Method for single-sided lapping of thin-film circuit ceramic

Abstract

The application discloses a thin film circuit ceramic single-side grinding method and relates to the field of ceramic surface fine grinding processing technology, which comprises the following steps: step one, symmetrically attaching ceramic substrates with white films to a ceramic disc smeared with paraffin wax; step two, cooling and bonding the ceramic disc after the ceramic substrates are attached, pressing the ceramic substrates and the ceramic disc by using the white film-attached rubber pad, and uniformly extruding the hot-melt paraffin wax; step three, after the cooling is completed, taking out the ceramic disc, testing the paraffin wax-attaching thickness error, comparing the ceramic disc plane with zero, and then testing the substrate thickness by using the five-point testing method on the ceramic substrate to the set tolerance fluctuation range; step four, when the disc surface of the ceramic disc reaches the set flatness, grinding is carried out according to the set fixed interval time; step five, after the grinding is completed, the thickness is retested, if the thickness is qualified, the grinding is completed, if the thickness is unqualified, the substrate is turned over by 180 degrees, the grinding is continuously carried out for the same time, and the grinding is not stopped until the thickness is qualified. The application can avoid scratches on the ceramic substrate and reduce the breakage rate.

Description

Technical Field

[0001] This invention relates to the field of ceramic surface fine grinding technology, and in particular to a method for single-sided grinding of thin-film circuit ceramics. Background Technology

[0002] Driven by the miniaturization and micro-sized requirements of user-end products, hybrid integrated circuits are also gradually developing towards lighter, thinner, and smaller designs. Thin-film circuits are an important component of electronic micro-assemblies, and most thin-film circuits use ceramic substrates such as alumina and aluminum nitride as substrate materials. The main process flow is: grinding and thinning, magnetron sputtering seed layer, surface treatment, patterning, and scribing. The miniaturization of components also means that the substrate requires higher precision thinning processes. Common thinning processes include grinding and polishing, but their purposes differ. Grinding aims to significantly reduce thickness, typically exceeding tens of micrometers, while polishing aims to improve the surface condition of the substrate, primarily reducing roughness, and typically only reducing thickness to a few micrometers.

[0003] Due to the unique nature of thin-film circuit products, the appearance requirements for the front-side pattern are high. Without special treatment, the original ceramic sintered surface must be preserved. Conventional double-sided grinding processes involve thinning both sides simultaneously, followed by polishing to reduce surface roughness before fabrication. Traditional single-sided grinding, using aluminum alloy fixtures with resin copper discs and coarse diamond polishing fluid, suffers from problems such as scratches on the original surface, large thickness tolerances, high breakage rates, and low efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a single-sided polishing method for thin-film circuit ceramics to solve the problems existing in the prior art, thereby avoiding scratches on the ceramic substrate and reducing the breakage rate.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a method for single-sided polishing of thin-film circuit ceramics, comprising the following steps:

[0007] Step 1: symmetrically attach the ceramic substrate with the white film to the ceramic plate coated with paraffin wax.

[0008] Step 2: After the ceramic substrate is bonded, the ceramic disk is cooled and bonded. The ceramic substrate and the ceramic disk are pressed together by the adhesive pad with the white film, and the hot-melted paraffin is evenly extruded.

[0009] Step 3: After cooling is complete, remove the ceramic disc and test the wax thickness error. Zero the temperature on the ceramic disc surface, and then test the substrate thickness on the ceramic substrate using the five-point test method until it reaches the set tolerance fluctuation range.

[0010] Step four, when the disc surface of the ceramic disc reaches the set flatness, the grinding is carried out according to the set fixed interval time;

[0011] Step five, after the grinding is completed, the thickness is re-measured, if qualified, the grinding is completed, if not qualified, the substrate is turned over by 180°, the grinding is continuously carried out for the same time until qualified.

[0012] Optionally, the step one comprises:

[0013] First step, the ceramic disc is preheated and heated to the set temperature, and the ceramic disc is placed at the position of the ceramic substrate and uniformly coated with paraffin;

[0014] Second step, the ceramic substrate is symmetrically attached to the ceramic disc after the white film is attached to the side close to the ceramic disc for protection;

[0015] Third step, the ceramic disc after the ceramic substrate is attached is cooled and bonded, the ceramic substrate and the ceramic disc are pressed by the adhesive pad of the attached white film, and the uniformly extruded hot-melt paraffin is obtained.

[0016] Optionally, the step four comprises:

[0017] First step, the diamond pad is attached to the aluminum alloy base, and no air hole gap is left after the attachment;

[0018] Second step, the ceramic disc is attached to the diamond pad, the disc flatness is tested, if the set flatness requirement is not reached, the surface is repaired by using the correction ring, after the set flatness requirement is reached, the grinding liquid is dripped by starting the grinding liquid stirrer;

[0019] Third step, the self-weight counterweight is added, and the grinding is started, and the fixed interval time is set.

