CN111885849A - QFP packaging chip welding method - Google Patents
QFP packaging chip welding method Download PDFInfo
- Publication number
- CN111885849A CN111885849A CN202010638734.8A CN202010638734A CN111885849A CN 111885849 A CN111885849 A CN 111885849A CN 202010638734 A CN202010638734 A CN 202010638734A CN 111885849 A CN111885849 A CN 111885849A
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- welding
- solder paste
- hole
- qfp
- steel mesh
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/341—Surface mounted components
- H05K3/3431—Leadless components
- H05K3/3442—Leadless components having edge contacts, e.g. leadless chip capacitors, chip carriers
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Electric Connection Of Electric Components To Printed Circuits (AREA)
Abstract
The invention provides a QFP packaging chip welding method in the technical field of chip welding, which comprises the following steps: preparing a welding steel mesh; placing the welding steel mesh on a PCB to be welded with the QFP packaging chip, and aligning the first through hole and the second through hole with a welding position; printing solder paste on the welding steel mesh, so that the solder paste permeates into the first through hole, the second through hole and the extension part; taking down the welding steel mesh from the PCB, and placing pins of the QFP packaging chip to be welded on solder paste of the PCB based on the welding position; and heating the solder paste on the PCB, adsorbing the grounding bonding pad upwards after the solder paste under the grounding bonding pad is heated, and fusing the solder paste under the pins with the pins after the solder paste is heated to complete the welding of the QFP packaging chip. The invention has the advantages that: the insufficient soldering rate of the QFP packaging chip is greatly reduced, and the product yield is improved.
Description
Technical Field
The invention relates to the technical field of chip welding, in particular to a QFP packaging chip welding method.
Background
With the integration of electronic chips becoming higher and higher, QFP packaging technology is in progress. QFP packages, which are Quad Flat packages (Quad Flat packages), are surface mount packages (smt) with four leads led out from four sides in a gull wing (L) shape, with small distance between the leads and thin pins, and are generally applied to large-scale or ultra-large-scale integrated circuits, and the number of the leads is generally over 100.
For the welding of the QFP packaged chip, a method of printing solder paste on a position to be welded by using a planar steel mesh is conventionally adopted. However, the conventional method has the following disadvantages: because the QFP packaging chip has a plurality of pins, the pins are not on the same plane with the grounding pad at the middle part, the pins are higher than the grounding pad by a certain distance, and the height difference exists, the grounding pad can not be effectively welded, and the false welding condition is easy to occur in the batch production process.
Therefore, how to provide a method for welding a QFP package chip to reduce the insufficient solder rate of the QFP package chip welding and improve the product yield is a problem to be solved urgently.
Disclosure of Invention
The invention aims to solve the technical problem of providing a QFP packaging chip welding method, which can reduce the false soldering rate of the welding of the QFP packaging chip and improve the product yield.
The invention is realized by the following steps: a QFP packaging chip welding method comprises the following steps:
preparing a welding steel mesh; the welding steel mesh is provided with a plurality of first through holes and a second through hole; the position of the first through hole corresponds to each pin of the QFP packaging chip, and the position of the second through hole corresponds to the grounding bonding pad of the QFP packaging chip; an extension part is arranged in the direction surrounding the second through hole; the height of the extension part is half of the height difference between the pins of the QFP packaging chip and the grounding bonding pad;
placing the welding steel mesh on a PCB to be welded with the QFP packaging chip, and aligning the first through hole and the second through hole with a welding position;
printing solder paste on the welding steel mesh, so that the solder paste permeates into the first through hole, the second through hole and the extension part;
taking down the welding steel mesh from the PCB, and placing pins of the QFP packaging chip to be welded on solder paste of the PCB based on the welding position;
and heating the solder paste on the PCB, adsorbing the grounding bonding pad upwards after the solder paste under the grounding bonding pad is heated, and fusing the solder paste under the pins with the pins after the solder paste is heated to complete the welding of the QFP packaging chip.
Further, the thickness of the welded steel mesh ranges from 0.1mm to 0.15 mm.
