CN203301856U - SMT element pad set and circuit board thereof - Google Patents
SMT element pad set and circuit board thereof Download PDFInfo
- Publication number
- CN203301856U CN203301856U CN2013202785572U CN201320278557U CN203301856U CN 203301856 U CN203301856 U CN 203301856U CN 2013202785572 U CN2013202785572 U CN 2013202785572U CN 201320278557 U CN201320278557 U CN 201320278557U CN 203301856 U CN203301856 U CN 203301856U
- Authority
- CN
- China
- Prior art keywords
- smt
- welding
- group
- component pads
- chamfering
- 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.)
- Expired - Fee Related
Links
Images
Abstract
The utility model discloses an SMT element pad set and a circuit board thereof. The SMT element pad set comprises at least two square welding pins used for welding a single SMT element. All the welding pins integrally form a square pad set matched with the SMT element. Each welding pin at each corner of the pad set is provided with a first chamfer. The first chamfer is positioned at one corner of the square pad set. According to the technical scheme of the utility model, the corners of the pad set for the SMT element are provided with one first chamfer respectively, so that the solder paste can spread to the first chambers of the welding pins when heated to spread in an arc shape. Meanwhile, the welding pins exposed out of the SMT element at the corners of the pad set can be covered by the solder paste. In this way, both the occurrence of solder balls generated by the excessive solder paste heated to be extruded and stuck to the side edges of the SMT element, and the copper exposed phenomenon at the corner parts of the welding pins after the welding process, can be avoided. Therefore, the welding quality of the circuit board is improved.
Description
Technical field
The utility model relates to pad group and the wiring board field thereof of welding same SMT element, and in particular a kind of wiring board that improves produces tin sweat(ing) and the SMT component pads group of revealing the copper problem.
Background technology
At present, on wiring board, be used to the leg that welds same SMT element, be square mostly, and the pad group of this SMT element that is formed by these square legs, its whole outer contour shape is also square usually, if it is square that the steel mesh of wire mark tin cream also is made into according to the size with this SMT component pads group 1:1, can realize all standing of all legs in this SMT component pads group; And wiring board be heated or Reflow Soldering after, the tin cream at SMT component pads group corner location place will expand mobile, and then is easy to produce tin sweat(ing) problem (being to be extruded and to form under its surface tension effects the phenomenon that tin sweat(ing) rolls and sticks to SMT element side after unnecessary tin cream is heated) at the periphery of SMT element.
for this reason, the solution of prior art is, as shown in Figure 1, Fig. 1 is the stack schematic diagram of certain SMT component pads group and its steel mesh outline line in prior art, take the LED element as example, this LED component pads group 110 has five square legs (111, 112, 113, 114 and 115) shape that is rectangle on forming a whole, four legs (111 wherein, 112, 113 and 114) lay respectively at this rectangular four corners up and down, another leg 115 is positioned at this rectangular center position, and the steel mesh outline line 120 of this LED element is also a rectangle, and coincide with the rectangle of LED component pads group 110, generally four turnings (for example the turning, bottom right 124) of steel mesh outline line 120 can be made to rounding or fall rectilinear angle (as shown in Figure 1), wiring board just can prevent at LED component periphery generation tin sweat(ing) afterwards in welding like this.
but, the tin cream curved expansion infiltration of can being heated during welding, be difficult to be penetrated into the corner of LED component pads group 110, and in order to realize that SMT welding climbing effect is to increase the fastness of welding, usually all can must be a little longer than the length of LED element 130 by the Design of length of LED component pads group 110, still take the LED component pads group in Fig. 1 as example, in conjunction with shown in Figure 2, Fig. 2 is the stack schematic diagram of certain SMT element outer contour and its pad group in prior art, because the length of the Length Ratio LED pad group 110 of element 130 is slightly shorter, after welding, described LED element 130 is fixed on this LED pad group 110 between two parties, although LED element 130 can cover the leg 115 of LED component pads group 110 centers fully, yet the two ends of described LED element 130 still can't cover the leg 114 of locating at turning in LED component pads group 110 (for example the turning, bottom right 124) fully (similarly also has leg 111, 112 and 113), thereby just caused wiring board the dew copper phenomenon that can visually arrive to occur.
