CN104485293B - A kind of method of balling ratio of the raising metal coupling in vacuum back-flow technique - Google Patents
A kind of method of balling ratio of the raising metal coupling in vacuum back-flow technique Download PDFInfo
- Publication number
- CN104485293B CN104485293B CN201410765890.5A CN201410765890A CN104485293B CN 104485293 B CN104485293 B CN 104485293B CN 201410765890 A CN201410765890 A CN 201410765890A CN 104485293 B CN104485293 B CN 104485293B
- Authority
- CN
- China
- Prior art keywords
- metal coupling
- vacuum
- vacuum back
- balling ratio
- projection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
- H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L24/10—Bump connectors ; Manufacturing methods related thereto
- H01L24/11—Manufacturing methods
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/10—Bump connectors; Manufacturing methods related thereto
- H01L2224/11—Manufacturing methods
- H01L2224/111—Manufacture and pre-treatment of the bump connector preform
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/30—Technical effects
- H01L2924/37—Effects of the manufacturing process
- H01L2924/37001—Yield
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Electric Connection Of Electric Components To Printed Circuits (AREA)
Abstract
The present invention provides a kind of method that balling ratio of the metal coupling in vacuum back-flow technique is improved in field of semiconductor package.Specifically include following steps：(1) spherical or square brazing metal projection is formed on UBM (metal under salient point)；(2) the brazing metal projection prepared by step (1) is cleaned by hairbrush；(3) the brazing metal projection treated by step (2) is placed in vacuum back-flow stove and flowed back；(4) metal coupling after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of vacuum.Using technical scheme, the problem of can improving metal coupling balling ratio is low in vacuum back-flow technique, balling ratio has brought up to 99.98% from original 99.5%, while also effectively improving the surface roughness after metal coupling balling-up.
Description
Technical field
The present invention relates to field of semiconductor package, more particularly to it is a kind of improve metal coupling in vacuum back-flow technique into
The method of ball rate.
Background technology
The making of tin-lead and tin-silver convex block is sophisticated semiconductor encapsulation (FC flip-chip type packages) necessary ring.Partly leading
Body encapsulate during, first prepare projection in the pad region of chip, then by chip back surface wear down to certain thickness simultaneously
Each independent chip is cut into, the metal coupling on chip is combined with the metal coupling on substrate weld pad.Solder projection system
As technology be flip-chip in a key technology, it is convex that the reliability of semiconductor devices is heavily dependent on each solder
The structure and material of block, and they be electrically interconnected effect.Therefore, the height of each solder projection and the uniformity of volume be to
Close important.
Solder projection will also pass through reflux technique after being formed, reflux technique be tin-lead and tin-silver convex block make together must
The process wanted (column-like projection block of electroforming is transformed into spherical protrusions).Traditional reflux technique is to be coated on scaling powder
Pass through the reflow ovens of traditional conveyer belt type on the established chip of column-like projection block again, again remove scaling powder after backflow balling-up,
This technique can not only consume a large amount of scaling powders, and pollution environment.
Advanced reflux technique is to use a kind of new vacuum back-flow stove, is returned in the case where not needing scaling powder
Stream, i.e., melted, cause metal coupling by original using the surface tension under the conditions of liquid under vacuum conditions by solder metal
First mushroom or hemispherical transformation globulate, wait rising again to after room temperature, solidification obtains the essentially identical ball of size, shape
Shape projection.Vacuum back-flow technique not only saves cost of material, simplifies technological process, while also more environmental protection, but make
Had one disadvantage in that with vacuum back-flow stove, the Solder Bumps balling ratio after backflow can only achieve about 99.5%, and traditional backflow
Technique balling ratio can reach about 99.98%, therefore, and balling ratio of the metal coupling in vacuum back-flow technique be low to be turned into one and treat
The technical problem of solution.
Chinese patent 200610027588.5 discloses a kind of solder projection and its manufacture method, and this method optimizes work
Skill, the reliability for reduce encapsulation volume, production efficiency being provided, encapsulation is added, but it is not directed to how to improve gold in the patent
The problem of belonging to balling ratio of the projection in reflux technique；Chinese patent 200910051849.0 discloses a kind of solder projection and made
Method, the problem of solving dot shape exception, bump height and the poor volume uniformity that prior art is formed, but also do not solve
The problem of certainly how improving balling ratio of the metal coupling in reflux technique；China 02124479.0 discloses a kind of high-resolution
The forming method of soldering projection, the soldering projection of high aspect ratio thin space high density, but this method can be made using this method
Not the problem of not referring to the balling ratio for how improving metal coupling in reflux technique yet.