The invention has the advantages that:
through the first through-hole of a plurality of and a second through-hole are established to the welding steel mesh, encircle the second through-hole upwards establishes an extension, just the height of extension is half of QFP encapsulation chip's pin and ground connection pad difference in height, promptly the welding steel mesh is the echelonment, and the position height that corresponds the ground connection pad is higher, can print more tin cream for tin cream after the printing shortens to half original with the distance of ground connection pad, upwards adsorbs the ground connection pad when the tin cream is heating, accomplishes the welding of ground connection pad, adopts the plane steel mesh because the distance is too far effectively adsorbs the ground connection pad for the tradition, very big reduction QFP encapsulation chip welded rosin joint rate, promoted the product yield.
Drawings
The invention will be further described with reference to the following examples with reference to the accompanying drawings.
Fig. 1 is a flow chart of a method for welding a QFP package chip of the invention.
Fig. 2 is a schematic structural view of a welded steel mesh according to the present invention.
Fig. 3 is a side view of the welded steel mesh of the present invention.
Fig. 4 is a schematic structural diagram of a QFP packaged chip of the invention.
Description of the labeling:
1-solder mesh, 2-QFP package chip, 11-first via, 12-second via, 13-extension, 21-ground pad, 22-pin.
Detailed Description
The technical scheme in the embodiment of the application has the following general idea: the soldering steel net 1 is designed to be step-shaped, that is, an extension portion 13 is annularly arranged upwards outside the second through hole 12 corresponding to the ground pad 21, the height of the extension portion 13 is half of the height difference between the pin 22 of the QFP packaged chip 2 and the ground pad 21, the distance between the solder paste and the ground pad 21 is shortened to be half of the original distance, and the solder paste can better adsorb the ground pad 21 to complete soldering when being heated.
Referring to fig. 1 to 3, a preferred embodiment of a method for soldering a QFP packaged chip of the present invention includes the following steps:
preparing a welding steel mesh 1; the welding steel mesh 1 is provided with a plurality of first through holes 11 and a second through hole 12; the first through holes 11 correspond to the pins 22 of the QFP package chip 2, and the second through holes 12 correspond to the grounding pads 21 of the QFP package chip 2; an extension part 13 is arranged upwards around the second through hole 12; the height of the extension part 13 is half of the height difference between the pins 22 and the grounding pads 21 of the QFP package chip 2;
placing the welding steel mesh 1 on a PCB (not shown) of the QFP package chip 2 to be welded, and aligning the first through hole 11 and the second through hole 12 with the welding positions of the PCB;
printing solder paste on the soldering steel mesh 1, so that the solder paste permeates into the first through hole 11, the second through hole 12 and the extension part 13;
taking the welding steel mesh 1 off the PCB, and placing pins 22 of the QFP packaging chip 2 to be welded on solder paste of the PCB based on the welding position;
and heating the solder paste on the PCB, adsorbing the solder paste under the grounding pad 21 upwards after heating, and fusing the solder paste under the pin 22 with the pin 22 after heating to complete the welding of the QFP package chip 2.
The thickness of the welding steel net 1 ranges from 0.1mm to 0.15 mm.
In summary, the invention has the advantages that:
through the first through-hole of a plurality of and a second through-hole are established to the welding steel mesh, encircle the second through-hole upwards establishes an extension, just the height of extension is half of QFP encapsulation chip's pin and ground connection pad difference in height, promptly the welding steel mesh is the echelonment, and the position height that corresponds the ground connection pad is higher, can print more tin cream for tin cream after the printing shortens to half original with the distance of ground connection pad, upwards adsorbs the ground connection pad when the tin cream is heating, accomplishes the welding of ground connection pad, adopts the plane steel mesh because the distance is too far effectively adsorbs the ground connection pad for the tradition, very big reduction QFP encapsulation chip welded rosin joint rate, promoted the product yield.
Although specific embodiments of the invention have been described above, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the appended claims.
