Method for producing high thermal conductivity ceramic circuit board

[0035] Example 1

[0036] The production method of a high thermal conductivity ceramic circuit board of the present invention includes the following steps:

[0037] a. Pretreatment of the substrate

[0038] Mainly include: incoming inspection → degreasing → micro-etching → pickling → copper electroplating → cleaning → drying and other processes;

[0039] The specific method is: clean the surface of the ceramic copper clad substrate that has passed the inspection, and use sodium persulfate or ammonium persulfate to microetch the copper clad layer of the ceramic copper clad substrate to remove oil stains and surface oxidation on the copper clad layer Compared with the use of physical methods to clean the circuit board substrate, this is more effective in preventing damage to the ceramic copper-clad substrate, because the physical method is generally to first compress the substrate, and then use a roller brush to rotate at high speed on its surface. The friction of the roller brush on the surface of the substrate cleans the oxides on the oily surface, but this method cannot be applied to the ceramic copper-clad substrate, because the ceramic layer of the ceramic copper-clad substrate is relatively brittle and easily broken.

[0040] The cleaned ceramic copper-clad substrate is pickled with a weak acid solution, and then a thicker copper layer is electroplated on the copper-clad layers on both sides of the ceramic copper-clad substrate. The surface gloss of this copper layer is higher than that of the rolled copper of the original ceramic copper-clad substrate It is more shiny and has good surface density; it is conducive to later processing; after electroplating copper, it is cleaned and dried to enter the next process;

[0041] b, graphics transfer

[0042] Mainly include: lamination → exposure → development → etching → film removal → drying → inspection and other processes;

[0043] The specific method is: print a layer of photosensitive ink or paste a photosensitive film on the copper clad layer of the above-mentioned ceramic copper clad substrate, and then use the light drawing circuit pattern film that has been made to place on the upper and lower sides of the ceramic copper clad substrate to expose the circuit pattern Develop the exposed ceramic copper-clad substrate to display the exposed and light-solid circuit pattern. Use an etching solution or an etching machine to etch the exposed ceramic copper-clad substrate, which requires three etchings, the first The etching is performed at 1.5m/min, the second etching is performed at 2.0m/min, and the third etching is performed at 5.5m/min. After the film is removed and dried, automatic optical equipment is used to detect and remove defective products; then clean and dry to the next step Process

[0044] c. Making vias

[0045] Mainly include: laser drilling → cleaning → silver paste filling → drying and other processes;

[0046] The specific method is: use laser drilling equipment to open holes through the upper and lower circuit boards in the set places for the above-mentioned ceramic copper-clad substrates, wash them with clean water and dry them, and then use silver paste to fill the holes. The holes that need to be connected are filled with silver paste, where the silver paste is a commercially available product, and then dried and molded to make it into a through hole; then clean and dry into the next step;

[0047] d. Printing solder mask ink

[0048] Mainly include: pretreatment → printing ink → pre-drying → exposure → development → thermal curing and other processes;

[0049] The specific method is: cleaning and drying the above-mentioned ceramic copper-clad substrate, and printing solder mask ink where no electronic components need to be soldered; exposure and development after low-temperature pre-drying in a drying box, and then thermal curing; printing; The solder resist ink can effectively prevent the solder from sticking to the non-solder area when soldering electronic components. At the same time, printing the solder resist ink can also protect some conductive layers on the circuit board from moisture corrosion and increase the aesthetics of the product; then clean and dry to enter Next step

[0050] e. Silkscreen text

[0051] Mainly include: silk screen text → heat curing and other processes;

[0052] The specific method is: according to the design requirements, silk-screen text on the corresponding place of the above-mentioned substrate and then heat curing; to facilitate the production and processing and then solder the electronic components in the corresponding place; to bring convenience to the assembly and production of the circuit board; then the cleaning and drying enter the next step Process

[0053] f. Electroless nickel and gold

[0054] Mainly include: degreasing → pickling → micro-etching → prepreg → immersion nickel → immersion gold → drying and other processes;

[0055] The specific method is: degreasing and cleaning the above-mentioned substrate, then pickling, microetching in sodium persulfate or ammonium persulfate solution, pre-soaking in nickel plating solution after cleaning, and then using electroless nickel and gold method Deposit a layer of chemical nickel with a thickness of 100-200μ" on the copper-clad layer of electronic components to be soldered, and then electroplate a layer of gold with a thickness of 3μ"; then clean and dry into the next step;

[0056] g, cutting and forming

[0057] Mainly include: laser cutting → cleaning → inspection → packaging and other processes;

[0058] The specific method is: use a laser cutting equipment of 8W or more to cut the electroless nickel and gold substrates into predetermined specifications, clean and dry with clean water, and then electronically detect them. The qualified product is the product of the present invention, and then it can be packaged.

