CN110927356A - Method for testing performance of solder paste - Google Patents
Method for testing performance of solder paste Download PDFInfo
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- CN110927356A CN110927356A CN201911315083.2A CN201911315083A CN110927356A CN 110927356 A CN110927356 A CN 110927356A CN 201911315083 A CN201911315083 A CN 201911315083A CN 110927356 A CN110927356 A CN 110927356A
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- solder paste
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/20—Metals
- G01N33/207—Welded or soldered joints; Solderability
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/20—Metals
- G01N33/205—Metals in liquid state, e.g. molten metals
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- Electric Connection Of Electric Components To Printed Circuits (AREA)
Abstract
The invention provides a method for testing the performance of solder paste, which comprises the following steps: a1, providing a test board and a printed board, wherein the test board is provided with a plurality of pads with the same size, the printed board is provided with a plurality of leak holes with gradually reduced apertures, and the printed board is laminated on the surface of the test board, so that the leak holes correspond to the pads on the test board one by one, and the sizes of the leak holes projected to the surface of the pads are smaller than those of the pads; a2, printing solder paste on the surface of the printing plate, and printing the solder paste on the surface of the pad along the leakage hole; a3, removing the printing plate; a4, confirming the lower tin shape of the tin paste on each bonding pad so as to confirm the lower tin performance of the tin paste in leak holes with different apertures; a5, heating the solder paste on the pads, melting the solder paste on the pad surfaces, and confirming the melting distribution and spread area of the solder paste on each pad. The quality of the solder paste can be simply, conveniently and quickly detected.
Description
Technical Field
The invention relates to the field of solder paste characteristic testing, in particular to a method for testing the performance of solder paste.
Background
Solder paste is also known as solder paste, the english name solder paste. Solder paste is a new type of soldering material produced by SMT (surface mount technology), and is a paste mixture formed by mixing solder powder, soldering flux, other surfactants, thixotropic agents, etc. The method is mainly used for welding electronic components such as surface resistance and capacitance of the PCB (printed circuit board) in the SMT industry.
The quality of the solder paste is good enough to influence whether the conductivity of the finished product is good or not, whether the circuit short circuit is easily caused or not and the like, but when the known manufacturing technology is used for detecting the performances of the solder paste, such as tin dropping property, tin melting capacity, wettability and the like, the adopted testing method is complex, each performance needs to be tested on specific detection equipment one by one, the cost of the whole production is increased, the operation time is prolonged, the production efficiency is reduced and the like.
Disclosure of Invention
Therefore, the invention provides a method for testing the performance of the solder paste, which can simply, conveniently and quickly detect the quality of the solder paste.
In order to achieve the purpose, the technical scheme provided by the invention is as follows:
a method for testing the performance of solder paste comprises the following steps:
a1, providing a test board and a printed board, wherein the test board is provided with a plurality of pads with the same size, the printed board is provided with a plurality of leak holes with gradually reduced apertures, and the printed board is laminated on the surface of the test board, so that the leak holes correspond to the pads on the test board one by one, and the sizes of the leak holes projected to the surface of the pads are smaller than those of the pads;
a2, printing solder paste on the surface of the printing plate, and printing the solder paste on the surface of the pad along the leakage hole;
a3, removing the printing plate;
a4, confirming the lower tin shape of the tin paste on each bonding pad so as to confirm the lower tin performance of the tin paste in leak holes with different apertures; if the shape of the solder paste on the bonding pad is complete, the tin dropping performance of the solder paste on the leak with the corresponding aperture is qualified; otherwise, the printing is unqualified and is not suitable for printing through the leak smaller than the aperture.
A5, heating the solder paste on the pads, melting the solder paste on the pad surfaces, and confirming the melting distribution and spread area of the solder paste on each pad. If the molten tin paste liquid can be gathered together, the tin melting capacity of the tin paste printing points printed by the leak holes with the apertures is qualified, otherwise, the tin melting capacity is not qualified; and further detecting the spreading area of the solder paste liquid on the printing points with qualified tin melting capacity, and further confirming the relation between the printing amount and the spreading area so as to confirm the wettability of the solder paste.
Further, in step a1, a plurality of leak holes with gradually decreasing apertures correspond to a plurality of pads with the same size on the test board one by one to form a group of test groups, and a plurality of groups of test groups are arranged on the test board and the printed board.
Further, in step a2, the same solder paste is printed in the leak holes of the test groups; in step a4, the number of complete under-tin shapes in the same-diameter leak holes in the multiple test sets was also confirmed.
Further, in step a2, different solder pastes are printed in the leak holes of the multiple test sets; in step a4, the shapes of the tin falling from the same-diameter holes in the test sets were also confirmed to confirm the tin falling performance of different solder pastes in the same-diameter holes.
