TWI643734B - A metal core printed circuit board with a hybrid resin layer - Google Patents

Abstract

The present invention discloses a metal printed circuit board having a composite resin layer. The metal printed circuit board comprises a metal substrate layer; a composite resin layer and a copper foil circuit layer. The material of the composite resin layer is formed by chemical grafting of an organic material and an inorganic nano ceramic material. The inorganic nano ceramic material is prepared as a sol gel. The metal printed circuit board with the composite resin layer proposed by the invention has better adhesion effect and higher breakdown voltage in a simple process.

Description

Metal printed circuit board with composite resin layer

The present invention relates to a metal printed circuit board, and more particularly to a metal printed circuit board having a composite resin layer composed of an organic inorganic material.

Conventional electronic products are not very powerful, and the heat dissipation problem is relatively unimportant. Therefore, it is sufficient to use a copper foil printed circuit board (FR4) for general electronics. At present, the lines of electronic products are getting more and more fine, and the power is getting bigger and bigger, and the requirements for heat dissipation are getting higher and higher. This board is not enough to meet the heat dissipation demand. For example, Light Emitting Diodes (LEDs) require high luminosity output under unit light sources in applications such as street lights, headlights, outdoor lighting, and ambient lighting. Challenges include temperature management and higher assembly costs. As a result, professional thermal material manufacturers have developed Metallic Printed Circuit Board (MCPCB), which has evolved from the early copper foil printed circuit board (FR4). The biggest difference between MCPCB and FR4 is that MCPCB uses metal as the core technology, using aluminum or copper metal as the substrate of the circuit board, and attaching a layer of copper foil or copper metal plate as a circuit on the insulating dielectric substrate of the middle layer. Accelerate heat dissipation to improve problems such as poor heat dissipation.

A bonding material conventionally used for attaching a printed circuit board to a metal plate is known as a film containing an epoxy resin composition. The film is an insulating dielectric substrate obtained by drying an epoxy resin impregnated with a composition of a glass fiber, a ceramic powder such as alumina (Al ₂ O ₃ ) or boron nitride (BN) to obtain an intermediate layer. The film forms a laminate with the upper copper foil metal plate and the lower aluminum metal plate, and the laminate is heated and pressurized to form a metal-clad laminate. A hole for a through hole is opened by a drill or the like on a metal-clad laminate, and gold plating is applied to the hole to form a through hole or the like, and the upper copper foil metal on the surface of the laminated body is etched to form a certain The circuit pattern is thereby used to obtain a printed circuit board.

However, conventional metal printed circuit boards have the following problems to be overcome. In order to increase the adhesion of the film to the upper and lower metal plates, the upper copper foil metal plate and the film follow-up surface usually form copper oxide, that is, block oxide; the lower aluminum metal plate and the film follow the surface usually Anode treatment with a thickness of 20 micrometers (μm) to 50 micrometers (μm). These surface treatments increase the manufacturing process and manufacturing costs. Further, a dicyandiamide-based curing agent is widely used in the production of the film containing the epoxy resin composition described above. The heat resistance of the epoxy resin hardened by using the dicyandiamide-based curing agent is low, and the heat resistance of the obtained metal printed circuit board is also lowered. An insulating dielectric substrate of an intermediate layer of a conventional metal printed circuit board is also dispersed in an epoxy resin using a ceramic powder such as alumina (Al ₂ O ₃ ) or boron nitride (BN), and dried to obtain an intermediate layer. Insulating the dielectric substrate to increase mechanical strength. In order to withstand a dielectric breakdown voltage of 3kV, the thickness of the film usually reaches 200 microns, which makes it more difficult to dissipate heat.

