A copper clad ceramic substrate peel strength test sample and method of making same

Abstract

This invention provides a copper-clad ceramic substrate peel strength test sample and its preparation method. The preparation method includes the following steps: (1) a copper sheet is sequentially laminated, exposed, developed, and etched to obtain a copper strip; a ceramic sheet is cut to obtain a ceramic strip; (2) the copper strip and ceramic strip are sequentially combined in the order of first copper strip, ceramic strip, and second copper strip, and then sintered to obtain the copper-clad ceramic substrate peel strength test sample. The preparation method of this invention simplifies the test sample manufacturing process, the test sample obtained by sintering can be immediately subjected to peel strength testing, and improves the utilization rate of test materials, making it suitable for widespread application.

Description

Technical Field

[0001] This invention relates to the field of semiconductor substrate technology, and in particular to a copper-clad ceramic substrate peel strength test sample and its preparation method. Background Technology

[0002] A tensile test strip is a device used to test the bonding strength between copper and ceramic sheets in copper-clad ceramic substrates. The tensile test strip is made from a copper-clad ceramic substrate and shaped specifically to test the bonding strength between copper and ceramic. In a specific device, the bottom ceramic sheet is fixed, and the copper strip on the surface is pulled vertically upwards to obtain the bonding force. Dividing the bonding force by the width of the copper surface gives the peel strength of the copper-clad ceramic substrate.

[0003] The existing preparation process for peel strength test samples of copper-clad ceramic substrates involves sintering the entire product and then making the tensile strip. This process is cumbersome, requiring film application, exposure, development, etching, and cutting into specific strip shapes. The time from the end of sintering to the start of peel strength testing is relatively long. Using copper-clad ceramic substrates to make tensile strips is costly and has low product utilization.

[0004] CN221926079U discloses a ceramic copper-clad substrate structure for easy peel strength testing, including a ceramic sheet, a fixing copper sheet, and a testing copper sheet. The fixing copper sheet is U-shaped and its open end extends to the right along the length of the ceramic sheet. A testing copper sheet is also provided on the front side of the ceramic sheet, relative to the fixing copper sheet, along its length, with its right end extending beyond the open end of the fixing copper sheet, thus forming a short end for testing. The ceramic sheet is cut on both sides relative to the short end using a laser cutting machine. After separating the short end from the ceramic sheet, the short end is bent upwards and inwards at a 90° angle using a standard 90° peel tester. The peel strength can then be tested by vertically lifting the short end, which is then fixed in place by the fixing copper sheet. However, the production of the tensile strips on the aforementioned ceramic copper-clad substrate structure requires sintering followed by film application, exposure, development, etching, and cutting. The process from the end of sintering to the start of peel strength testing takes a long time. The cost of producing tensile strips on ceramic copper-clad substrates is high, and the utilization rate is low.

[0005] CN116223363A discloses a method for peel testing of copper-clad ceramic substrates, comprising the following steps: copper foil etching and solder etching are performed on both sides of the copper-clad ceramic substrate to form a substrate. The substrate includes a front copper foil layer, a substrate, and a back copper foil layer. Both the front and back copper foil layers include an A-side copper foil sheet and a B-side copper foil sheet. Laser cutting is performed on the substrate surface in contact with the B-side copper foil sheet. The cut substrate is divided into test pieces through a slitting process. Each test piece includes an A-side copper foil sheet, a substrate, and a B-side copper foil sheet. A tension strip is provided on the A-side copper foil sheet. The test piece is bent at a right angle to form a horizontal part and a vertical part. The horizontal part is inserted into the fixture of a peel testing machine for positioning. The clamp holds and pulls the vertical part upward to separate the tension strip from the substrate, thereby obtaining the peel strength tensile force. The above-mentioned method for peel testing of copper-clad ceramic substrates still suffers from the problem of complex test piece manufacturing process.

