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A method to reduce the warpage of multi-layer board

A warpage, multi-layer board technology, used in printed circuits, electrical components, printed circuit manufacturing, etc., can solve the problems of reduced resin fluidity, increased viscosity, and obvious influence of warpage of finished boards, so as to reduce warpage. degree, reduce the degree of board warpage, and improve the effect of placement difficulties

Active Publication Date: 2019-03-05
SHENZHEN SUNTAK MULTILAYER PCB
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The lamination process in the prior art adopts a continuous high-pressure lamination method, such as figure 1 As shown, during the transition stage of the resin from the molten state to the glass state, the fluidity of the resin decreases and the viscosity increases. If the internal stress accumulates and concentrates during this process, it is easy to cause the laminated board to warp. The stress cannot be fully released, which has a significant impact on the warpage of the finished board, exceeding the acceptance standard of 0.75%.
The warpage of the circuit board will prevent the insertion and placement of electronic components from being carried out smoothly, and it will also make some solder joints not in contact with the solder surface, resulting in solder failure. In addition to disc tightness, the stress caused by warpage may also cause the contact to break and cause the product to be scrapped

Method used

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  • A method to reduce the warpage of multi-layer board
  • A method to reduce the warpage of multi-layer board

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The inner core board, outer copper foil and prepreg are cut according to the predetermined size, and then cleaned, browned and stacked by conventional means, followed by hot pressing. During the hot pressing process, the hot pressing temperature is controlled at 140-220°C.

[0019] Such as figure 2 As shown, in this embodiment, the hot pressing adopts high and low pressure pulse pressurization for pressing, and the high and low pressure pulse pressurization includes a continuous initial step-up step-up section, a first step-down section, At least three pulse-type pressurization processes, the pressure of the initial step-up step-up section increases from 100-140KPa to 300-400KPa, and the boost time is 100-160min; the first step-down section drops from 300-400KPa to 100-140KPa, the depressurization time is 3-6min; the low pressure is 100-140KPa, and the high pressure is 300-400KPa in the pulse pressurization process.

[0020] Wherein, the stepped boosting section inclu...

Embodiment 2

[0025] The inner core board, outer copper foil and prepreg are cut according to the predetermined size, and then cleaned, browned and stacked by conventional means, followed by hot pressing. During the hot pressing process, the hot pressing temperature is controlled at 140-220°C.

[0026] In this embodiment, the hot pressing adopts a high and low pressure pulse pressurization method for pressing, and the high and low pressure pulse pressurization includes a continuous initial step-up step-up section, a first step-down section, at least three In the pulse pressurization process, the pressure in the initial step-up step-up section increases from 100-140KPa to 300-400KPa, and the boost time is 100-160min; the first step-down section drops from 300-400KPa to 100-140KPa , the depressurization time is 3-6min; the low pressure is 100-140Kpa and the high pressure is 300-400KPa in the pulse pressurization process.

[0027] Wherein, the stepped boosting section includes an initial kiss ...

Embodiment 3

[0032]The inner core board, outer copper foil and prepreg are cut according to the predetermined size, and then cleaned, browned and stacked by conventional means, followed by hot pressing. During the hot pressing process, the hot pressing temperature is controlled at 140-220°C.

[0033] In this embodiment, the hot pressing adopts a high and low pressure pulse pressurization method for pressing, and the high and low pressure pulse pressurization includes a continuous initial step-up step-up section, a first step-down section, at least three In the pulse pressurization process, the pressure in the initial step-up step-up section increases from 100-140KPa to 300-400KPa, and the boost time is 100-160min; the first step-down section drops from 300-400KPa to 100-140KPa , the depressurization time is 3-6min; the low pressure is 100-140Kpa and the high pressure is 300-400KPa in the pulse pressurization process.

[0034] Wherein, the stepped boosting section includes an initial kiss p...

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Abstract

The invention discloses a method for reducing the warping degree of a multilayer board. The method comprises a hot-pressing procedure, press-fitting is performed in a high and low pressure pulse type pressurization manner during hot-pressing, and high and low pressure pulse type pressurization includes a starting step-wise pressure increasing section, a first pressure reducing section and at least three pulse type pressurization processes. A traditional continuous high pressure press-fitting manner is changed into the high and low pressure pulse type pressurization press-fitting manner, internal stress release windows of a high-layer board can be increased in the manner, most internal stress is released in a high-temperature environment, the warping degree of the board is reduced, and warpage of the press-fit board is effectively controlled to be lower than or equal to 0.75%, so that product quality problems of difficulty in attachment, difficulty in tin soldering, breakage of joints and the like caused by warping of a circuit board are significantly solved.

Description

technical field [0001] The invention belongs to the technical field of printed circuit board production, and relates to a multilayer laminated board, in particular to a method for reducing the warpage of a multilayer board. Background technique [0002] During the pressing process of the printed circuit board, the resin is cured and molded by high temperature and high pressure, and the laminated molding process of the high-layer board is completed. The lamination process in the prior art adopts a continuous high-pressure lamination method, such as figure 1 As shown, during the transition stage of the resin from the molten state to the glass state, the fluidity of the resin decreases and the viscosity increases. If the internal stress accumulates and concentrates during this process, it is easy to cause the laminated board to warp. The stress cannot be completely released, which has a significant impact on the warpage of the finished board, which exceeds the acceptance stand...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H05K3/00
CPCH05K3/0014H05K2203/0278H05K2203/068
Inventor 喻恩赵波周文涛
Owner SHENZHEN SUNTAK MULTILAYER PCB