U.S. Patent No. 5,162,977, entitled "Printed Circuit Board with Integrated Decoupling Capacitor Elements, Printed Circuit Board having an Integrated decoupling capacitive element", which proposes how to use a ground ceramic nanopowder to increase the capacitance of the dielectric layer and how to produce a capacitance four times greater than that obtained using only an epoxy-based dielectric. However, the ground ceramic nano-nano The typical size of the powder particles is from 500 nanometers (nm) to 20,000 nanometers (nm). The particle distribution in this range is usually quite broad, indicating that 500 nanometer particles and 10,000 nanometer particles coexist. Due to the presence of larger particles, The distribution of particles of different sizes in the electrical layer can form a major obstacle to the microchannel. In addition, the presence of relatively ceramic particles in the ceramic nanopowder in the dielectric layer prevents the use of ultrathin layers, and the boundary of continuous large particles provides a path for voltage collapse. , reducing the dielectric breakdown capability of the dielectric layer withstanding high voltage.

In view of this, it is necessary to propose a metal printed circuit board, which can simplify the manufacturing process, produce a thinner and more adhesive intermediate layer, and enable the metal printed circuit board to have a higher breakdown voltage. Improve its applicability and practicality.

The present invention mainly provides a metal printed circuit board having a composite resin layer which is formed by a simplified process to produce a metal printed circuit board having a thin thickness, high adhesion, and high dielectric breakdown strength.

For the main purpose of the present invention, the present invention provides a metal printed circuit board having a composite resin layer, comprising: a metal substrate layer; a composite resin layer overlying the metal substrate layer; and a a copper foil circuit layer disposed above the composite resin layer; wherein the material of the composite resin layer is formed by chemical grafting of an organic material and an inorganic nano ceramic material, the inorganic The weight ratio of the nano ceramic material in the composite resin layer is between 50% and 90%, and the inorganic nano ceramic material has a powder size of between 5 nm and 100 nm.

According to a feature of the invention, the composite resin layer has a thickness of between 5 microns and 50 microns.

According to another feature of the invention, the inorganic nanoceramic material is selected from the group consisting of nano alumina, nano cerium oxide, nano zirconia, nano titanium oxide, and nano boron nitride.

According to still another feature of the invention, the inorganic nanoceramic material is prepared using a sol gel process.

The metal printed circuit board having the composite resin layer of the present invention has the following effects:

1. The material of the composite resin layer of the present invention is formed by chemical grafting of an organic material and an inorganic nano ceramic material, and the upper and lower metal layers can have good adhesion without additional surface treatment.

2. The thickness of the composite resin layer of the present invention (5 micrometers to 50 micrometers) is thinner than the thickness of the conventional insulating layer (150 micrometers to 250 micrometers), so that the amount of materials can be reduced to reduce the cost.

3. The metal printed circuit board having the composite resin layer of the present invention has a higher breakdown voltage than the general metal printed circuit board, and thus the application range is wider than that of the conventional metal printed circuit board.

4. The composite resin layer of the present invention can be coated on the upper and lower metal sheets by a barrel plating method, a spin coating method, a dip plating method or a spray coating method, and the production method is simpler and faster, and is less prone to aging.

5. The metal printed circuit board having the composite resin layer of the present invention has a better heat dissipation effect, so that the loaded electronic component achieves better performance.

100‧‧‧Metal printed circuit board with composite resin layer

110‧‧‧Metal substrate layer

120‧‧‧Composite resin layer

130‧‧‧copper circuit layer

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view showing the structure of a metal printed circuit board having a composite resin layer of the present invention.

While the invention may be embodied in a variety of forms, the embodiments shown in the drawings and illustrated herein are the preferred embodiments of the invention. Those skilled in the art will appreciate that the devices and methods specifically described herein and illustrated in the drawings are considered as an example of the invention, non-limiting exemplary embodiments, and the scope of the invention Defined. Features illustrated or described in connection with an exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be included within the scope of the invention.