Claims (2)
1. A QFP packaging chip welding method is characterized in that: the method comprises the following steps:
preparing a welding steel mesh; the welding steel mesh is provided with a plurality of first through holes and a second through hole; the position of the first through hole corresponds to each pin of the QFP packaging chip, and the position of the second through hole corresponds to the grounding bonding pad of the QFP packaging chip; an extension part is arranged in the direction surrounding the second through hole; the height of the extension part is half of the height difference between the pins of the QFP packaging chip and the grounding bonding pad;
placing the welding steel mesh on a PCB to be welded with the QFP packaging chip, and aligning the first through hole and the second through hole with a welding position;
printing solder paste on the welding steel mesh, so that the solder paste permeates into the first through hole, the second through hole and the extension part;
taking down the welding steel mesh from the PCB, and placing pins of the QFP packaging chip to be welded on solder paste of the PCB based on the welding position;
and heating the solder paste on the PCB, adsorbing the grounding bonding pad upwards after the solder paste under the grounding bonding pad is heated, and fusing the solder paste under the pins with the pins after the solder paste is heated to complete the welding of the QFP packaging chip.
2. The method for bonding the QFP package chip as claimed in claim 1, wherein: the thickness range of the welding steel mesh is 0.1mm to 0.15 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010638734.8A CN111885849A (en) | 2020-07-06 | 2020-07-06 | QFP packaging chip welding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010638734.8A CN111885849A (en) | 2020-07-06 | 2020-07-06 | QFP packaging chip welding method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111885849A true CN111885849A (en) | 2020-11-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010638734.8A Pending CN111885849A (en) | 2020-07-06 | 2020-07-06 | QFP packaging chip welding method |
Country Status (1)
| Country | Link |
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| CN (1) | CN111885849A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114567973A (en) * | 2022-02-10 | 2022-05-31 | 上海航天电子通讯设备研究所 | PCB packaging method for CQFP chip with non-metallized through hole |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105397221A (en) * | 2015-12-01 | 2016-03-16 | 长沙奥托自动化技术有限公司 | PCB packaging design and welding method of TQFP chip |
| CN205213155U (en) * | 2015-11-09 | 2016-05-04 | 东莞市浩远电子有限公司 | Ladder steel mesh |
| CN207305075U (en) * | 2017-10-18 | 2018-05-01 | 湖南恒茂高科股份有限公司 | PCB pads and QFN die-bonding devices |
| JP2019214195A (en) * | 2018-06-14 | 2019-12-19 | 株式会社プロセス・ラボ・ミクロン | Screen printing plate, and method of manufacturing the same |
-
2020
- 2020-07-06 CN CN202010638734.8A patent/CN111885849A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205213155U (en) * | 2015-11-09 | 2016-05-04 | 东莞市浩远电子有限公司 | Ladder steel mesh |
| CN105397221A (en) * | 2015-12-01 | 2016-03-16 | 长沙奥托自动化技术有限公司 | PCB packaging design and welding method of TQFP chip |
| CN207305075U (en) * | 2017-10-18 | 2018-05-01 | 湖南恒茂高科股份有限公司 | PCB pads and QFN die-bonding devices |
| JP2019214195A (en) * | 2018-06-14 | 2019-12-19 | 株式会社プロセス・ラボ・ミクロン | Screen printing plate, and method of manufacturing the same |
Non-Patent Citations (3)
| Title |
|---|
| 张伟: "《电子工艺实训教程》", 31 August 2018 * |
| 李春灵: "QFN封装的焊盘和印刷网板的设计", 《电子信息技术的理论与应用-中国电子学会第十四届青年学术年会论文集》 * |
| 詹跃明: "《表面组装技术》", 30 September 2018 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114567973A (en) * | 2022-02-10 | 2022-05-31 | 上海航天电子通讯设备研究所 | PCB packaging method for CQFP chip with non-metallized through hole |
| CN114567973B (en) * | 2022-02-10 | 2024-04-12 | 上海航天电子通讯设备研究所 | PCB packaging method for CQFP chip with non-metallized through holes |
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Application publication date: 20201103 |
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| RJ01 | Rejection of invention patent application after publication |