[0059] Example 2

[0060] The production method of a high thermal conductivity ceramic circuit board of the present invention includes the following steps:

[0061] a. Pretreatment of the substrate

[0062] Mainly include: incoming inspection → degreasing → micro-etching → pickling → copper electroplating → cleaning → drying and other processes;

[0063] The specific method is to clean the surface of the ceramic copper clad substrate that has passed the inspection. The specific method is to use sodium persulfate or ammonium persulfate to microetch the copper clad layer of the ceramic copper clad substrate to remove the oil and dirt on the copper clad layer. The oxide on the surface is more effective than the physical method used to clean the circuit board substrate, which is more effective in preventing damage to the ceramic copper-clad substrate, because the physical method is generally to first compress the substrate, and then use a roller brush on its surface at high speed Rotation, through the friction of the roller brush on the surface of the substrate, clean the oxide on the oily surface, but this method cannot be applied to the ceramic copper-clad substrate, because the ceramic layer of the ceramic copper-clad substrate is relatively brittle and easy fracture.

[0064] The cleaned ceramic copper-clad substrate is pickled with a weak acid solution, and then a thicker copper layer is electroplated on the copper-clad layers on both sides of the ceramic copper-clad substrate. The surface gloss of this copper layer is higher than that of the rolled copper of the original ceramic copper-clad substrate It is more shiny and has good surface density; it is conducive to later processing; after electroplating copper, it is cleaned and dried to enter the next process;

[0065] b, graphics transfer

[0066] Mainly include: lamination → exposure → development → etching → film removal → drying → inspection and other processes;

[0067] The specific method is: print a layer of photosensitive ink or paste a photosensitive film on the copper clad layer of the above-mentioned ceramic copper clad substrate, and then use the light drawing circuit pattern film that has been made to place on the upper and lower sides of the ceramic copper clad substrate to expose the circuit pattern Develop the exposed ceramic copper-clad substrate to display the exposed and light-solid circuit pattern. Use an etching solution or an etching machine to etch the exposed ceramic copper-clad substrate, which requires three etchings, the first The etching is performed at 1.5m/min, the second etching is performed at 2.0m/min, and the third etching is performed at 5.5m/min. After the film is removed and dried, automatic optical equipment is used to detect and remove defective products; then clean and dry to the next step Process

[0068] c. Making vias

[0069] Mainly include: high-hardness drill drilling → cleaning → copper grout grouting → drying and other processes;

[0070] The specific method is to use a high-hardness drill bit for the above-mentioned ceramic copper-clad substrate to open a hole through the upper and lower circuit boards at the set place, wash it with clean water and dry it, and use the copper slurry to fill the hole. The conductive holes are filled with copper paste, wherein the copper paste is a commercially available product, and then dried and formed into a through hole; then the cleaning and drying enter the next step;

[0071] d. Printing solder mask ink

[0072] Mainly include: pretreatment → printing ink → pre-drying → exposure → development → thermal curing and other processes;

[0073] The specific method is: cleaning and drying the above-mentioned ceramic copper-clad substrate, and printing solder mask ink where no electronic components need to be soldered; exposure and development after low-temperature pre-drying in a drying box, and then thermal curing; printing; The solder resist ink can effectively prevent the solder from sticking to the non-solder area when soldering electronic components. At the same time, printing the solder resist ink can also protect some conductive layers on the circuit board from moisture corrosion and increase the aesthetics of the product; then clean and dry to enter Next step

[0074] e. Silkscreen text

[0075] Mainly include: silk screen text → heat curing and other processes;

[0076] The specific method is: according to the design requirements, silk-screen text on the corresponding place of the above-mentioned substrate and then heat curing; to facilitate the production and processing and then solder the electronic components in the corresponding place; to bring convenience to the assembly and production of the circuit board; then the cleaning and drying enter the next step Process

[0077] f. Electroless nickel and gold

[0078] Mainly include: degreasing → pickling → micro-etching → prepreg → immersion nickel → immersion gold → drying and other processes;

[0079] The specific method is: degreasing and cleaning the above-mentioned substrate, then pickling, microetching in sodium persulfate or ammonium persulfate solution, pre-soaking in nickel plating solution after cleaning, and then using electroless nickel and gold method Plating a layer of chemical nickel with a thickness of 100-200μ" on the copper-clad layer of electronic components to be soldered, and then electroplating a layer of gold with a thickness of 3μ"; then cleaning and drying enter the next step;

[0080] g, silk screen blue glue

[0081] The specific method is to print a circle of blue glue around the predetermined fluorescent glue area, and then dry it. During the processing, apply fluorescent glue in the area enclosed by the blue glue as needed, because the surface of the blue glue is rough after curing. , Effectively prevent the fluorescent glue from flowing outside the predetermined area;

[0082] h, cutting and forming

[0083] Mainly include: laser cutting → cleaning → inspection → packaging and other processes;

[0084] The specific method is: use a laser cutting equipment of 8W or more to cut the electroless nickel and gold substrates into predetermined specifications, clean and dry with clean water, and then electronically detect them. The qualified product is the product of the present invention, and then it can be packaged.