The present invention will disclose a metal printed circuit board having a composite resin layer. Referring to FIG. 1 , it is a schematic structural view of a metal printed circuit board 100 having a composite resin layer according to the present invention. The method includes at least a metal substrate layer 110 and a composite resin layer 120 coated on the metal substrate layer 110. Upper; and a copper foil circuit layer 130 disposed above the composite resin layer 120. Wherein, the material of the composite resin layer 120 is formed by chemical grafting of an organic material and an inorganic nano ceramic material, and the weight ratio of the inorganic nano ceramic material in the composite resin layer is between 50% and 90%. And the inorganic nano ceramic material has a powder size of between 5 nm and 100 nm.

The weight ratio is defined as follows: if the weight of the organic material is X grams, and the weight of the inorganic nano ceramic material is Y grams, the weight of the composite resin layer is (X+Y) grams, and the organic material is The weight ratio of the composite resin layer is X/(X+Y), and the weight ratio of the inorganic nano ceramic material to the composite resin layer is Y/(X+Y).

The metal substrate layer 110 is composed of a metal plate having a specific thickness, and is mainly used as a mechanical structure of a metal printed circuit board. The metal substrate layer 110 is selected from one of an aluminum plate, an aluminum alloy metal plate, an aluminum plate, and a copper alloy metal plate.

The copper foil circuit layer 130 is disposed above the composite resin layer 120, and is mounted thereon with electronic components such as light emitting diodes or other electronic components. Therefore, the copper foil circuit layer 130 is constructed with electrical components arranged according to the loaded electronic components. Traces.

The thickness of the composite resin layer is between 5 micrometers and 50 micrometers, and a sufficient breakdown voltage can be obtained; preferably, the thickness of the composite resin layer is between 15 micrometers and 40 micrometers, and a sufficient breakdown voltage can be obtained. Good adhesion. The breakdown voltage of the composite resin layer is greater than 3000 volts.

The material of the composite resin layer 120 is a Graft copolymers formed by chemical grafting of an organic material and an inorganic nano ceramic material. The graft copolymer is structurally a branched polymer having a main chain and a longer branch, and the main chain and the branch are composed of different structural units.

In the present invention, different structural units use an organic material and an inorganic nano ceramic material, and since the inorganic nano ceramic material of the present invention is prepared by a sol-gel method, and the powder of the inorganic nano ceramic material The size is between 5 nm and 100 nm, so that on the surface of the inorganic nano ceramic material, there is a graft copolymer which has good reaction ability and can be chemically grafted with an organic material. The inorganic nano ceramic material is selected from the group consisting of nano alumina, nano cerium oxide, nano zirconia, nano titanium oxide and nano boron nitride. That is, the inorganic nano ceramic material is selected from a single nano alumina, or a single nano cerium oxide, or a single nano titanium oxide, or the inorganic nano ceramic material can be composed of nano alumina, nano Cerium oxide and nano titanium oxide are composed in different proportions.

The organic material is selected from the group consisting of epoxy resin, acrylic resin, oxime resin, fluorocarbon resin acid alcohol resin, amino resin, phenolic resin, and acrylic resin. Preferably, the weight ratio of the organic material to the composite resin layer is between 10% and 50%.

In order to enable the metal printed circuit board 100 having the composite resin layer of the present invention to have a function of dissipating heat, the crystal structure of the inorganic nano ceramic material of the composite resin layer 120 may be a rock salt type, a wurtzite type, a sphalerite type, or Perovskite, composite perovskite, layered perovskite, perovskite, steel jade, pyrochlore, ilmenite, rutile, spinel, anti-spinel One of type, fluorite type, anti-fluorite type, calcium chloride type, tungsten bronze type, lithium niobate type, bismuth citrate type and citrate type.

The inorganic nano ceramic material is prepared by using a nano ceramic solution and a heating process when prepared by a sol-gel method. Wherein, the nano ceramic solution is composed of at least one or more organometallic oxides and has a protecting group for stable storage of the nano ceramic solution.