[0006] Therefore, it is of great significance to develop a simplified test sample manufacturing process for copper-clad ceramic substrates that allows for immediate testing of peel strength after sintering, as well as its preparation method. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention provides a copper-clad ceramic substrate peel strength test sample and its preparation method. First, copper strips and ceramic strips are prepared, and then they are combined in a specific order and sintered. The prepared copper-clad ceramic substrate peel strength test sample can be immediately tested for peel strength, which greatly improves the testing efficiency. Moreover, the copper-clad ceramic substrate peel strength test sample is simple to make and easy to operate, making it suitable for widespread application.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a copper-clad ceramic substrate peel strength test sample, the preparation method comprising the following steps: (1) Copper sheets are sequentially coated, exposed, developed and etched to obtain copper strips; ceramic sheets are cut to obtain ceramic strips; (2) The copper strip and the ceramic strip are combined in the order of first copper strip, ceramic strip and second copper strip and then sintered to obtain the peel strength test sample of the copper-clad ceramic substrate.

[0009] The method for preparing peel strength test samples for copper-clad ceramic substrates described in this invention eliminates the need to cut and remake existing sintered copper-clad ceramic substrate products, simplifying the sample preparation process, improving the utilization rate of test materials, and reducing testing costs. This invention sequentially processes copper sheets through lamination, exposure, development, and etching to obtain copper strips; ceramic sheets are cut to obtain ceramic strips, allowing for advance material preparation; then, two copper strips and one ceramic strip are arranged in a "sandwich" structure according to the order of first copper strip, ceramic strip, and second copper strip, followed by sintering. Peel strength testing can begin immediately after sintering, significantly improving the efficiency of peel strength testing for copper-clad ceramic substrates.

[0010] In the peel strength test of the copper-clad ceramic substrate described in this invention, the ceramic strip is fixed, and then force is applied to peel off the second copper strip. To avoid the ceramic strip cracking or breaking during the peeling process of the second copper strip, which would lead to test failure or inaccurate test data, a first copper strip is provided to make the ceramic strip more securely fixed.

[0011] The present invention does not specify the film used for the copper sheet in step (1) in detail; any film commonly used in the art can be used.

[0012] The present invention does not impose detailed limitations on the operation parameters of exposure, development, etching and ceramic sheet cutting after film application in step (1), and the operation parameters commonly used in the field can be adopted.

[0013] Preferably, the width of the first copper strip is 5 to 20 mm, for example, it can be 5 mm, 8 mm, 11 mm, 14 mm, 17 mm or 20 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] Preferably, the length of the first copper strip is 140~180mm, for example, it can be 140mm, 148mm, 156mm, 164mm, 172mm or 180mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] Preferably, the width of the second copper strip is 5 to 8 mm, for example, it can be 5 mm, 5.5 mm, 6 mm, 6.8 mm, 7.4 mm or 8 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, the width of the second copper strip in this invention is 5-8 mm. The width of the second copper strip cannot exceed the width of the first copper strip. The width of the second copper strip is the denominator in the calculation of peel strength, and its accuracy directly determines the accuracy of the final result. If the width of the second copper strip is too small, the edge effect will be significant, leading to distortion of the final peel strength data. If the width of the second copper strip is too large, the stress distribution at the peel front will be uneven, making the measured value unable to represent the true peel strength. The length of the second copper strip should be greater than or equal to the length of the first copper strip, and one end should protrude more than the first copper strip. If the length is too small, resulting in no protruding end, clamping tests will be impossible.

[0017] Preferably, the length of the second copper strip is 150~180mm, for example, it can be 150mm, 155mm, 160mm, 165mm, 170mm or 180mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, the width of the ceramic strip is 5 to 20 mm, for example, it can be 5 mm, 8 mm, 11 mm, 14 mm, 17 mm or 20 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Preferably, the length of the ceramic strip is 150~180mm, for example, it can be 150mm, 155mm, 160mm, 165mm, 170mm or 180mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] The preferred length of the ceramic strip in this invention is 150-180mm, which enables stable clamping of the copper-clad ceramic substrate peel strength test sample and ensures that the peel angle remains constant within the specified test length (e.g., 90° vertical peel). If the ceramic strip is too short, the actual peel angle may deviate from the set value (e.g., decreasing from 90°) due to changes in the stress point during the later stages of peeling, thus affecting the test results. Conversely, if the ceramic strip is too long, it leads to material waste and increases the cost of peel strength testing.

