A double-sided blind cavity structure HTCC tube shell product and a preparation method thereof
By constructing double-sided blind cavity HTCC shell products through mechanical drilling and milling, the problem of bulging or warping at the double-sided blind cavity position is solved, achieving a high-quality cavity structure and a high yield rate, meeting the needs of high-density integrated assembly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING INST OF RADIO MEASUREMENT
- Filing Date
- 2026-04-21
- Publication Date
- 2026-07-14
AI Technical Summary
Existing HTCC manufacturing processes suffer from bulging or warping at the double-sided blind cavity position when preparing double-sided blind cavity HTCC shell structures, resulting in poor cavity structure flatness and low product qualification rate.
The double-sided blind cavity is constructed by mechanical drilling and milling. The green ceramic blank is fixed by a clamping fixture, and the blind cavity on the front and back sides is mechanically formed. The micro-holes, hanging holes and conductor patterns are processed by HTCC process, and finally thermal cutting and sintering are performed.
It significantly improves the cavity quality and overall pass rate of double-sided blind cavity products, ensures the flatness and consistency of the products, meets the requirements of high-density integrated assembly, and improves assembly efficiency and quality.
Smart Images
Figure CN122380871A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of process technology for shell and tube products, and in particular relates to an HTCC shell and tube product with a double-sided blind cavity structure and its preparation method. Background Technology
[0002] High-Temperature Co-fired Ceramic (HTCC) is a three-dimensional interconnect structure formed by sintering multilayer ceramic strips with refractory metals at temperatures above 1500℃. Due to its low dielectric loss, chemical stability, high mechanical strength, and high thermal conductivity, it is widely used in high-frequency, high-power TR modules. Typically, the double-sided blind cavity portion of the HTCC shell requires the mounting of molybdenum-copper and the chip to meet the product's high heat dissipation requirements. Therefore, the flatness and consistency of the HTCC blind cavity structure directly determine the reliability of the subsequent shell assembly. For high thermal conductivity requirements, conventional HTCC processes (first forming a single-layer green ceramic cavity, then laminating the wafers) often result in bulging or warping at the double-sided blind cavity position, leading to poor shell cavity structure flatness and low product yield. Summary of the Invention
[0003] The purpose of this invention is to provide a double-sided blind cavity structure HTCC shell product and its preparation method, which can significantly improve the cavity quality and overall qualification rate of double-sided blind cavity products.
[0004] To achieve the above objectives, one aspect of the present invention provides a method for manufacturing a double-sided blind cavity structure HTCC shell product, comprising: Provide green ceramic tapes from the first to the eighth layers, process electrical interconnection vias on each layer of green ceramic tape, and fill the electrical interconnection vias with metal paste using a screen printing machine; The front and back conductor patterns of the first to eighth layers of green ceramic tape are printed using a screen printing machine; The green porcelain strips are stacked in the order of the first to the eighth layers. After stacking, they are laminated using an isostatic press to form a green porcelain body. The first layer of the green porcelain blank is placed upward and fixed in the first clamping fixture. The first clamping fixture is placed and fixed on the worktable of the mechanical drilling and milling equipment. The mechanical drilling and milling equipment is used to mechanically form the front blind cavity. The eighth layer of the green porcelain blank is placed with its back side facing up and fixed in the second clamping fixture. The second clamping fixture is placed and fixed on the worktable of the mechanical drilling and milling equipment, and the mechanical drilling and milling equipment is used to mechanically form the back blind cavity. The green ceramic blank is thermally cut to obtain unit products, and the cut tube shell products are placed in an HTCC sintering furnace for sintering.
[0005] Another aspect of the present invention provides an HTCC shell product with a double-sided blind cavity structure, which is prepared using the method described above.
