A large size DCB substrate sintering process

Abstract

The application relates to the technical field of bonding processing. A sintering process for a large-size DCB substrate, an oxidation process is performed on a copper foil, the oxidized copper foil is covered on a ceramic substrate to perform a sintering process, and a copper-clad ceramic mother plate is obtained; the size of the copper-clad ceramic mother plate is 5.5*9.0 inch; during the oxidation process, three oxidation temperature rising zones, five oxidation constant temperature zones and three oxidation temperature dropping zones are sequentially arranged from front to back along a conveying direction, the three oxidation temperature rising zones are sequentially a first oxidation temperature rising zone, a second oxidation temperature rising zone and a third oxidation temperature rising zone from front to back, the second oxidation temperature rising zone and the third oxidation temperature rising zone are connected with oxygen, the oxygen content of the second oxidation temperature rising zone is 580-600 ppm, and the oxygen content of the third oxidation temperature rising zone is 780-800 ppm. The application improves the utilization rate of raw materials, and solves the problems of many bubbles and low yield during sintering of the large-size mother plate.

Description

Technical Field

[0001] This invention relates to the field of DCB substrate manufacturing, and specifically to the sintering process of DCB substrates. Background Technology

[0002] Currently, the largest DCB substrate motherboard size that can be produced is 5.5×7.5 inches. This size motherboard is sintered first, and then slit into smaller products in subsequent processes. However, as smaller products increasingly require high current and high voltage applications, their dimensions also need to increase. This reduces the number of smaller products that can be arranged on the original motherboard size, leading to more material waste in the edge areas during layout or layout difficulties, thus increasing production costs. Increasing the size of the substrate motherboard, however, results in a lower sintering yield due to limitations in sintering technology, making normal production impossible.

[0003] There is an urgent need for a sintering process suitable for sintering motherboards with a size of 5.5×9.0 inches. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a sintering process for large-size DCB substrates, which solves at least one of the aforementioned technical problems.

[0005] The technical solution of the present invention is: a sintering process for a large-size DCB substrate, characterized in that an oxidation process is performed on copper foil, and the oxidized copper foil is covered on a ceramic substrate for sintering to obtain a copper-clad ceramic motherboard.

[0006] The copper-clad ceramic motherboard measures 5.5 x 9.0 inches.

[0007] During the oxidation process, three oxidation heating zones, five oxidation constant temperature zones, and three oxidation cooling zones are arranged sequentially from front to back along the conveying direction. The three oxidation heating zones are, from front to back, the first oxidation heating zone, the second oxidation heating zone, and the third oxidation heating zone. Oxygen is introduced into the second and third oxidation heating zones. The oxygen content in the second oxidation heating zone is 580-600 ppm, and the oxygen content in the third oxidation heating zone is 780-800 ppm.

[0008] During the sintering process, six sintering heating zones, seven sintering constant temperature zones, and three sintering cooling zones are arranged sequentially from front to back along the conveying direction.

[0009] More preferably, the temperature of the first oxidation heating zone is 495–500°C;

[0010] The temperature of the second oxidation heating zone is 665–670°C;

[0011] The temperature of the third oxidation heating zone is 775–780°C.

[0012] Further preferably, the total time for the three oxidation heating zones is 8–11 min.

[0013] Further preferred, the temperature of the five oxidation isothermal zones is 795–800°C.

[0014] Further preferred, the total time for the five oxidation isothermal zones is 15-18 minutes.

[0015] More preferably, the temperatures of the three oxidation cooling zones are 775–785°C, 675–685°C, and 645–655°C respectively along the conveying direction;

[0016] The total time for the three oxidation cooling zones is 8-11 minutes.

[0017] More preferably, the temperatures of the six sintering heating zones along the conveying direction are 595–600℃, 675–680℃, 755–760℃, 855–860℃, 935–940℃, and 1025–1030℃, respectively.

[0018] The total time for the six sintering heating zones is 14–17 minutes.

[0019] Further preferably, the temperature of the seven sintering isothermal zones is 1090–1095°C;

[0020] The total time for the seven sintering isothermal zones is 16-19 minutes.

[0021] More preferably, the temperatures of the three sintering cooling zones are 1035–1040°C, 975–980°C, and 945–950°C respectively along the conveying direction;

[0022] The total time for the three sintering cooling zones is 6–8 minutes.

[0023] More preferably, the conveying rate for both the oxidation and sintering processes is 170 mm / min.

[0024] Beneficial effects:

[0025] This invention improves the utilization rate of raw materials by increasing the number of small products arranged on the mother plate, while solving the problem of many bubbles and low yield during the sintering of large-size mother plates. Detailed Implementation

[0026] Specific embodiment 1, a large-size DCB substrate sintering process, involves oxidizing copper foil, covering the oxidized copper foil onto a ceramic substrate, and then sintering to obtain a copper-clad ceramic motherboard; the copper-clad ceramic motherboard has a size of 5.5 × 9.0 inches;

[0027] During the oxidation process, three oxidation heating zones, five oxidation isothermal zones, and three oxidation cooling zones are arranged sequentially from front to back along the conveying direction. The three oxidation heating zones are, from front to back, the first oxidation heating zone, the second oxidation heating zone, and the third oxidation heating zone. Oxygen is introduced into the second and third oxidation heating zones. The oxygen content in the second oxidation heating zone is 580-600 ppm, and the oxygen content in the third oxidation heating zone is 780-800 ppm.

[0028] The temperature of the first oxidation heating zone is 495–500℃, the temperature of the second oxidation heating zone is 665–670℃, and the temperature of the third oxidation heating zone is 775–780℃. The total time for the three oxidation heating zones is 8–11 minutes.

