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Method for forming convex point on back side of single side flexible sustrate

A flexible substrate, bump technology, applied in separation methods, microstructure devices composed of deformable elements, chemical instruments and methods, etc. Save time, maintain solid-state operations, good interconnect strength

Inactive Publication Date: 2006-10-04
HUAZHONG UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This kind of bump preparation method has the following disadvantages: it takes time to dry and harden after the photoresist is covered; the development and imaging process must make an additional mask, which increases the manufacturing cost; after the first reflow treatment, the photoresist must be chemically or physically removal, the whole process is tedious and time-consuming
Moreover, it is sometimes impossible to use this process for MEMS packaging, because some MEMS sensitive components require to maintain solid state operation.

Method used

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  • Method for forming convex point on back side of single side flexible sustrate
  • Method for forming convex point on back side of single side flexible sustrate
  • Method for forming convex point on back side of single side flexible sustrate

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Embodiment Construction

[0022] refer to figure 1 - The schematic diagram of the process of forming bumps on the back side of the single-sided flexible substrate shown in FIG. 6 . The substrate used in one embodiment of the present invention is a three-layer composite flexible substrate, such as figure 1 shown. Pads 1 or other electrodes, circuits and components are fixed on the front of the bottom flexible substrate 2, and the middle layer 3 is a rigid resin board, which can enhance the rigidity of the entire substrate, thereby making the substrate more operable. The outermost layer of the substrate is a synthetic tape 4, which is closely bonded to the middle layer, but is relatively easy to tear off directly, and has good heat resistance and stability. Referring to Figure 2-Figure 6, the specific manufacturing process is:

[0023] a. Using program-controlled laser positioning and drilling technology, in figure 1 Drill holes at the locations indicated by the dotted lines. The drilling completely...

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Abstract

A method for forming convex at the back of single-side flexible substrate applies complex flexible substrate composed of a flexible substrate and synthetic rubber belt surface layer with fixed soldered disk, electrode or elements on the front. The process steps are as follow: 1. to punch blind holes on complex flexible substrate with laser 2. to fill soldered paste to the blind holes with print plate 3. to melt the soldered paste to soldered ingot by high temperature reflow soldering 4. to eliminate the synthetic rubber belt surface 5. to solder to convex by second time of high temperature backflow soldering.

Description

technical field [0001] The invention belongs to the field of packaging of printed circuits and microelectronic components, and in particular relates to a packaging structure for introducing bumps on the back of a single-sided flexible substrate and a forming method for the bumps. Background technique [0002] The new generation of high-density packaging technology is dominated by surface array packaging, including Ball-Grid-Array (BGA), Chip-Scale-Package (CSP), Flip-Chip (Flip-Chip) ) technology, etc. The flip-chip packaging technology in a broad sense refers to flipping the chip and bonding it to the substrate through a metal conductor in a face-down manner to realize interconnection. The technology has also been introduced into the interconnect packaging of microelectromechanical systems (MEMS). MEMS devices often use a flexible substrate structure (FlexSubstrate) in the form of BGA to meet the needs of practical applications. One side of the flexible substrate can be ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L21/48H01L21/60H05K3/00B81B1/00B81B3/00
CPCH01L2224/11
Inventor 吴懿平吴丰顺张乐福崔昆邬博义谯锴郑宗林刘一波陈力
Owner HUAZHONG UNIV OF SCI & TECH