The chemical formula of the organometallic oxide may be (OR) _x MOM(OR) _x , (R) _y (OR) _xy MOM(OR) _xy (R) _y , M(OR) _x , M(OR) _xy (R _y and (OR) _x MOM(OR) _x , where x is the valence of the cation and y is the valence of the anion. Generally, the valence of the cation is between 1 and 6, and the valence of the anion is between 1 and 6. The M system may be selected from the group consisting of aluminum (Al), iron (Fe), titanium (Ti), zirconium (Zr), hafnium (Hf), cerium (Si), rhenium (Rh), cerium (Cs), platinum (Pt), One of metal elements such as indium (In), tin (Sn), gold (Au), germanium (Ge), copper (Cu) or tantalum (Ta). R may be one of an alkyl group, an alkenyl group, an aromatic group (Aryl), a haloalkyl group (Alkylhalide), and hydrogen (Hydrogen).

The prepared nano ceramic solution is added to the organic acid. The pH (pH value) of the nano ceramic solution is adjusted by an organic acid so that the pH is between 3 and 11, preferably between 4 and 10. After the condensation reaction of the organic acid with water, a gelatinous nano ceramic solution having a chemically grafted protecting group is formed, and the chemically grafted protecting group enables stable storage of the nano ceramic solution.

Preferably, the organic acid is of the formula R-(COOH), (HO)-R-(COOH), (HOOC)-R-(COOH) and (R ₁ O), (R ₂ O)-( POOH). R may be one of an alkyl group, an alkenyl group, an aryl group, a haloalkyl group or a hydrogen or alkynyl group. If R is an alkyl group, the organic acid is an alkanoic acid; if R is an alkenyl group, the organic acid is an olefinic acid; if R is an aromatic group, the organic acid is an aromatic acid; and if R is a haloalkyl group, the organic acid is Haloalkanic acid; if R is hydrogen, the organic acid is formic acid; if R is alkynyl, the organic acid is acetylenic acid. The inorganic acid may be one of hydrochloric acid, nitric acid or sulfuric acid.

Preferably, the chemically grafted protecting group has the chemical formula A-(CO-B-CO)-C, which enables stable storage of the nano ceramic solution. Among them, the A system may be one of an alkyl group, an alkenyl group, an aromatic group, a haloalkyl group, a hydrogen group, and an alkynyl group. The B system may be one of an alkyl group, an alkenyl group, an aromatic group, a haloalkyl group, a hydrogen group, and an alkynyl group. The C system may be one of an alkyl group, an alkenyl group, an aromatic group, a haloalkyl group, a hydrogen group, and an alkynyl group.

Hereinafter, an embodiment of a gel-like composite resin gel formed by chemically grafting an inorganic nano ceramic material prepared by a sol-gel method with an organic material will be described.

In one embodiment, first, 10 grams of sulphate concentrate (Silbondcondense) is added, 14.4 grams of isopropanol is added for stirring for 10 minutes, and then 4 gram of a mixture of second butoxide aluminum (C ₁₂ H ₂₇ O ₃ Al) is added. After stirring for 10 minutes, 10 g of trimethoxyvinyl hydrazine (C ₅ H ₁₂ O ₃ Si) was added and stirred for 10 minutes, and then 9.7 g of ethylene glycol monobutylether (BCS) was added, and 0.1 g of nitric acid was mixed and stirred. After 10 minutes, 15 g of water was added, and the mixture was stirred for 2 hours to further condense the solution, and 1.6 g of a protective group of ethyl acetate (Acetoacetate, AcAc) was added thereto, and the mixture was stirred for 1 hour to form a gel-like composite resin having a chemical graft protecting group. Glue and stable storage for long periods of time.

The composite resin layer 120 is formed by chemically grafting an inorganic nano ceramic material prepared by a sol-gel method with an organic material to form a gel-like composite resin paste, and is coated on the metal substrate layer 110 and the copper foil. A metal printed circuit board 100 having a composite resin layer is formed between the circuit layers 130 via a heat curing process or a photocuring process.