[0021] Preferably, the sintering temperature in step (2) is 830℃~950℃, for example, it can be 830℃, 850℃, 880℃, 900℃, 920℃, 940℃ or 950℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] Preferably, the sintering time in step (2) is 30 min to 70 min, for example, it can be 30 min, 40 min, 45 min, 50 min, 55 min, 60 min or 70 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] As a preferred technical solution of the present invention, the preparation method includes the following steps: (1) Copper sheets are sequentially coated, exposed, developed and etched to obtain copper strips; ceramic sheets are cut to obtain ceramic strips; (2) The copper strip and ceramic strip are combined in the order of first copper strip, ceramic strip and second copper strip and then sintered at a temperature of 830℃~950℃ for 30min~70min to obtain the copper-clad ceramic substrate peel strength test sample. The width of the first copper strip is 5~20mm, and the length is 140~180mm; The second copper strip has a width of 5-8mm and a length of 150-180mm; The width of the ceramic strip is 5~20mm and the length is 150~180mm.

[0024] In a second aspect, the present invention also provides a method for preparing a copper-clad ceramic substrate peel strength test sample as described in the first aspect.

[0025] The copper-clad ceramic substrate peel strength test sample of the present invention has a simple structure and a simple preparation method, which can quickly and accurately test the peel strength of the copper-clad ceramic substrate, and is suitable for widespread application.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects: The method for preparing peel strength test samples for copper-clad ceramic substrates provided by this invention is rationally designed and simple to operate. Prepared copper and ceramic strips are combined in a specific order and then sintered to obtain peel strength test samples for copper-clad ceramic substrates that can be tested immediately. This simplifies the sample preparation process, improves the utilization rate of copper-clad ceramic substrates, and reduces testing costs. Furthermore, the peel strength results obtained using these copper-clad ceramic substrate peel strength test samples are accurate and highly reliable. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the front structure of the copper-clad ceramic substrate peel strength test sample in Embodiment 1 of the present invention.

[0028] In the diagram: 1 - First copper strip; 2 - Ceramic strip; 3 - Second copper strip. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0031] It should be understood that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Example 1 This embodiment provides a method for preparing a copper-clad ceramic substrate peel strength test sample, the preparation method including the following steps: (1) Copper sheets are sequentially coated, exposed, developed and etched to obtain copper strips; ceramic sheets are cut to obtain ceramic strips; (2) The copper strip and ceramic strip are sequentially combined in the order of first copper strip 1, ceramic strip 2, and second copper strip 3, and then sintered at 900℃ for 50 minutes to obtain the copper-clad ceramic substrate peel strength test sample. A schematic diagram of the front structure of the copper-clad ceramic substrate peel strength test sample in this embodiment is shown below. Figure 1 As shown.

[0034] The first copper strip 1 has a width of 15mm and a length of 180mm. The second copper strip 3 has a width of 5mm and a length of 180mm; The ceramic strip 2 has a width of 10mm and a length of 150mm.

[0035] Example 2 This embodiment provides a method for preparing a copper-clad ceramic substrate peel strength test sample, the preparation method including the following steps: (1) Copper sheets are sequentially coated, exposed, developed and etched to obtain copper strips; ceramic sheets are cut to obtain ceramic strips; (2) The copper strip and ceramic strip are combined in the order of first copper strip, ceramic strip and second copper strip and then sintered at 830°C for 70 minutes to obtain the copper-clad ceramic substrate peel strength test sample. The first copper strip has a width of 5mm and a length of 180mm; The second copper strip is 5mm wide and 150mm long; The ceramic strip is 5mm wide and 150mm long.

[0036] Example 3 This embodiment provides a method for preparing a copper-clad ceramic substrate peel strength test sample, the preparation method including the following steps: (1) Copper sheets are sequentially coated, exposed, developed and etched to obtain copper strips; ceramic sheets are cut to obtain ceramic strips; (2) The copper strip and ceramic strip are combined in the order of first copper strip, ceramic strip and second copper strip and then sintered at 950°C for 30 minutes to obtain the copper-clad ceramic substrate peel strength test sample. The first copper strip has a width of 20mm and a length of 170mm; The second copper strip is 8mm wide and 150mm long; The ceramic strip is 20mm wide and 150mm long.