Therefore, prior art still haves much room for improvement and develops.
The utility model content
For solving the problems of the technologies described above, the utility model provides a kind of SMT component pads, can under the prerequisite that does not produce tin sweat(ing), avoid occurring revealing the phenomenon of copper.
Simultaneously, the utility model also provides a kind of wiring board, and its pad neither can produce tin sweat(ing) and not there will be again the problem of revealing copper after welding SMT element.
The technical solution of the utility model is as follows: a kind of SMT component pads group, comprise that at least two be used to welding the square leg of same SMT element, all legs form the square pad group of one group of adaptive this SMT element on the whole, wherein: on the leg of described pad group corner, be provided with the first chamfering, described the first chamfering is positioned on the turning of described square pad group.
Described SMT component pads group, wherein: be positioned on described pad group sideline and welding after exceed on the leg of described SMT element coverage and be provided with the second chamfering, described the second chamfering is positioned on the sideline of described square pad group.
Described SMT component pads group, wherein: described the first chamfering and the second chamfering be for falling rectilinear angle, or described the first chamfering and the second chamfering are for falling curvilinear angle.
Described SMT component pads group, wherein: described curvilinear angle comprises rounding.
Described SMT component pads group, wherein: the radius R of described rounding equals on its place leg two adjacent edge length L 1 and 1/8th of L2 sum.
Described SMT component pads group, wherein: when the radius R of described rounding>L1/2, the value of this radius R equals the smaller value in L1/3 and L2/3.
Described SMT component pads group, wherein: when the radius R of described rounding>L2/2, the value of this radius R equals the smaller value in L1/3 and L2/3.
Described SMT component pads group, wherein: the value margin of tolerance of the radius R of described rounding is between ± 15%.
A kind of wiring board, its surface are provided be used to welding the pad group of same SMT element, wherein: described pad group is the described SMT component pads of above-mentioned middle any one group.
a kind of SMT component pads group provided by the utility model and wiring board thereof, owing on the leg in SMT component pads group corner, having adopted the technological means of the first chamfering, the principle of curved expansion infiltration while being heated based on tin cream, tin cream can be penetrated into the first chamfering place of leg, and cover in the leg that this SMT element exposes in SMT component pads group corner, the side that is extruded when unnecessary tin cream is heated and sticks to the SMT element forms tin sweat(ing), avoided again the phenomenon of copper at the corner location place of leg, occurring revealing after welding, and then improved the quality of wiring board welding.
The accompanying drawing explanation
Fig. 1 is the stack schematic diagram of certain SMT component pads group and its steel mesh outline line in prior art.
Fig. 2 is the stack schematic diagram of certain SMT element outer contour and its pad group in prior art.
Fig. 3 is certain the SMT component pads group floor map on the utility model wiring board.
Fig. 4 is the stack schematic diagram of the utility model SMT element outer contour and its pad group.
Embodiment
Below with reference to accompanying drawing, embodiment of the present utility model and embodiment are described in detail, described specific embodiment only, in order to explain the utility model, is not intended to limit embodiment of the present utility model.