Further, in step a5, the melting distribution and the spreading area of the solder paste were confirmed by taking the solder paste having the intact shape of the lower solder in step a 4.
Further, in step a4, the solder paste thickness is measured using a microscope and/or a solder paste thickness tester to confirm the under-tin shape of the solder paste on each pad.
Further, the plurality of printing plates are arranged, the thicknesses of the plurality of printing plates are different, and the steps A1 to A5 are repeated by adopting the plurality of printing plates with different thicknesses so as to confirm the tin property, the melting distribution condition and the spreading area of the tin paste on the printing plates with different thicknesses.
Furthermore, the leak holes and the bonding pads are the same in shape, and the leak holes and the corresponding bonding pads are arranged concentrically.
Furthermore, the leak hole and the pad are both circular.
Through the technical scheme provided by the invention, the method has the following beneficial effects:
the performance of the tin dropping property, the tin melting capability and the wettability of the tin paste can be detected at one time through the steps, and the method is simple, convenient and quick; and the adopted equipment has low cost.
Drawings
FIG. 1 is a block diagram of a method for testing solder paste properties in an embodiment;
FIG. 2 is a schematic view showing the assembly of a test plate and a printed board in the example;
FIG. 3 is a cross-sectional view showing the fitting of the test plate and the printing plate in the example;
FIG. 4 is a schematic diagram illustrating the confirmation of step A4 of the method for testing the performance of solder paste in the embodiment;
FIG. 5 is a first schematic view of a step A5 of the method for testing solder paste performance in the embodiment;
FIG. 6 is a second schematic view illustrating the confirmation of step A5 of the method for testing solder paste performance in the embodiment.
Detailed Description
To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.
The invention will now be further described with reference to the accompanying drawings and detailed description.
Example one
Referring to fig. 1, the method for testing performance of solder paste provided in this embodiment includes the following steps:
a1, referring to fig. 2, providing a testing board 10 and a printing board 20, where the testing board 10 is provided with a plurality of pads 11 with the same size, the printing board 20 is provided with a plurality of vias 21 with gradually decreasing pore diameters, and the printing board 20 is laminated on the surface of the testing board 10, so that the plurality of vias 21 are in one-to-one correspondence with the plurality of pads 11 on the testing board 10, and the size of the projection of the vias 21 onto the surface of the pads 11 is smaller than that of the pads 11.
Specifically, in this embodiment, the pad 11 is a circular pad, and the diameter of the circular pad is 0.5 mm; the leak holes 21 are circular leak holes, the number of each group of test groups is five, and the diameters of the test groups are 0.4mm, 0.35mm, 0.3mm, 0.25mm and 0.2mm respectively; that is, as shown in fig. 3, the first orifice 211 has a diameter of 0.4mm, the second orifice 212 has a diameter of 0.35mm, the third orifice 213 has a diameter of 0.3mm, the fourth orifice 214 has a diameter of 0.25mm, and the fifth orifice 215 has a diameter of 0.2 mm. The leak holes 21 are concentrically arranged with the corresponding pads 11. Of course, in other embodiments, the size of the pads 11 and the number and size of the weep holes 21 are not limited thereto.
More specifically, the plurality of vias 21 with gradually decreasing apertures correspond to the plurality of pads 11 with the same size on the test board 10 one by one to form a group of test groups, that is, the above five vias 21 with different apertures and the corresponding five pads 11 form a group of test groups, and the test board 10 and the printed board 20 are provided with a plurality of groups of test groups, specifically, the number of test groups in this embodiment is five groups, and further form a5 × 5 array, of course, in other embodiments, the number of test groups is not limited thereto, and may also be provided with one group or more than two groups.
A2, printing solder paste on the surface of the printed board 20, and printing the solder paste on the surface of the pad 11 along the drain hole 21; the printing may be carried out using a doctor blade as is conventional in the art. In this embodiment, the same solder paste is printed in each of the five test sets of the weep holes 21.
A3, removing the printing plate 20, the printing plate 20 being removed in the axial direction of the weep hole 21, preventing damage to the printed solder paste.
A4, confirming the lower tin shape of the solder paste on each pad 11 to confirm the lower tin performance of the solder paste in the leak holes 21 with different apertures; if the shape of the solder paste on the bonding pad 11 is complete, the lower tin performance of the solder paste on the leak 21 with the corresponding aperture is qualified; otherwise, the printing is not qualified, and the printing is not suitable for the leak 21 with the diameter smaller than the aperture.
As shown in fig. 4, in the present embodiment, the solder paste printed on the leak 21 with a diameter of 0.2mm (specifically, the solder paste on the right most side in fig. 4) has a non-complete cylindrical shape (specifically, the solder paste on the right most side in fig. 4), and the solder paste printed on the leak 21 with other diameters has a complete cylindrical shape; thus, it was found that the tin dropping property of the leak hole 21 having a diameter of 0.25mm or more was acceptable. With five test sets, a comparison of reproducibility of the sets is achieved, i.e. if, in five 0.25mm weep holes 21, an incomplete shape of the solder paste appears, indicating that there is a risk of solder paste sagging in the 0.25mm weep holes 21, it is preferable to work with weep holes 21 having a diameter of 0.3mm or more.
Specifically, the device for detecting the shape of the lower tin can be observed by a microscope, or can be confirmed by testing the thickness of the tin paste by a tin paste thickness tester, or can be synchronously detected by the two methods. The above confirmation method is prior art and will not be described in detail herein.
A5, the solder paste on the lands 11 was heated and melted on the surfaces of the lands 11, and the distribution of the solder paste on the respective lands 11 and the spread area were confirmed. Specifically, the test board can be placed in an oven to be heated by melting the solder paste, if the molten solder paste liquids 1 can be collected together, as shown in fig. 6, the molten solder paste liquids 1 can be collected together to form a circle, the tin melting capability of the solder paste printing point printed by the leak hole with the aperture is qualified, otherwise, if the molten solder paste liquids 1 are distributed dispersedly, as shown in fig. 5, the solder paste liquids 1 are distributed into two parts, the tin melting capability is not qualified; and further detecting the spreading area of the solder paste liquid on the printing points with qualified tin melting capacity, and further confirming the relation between the printing amount and the spreading area so as to confirm the wettability of the solder paste.
In the present embodiment, the solder paste liquid is distributed dispersedly as shown in fig. 5 after the solder paste on the leak hole 21 with a diameter of 0.25mm is melted; the solder paste liquid after the solder paste on the leak hole 21 with the diameter of 0.3mm is melted is gathered as shown in FIG. 6, which shows that the solder paste printed on the leak hole 21 with the diameter of 0.25mm has unqualified tin melting capability; the tin melting capability of the tin paste on the leak hole 21 with the diameter of more than 0.3mm is qualified.
Observing the spreading area of the solder paste liquid 1 on the bonding pad 11, for example, the solder paste liquid 1 can spread 50% of the area of the bonding pad 11 after the solder paste printed on the leak hole 21 with the diameter of 0.3mm is melted, and the solder paste liquid 1 can spread 60% -70% of the area of the bonding pad 11 after the solder paste printed on the leak hole 21 with the diameter of 0.35mm is melted; on the other hand, the solder paste printed on the leak hole 21 having a diameter of 0.4mm is melted, and the solder paste liquid spreads over 80% or more of the area of the pad 11, and the wettability of the solder paste can be obtained from the relationship between the printing amount and the spread area.
The performance of the tin dropping property, the tin melting capability and the wettability of the tin paste can be detected at one time through the steps, and the method is simple, convenient and quick; and the adopted equipment has low cost.
In the embodiment, a plurality of groups of test groups are adopted for simultaneous detection, so that the accuracy is higher.
Further, in this embodiment, in step a5, the molten distribution and the spread area of the solder paste are confirmed by taking the solder paste with the complete lower tin shape in step a4, the defective lower tin property is not applied to the actual production, and the printed dots with the defective lower tin property are ignored, so that the efficiency can be effectively improved. Of course, in other embodiments, if the detection needs, the melting distribution of the printed dots with unqualified tin properties and the performance of the spreading area can be synchronously confirmed.
Further, in this embodiment, the shape of the leak 21 is the same as that of the pad 11, and the leak 21 and the corresponding pad 11 are concentrically arranged. Can guarantee that the solder paste printing point can be located the center of pad 11 after the printing, when the melting solder paste, the equidistance of solder paste liquid can expand outward. Of course, in other embodiments, if the size of the pad 11 is large enough, the pad may not be arranged concentrically.
Further, in the present embodiment, the leak hole 21 and the pad 11 are both circular. The circular leak hole has no sharp corner, when the printing plate 20 is removed, the influence of the removal of the printing plate 20 on the printing point of the solder paste is minimum, the circular pad is matched with the circular leak hole, and the equal-distance outward expansion of the solder paste liquid is realized. Of course, in other embodiments, the shapes of the leak 21 and the pad 11 may also be triangular, square, etc.