[0020] Optionally, the ceramic disc is a cylindrical ceramic disc, and the diameter of the cylindrical ceramic disc is between 200mm and 300mm.

[0021] Optionally, the thickness of the ceramic disc is between 5mm and 15mm.

[0022] Optionally, in the step three, the thickness tolerance fluctuation of the ceramic substrate is less than ±15um.

[0023] Optionally, in the step one, the ceramic disc damage is uniformly and symmetrically attached to 3-8 ceramic substrates.

[0024] Optionally, the surface flatness of the ceramic disc is not greater than 2um.

[0025] The present application has the following technical effects relative to the prior art:

[0026] The application provides a thin film circuit ceramic single surface grinding process method, which is special for the single surface grinding processing of alumina, aluminum nitride, beryllium oxide and other ceramics. The original surface, i.e. the sintering surface, is reserved, the thickness tolerance reaches below ±0.025mm, the white film is used to protect the ceramic substrate, and the scratch on the original sintering surface of the ceramic substrate is avoided when the ceramic substrate is taken out after grinding, so that the appearance yield of the thin film circuit product in the subsequent process is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described in the following are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0028] Figure 1 The application provides a thin film circuit ceramic single surface grinding process method. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0030] The purpose of the present application is to provide a thin film circuit ceramic single surface grinding method to solve the problems in the prior art, which can avoid scratches on the ceramic substrate and reduce the damage rate.

[0031] In order to make the above-mentioned purposes, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail with reference to the drawings and specific embodiments.

[0032] REFERENCE Figure 1 The present application provides a thin film circuit ceramic single surface grinding method, which comprises the following steps:

[0033] Step one, symmetrically paste the ceramic substrate with white film on the ceramic disc coated with paraffin wax;

[0034] Step two, cool the ceramic disc after pasting the ceramic substrate, use the white film adhesive pad to press the ceramic substrate and the ceramic disc, and make the hot melted paraffin wax evenly extruded;

[0035] Step three, after cooling, take out the ceramic disc, test the paraffin thickness error, and test the substrate thickness on the ceramic substrate by five-point test method to the set tolerance fluctuation range.

[0036] Step four, when the ceramic disc surface reaches the set flatness, grind according to the set fixed interval time;

[0037] Step five, complete the grinding, retest the thickness, if qualified, complete the grinding, if not, flip the substrate 180°, continue to grind for the same time until qualified.

[0038] In a specific embodiment, the thin film circuit ceramic single-sided grinding method steps are as follows:

[0039] Step one, preheat the cylindrical ceramic disc with a diameter of 200-300 mm, a thickness of 5-15 mm, and a surface flatness of 2 um or less at 50-70°C, heat the ceramic disc at 70-100°C, spin coat the paraffin column to the pre-placed position of the ceramic substrate, melt the paraffin, and then use the paraffin column to evenly apply it;

[0040] Step two, protect the ceramic substrate with white film, then symmetrically place ceramic substrates with a size of 50.8*50.8 mm, 3-8 pieces, wear asbestos gloves, and correct the position of the ceramic substrate to make it symmetrically distributed;

[0041] Step three, transfer to the water cooling machine, cool the bond, add a rubber pad in the middle, reapply white film on the rubber pad according to the distribution position of the substrate, press the ceramic substrate and ceramic disc tightly, and make the hot melted paraffin evenly extruded;

[0042] Step four, after cooling, take out the ceramic disc, test the paraffin thickness error, and test the substrate thickness on the ceramic disc plane, the thickness tolerance fluctuation is less than ±15 um, and the next step can be performed;

[0043] Step five, apply the pre-prepared diamond pad to the aluminum alloy base, pay attention to the flatness, and do not leave air holes or gaps;

[0044] Step six, place the ceramic disc upside down on the diamond pad, measure the disc surface flatness using a micrometer, the flatness requirement is less than ±10 um, if not, use a correction ring to finish the surface, then start the grinding liquid stirrer and add the grinding liquid;

[0045] Step seven, add self-weight counterweights, start grinding, set fixed interval times of 5 min, 10 min, 15 min, etc.

[0046] Step eight, complete the grinding, retest the thickness, if qualified, complete the grinding, if not, flip the substrate 180°, continue to grind for the same time until qualified.

[0047] Example one

[0048] Take 3-7 pieces of 50*50*0.635mm ceramic substrate, a cylindrical ceramic disc with a diameter of 200mm to 300mm, a thickness of 5mm to 15mm, and a surface flatness of 2um or less, preheat the ceramic disc at 50-70℃, heat the ceramic disc at 70-100℃, spin-coat the paraffin column to the pre-placed position of the ceramic substrate, melt the paraffin, and then use the paraffin column to evenly apply it; protect the ceramic back with white film, then symmetrically place 3-7 pieces of ceramic substrate, wear asbestos gloves, correct the position of the ceramic substrate to make it symmetrically distributed; transfer to a water-cooled machine, cool the bonding, add a rubber pad in the middle, and then stick white film on the rubber pad according to the distribution position of the substrate, press the ceramic substrate and ceramic disc tightly, and make the hot melted paraffin evenly extruded; after cooling, take out the ceramic disc, test the wax thickness error, and then test the substrate thickness on the ceramic substrate with five-point test method, the thickness tolerance fluctuation is less than ±15um, and the next step can be performed; stick the pre-prepared diamond pad to the aluminum alloy base, pay attention to the flatness, and do not leave air holes or gaps; turn the ceramic disc upside down on the diamond pad, use a micrometer to measure the flatness of the disc surface, and the flatness requirement is less than ±10um, if it cannot be achieved, use a correction ring to finish the surface, after completion, start the grinding liquid stirrer and drop in the grinding liquid; add self-weight counterweight, start grinding, set fixed interval time of 5min, 10min, 15min, etc.; complete grinding, retest thickness, if qualified, complete grinding; if not qualified, flip the substrate 180°, continue to grind for the same time, the final thickness of grinding is within 0.500mm±0.025mm.

[0049] Example Two

[0050] Take 3-7 ceramic substrates (50*50*0.508mm). Place them on a cylindrical ceramic disk with a diameter of 200mm-300mm, a thickness of 5mm-15mm, and a surface flatness of less than 2µm. Preheat the ceramic disk to 50-70℃, then heat it to 70-100℃. Spin-coat paraffin wax onto the pre-positioned areas of the ceramic substrates. After melting the paraffin wax, spread it evenly using the wax sticks. Apply a white film to the back of the ceramic substrate for protection. Then, symmetrically place 3-7 ceramic substrates, wearing asbestos gloves, and adjust the position of the ceramic substrates to ensure symmetrical distribution. Transfer to a water-cooling machine for cooling and bonding. Add a rubber pad in the middle, and apply another white film to the pad according to the substrate distribution. Press the ceramic substrates firmly onto the ceramic disk, and squeeze out the molten paraffin wax evenly. After cooling, remove the ceramic disk and test the wax thickness. The error is zeroed out on the ceramic disc surface. Then, the thickness of the ceramic substrate is tested using a five-point test method. The thickness tolerance fluctuation is less than ±15um before proceeding to the next step. The pre-made diamond pad is attached to the aluminum alloy base, ensuring it is flat and without any air holes or gaps. The ceramic disc is then placed upside down on the diamond pad, and the flatness of the disc surface is measured using a micrometer. The flatness requirement is less than ±10um. If it is not met, a correction ring is used to smooth the surface. After completion, the grinding slurry stirrer is started, and the grinding slurry is added. A self-weight counterweight is added, and grinding is started, with fixed time intervals of 5min, 10min, and 15min. After grinding is completed, the thickness is measured again. If it is qualified, grinding is complete. If it is not qualified, the substrate is flipped 180°, and grinding continues for the specified time. The final grinding thickness is within 0.400mm ± 0.025mm.

[0051] Example 3

[0052] Take 3-7 pieces of 50*50*0.381mm ceramic substrate, a cylindrical ceramic disc with a diameter of 200mm to 300mm, a thickness of 5mm to 15mm, and a surface flatness of 2um or less, preheat the ceramic disc at 50-70℃, heat the ceramic disc at 70-100℃, spin-coat the paraffin column to the pre-placed position of the ceramic substrate, melt the paraffin, and then use the paraffin column to evenly apply it; protect the ceramic back with white film, then symmetrically place 3-7 pieces of ceramic substrate, wear asbestos gloves, correct the position of the ceramic substrate to make it symmetrically distributed; transfer to a water-cooled machine, cool the bonding, add a rubber pad in the middle, and then stick white film on the rubber pad according to the distribution position of the substrate, press the ceramic substrate and ceramic disc tightly, and make the hot melted paraffin evenly extruded; after cooling, take out the ceramic disc, test the wax thickness error, and then test the substrate thickness on the ceramic substrate with five-point test method, the thickness tolerance fluctuation is less than ±15um, and the next step can be performed; stick the pre-prepared diamond pad to the aluminum alloy base, pay attention to the flatness, and do not leave air holes or gaps; turn the ceramic disc upside down on the diamond pad, use a micrometer to measure the flatness of the disc surface, and the flatness requirement is less than ±10um, if it cannot be achieved, use a correction ring to finish the surface, after completion, start the grinding liquid stirrer and drop in the grinding liquid; add self-weight counterweight, start grinding, set fixed interval time of 5min, 10min, 15min, etc.; complete grinding, retest thickness, if qualified, complete grinding; if not qualified, flip the substrate 180°, continue to grind for the same time, the final thickness of grinding is within 0.300mm±0.025mm.