The content of the invention
To overcome the problem of balling ratio of the metal coupling present in prior art in vacuum back-flow technique is low, the present invention
There is provided a kind of method of balling ratio of raising metallic lead projection in vacuum back-flow technique, following steps are specifically included：
(1) spherical or square brazing metal projection is formed on UBM (metal under salient point)；
(2) the brazing metal projection prepared by step (1) is cleaned by hairbrush；
(3) the brazing metal projection treated by step (2) is placed in vacuum back-flow stove and flowed back；
(4) the brazing metal projection after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of vacuum.
The middle brazing metal projection of the step (1) is one kind in Solder Bumps, tin-silver convex block；
The method that metal coupling is formed described in the step (1) is evaporation deposition method, galvanoplastic, ailhead projection method, micro-
One kind in ball；
The time that hairbrush is cleaned in the step (2) is 30-240 seconds；
Hairbrush in the step (2) is nylon bristle roller, brush roll be steel band winded, it is woven, slot it is embedded,
Circular hole is embedded, one kind of offset plate implanted；Contain carborundum or aluminum oxide in the nylon pin of the nylon bristle；Carborundum or
The granularity of aluminum oxide is 180-2000 mesh；
In the step (3), the reflux temperature of vacuum back-flow stove is 180-240 DEG C, and return time is 3min.
In the inventive solutions, the vacuum environment of vacuum back-flow stove can also be replaced with inert protective gas,
Such as nitrogen etc., is also possible to prevent solder surface oxidation and prevents backflow balling-up, improve balling ratio.
Compared with prior art, the beneficial effects of the invention are as follows：Improve metal coupling balling ratio in vacuum back-flow technique
Low the problem of, balling ratio has brought up to 99.98% from original 99.5%, while also effectively improving after metal coupling balling-up
The roughness on surface.
Brief description of the drawings
Fig. 1 is the tin-lead sphere surface image without cleaning before backflow；
Fig. 2 is the surface image for the Solder Bumps non-balling-up upon reflowing cleaned without hairbrush before backflow；
Fig. 3 is the preceding surface image after the Solder Bumps balling-up that hairbrush is cleaned of backflow.
Embodiment
Below in conjunction with drawings and examples, the present invention will be described in further detail.It should be appreciated that described herein
Specific embodiment only to explain the present invention, is not intended to limit the present invention.
Embodiment 1
A kind of method of balling ratio of raising metallic lead projection in vacuum back-flow technique, including following steps：
(1) spherical or square brazing metal projection is formed on UBM (metal under salient point)；
(2) the brazing metal projection prepared by step (1) is cleaned by hairbrush；
(3) the brazing metal projection treated by step (2) is placed in vacuum back-flow stove and flowed back；
(4) the brazing metal projection after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of vacuum.
Wherein, the middle brazing metal projection of step (1) is Solder Bumps, and the method for forming Solder Bumps is galvanoplastic, its
Preparation method is first on a wafer with the method deposition projection bottom metal layer of sputter, then in projection bottom metal layer overlying
One layer of photoresist layer of lid, is exposed development and forms the region of soldering projection, then plated solder, remove photoresist and etch.
In step (2), the time that hairbrush is cleaned is 30-240 seconds, and it is clear that table 1 gives hairbrush in this embodiment
Wash the relation of time and metal coupling balling-up.
The relation of the hairbrush scavenging period of table 1 and metal coupling balling ratio
| Scavenging period | 30 seconds | 60 seconds | 90 seconds | 120 seconds | 150 seconds | 180 seconds | 240 seconds |
| Projection balling ratio | 99.85% | 99.92% | 99.95% | 99.98% | 99.98% | 99.8% | 99.9% |
As can be seen from the table, it 120 seconds is optimal cleaning parameter that washing time, which is,.
Hairbrush in the step (2) is nylon bristle roller, and brush roll typically has steel band winded, woven, fluting
Five kinds of modes such as embedded, circular hole is embedded, offset plate implanted, mainly using steel band winded, woven in this experiment
With embedded three kinds of modes of circular hole, carried out cleaning the experimental result difference drawn less with the brush roll of this three kinds of modes.Experiment
In used brush roll be mainly in nylon bristle, and the nylon pin of hairbrush and contain carborundum, the granularity of carborundum can be 180
Mesh, 240 mesh, 320 mesh, 400 mesh, 500 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, 1500 mesh, 2000 mesh, experimental result table
When the carborundum granularity that face works as in hairbrush is 2000 mesh, best results.
