Technological method for eliminating solder paste from contaminating flash memory packaging substrate bonding pad
By spraying a water-soluble solder resist onto the pads of the wire bonding fingers to form a protective film, the problem of solder paste contaminating the wire bonding fingers is solved, ensuring the success of the wire bonding process and improving the packaging yield.
Patent Information
- Application Number
- CN202511104026.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-11-14
AI Technical Summary
In embedded 3D flash memory packaging technology, solder paste is easily contaminated with the pads of the bonding wire fingers during printing, which can lead to bonding failure after reflow soldering and poor packaging.
A water-soluble solder resist is sprayed onto the pads of the wire fingers and cured to form a protective film, preventing solder paste contamination. After reflow soldering, the solder resist is removed by rinsing with water, thus protecting the pads of the wire fingers.
It effectively prevents solder paste from contaminating the pads on the wire bonding fingers, ensuring smooth wire bonding and improving packaging yield.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of chip packaging technology, specifically a process method for eliminating solder paste contamination of flash memory packaging substrate pads. Background Technology
[0002] Currently, in the embedded 3D NAND flash memory packaging process, solder paste is printed onto the target pads. During solder paste printing, there is a problem where solder paste overflows from the mesh and drips onto the bonding pads. This contaminated solder paste then re-solders onto the bonding pads during reflow soldering, leading to subsequent bonding failures and poor packaging. Summary of the Invention
[0003] To overcome the shortcomings of the prior art, the present invention provides a process method for eliminating solder paste contamination of the flash memory packaging substrate pads.
[0004] To achieve the above objectives, a process method for eliminating solder paste contamination of flash memory package substrate pads is designed, comprising the following steps: S1 provides a substrate; S2, Spray solder resist on the solder pads of the wire bonding fingers; S3, Solder resist curing; S4, Print solder paste on the target pads for solder paste printing; S5, surface mount electronic components; S6, reflow soldering; S7, remove solder resist; S8, surface mount chip; S9, wire bonding, bonds the chip to the substrate.
[0005] The solder resist is selected as a water-soluble solder resist, and the solder resist is removed by washing with water in step S7.
[0006] In step S3, the cured solder resist forms a temporary protective film on the wire finger pads, which protects the wire finger pads and prevents solder paste from being soldered onto the wire finger pads during reflow soldering.
[0007] In step S5, the mounted electronic components include, but are not limited to, resistors and capacitors.
[0008] The pad printing process and wire bonding process are completed on the same side surface of the substrate.
[0009] Compared with the prior art, this invention prevents solder paste from getting onto the bonding pads of the bonding fingers during printing, thereby preventing failure in subsequent bonding processes and ensuring packaging yield. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the process of the present invention.
[0011] Figure 2 This is a flowchart of the present invention.
[0012] Figure 3 This is a schematic diagram of the prior art before the improvement of this invention. Detailed Implementation
[0013] The present invention will now be further described with reference to the accompanying drawings.
[0014] like Figures 1 to 2 As shown, the process for eliminating solder paste contamination of the flash memory package substrate pads in this embodiment includes the following steps: S1, Provide substrate 1; S2, Spray solder resist on the bonding finger pads 2; S3, Solder resist cures; S4, Print solder paste on the target pads 3 for solder paste printing; S5, Mount electronic components such as resistors and capacitors; S6, Reflow soldering; S7, Remove solder resist; S8, Mount chip 4; S9, Wire bonding, Bond chip 4 to substrate 1.
[0015] In this embodiment, a water-soluble solder resist is selected, and the solder resist is removed by washing with water in step S7.
[0016] In step S3, the cured solder resist forms a temporary protective film on the wire finger pad 2, which protects the wire finger pad 2 and prevents the solder paste from being soldered onto the wire finger pad 2 during reflow soldering.
[0017] In this embodiment, the pad printing process and the wire bonding process are completed on the same side surface of the substrate 1.
[0018] This invention utilizes a water-soluble solder resist to temporarily protect the bonding pads 2 of the bonding fingers, preventing solder paste from adhering to the bonding pads and facilitating the removal of the solder resist by washing in subsequent processes, thus removing the solder paste that has fallen onto the solder resist film and reducing the impact on subsequent bonding processes.
Claims
1. A process for eliminating solder paste contamination of flash memory package substrate pads, characterized in that: Includes the following steps: S1, providing a substrate (1); S2, apply solder resist to the solder pad (2) of the solder wire finger; S3, Solder resist curing; S4, Print solder paste on the target pad (3) for solder paste printing; S5, surface mount electronic components; S6, reflow soldering; S7, remove solder resist; S8, chip mounting (4); S9, wire bonding, bonding the chip (4) to the substrate (1).
2. The process method for eliminating solder paste contamination of flash memory package substrate pads according to claim 1, characterized in that: The solder resist is selected as a water-soluble solder resist, and the solder resist is removed by washing with water in step S7.
3. The process method for eliminating solder paste contamination of flash memory package substrate pads according to claim 1, characterized in that: In step S3, the cured solder resist forms a temporary protective film on the wire finger pad (2), which protects the wire finger pad (2) and prevents the solder paste from being soldered onto the wire finger pad (2) during the reflow soldering process.
4. The process method for eliminating solder paste contamination of flash memory package substrate pads according to claim 1, characterized in that: In step S5, the mounted electronic components include, but are not limited to, resistors and capacitors.
5. The process method for eliminating solder paste contamination of flash memory package substrate pads according to claim 1, characterized in that: The pad printing process and wire bonding process are completed on the same side surface of the substrate (1).