[0037] Based on Examples 1-3, it can be concluded that the preparation method of the copper-clad ceramic substrate peel strength test sample provided by the present invention is reasonably designed and simple to operate. The prepared copper strips and ceramic strips are combined in a specific order and then sintered. The resulting copper-clad ceramic substrate peel strength test sample can be immediately tested for peel strength, which simplifies the test sample preparation process, improves the utilization rate of copper-clad ceramic substrates, and reduces testing costs.

[0038] Example 4 This embodiment provides a method for preparing a copper-clad ceramic substrate peel strength test sample. The preparation method is the same as in Embodiment 1, except that the width of the second copper strip is 2 mm.

[0039] Example 5 This embodiment provides a method for preparing a copper-clad ceramic substrate peel strength test sample. The preparation method is the same as in Embodiment 1, except that the width of the second copper strip is 10 mm.

[0040] It can be seen from the combined examples 1 and 4-5 that in example 4, the width of the second copper strip is too small, which leads to a greater impact of the edge effect and the final peel strength data is inaccurate; in example 5, the width of the second copper strip is too large, which leads to uneven stress distribution at the peel front, making the measured value unable to represent the true peel strength.

[0041] Example 6 This embodiment provides a method for preparing a sample for peel strength testing of a copper-clad ceramic substrate. The preparation method is the same as in Embodiment 1, except that the length of the ceramic strip is 130 mm.

[0042] Example 7 This embodiment provides a method for preparing a test sample for peel strength of a copper-clad ceramic substrate. The preparation method is the same as in Embodiment 1, except that the length of the ceramic strip is 200 mm.

[0043] As can be seen from Examples 1 and 6-7, the ceramic strip in Example 6 is relatively short, and the actual peeling angle deviates from the set value due to the change of the force point in the later stage of peeling, resulting in inaccurate peeling strength test results; the ceramic strip in Example 7 is relatively long, which leads to waste of ceramic strip material and increases the cost of peeling strength test.

[0044] Comparative Example 1 This comparative example provides a method for preparing a copper-clad ceramic substrate peel strength test sample. The preparation method is the same as in Example 1 except that the first copper strip is not set, that is, step (2) is replaced by directly combining the copper strip and the ceramic strip.

[0045] Because this comparative example does not include a first copper strip, the ceramic strip will break during the peel strength test, resulting in inaccurate peel strength test data for the copper-clad ceramic substrate.

[0046] In summary, the method for preparing the peel strength test sample of copper-clad ceramic substrate provided by the present invention is reasonably designed and simple to operate. It prepares a peel strength test sample of copper-clad ceramic substrate that can be tested immediately, simplifies the test sample preparation process, reduces testing costs, and the peel strength results obtained by using the peel strength test sample of copper-clad ceramic substrate are accurate and highly reliable, with broad prospects for wide-ranging application.

[0047] It should be noted that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a sample for testing the peel strength of a copper-clad ceramic substrate, characterized in that, The preparation method includes the following steps: (1) Copper sheets are sequentially coated, exposed, developed and etched to obtain copper strips; ceramic sheets are cut to obtain ceramic strips; (2) The copper strip and the ceramic strip are combined in the order of first copper strip, ceramic strip and second copper strip and then sintered to obtain the peel strength test sample of the copper-clad ceramic substrate.

2. The preparation method according to claim 1, characterized in that, Step (2) The width of the first copper strip is 5~20mm.

3. The preparation method according to claim 1 or 2, characterized in that, Step (2) The length of the first copper strip is 140~180mm.

4. The preparation method according to any one of claims 1 to 3, characterized in that, Step (2) The width of the second copper strip is 5~8mm.

5. The preparation method according to any one of claims 1 to 4, characterized in that, Step (2) The length of the second copper strip is 150~180mm.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The width of the ceramic strip in step (2) is 5~20mm.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The length of the ceramic strip in step (2) is 150~180mm.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The sintering temperature in step (2) is 830℃~950℃.

9. The preparation method according to any one of claims 1 to 8, characterized in that, The sintering time in step (2) is 30 min to 70 min.

10. A copper-clad ceramic substrate peel strength test sample prepared by the method of preparing a copper-clad ceramic substrate peel strength test sample according to any one of claims 1 to 9.

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