In the step (3), the reflux temperature of vacuum back-flow stove is 180-240 DEG C, in backflow, reflux temperature be according to
What certain gradient was set, reflux temperature curve near parabolic, i.e. the first temperature than relatively low, then gradient is presented
Slowly heat up, when reaching the maximum temperature of setting, then into gradient cooling.The setting of specific reflux temperature is needed according to metal
The property of convex material and the technological parameter of vacuum back-flow stove and set, it is however generally that, the treatment temperature of slicker solder projection is generally 210
DEG C -220 DEG C, and the peak value of tin-silver convex block is at least 235-245 DEG C, temperature is higher, it is desirable to which the time of processing is longer.This is implemented
6 step temperatures of mode are 180 DEG C, 190 DEG C, 205 DEG C, 220 DEG C, 210 DEG C, 190 DEG C successively, and return time is 3min.
Compared with prior art, the beneficial effects of the invention are as follows：Improve metal coupling balling ratio in vacuum back-flow technique
Low the problem of, balling ratio has brought up to 99.98% from original 99.5%.Metal coupling outward appearance after backflow it is specific as Fig. 1,
2nd, shown in 3.
If Fig. 1 is the tin-lead sphere surface image without being cleaned before backflow；Fig. 2 is that the preceding tin-lead without hairbrush cleaning of backflow is convex
The surface image of block non-balling-up upon reflowing；Fig. 3 is the preceding surface image after the Solder Bumps balling-up that hairbrush is cleaned of backflow.
It can be seen that and flowed back again after hairbrush is handled from above three figure, also effectively improve the surface after Solder Bumps balling-up
Roughness.
Embodiment 2
The method of balling ratio of a kind of raising metallic lead projection in vacuum back-flow technique, it is characterised in that including following
Several steps：
(1) spherical or square brazing metal projection is formed on UBM (metal under salient point)；
(2) the brazing metal projection prepared by step (1) is cleaned by hairbrush；
(3) the brazing metal projection treated by step (2) is placed in vacuum back-flow stove and flowed back；
(4) the brazing metal projection after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of vacuum.
Wherein, the middle brazing metal projection of step (1) is tin-silver convex block, and the method for forming tin-silver convex block is galvanoplastic, its
Preparation method is with previous embodiment 1.
In step (2), the time that hairbrush is cleaned is 120 seconds, and it in mao pin containing granularity is the oxidation of 2000 mesh that hairbrush, which is,
The steel band winded nylon bristle roller of aluminium.
In step (3), the reflux temperature of vacuum back-flow stove is 180-240 DEG C, and in backflow, reflux temperature is according to certain
Gradient set, reflux temperature curve is near parabolic, 6 step temperatures of setting are 180 DEG C successively, 190 DEG C,
215 DEG C, 235 DEG C, 215 DEG C, 190 DEG C, return time is 3min.
Embodiment 3
The method of balling ratio of a kind of raising metallic lead projection in vacuum back-flow technique, it is characterised in that including following
Several steps：
(1) spherical or square brazing metal projection is formed on UBM (metal under salient point)；
(2) the brazing metal projection prepared by step (1) is cleaned by hairbrush；
(3) the brazing metal projection treated by step (2) is placed in vacuum back-flow stove and flowed back；
(4) metal coupling after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of vacuum.
Wherein, the middle brazing metal projection of step (1) is tin-lead or tin-silver convex block, forms tin-lead or the method for tin-silver convex block
It is ailhead projection method.
In step (2), the time that hairbrush is cleaned is 120 seconds, and it in mao pin containing granularity is the carbonization of 1500 mesh that hairbrush, which is,
The embedded nylon bristle roller of circular hole of silicon.
In step (3), the reflux temperature of vacuum back-flow stove is 180-240 DEG C, and in backflow, reflux temperature is according to certain
Gradient set, reflux temperature curve is near parabolic, and return time is 3min.
Embodiment 4
Spirit of the invention is the discussion that this method of processing is carried out to the surface of metal coupling, and technological parameter is this
Inevitable outcome after method processing.So, the vacuum environment of vacuum back-flow stove can also be replaced in technical scheme
For inert protective gas, such as nitrogen etc. can also reach same technique effect.