The coating method includes a barrel plating method, a spin coating method, a dip plating method, or a spray coating method. A preferred coating method is a barrel plating method in which the gel-like composite resin paste is uniformly applied onto the metal substrate layer 110 by a roller coating. Another common The immersion plating method is a method of coating the metal substrate layer 110 into a groove containing the gel-like composite resin glue, and after the immersion is completed, the metal substrate layer 110 is superfluided by a cantilever or a tray. The coating solution is dripped into the tank to achieve the recycling effect, and the batching method can be batch processed by using the transportation belt, which is quite convenient. However, in this way, considerable care must be taken to control the circulation, filtration, and temperature and viscosity of the coating solution.

The coated metal substrate layer 110 is subjected to a heat curing process or an illuminating curing process. The heat curing process or the photo-curing process can cause molecular bonding between the gel-like composite resin glue and the metal substrate layer 110, so that the gel-like composite resin glue can be smoothly attached to the metal substrate layer 110. The composite resin layer 120. Preferably, the temperature range of the heat curing process is between 50 ° C and 200 ° C; moreover, the heating process temperature range is between 80 ° C and 150 ° C.

In one embodiment of fabricating the metal printed circuit board 100 having a composite resin layer, the metal substrate layer 110, for example, a metal aluminum plate, is first subjected to degreasing treatment to remove surface oil, and after washing with water, the surface of the metal substrate layer 110 is maintained. clean. The metal substrate layer 110 is immersed in the gel-like composite resin paste of the present invention for 2 minutes so that the gel-like composite resin paste covers the surface of the metal substrate layer 110. The surface of the metal substrate layer 110 after the film formation was dried at 180 ° C for about 20 minutes. By repeating the above steps 5 to 8 2 to 5 times, the composite resin layer 120 having a thickness of about 5 to 50 μm is coated on the metal substrate layer 110.

After the degreasing treatment and the water washing, the metal substrate layer 110 may be further placed in a high temperature co-bath in the organic-inorganic acid mixed solution, and the surface of the metal substrate layer 110 is subjected to acid etching. The temperature of the high temperature co-bath is 40. °C~80°C. The organic acid is selected from the group consisting of acids, alkyds, diacids, and phosphonic acids; the inorganic acid is selected from the group consisting of inorganic acids containing trivalent chromium, phosphoric acid, nitric acid, boric acid, and hydrochloric acid. Rinse with water to remove excess organic-inorganic acid mixed solution. The acid-etched metal substrate layer 110 is placed in an acid or alkaline solution to remove surface oxides, during which the surface of the metal substrate layer 110 will form a hydroxyl group. Finally, the acid or alkali solution on the surface of the metal substrate layer 110 is washed with water, and then a subsequent coating process is performed.

The process of the metal printed circuit board 100 having the composite resin layer of the present invention does not require additional surface treatment of the upper and lower metal sheets, such as the black oxide of the upper copper foil metal sheet and the anode treatment of the lower aluminum metal sheet. Therefore, the steps of the process are simplified.

The composite resin layer 120 is disposed between the metal substrate layer 110 and the copper foil circuit layer 130, and mainly isolates the metal substrate layer 110 from the copper foil circuit layer 130, so as to avoid short circuit and not sacrifice too much. The heat dissipation rate is increased, and the metal substrate layer 110 and the copper foil circuit layer 130 are provided with a good bonding effect, and the reliability of the metal printed circuit board 100 having the composite resin layer as a whole is increased. Moreover, since the metal substrate layer 110 has a better heat dissipation effect, the composite resin layer 120 can minimize the thermal resistance, so that heat dissipation of the electronic product can be quickly conducted to the metal substrate layer 110 through the composite resin layer 120. Release, greatly improving the heat dissipation efficiency of electronic products, thereby improving the performance of electronic products.

Comparing the insulating dielectric substrate of the intermediate layer of the prior art, the composite resin layer 120 of the present invention has a relatively high breakdown voltage, can have a breakdown voltage exceeding 3000 volts (3 kV), and is preferably a breakdown voltage exceeding 4000 volts. .