as shown in Figure 3, Fig. 3 is certain the SMT component pads group floor map on the utility model wiring board, or take the SMT element of LED as example, the shape that this LED component pads group 210 is rectangle on also being formed a whole by five square legs (211,212,213,214 and 215), four legs (211,212,213 and 214) wherein lay respectively at this rectangular four corners, and another leg 215 is positioned at this rectangular center position, still take the LED component pads group in Fig. 3 as example, again in conjunction with shown in Figure 4, Fig. 4 is the stack schematic diagram of the utility model SMT element outer contour and its pad group, after welding, described LED element 130 is fixed on this LED pad group 210 between two parties, because the length of LED element 130 is short than the length of its LED pad group 210, although LED element 130 can cover the leg 215 of LED component pads group 210 centers fully, yet the two ends of described LED element 130 still can't cover the leg 214 of locating at turning in LED component pads group 210 (for example turning, bottom right 224a) fully (similarly also has leg 111, 212 and 213), in order to overcome the defect that copper occurs revealing, just need on the leg 214 that LED component pads group 210 turnings (for example turning, bottom right 224a) locates, the first chamfering be set, it is positioned to the right angle of locating at LED component pads group 210 turnings (being turning, bottom right 224a) and is processed into the first chamfering (leg 111 in addition of similar processing, 212 and 213), so that tin cream can be penetrated into the first chamfering place when being heated, and then just can cover in afterwards in welding the copper sheet that LED element 130 exposes in LED component pads group 210 corners, in the time of both can having prevented from welding thus, produce unnecessary tin cream, can avoid again the rear phenomenon that copper occurs revealing of wiring board welding.
further, with regard to described leg 214, except it being positioned to the right angle of locating at LED component pads group 210 turnings (being turning, bottom right 224a), be processed into the first chamfering, also it can be positioned on LED component pads group 210 sidelines and welding after exceed LED element 130 coverages right angle (being the upper right corner 214b of leg 214) be processed into the second chamfering (similar processing also have leg 111, 212 and 213), so that tin cream can also be penetrated into the second chamfering place when being heated, and then in welding, just can cover in afterwards the copper sheet that exposes LED element 130 on LED component pads group 210 sidelines, two ends, and just can cover in the copper sheet that LED component pads group 210 is exposed LED element 130 fully in conjunction with the first chamfering, thoroughly stop the rear phenomenon that copper occurs revealing of wiring board welding.
In the preferred implementation of the SMT component pads on the utility model wiring board, concrete, this chamfering of two types (upper right corner 214b that comprises LED component pads group 210 turning, bottom right 224a and leg 214) both can be made down rectilinear angle, also can make down curvilinear angle; And falling in curvilinear angle, include but not limited to the rounding shown in Fig. 3 and Fig. 4, because the shape of rounding meets tin cream more while being heated with the characteristic of camber line expansion infiltration, and according to verification experimental verification, the effect of rounding also is better than down rectilinear angle.
Be preferably, the radius R of described rounding numerically can be selected to equal on the square leg in its place two adjacent edge length L 1 and 1/8th of L2 sum, the result of experiment shows, quality after welding in such cases is best, neither can produce tin sweat(ing) and not there will be again dew copper, and the slightly little rounding radius R of numerical value also there will be a small amount of dew copper after welding, and the slightly large rounding radius R of numerical value, after welding, can produce tin sweat(ing) again.
Further, when the radius R>L1/2 of described rounding or R>L2/2, the value of this radius R will be got the smaller value in L1/3 and L2/3 and the value margin of tolerance of radius R also can be selected in ± 15% between, can guarantee like this to have Maximum Contact and area of dissipation under the prerequisite that can not reveal copper.
Based on above-mentioned SMT component pads group, the utility model has also proposed a kind of wiring board, on the surface of this wiring board, be provided with an assembly welding dish group, for welding same SMT element, wherein: this pad group is the SMT component pads group described in above-mentioned any one embodiment, to improve the welding quality of wiring board.
For example, take the pad size on the required wiring board of certain SMT element as example, the L1=8mm of the square leg of described SMT component pads group corner, L2=2mm, the radius R of this leg corner rounding=(L1+L2)/8=(8+2)/8=1.25mm, and L2/2=2/2=1mm, meet the condition of R>L2/2, therefore radius R=min (L1/3 of this leg corner (comprising the first chamfering and the second chamfering) rounding after revising, L2/3)=min (8/3,2/3)=2/3 ≈ 0.67mm.