[0006] According to the above-described aspects of the HTCC shell product with double-sided blind cavity structure and its preparation method, the double-sided blind cavity of the product is constructed sequentially by mechanical drilling and milling, which can significantly improve the cavity quality and overall qualification rate of double-sided blind cavity products. Attached Figure Description
[0007] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a top view of an HTCC tube shell product with a double-sided blind cavity structure according to an embodiment of the present invention; Figure 2 for Figure 1 Sectional view of AA in the middle; Figure 3 This is a schematic diagram of the first positioning tool used in forming a front blind cavity according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the second positioning tool used in the back blind cavity molding according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the gasket used in the thermal cutting of a tube shell product according to an embodiment of the present invention. Detailed Implementation
[0008] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0009] One embodiment of the present invention provides a method for manufacturing a double-sided blind cavity structure HTCC casing product. The double-sided blind cavity structure HTCC casing product prepared using the method of this embodiment is as follows: Figure 1 and Figure 2As shown, the green ceramic strip 1 comprises layers 1 to 8, with blind cavity structures on both the front and back sides. The blind cavities on the front and back sides are not interconnected. The front blind cavity structure 2 exists in layers 1 to 4 of the green ceramic strip, and the back blind cavity structure 3 exists in layers 7 to 8 of the green ceramic strip. The method of this embodiment includes the following steps S1 to S11.
[0010] Step S1, Micro-hole processing: First to eighth layers of green ceramic tape are provided. A mechanical punching machine is used to process electrical interconnection through-holes 4, printing alignment holes, cavity forming alignment holes, and stacking alignment holes on each layer of green ceramic tape. In this embodiment, the thickness of the first to fifth layers of green ceramic tape is 196 μm, and the thickness of the sixth to eighth layers is 260 μm. The size of each layer of green ceramic tape is 203*203 mm (eight inches). A multi-in-one method is used for layout; before subsequent stacking, an ultraviolet laser is used to divide each green ceramic tape into four four-inch green ceramic sheets.
[0011] Step S2, Micro-hole filling: Use a screen printing machine to fill the electrical interconnection through holes with metal pastes such as W and Mo. The drying temperature after filling the first to fifth green ceramic tapes is 55℃ and the holding temperature is 15min. The drying temperature after filling the sixth to eighth green ceramic tapes is 55℃ and the holding temperature is 25min. All green ceramic tapes need to be leveled after drying.
[0012] Step S3, Hanging Hole Forming: Use an ultraviolet laser device to process hanging holes on the sixth to eighth layers of green ceramic tape to form metal hanging holes 6. The laser parameters are power 4.5~5.5W, pulse frequency 45~60Hz, cutting speed 500~700mm / s, processing method is selected as inward processing, and path width is set to 15~25um.
[0013] Step S4, Hole Filling: Use a screen printing machine to print holes on the sixth to eighth layers of green ceramic tape. Then transfer the green ceramic tape to a hole-filling device to remove the paste outside the hole sidewalls. The stencil thickness used in the process is 50um, and vacuum adsorption is performed for 30s. Finally, the printed paste on the hole sidewalls is dried at a temperature of 55℃ for 15min. Step S5, Conductor Printing: The front and back metal conductor patterns 5 and solder resist patterns of the first to eighth layers of green ceramic tape are printed using a screen printing machine. The drying temperature of the conductor patterns and solder resist patterns is 55°C, and the temperature is maintained for 15 minutes.
[0014] Step S6, ceramic tile segmentation: Each layer of green ceramic tape is segmented into four four-inch green ceramic tiles using an ultraviolet laser device. The main parameters of the laser during segmentation are: power 4.5~5.5W, pulse frequency 45~60Hz, and cutting speed 500~700mm / s.
[0015] Step S7, Lamination: Take one four-inch green ceramic tile from step S6 and stack them in the order of the first to the eighth layer. After stacking, use an isostatic press to laminate the tiles. The lamination parameters are: temperature 60℃, pressure 1400psi, preheating for 6 minutes, holding pressure for 12 minutes, and lamination method is isostatic pressing.