In summary, the metal printed circuit board 100 having the composite resin layer of the present invention has the following effects:

1. The material of the composite resin layer of the present invention is formed by chemical grafting of an organic material and an inorganic nano ceramic material, and the upper and lower metal layers can have good adhesion without additional surface treatment.

2. The thickness of the composite resin layer of the present invention (5 to 50 μm) is thinner than the thickness of the conventional insulating layer (150 to 250 μm), so that the amount of the material can be reduced to reduce the cost.

3. The metal printed circuit board having the composite resin layer of the present invention has a higher breakdown voltage than the general metal printed circuit board, and thus the application range is wider than that of the conventional metal printed circuit board.

4. The composite resin layer of the present invention can be coated on the upper and lower metal plates by a spin coating method, a dip plating method or a spray coating method, and the production method is simpler and faster, and is less prone to aging.

5. The metal printed circuit board having the composite resin layer of the present invention has a better heat dissipation effect, so that the loaded electronic component achieves better performance.

While the present invention has been described in its preferred embodiments, it is not intended to limit the scope of the invention, and various modifications and changes can be made without departing from the spirit and scope of the invention. As explained above, various modifications and variations can be made without departing from the spirit of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (8)

A metal printed circuit board having a composite resin layer comprising: a metal substrate layer; a composite resin layer overlying the metal substrate layer, the composite resin layer having a thickness of between 5 micrometers and 50 micrometers; and a copper foil circuit layer disposed above the composite resin layer; wherein the composite resin layer is chemically grafted by an organic material and an inorganic nano ceramic material by an organic acid catalyzed condensation reaction with water Forming a colloidal graft copolymer selected from the group consisting of nano alumina prepared by a sol-gel method, nano cerium oxide, nano zirconia, nano titanium oxide and nano nitriding a group consisting of boron, the weight ratio of the inorganic nano ceramic material in the composite resin layer is between 50% and 90%, and the powder size of the inorganic nano ceramic material is between 5 nm and 100 Between the rice. The metal printed circuit board of claim 1, wherein the composite resin layer has a breakdown voltage of greater than 3000 volts. The metal printed circuit board having a composite resin layer according to claim 1, wherein the organic material is selected from the group consisting of epoxy resin, acrylic resin, oxime resin, fluorocarbon resin, acid alcohol resin, amino resin, phenol resin and A group of acrylic resins. The metal printed circuit board according to claim 1, wherein the inorganic nano ceramic material is synthesized by using a nano ceramic solution in combination with a heating process, and the nano ceramic solution is composed of at least one organic metal oxide. And has a protecting group. A metal printed circuit board having a composite resin layer as claimed in claim 1, wherein the composite resin layer is formed between the metal substrate layer and the copper foil wiring layer and formed by a heat curing process. A metal printed circuit board having a composite resin layer as claimed in claim 1, wherein the metal substrate layer is selected from the group consisting of an aluminum plate, an aluminum alloy metal plate, an aluminum plate, and a copper alloy metal plate. A metal printed circuit board having a composite resin layer as claimed in claim 1, wherein the organic acid is of the formula R-(COOH), (HO)-R-(COOH), (HOOC)-R-(COOH) And (R ₁ O), (R ₂ O)-(POOH), R may be an alkyl group, an alkenyl group, an aryl group, a haloalkyl group or one of hydrogen or an alkynyl group; if R is an alkyl group, the organic acid is An alkanoic acid; if R is an alkenyl group, the organic acid is an olefinic acid; if R is an aromatic group, the organic acid is an aromatic acid; if R is a haloalkyl group, the organic acid is a haloalkanic acid; if R is hydrogen, The organic acid is formic acid; if R is an alkynyl group, the organic acid is an acetylic acid. A metal printed circuit board having a composite resin layer as claimed in claim 5, wherein the heat curing process has a temperature range of between 50 ° C and 200 ° C.