For another example, take the pad size on the required wiring board of certain LED element as example, the L1=1.25mm of the square leg of described LED component pads group corner, L2=0.95mm, the radius R of this leg corner rounding=(L1+L2)/8=(1.25+0.95)/8=0.275mm, and L1/2=1.25/2=0.625mm, L2/2=0.95/2=0.475mm, all do not meet the condition of R>L1/2 or R>L2/2, therefore the radius R=0.275mm of this leg corner (comprising the first chamfering and the second chamfering) rounding.
This wiring board that welds this LED element for SMT shows through actual production checking: first month has welded the wiring board of 46018 leg corners without chamfering, wherein just there are 890 wiring boards dew copper to occur, account for 2%, and the wiring board of generation tin sweat(ing) also there are 81; Ensuing second month has welded the wiring board of 84852 leg corner roundings and radius R=0.2mm, wherein there are 553 wiring boards dew copper to occur, account for 0.65%, without the situation of chamfering is existing, significantly descend, also welded simultaneously the wiring board of 200 leg corner roundings and radius R=0.35mm this moon, the wiring board that wherein produces tin sweat(ing) has 7, accounts for 3.5%; Welded the wiring board of 101695 leg corner roundings and radius R=0.275mm in ensuing the 3rd month, all the time do not have a wiring board copper occurs revealing and produce tin sweat(ing), weld again the wiring board of 23656 leg corner roundings and radius R=0.275mm in ensuing the 4th month, also do not had all the time a wiring board copper occurs revealing and produce tin sweat(ing); As can be seen here, after the leg of SMT component pads group corner is selected the rounding of suitable size, really the heat that can effectively evade tin cream is oozed dead angle, the quality problem that can effectively stop to produce tin sweat(ing) and copper occur revealing, and the tin cream that covers LED element surrounding is mellow and full full, has guaranteed welding performance and the heat dispersion of this LED element.
should be understood that, the foregoing is only preferred embodiment of the present utility model, be not sufficient to limit the technical solution of the utility model, for those of ordinary skills, within spirit of the present utility model and principle, can be increased and decreased according to the above description, replace, conversion or improvement, for example, the chamfered at the above-mentioned corner location of pad to wiring board place equally also can be applied to the corner location place to aspects such as the solder mask window of wiring board and circuit etchings, and all these increases and decreases, replace, technical scheme after conversion or improvement, all should belong to the protection range of the utility model claims.
Claims (9)
1. SMT component pads group, comprise that at least two be used to welding the square leg of same SMT element, all legs form the square pad group of one group of adaptive this SMT element on the whole, it is characterized in that: on the leg of described pad group corner, be provided with the first chamfering, described the first chamfering is positioned on the turning of described square pad group.
2. SMT component pads group according to claim 1, it is characterized in that: be positioned on described pad group sideline and welding after exceed on the leg of described SMT element coverage and be provided with the second chamfering, described the second chamfering is positioned on the sideline of described square pad group.
3. SMT component pads group according to claim 2 is characterized in that: described the first chamfering and the second chamfering be for falling rectilinear angle, or described the first chamfering and the second chamfering are for falling curvilinear angle.
4. SMT component pads group according to claim 3 is characterized in that: the described curvilinear angle of falling comprises rounding.
5. SMT component pads group according to claim 4 is characterized in that: the radius R of described rounding equals on its place leg two adjacent edge length L 1 and 1/8th of L2 sum.
6. SMT component pads group according to claim 5 is characterized in that: when the radius R of described rounding>L1/2, the value of this radius R equals the smaller value in L1/3 and L2/3.
7. SMT component pads group according to claim 5 is characterized in that: when the radius R of described rounding>L2/2, the value of this radius R equals the smaller value in L1/3 and L2/3.
8. SMT component pads group according to claim 5, it is characterized in that: the value margin of tolerance of the radius R of described rounding is between ± 15%.