[0029] The temperature of the five oxidation isothermal zones ranged from 795 to 800℃. The total time for the five oxidation isothermal zones was 15-18 minutes.

[0030] The temperatures of the three oxidation cooling zones are 775–785℃, 675–685℃, and 645–655℃ respectively along the conveying direction; the total time for the three oxidation cooling zones is 8–11 minutes.

[0031] During the sintering process, six sintering heating zones, seven sintering constant temperature zones, and three sintering cooling zones are arranged sequentially from front to back along the conveying direction.

[0032] The temperatures of the six sintering heating zones along the conveying direction are 595–600℃, 675–680℃, 755–760℃, 855–860℃, 935–940℃, and 1025–1030℃, respectively; the total time for the six sintering heating zones is 14–17 minutes.

[0033] The temperature of the seven sintering isothermal zones is 1090–1095℃; the total time for the seven sintering isothermal zones is 16–19 min. The temperatures of the three sintering cooling zones are 1035–1040℃, 975–980℃, and 945–950℃ respectively along the conveying direction; the total time for the three sintering cooling zones is 6–8 min.

[0034] The long side of the product is parallel to the conveying direction.

[0035] 1) Heating Zone

[0036]

[0037] 2) Constant temperature zone

[0038]

[0039] 3) Cooling Zone

[0040]

[0041] Comparative Example 1: The original specification product (5.5×7.5 inch) motherboard was subjected to oxidation and sintering processes in sequence;

[0042] During the oxidation process, three oxidation heating zones, five oxidation constant temperature zones, and three oxidation cooling zones are arranged sequentially from front to back along the conveying direction. The three oxidation heating zones are, from front to back, the first oxidation heating zone, the second oxidation heating zone, and the third oxidation heating zone. Oxygen is introduced into the third oxidation heating zone, and the oxygen content in the third oxidation heating zone is 780-800 ppm.

[0043] The temperature of the first oxidation heating zone is 495–500℃, the temperature of the second oxidation heating zone is 665–670℃, and the temperature of the third oxidation heating zone is 775–780℃. The total time for the three oxidation heating zones is 8–11 minutes.

[0044] The temperature of the five oxidation isothermal zones ranged from 795 to 800℃. The total time for the five oxidation isothermal zones was 15-18 minutes.

[0045] The temperatures of the three oxidation cooling zones are 775–785℃, 675–685℃, and 645–655℃ respectively along the conveying direction; the total time for the three oxidation cooling zones is 8–11 minutes.

[0046] During the sintering process, seven sintering heating zones, five sintering constant temperature zones, and four sintering cooling zones are arranged sequentially from front to back along the conveying direction.

[0047] The temperatures of the seven sintering heating zones along the conveying direction are 575–580℃, 655–660℃, 735–740℃, 835–840℃, 915–920℃, 1005–1010℃, and 1030–103℃, respectively; the total time for the six sintering heating zones is 16–19 minutes.

[0048] The temperature of the five sintering isothermal zones was 1090–1095℃; the total time for the five sintering isothermal zones was 11–14 min.

[0049] The temperatures of the four sintering cooling zones, along the conveying direction, are 1035–1040℃, 995–1000℃, 965–970℃, and 915–920℃, respectively. The total time for the four sintering cooling zones is 9–11 minutes.

[0050] 1) Heating Zone

[0051]

[0052] 2) Constant temperature zone

[0053]

[0054] 3) Cooling Zone

[0055]

[0056] The performance comparison between Specific Example 1 and Comparative Example 1 is as follows:

[0057]

[0058] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A sintering process for large-size DCB substrates, characterized in that, The copper foil is oxidized, and the oxidized copper foil is then covered on a ceramic substrate and sintered to obtain a copper-clad ceramic motherboard. The copper-clad ceramic motherboard measures 5.5 x 9.0 inches. During the oxidation process, three oxidation heating zones, five oxidation constant temperature zones, and three oxidation cooling zones are arranged sequentially from front to back along the conveying direction. The three oxidation heating zones are, from front to back, the first oxidation heating zone, the second oxidation heating zone, and the third oxidation heating zone. Oxygen is introduced into the second and third oxidation heating zones. The oxygen content in the second oxidation heating zone is 580-600 ppm, and the oxygen content in the third oxidation heating zone is 780-800 ppm. During the sintering process, six sintering heating zones, seven sintering constant temperature zones, and three sintering cooling zones are arranged sequentially from front to back along the conveying direction.

2. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The temperature of the first oxidation heating zone is 495–500°C; The temperature of the second oxidation heating zone is 665–670°C; The temperature of the third oxidation heating zone is 775–780°C.

3. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The total time for the three oxidation heating zones is 8–11 min.

4. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The temperatures of the five oxidation isothermal zones range from 795 to 800°C.

5. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The total time for the five oxidation isothermal zones is 15-18 minutes.

6. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The temperatures of the three oxidation cooling zones are 775–785℃, 675–685℃, and 645–655℃ respectively along the conveying direction; The total time for the three oxidation cooling zones is 8-11 minutes.

7. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The temperatures of the six sintering heating zones along the conveying direction are 595–600℃, 675–680℃, 755–760℃, 855–860℃, 935–940℃, and 1025–1030℃, respectively. The total time for the six sintering heating zones is 14–17 minutes.

8. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The temperature of the seven sintering isothermal zones was 1090–1095℃. The total time for the seven sintering isothermal zones is 16-19 minutes.

9. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The temperatures of the three sintering cooling zones are 1035–1040℃, 975–980℃, and 945–950℃ respectively along the conveying direction; The total time for the three sintering cooling zones is 6–8 minutes.

10. The sintering process for a large-size DCB substrate according to claim 1, characterized in that: The conveying rate for both the oxidation and sintering processes is 170 mm / min.

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