The method of balling ratio of a kind of raising metallic lead projection in reflux technique, it is characterised in that including following
Step：
(1) spherical or square brazing metal projection is formed on UBM (metal under salient point)；
(2) the brazing metal projection prepared by step (1) is cleaned by hairbrush；
(3) the brazing metal projection treated by step (2) is placed in the reflow ovens of nitrogen protection atmosphere and carried out
Backflow；
(4) the brazing metal projection after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of nitrogen protection atmosphere.
Wherein, the middle brazing metal projection of step (1) is Solder Bumps, and the method for forming Solder Bumps is galvanoplastic, its
Preparation method is with previous embodiment 1.
In step (2), the time that hairbrush is cleaned is 120 seconds, and it in mao pin containing granularity is the oxidation of 2000 mesh that hairbrush, which is,
The steel band winded nylon bristle roller of aluminium.
It is 180-240 DEG C in the reflux temperature of nitrogen protection atmosphere reflow ovens in step (3), in backflow, reflux temperature
It is to be set according to certain gradient, reflux temperature curve is near parabolic, 6 step temperatures of setting are successively
180 DEG C, 190 DEG C, 205 DEG C, 220 DEG C, 210 DEG C, 190 DEG C, return time is 3min.
The preferred embodiments of the present invention have shown and described in described above, as previously described, it should be understood that not office of the invention
Be limited to form disclosed herein, be not to be taken as the exclusion to other embodiment, and available for various other combinations, modification and
Environment, and can be changed in invention contemplated scope described herein by the technology or knowledge of above-mentioned teaching or association area
It is dynamic., then all should be appended by the present invention and the change and change that those skilled in the art are carried out do not depart from the spirit and scope of the present invention
In scope of the claims.
Claims (9)
1. the method for balling ratio of a kind of raising metal coupling in vacuum back-flow technique, it is characterised in that including following
Step：
(1) spherical or square brazing metal projection is formed on UBM；
(2) the brazing metal projection prepared by step (1) is subjected to cleaning 30-240 seconds by hairbrush；
(3) the brazing metal projection treated by step (2) is placed in vacuum back-flow stove and flowed back；
(4) the brazing metal projection after being flowed back in step (3) is cooled to less than 40 DEG C under conditions of vacuum.
2. the method for balling ratio of the raising metal coupling according to claim 1 in vacuum back-flow technique, its feature exists
In：The middle metal coupling of the step (1) is one kind in Solder Bumps, tin-silver convex block.
3. the method for balling ratio of the raising metal coupling according to claim 1 in vacuum back-flow technique, its feature exists
In：In the method for metal coupling is formed described in the step (1) being evaporation deposition method, galvanoplastic, ailhead projection method, microballoon method
One kind.
4. the method for balling ratio of the raising metal coupling according to claim 1 in vacuum back-flow technique, its feature exists
In：Hairbrush in the step (2) is nylon bristle roller, and brush roll is steel band winded, woven, embedded, circular hole of slotting
Embedded, offset plate implanted one kind.
5. the method for balling ratio of the raising metal coupling according to claim 4 in vacuum back-flow technique, its feature exists
In：Contain carborundum or aluminum oxide in the nylon pin of the nylon bristle.
6. the method for balling ratio of the raising metal coupling according to claim 5 in vacuum back-flow technique, its feature exists
In：The granularity of the carborundum or aluminum oxide is 180-2000 mesh.
7. the method for balling ratio of the raising metal coupling according to claim 1 in vacuum back-flow technique, its feature exists
In：In the step (3), the reflux temperature of vacuum back-flow stove is 180-240 DEG C, and return time is 3min.
8. the method for balling ratio of the raising metal coupling according to claim 7 in vacuum back-flow technique, its feature exists
In：The temperature of the vacuum back-flow stove is set by gradient.