9. wiring board, its surface is provided be used to welding the pad group of same SMT element, it is characterized in that: described pad group is the described SMT component pads of any one group in claim 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013202785572U CN203301856U (en) | 2013-05-21 | 2013-05-21 | SMT element pad set and circuit board thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013202785572U CN203301856U (en) | 2013-05-21 | 2013-05-21 | SMT element pad set and circuit board thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203301856U true CN203301856U (en) | 2013-11-20 |
Family
ID=49577832
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013202785572U Expired - Fee Related CN203301856U (en) | 2013-05-21 | 2013-05-21 | SMT element pad set and circuit board thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203301856U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104955269A (en) * | 2015-06-22 | 2015-09-30 | 安徽方兴科技股份有限公司 | FPC (Flexible Printed Circuit) golden finger |
| CN105772896A (en) * | 2016-04-15 | 2016-07-20 | 株洲中车时代电气股份有限公司 | Patch positioning tool |
| CN106455315A (en) * | 2016-12-13 | 2017-02-22 | 郑州云海信息技术有限公司 | 0201 element bonding pad design method and PCB (printed circuit board) |
-
2013
- 2013-05-21 CN CN2013202785572U patent/CN203301856U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104955269A (en) * | 2015-06-22 | 2015-09-30 | 安徽方兴科技股份有限公司 | FPC (Flexible Printed Circuit) golden finger |
| CN105772896A (en) * | 2016-04-15 | 2016-07-20 | 株洲中车时代电气股份有限公司 | Patch positioning tool |
| CN106455315A (en) * | 2016-12-13 | 2017-02-22 | 郑州云海信息技术有限公司 | 0201 element bonding pad design method and PCB (printed circuit board) |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203301856U (en) | SMT element pad set and circuit board thereof | |
| CN102689065A (en) | Method for welding circuit board components | |
| CN108337821A (en) | A kind of welding method of circuit board | |
| US8908386B2 (en) | Printed circuit board assembly chip package component and soldering component | |
| TW201343008A (en) | Printed circuit board structure | |
| CN201965402U (en) | Green oil film for semiautomatic exposure machine | |
| US20130248237A1 (en) | Printed circuit board | |
| CN215345236U (en) | Electronic component packaging structure | |
| CN209283623U (en) | A kind of connection frame plate and mobile terminal | |
| JP2005175186A (en) | Printed wiring board having 4-direction lead flat packaged ic mounted thereon, air conditioner provided with it, and soldering method of 4-direction lead flat packaged ic | |
| WO2016074286A1 (en) | Printed circuit board | |
| CN108990266A (en) | A kind of pcb board | |
| CN107498132B (en) | Welder and welding method | |
| JP4238426B2 (en) | Printed wiring board | |
| CN203617457U (en) | Terminal with a terminal body | |
| CN105491815A (en) | Reflow soldering template, template component, tin paste printing device and reflow soldering method | |
| US20210227701A1 (en) | Design and packaging method for pcb board to avoid patch element tombstone and pcb board | |
| CN203590586U (en) | Circuit board | |
| CN211267256U (en) | Packaging structure for improving reliability welding of high-power device | |
| CN209593989U (en) | A kind of low cost wiring board | |
| CN207854264U (en) | The processing unit (plant) of optical recognized point in flexible circuit board | |
| CN209608955U (en) | Pcb board with inserted thin film fuse | |
| CN213071398U (en) | Electronic part pin, electronic part and PCB board of prevention even tin | |
| CN211128403U (en) | FPC with irritate tin steel sheet ground connection | |
| CN203883170U (en) | Heat dissipation area-increased connecting structure used for BGA encapsulation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 516001 Guangdong province Huizhou Zhongkai hi tech Development Zone No. 19 district Patentee after: HUIZHOU HUARUI LIGHT SOURCE SCIENCE & TECHNOLOGY CO., LTD. Address before: 516001 Guangdong province Huizhou Zhongkai hi tech Development Zone No. 19 district Patentee before: TCL Hong Qi technology (Huizhou) Co., Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131120 Termination date: 20190521 |