[0016] Step S8, Frontal Blind Cavity Forming: Take the stacked green porcelain blank from Step S7, and place it with the first layer facing upwards. Figure 3 The first positioning fixture is installed in the positioning groove 8 of the first positioning fixture, and the first positioning pin 9 is installed in the positioning holes at the four corners of the green ceramic blank. The first positioning fixture is placed on the worktable of the mechanical drilling and milling equipment and fixed by the second positioning pin 7. The worktable is a separately controllable table with vacuum adsorption to better fix the product to be processed. The size of the positioning groove 8 on the first positioning fixture is 100~150um larger than the size of the laminated green ceramic blank. Vacuum adsorption is started, and the blank is adsorbed by the suction hole 10 on the first positioning fixture. After automatic identification and alignment by the mechanical drilling and milling equipment, the front blind cavity of the first to fourth layers of green ceramic is mechanically formed. The machining parameters of the drill bit during the front blind cavity forming are: the spindle speed of the drill bit is 40000rpm, and the feed rate is 4~7mm / s; the machining parameters of the milling cutter are: the spindle speed of the milling cutter is 60000rpm, and the feed rate is 6~10mm / s.
[0017] Step S9, Backside Blind Cavity Forming: Place the green porcelain blank processed in step S8, with the back side facing upwards, on the eighth layer. Figure 4 In the second positioning fixture shown, after installing the first positioning pin 9 in the positioning groove 8, the second positioning fixture is placed on the worktable of the mechanical drilling and milling equipment. The difference between the second and first positioning fixtures is that the second positioning fixture also has a support boss 11 for the front blind cavity of each tube shell unit. The size of the support boss 11 is 50-100 μm smaller than the size of the front blind cavity. After fixing the blank to the second positioning fixture using the first positioning pin 9, tape is used to attach it around the blank. Both the first and second positioning fixtures are made of FR4 and are assembled after being processed by ultraviolet laser. Vacuum adsorption is started, and the blank is adsorbed using the suction hole 10 on the second positioning fixture. After the mechanical drilling and milling equipment automatically identifies and aligns the blank, the back blind cavity of the seventh and eighth layers of green ceramic is mechanically formed. The machining parameters for the back blind cavity are different from those for the front blind cavity. When forming the back blind cavity, the machining parameters for the drill bit are: the drill spindle speed is 40,000 rpm and the feed rate is 2~4 mm / s; the machining parameters for the milling cutter are: the milling cutter spindle speed is 60,000 rpm and the feed rate is 3~5 mm / s.
[0018] The drill bit used for forming the front and back blind cavities is, for example, a 1.5 mm diameter spiral drill bit, and the end mill is, for example, a 1 mm diameter profile end mill.
[0019] Step S10, Hot Cutting: The laminated blank from step S9 is hot-cut. During cutting, the first layer of the blank is placed upwards on the pad film, then placed on the cutting machine table. The cutting temperature is 60℃, preheated for 10 minutes, and the cutting depth is 5-10µm less than the thickness of the pad film below the blank. A 50µm Malan film is selected as the pad film. Figure 5 As shown, the vent holes 12 on the pad film need to be avoided in the product cavity during processing, that is, they only exist in the non-cavity positions of the product, to prevent the cavity from deforming or collapsing when the vacuum adsorption is activated after the product is heated.
[0020] Step S11, High-temperature sintering: The unit products cut in step S10 are placed one by one on the sintering plate, and then placed in an HTCC sintering furnace for debinding and sintering. The maximum sintering temperature is 1550℃.
[0021] In summary, according to the embodiments of the present invention, the HTCC shell product with a double-sided blind cavity structure and its preparation method are characterized by the following: the blind cavity structure is processed by mechanical drilling and milling, while the other parts are mainly processed using HTCC technology, including the construction of electrical interconnection through holes in the shell, the preparation of conductor circuits, and thermal cutting. First, the micro-holes, hanging holes, and conductor patterns are processed using HTCC technology. Then, after the green ceramic blank is fixed with the help of a clamping fixture, mechanical drilling and milling of the front and back blind cavity structures are realized, ultimately producing an HTCC shell product with good cavity flatness, high consistency, and the ability to meet the subsequent assembly quality requirements.
[0022] The HTCC shell product with double-sided blind cavity structure and its preparation method according to the embodiments of the present invention have the following beneficial effects: 1) Compared with the method of forming a single-layer green ceramic tile cavity and then stacking and laminating it, the preparation, installation and disassembly process of the stacking rubber mold is eliminated by the preparation method of the stacking rubber mold, which shortens the cavity forming time and improves efficiency; 2) Through the process method of the present invention, the cavity quality and overall qualification rate of double-sided blind cavity products are greatly improved, ensuring the assembly efficiency and assembly quality of the shell product in subsequent automated assembly, and meeting the requirements of high assembly consistency of current HTCC shell products under high-density integration.
[0023] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.
Claims
1. A method for manufacturing a double-sided blind cavity structure HTCC tube shell product, characterized in that, include: Provide green ceramic tapes from the first to the eighth layers, process electrical interconnection vias on each layer of green ceramic tape, and fill the electrical interconnection vias with metal paste using a screen printing machine; The front and back conductor patterns of the first to eighth layers of green ceramic tape are printed using a screen printing machine; The green porcelain strips are stacked in the order of the first to the eighth layers. After stacking, they are laminated using an isostatic press to form a green porcelain body. The first layer of the green porcelain blank is placed upward and fixed in the first clamping fixture. The first clamping fixture is placed and fixed on the worktable of the mechanical drilling and milling equipment. The mechanical drilling and milling equipment is used to mechanically form the front blind cavity. The eighth layer of the green porcelain blank is placed with its back side facing up and fixed in the second clamping fixture. The second clamping fixture is placed and fixed on the worktable of the mechanical drilling and milling equipment, and the mechanical drilling and milling equipment is used to mechanically form the back blind cavity. The green ceramic blank is thermally cut to obtain unit products, and the cut tube shell products are placed in an HTCC sintering furnace for sintering.
2. The method as described in claim 1, characterized in that, Mechanical punching machines are used to process electrical interconnection through holes, printed alignment holes, cavity forming alignment holes, and stacking alignment holes on each layer of green ceramic tape.
3. The method as described in claim 1 or 2, characterized in that, Each layer of green ceramic tape is eight inches in size. The method also includes using an ultraviolet laser device to divide each layer of green ceramic tape into four four-inch green ceramic sheets before stacking. When stacking, take one of the divided four-inch green ceramic sheets and stack the green ceramic sheets in the order of the first to the eighth layers.
4. The method as described in claim 1 or 2, characterized in that, The method further includes, after the metal paste filling and before the conductor pattern printing: Using ultraviolet laser equipment to process hanging holes in the sixth to eighth layers of green ceramic tape; The sixth to eighth layers of green ceramic tape are printed with hanging holes using a screen printing machine. The green ceramic tape is then transferred to a hanging hole device to remove the slurry outside the hanging hole sidewalls.
5. The method as described in claim 4, characterized in that, The laser parameters for hole drilling are: power 4.5~5.5W, pulse frequency 45~60Hz, cutting speed 500~700mm / s, processing method is inward processing, and path width is set to 15~25um.
6. The method as described in claim 1 or 2, characterized in that, The first and second positioning fixtures include a positioning groove, a first positioning pin, a second positioning pin, and a suction hole; The slotted groove is used to place the green porcelain blank, the first positioning pin is used to fix the four corners of the green porcelain blank, the second positioning pin is used to fix the first and second slotted fixtures to the worktable of the mechanical drilling and milling equipment, and the suction hole is used to vacuum adsorb the green porcelain blank.
7. The method as described in claim 1 or 2, characterized in that, The second positioning fixture also includes a support boss for supporting the front blind cavity of the tube shell unit. The size of the support boss is 50~100um smaller than the size of the front blind cavity.
8. The method as described in claim 1 or 2, characterized in that, The machining parameters for forming the front blind cavity are as follows: the spindle speed of the drill bit is 40,000 rpm, and the feed rate is 4~7 mm / s; the spindle speed of the end mill is 60,000 rpm, and the feed rate is 6~10 mm / s.
9. The method as described in claim 1 or 2, characterized in that, The machining parameters for forming the back blind cavity are as follows: the drill spindle speed is 40,000 rpm and the feed rate is 2~4 mm / s; the milling cutter spindle speed is 60,000 rpm and the feed rate is 3~5 mm / s.
10. The method as described in claim 1 or 2, characterized in that, During thermal cutting, the vent holes on the underside of the product should only exist in non-cavity locations of the product.
11. A double-sided blind cavity structure HTCC tube shell product, characterized in that, It is prepared using the method described in any one of claims 1-10.