Example two
The method for testing the performance of the solder paste provided by the embodiment is substantially the same as the method provided by the first embodiment, and is different from the first embodiment in that: in this embodiment, in step a2, different solder pastes are printed in the leak holes 21 of the multiple test sets; in step a4, the shapes of the solder dropping from the leak holes 21 with the same aperture in the multiple test sets are also confirmed, so that the solder dropping from different solder pastes in the leak holes 21 with the same aperture can be synchronously confirmed. In step a5, the tin melting ability and wettability of multiple solder pastes were also tested simultaneously under the condition of the leak 21 with the same pore diameter. An effective comparison is made between the various solder pastes.
In the present embodiment, five different solder pastes are respectively corresponding to the five test sets, and in the wicking test of step a2, the shape printed on the leak 21 with a diameter of 0.2mm by only one of the solder pastes is a complete column, which indicates that the wicking property of the solder paste is better than that of other solder pastes. Similarly, in step A5, the same is true for the comparison of tin melting ability and wettability.
EXAMPLE III
The method for testing the performance of the solder paste provided by the embodiment is substantially the same as the method provided by the first embodiment or the second embodiment, and the difference is that: the number of the printing plates 20 is multiple, the thickness of the printing plates 20 is different, for example, in this embodiment, three printing plates 20 with different thicknesses are adopted, the thickness is 0.1mm, 0.15mm and 0.2mm, and the steps a1 to a5 are repeated by adopting the printing plates 20 with different thicknesses, so as to confirm the tin property, the melting distribution condition and the spreading area of the tin paste on the printing plates 20 with different thicknesses.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (9)
1. A method for testing the performance of solder paste is characterized in that: the method comprises the following steps:
a1, providing a test board and a printed board, wherein the test board is provided with a plurality of pads with the same size, the printed board is provided with a plurality of leak holes with gradually reduced apertures, and the printed board is laminated on the surface of the test board, so that the leak holes correspond to the pads on the test board one by one, and the sizes of the leak holes projected to the surface of the pads are smaller than those of the pads;
a2, printing solder paste on the surface of the printing plate, and printing the solder paste on the surface of the pad along the leakage hole;
a3, removing the printing plate;
a4, confirming the lower tin shape of the tin paste on each bonding pad so as to confirm the lower tin performance of the tin paste in leak holes with different apertures;
a5, heating the solder paste on the pads, melting the solder paste on the pad surfaces, and confirming the melting distribution and spread area of the solder paste on each pad.
2. The method for testing the performance of solder paste according to claim 1, wherein: in step a1, a plurality of leak holes with gradually decreasing pore diameters correspond to a plurality of pads with the same size on the test board one by one to form a group of test groups, and a plurality of groups of test groups are arranged on the test board and the printed board.
3. The method for testing the performance of solder paste according to claim 2, wherein: in step a2, the same solder paste is printed in the leak holes of the test sets; in step a4, the number of complete under-tin shapes in the same-diameter leak holes in the multiple test sets was also confirmed.
4. The method for testing the performance of solder paste according to claim 2, wherein: in step A2, printing different solder pastes in the leak holes of a plurality of test groups; in step a4, the shapes of the tin falling from the same-diameter holes in the test sets were also confirmed to confirm the tin falling performance of different solder pastes in the same-diameter holes.
5. A method for testing the performance of solder paste according to claim 1, 3 or 4, wherein: in step a5, the melting distribution and the spread area of the solder paste were confirmed by taking the solder paste with the intact shape of the lower tin in step a 4.
6. The method for testing the performance of solder paste according to claim 1, wherein: in step a4, the solder paste thickness is tested using a microscope and/or a solder paste thickness tester to confirm the under-tin shape of the solder paste on each pad.
7. The method for testing the performance of solder paste according to claim 1, wherein: the printing plates are provided with a plurality of printing plates with different thicknesses, and the steps A1 to A5 are repeated by adopting the printing plates with different thicknesses so as to confirm the tin dropping property, the melting distribution condition and the spreading area of the tin paste on the printing plates with different thicknesses.
8. The method for testing the performance of solder paste according to claim 1, wherein: the leak hole and the pad are the same in shape, and the leak hole and the corresponding pad are arranged concentrically.
9. The method of testing the performance of a solder paste of claim 8, further comprising: the leak hole and the bonding pad are both circular.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201911315083.2A CN110927356A (en) | 2019-12-19 | 2019-12-19 | Method for testing performance of solder paste |
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| CN201911315083.2A CN110927356A (en) | 2019-12-19 | 2019-12-19 | Method for testing performance of solder paste |
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| CN110927356A true CN110927356A (en) | 2020-03-27 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113960048A (en) * | 2021-10-19 | 2022-01-21 | 广东斯特纳新材料有限公司 | Solderability testing method of solder paste for MWT component |
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