9. the method for balling ratio of the raising metal coupling according to claim 1 in vacuum back-flow technique, its feature exists
In：Vacuum environment is replaced with nitrogen medium environment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410765890.5A CN104485293B (en) | 2014-12-12 | 2014-12-12 | A kind of method of balling ratio of the raising metal coupling in vacuum back-flow technique |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410765890.5A CN104485293B (en) | 2014-12-12 | 2014-12-12 | A kind of method of balling ratio of the raising metal coupling in vacuum back-flow technique |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104485293A CN104485293A (en) | 2015-04-01 |
| CN104485293B true CN104485293B (en) | 2017-08-11 |
Family
ID=52759829
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410765890.5A Active CN104485293B (en) | 2014-12-12 | 2014-12-12 | A kind of method of balling ratio of the raising metal coupling in vacuum back-flow technique |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104485293B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101026106A (en) * | 2006-02-24 | 2007-08-29 | 中芯国际集成电路制造(上海)有限公司 | Solder bump lead-free flux preparing process |
| CN101197296A (en) * | 2006-12-04 | 2008-06-11 | 中芯国际集成电路制造(上海)有限公司 | Convex point reflow process without soldering flux |
| CN201872045U (en) * | 2010-11-05 | 2011-06-22 | 云南锡业微电子材料有限公司 | Smooth finish processing equipment for BGA (Ball Grid Array) solder ball |
| CN102881604A (en) * | 2011-07-12 | 2013-01-16 | 格罗方德半导体公司 | Solder bump cleaning before reflow |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100521081B1 (en) * | 2002-10-12 | 2005-10-14 | 삼성전자주식회사 | Fabrication and installation method of flip chip |
-
2014
- 2014-12-12 CN CN201410765890.5A patent/CN104485293B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101026106A (en) * | 2006-02-24 | 2007-08-29 | 中芯国际集成电路制造(上海)有限公司 | Solder bump lead-free flux preparing process |
| CN101197296A (en) * | 2006-12-04 | 2008-06-11 | 中芯国际集成电路制造(上海)有限公司 | Convex point reflow process without soldering flux |
| CN201872045U (en) * | 2010-11-05 | 2011-06-22 | 云南锡业微电子材料有限公司 | Smooth finish processing equipment for BGA (Ball Grid Array) solder ball |
| CN102881604A (en) * | 2011-07-12 | 2013-01-16 | 格罗方德半导体公司 | Solder bump cleaning before reflow |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104485293A (en) | 2015-04-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7397119B2 (en) | Wafer-level diamond spreader | |
| US9543185B2 (en) | Packaging process tools and systems, and packaging methods for semiconductor devices | |
| CN102214565A (en) | Method for thinning carborundum wafer | |
| CN106793559B (en) | A kind of BGA ball-establishing method | |
| US6637638B1 (en) | System for fabricating solder bumps on semiconductor components | |
| TWI556310B (en) | Passivation layer for semiconductor device packaging | |
| CN1701649B (en) | Method for supplying solder and solder projection forming method | |
| CN101740420B (en) | Process for manufacturing copper strut | |
| CN104485293B (en) | A kind of method of balling ratio of the raising metal coupling in vacuum back-flow technique | |
| CN100552927C (en) | Composite packing structure and method for packing thereof with girth member | |
| CN1930682A (en) | Various structure/height bumps for wafer level-chip scale package | |
| US9050654B2 (en) | Method of manufacturing composite ball for electronic parts | |
| Huang et al. | A novel bumping process for fine pitch Sn–Cu lead-free plating-based flip chip solder bumps | |
| CN105932070A (en) | Low-power-consumption and high-surge capacity diode rectifier chip and production technology thereof | |
| US20070243663A1 (en) | Method of wafer level chip size packaging | |
| CN211177965U (en) | Device for sintering ceramics | |
| US20080314742A1 (en) | Electrolytic ni plating apparatus and method of manufacturing semiconductor device | |
| TWI265554B (en) | Method for reducing lead precipitation during wafer processing | |
| Jun et al. | Characteristics of electroplated Sn bumps fabricated without a PR mould on a Si chip for 3D packaging | |
| CN104078367B (en) | A kind of manufacture craft of flip chip package Schottky diode salient point | |
| Huang et al. | High coplanarity and fine pitch copper pillar bumps fabrication method | |
| JP5577378B2 (en) | Solder bump formation method | |
| JPH04304640A (en) | Semiconductor device and manufacture thereof | |
| KR20150131895A (en) | Method and apparatus for wafer bump reflow | |
| Kiumi et al. | Process development of electroplate bumping for ULSI flip chip technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Jiangsu province Nantong City Chongchuan road 226004 No. 288 Applicant after: Tongfu Microelectronics Co., Ltd. Address before: Jiangsu province Nantong City Chongchuan road 226004 No. 288 Applicant before: Fujitsu Microelectronics Co., Ltd., Nantong |
|
| COR | Change of bibliographic data | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |