, an epoxy group, an isocyanate group, and a double bond. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to any one of claims 1 to 5, wherein the adhesive layer comprises a second reactive functional resin, the second reaction The functional functional resin comprises at least one reactive functional group selected from the group consisting of a carboxyl group, an amine group, an epoxy group, and a hydroxyl group. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to claim 14, wherein the adhesive layer comprises a second crosslinking agent, and the second crosslinking agent is selected from the group consisting of two a group consisting of an aromatic compound having a cross-linking reactive functional group and an aliphatic compound having two or more cross-linking reactive functional groups, wherein the cross-linking reactive functional group of the second crosslinking agent comprises at least one selected From a functional group in the group consisting of a carboxyl group, an acid anhydride, an amine group, a hydroxyl group, an epoxy group, and an isocyanate group. The cover protective film for a printed circuit board having high temperature resistance and high reflectivity according to any one of claims 1 to 5, wherein the absorption rate of the high temperature resistant polymer film is less than 35 in the range of 415 to 700 nm. %, with high resistance The overall reflectivity of the cover film for the printed circuit board with temperature and high reflectivity is greater than 89%.