[0053] Example Four

[0054] Take 3-7 pieces of 50*50*0.254mm ceramic substrate, a cylindrical ceramic disc with a diameter of 200mm to 300mm, a thickness of 5mm to 15mm, and a surface flatness of 2um or less, preheat the ceramic disc at 50-70℃, heat the ceramic disc at 70-100℃, spin the paraffin column to the pre-placed position of the ceramic substrate, melt the paraffin, and then use the paraffin column to evenly apply it; then, protect the back of the ceramic with a white film, and then symmetrically place 3-7 pieces of ceramic substrate, wear asbestos gloves, and correct the position of the ceramic substrate to make it symmetrically distributed; transfer to a water cooling machine, cool the bonding, add a rubber pad in the middle, and then stick a white film on the rubber pad according to the distribution position of the substrate, press the ceramic substrate and the ceramic disc tightly, and make the hot melted paraffin evenly extruded; after cooling, take out the ceramic disc, test the wax thickness error, and then test the thickness of the ceramic substrate with a five-point test method, and the thickness tolerance fluctuation is less than ±15um, and the next step can be performed; stick the pre-prepared diamond pad to the aluminum alloy base, pay attention to the flatness, and do not leave air holes or gaps; turn the ceramic disc upside down and stick it to the diamond pad, use a micrometer to measure the flatness of the disc surface, and the flatness requirement is less than ±10um, if it cannot be achieved, use a correction ring to finish the surface, start the grinding liquid stirrer after finishing, and drop the grinding liquid; add a self-weight counterweight, start the grinding, set the fixed interval time of 5min, 10min, 15min, etc.; complete the grinding, retest the thickness, if it is qualified, the grinding is completed; if it is not qualified, turn the substrate 180°, continue to grind for the same time, and the final thickness of the grinding is within 0.100mm±0.025mm.

[0055] In the description of the present application, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] In the present application, specific examples are applied to illustrate the principles and implementation modes of the present application, and the above examples are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In view of the above, the content of the specification should not be understood as limiting the present application.

Claims

1. A thin film circuit ceramic single-sided polishing method, characterized by, It comprises the following steps: Step one, symmetrically paste the ceramic substrate with white film on the ceramic disc smeared with paraffin wax; the step one comprises: First, preheat and heat the ceramic disc to the set temperature, and evenly smear paraffin wax on the position of the ceramic substrate; Second, symmetrically paste the ceramic substrate on the ceramic disc after protecting the side of the ceramic substrate close to the ceramic disc with white film; Third, cool the ceramic disc after pasting the ceramic substrate, press the ceramic substrate and the ceramic disc with the white film pasted rubber pad, and evenly extrude the hot melted paraffin wax; Step two, cool the ceramic disc after pasting the ceramic substrate, press the ceramic substrate and the ceramic disc with the white film pasted rubber pad, and evenly extrude the hot melted paraffin wax; Step three, after cooling, take out the ceramic disc, test the paraffin wax thickness error, calibrate zero on the ceramic disc plane, and then test the substrate thickness on the ceramic substrate by five-point test method to the set tolerance fluctuation range; Step four, when the disc surface of the ceramic disc reaches the set flatness, grind according to the set fixed interval time; the step four comprises: First, paste the prepared diamond pad to the aluminum alloy base, and do not leave air hole gap after pasting; Second, test the disc flatness by pasting the ceramic disc to the diamond pad, if the set flatness requirement is not met, use the correction ring to grind the surface, and after the set flatness requirement is met, start the grinding liquid stirrer and drop the grinding liquid; Third, add self-weight counterweight, start grinding, and set the fixed interval time; Step five, complete the grinding, retest the thickness, if it is qualified, complete the grinding, if it is unqualified, turn over the substrate by 180°, continue to grind for a certain time, until it is qualified.

2. The thin film circuit ceramic single-side polishing method according to claim 1, characterized by, The ceramic disc is a cylindrical ceramic disc, and the diameter of the cylindrical ceramic disc is between 200mm and 300mm.

3. The thin film circuit ceramic single-side polishing method according to claim 1, wherein The thickness of the ceramic disc is between 5mm and 15mm.

4. The thin film circuit ceramic single-side polishing method according to claim 1, wherein In the step three, the thickness tolerance fluctuation of the ceramic substrate is less than ±15µm.

5. The thin film circuit ceramic single-side polishing method according to claim 1, wherein In the step one, 3-8 ceramic substrates are symmetrically pasted on the ceramic disc.

6. The thin film circuit ceramic single-side polishing method according to claim 1, wherein The surface flatness of the ceramic disc is not greater than 2µm.

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