CN115884528A

Movatterモバイル変換

Info

Publication number: CN115884528A
Application number: CN202111126902.6A
Authority: CN
Inventors: 张亚妹; 初英男; 林蓉; 王春克; 阎鹏朋; 曲忠波; 刘畅
Original assignee: Aerospace Science and Industry Inertia Technology Co Ltd
Current assignee: Aerospace Science and Industry Inertia Technology Co Ltd
Priority date: 2021-09-26
Filing date: 2021-09-26
Publication date: 2023-03-31

Abstract

The invention provides a tin bead prevention printing template opening method and a tin bead prevention printing template, and the method comprises the following steps: acquiring each welding terminal area of the QFN device and each welding pad area of the PCB; determining the distance between every two oppositely arranged welding ends; determining the distance between every two bonding pads; determining the length of the inner side end of each bonding pad extending out of the inner side end of the corresponding welding end; determining the length of the inner side end of each bonding pad extending out of the inner side end of the corresponding opening in the printing template and the length of the outer side end of each opening extending out of the outer side end of the corresponding bonding pad; determining the position of the inner side end and the position of the outer side end of an opening on a printing template; and determining the positions of the upper side end and the lower side end of the opening in the printing template according to the center distance between every two adjacent bonding pads, and determining the opening area of the printing template according to the positions of the inner side end, the outer side end, the upper side end and the lower side end of the opening in the printing template. The invention can solve the technical problem that the bottom of the QFN device generates tin bead surplus objects after welding at present.

Description

Translated fromChinese

一种防锡珠印刷模板开孔方法及防锡珠印刷模板A method for opening holes in an anti-tin bead printing template and an anti-tin bead printing template

技术领域technical field

本发明涉及电子装联技术领域，尤其涉及一种防锡珠印刷模板开孔方法及防锡珠印刷模板。The invention relates to the technical field of electronic assembly, in particular to a method for opening holes in an anti-tin bead printing template and an anti-tin bead printing template.

背景技术Background technique

随着电子产品多功能、小体积的发展趋势，元器件更加趋于小型化、高精密度集成化，QFN(Quad Flat Non-lead)器件是一种方形扁平无引脚封装的器件，器件本体底部四周有实现电气连接的导电焊端。此类器件具有封装体积小、集成度高、功率大等优点。但由于该类器件的引脚间距小，焊端不可见，在封装焊接后与焊盘焊锡连接形成底部焊点后，容易底部产生锡珠多余物，位于焊端与焊端之间，或者焊端与散热盘之间，减小电气绝缘间隙，甚至造成短路。由于底部焊点的隐藏性，锡珠无法通过拨除或清洗等方法清除，因此解决锡珠产生是亟须解决的重要课题。With the development trend of multi-function and small size of electronic products, components tend to be miniaturized and integrated with high precision. QFN (Quad Flat Non-lead) device is a quad flat non-lead packaged device. There are conductive solder terminals around the bottom to make the electrical connection. Such devices have the advantages of small package size, high integration, and high power. However, due to the small pin spacing of this type of device, the soldering end is not visible. After the package is soldered and connected with the pad solder to form the bottom solder joint, it is easy to generate excess tin beads at the bottom, which are located between the soldering end and the soldering end, or soldered Between the terminal and the heat sink, reduce the electrical insulation gap, or even cause a short circuit. Due to the hidden nature of the solder joints at the bottom, solder balls cannot be removed by removing or cleaning. Therefore, solving the problem of solder balls is an important issue that needs to be solved urgently.

在焊接前，印刷模板上设有开相应的开孔，利用印刷机的刮刀将焊锡膏填充到印刷模板的开孔中，印刷模板脱离PCB后，在PCB焊盘上留下了固定形状及厚度的锡膏。Before soldering, there are corresponding openings on the printing template. Use the scraper of the printing machine to fill the solder paste into the openings of the printing template. After the printing template is separated from the PCB, a fixed shape and thickness are left on the PCB pad. of solder paste.

为了避免上述底部锡珠多余物的情况，现有技术提供了两种方法：In order to avoid the above-mentioned situation of excess tin beads at the bottom, the prior art provides two methods:

一、目前用于印刷产品PCB的印刷模板的厚度为0.13mm、0.12mm、0.1mm，可通过更改印刷模板的厚度对QFN器件的锡量进行整体控制，但由于产品上的器件间距差异较大，对印刷模板的厚度要求不一，所以整体减小印刷模板的厚度容易引起其它器件由于锡膏量不足引发的焊点缺陷。1. At present, the thickness of the printing template used to print the PCB of the product is 0.13mm, 0.12mm, 0.1mm. The tin amount of the QFN device can be controlled as a whole by changing the thickness of the printing template, but due to the large difference in the device spacing on the product , There are different requirements for the thickness of the printing stencil, so reducing the thickness of the printing stencil as a whole is likely to cause solder joint defects in other devices due to insufficient solder paste.

二、目前可通过阶梯印刷模板的设计方案实现局部锡量控制。但由于器件布局密度大，阶梯印刷模板的梯度不易实现，而且在印刷机刮刀压力的控制上也增加了难度，印刷模板成本也会增加。2. At present, the local tin quantity control can be realized through the design scheme of the step printing template. However, due to the high density of the device layout, the gradient of the step printing template is not easy to realize, and it is also more difficult to control the pressure of the squeegee of the printing machine, and the cost of the printing template will also increase.

发明内容Contents of the invention

本发明提供了一种防锡珠印刷模板开孔方法及防锡珠印刷模板，能够解决目前QFN器件焊接后底部产生锡珠多余物的技术问题。The invention provides a method for opening holes in an anti-tin ball printing template and an anti-tin ball printing template, which can solve the current technical problem of redundant tin balls at the bottom of a QFN device after welding.

根据本发明的一方面，提供了一种防锡珠印刷模板开孔方法，所述方法包括：According to one aspect of the present invention, a method for opening holes in an anti-tin ball printing template is provided, the method comprising:

获取QFN器件的每个焊端区域和PCB的每个焊盘区域，每个焊端区域与每个焊盘区域一一对应设置；Obtain each pad area of the QFN device and each pad area of the PCB, and each pad area is set in one-to-one correspondence with each pad area;

根据QFN器件的每个焊端区域确定不在同一条边上的每两个相对设置的焊端之间的间距；Determining the distance between every two oppositely arranged solder ends that are not on the same side according to each solder end area of the QFN device;

根据PCB的每个焊盘区域确定与每两个相对设置的焊端相对应的两个焊盘之间的间距；Determining the spacing between two pads corresponding to each two oppositely disposed soldering ends according to each pad area of the PCB;

将QFN器件放置在PCB上，使每个焊端区域与每个焊盘区域一一对应，根据每两个相对设置的焊端之间的间距和每两个相对设置的焊盘之间的间距确定每个焊盘的内侧端伸出对应焊端的内侧端的长度；Place the QFN device on the PCB so that each solder terminal area corresponds to each pad area one by one, according to the spacing between every two oppositely arranged solder terminals and the distance between every two oppositely arranged pads determine the length by which the inner end of each land extends beyond the inner end of the corresponding solder end;

根据每个焊盘的内侧端伸出对应焊端的内侧端的长度确定每个焊盘的内侧端伸出印刷模板上对应开孔的内侧端的长度和每个开孔的外侧端伸出对应焊盘的外侧端的长度；Determine the length of the inner end of each pad protruding from the inner end of the corresponding opening on the printed template and the length of the outer end of each opening protruding from the corresponding pad according to the length of the inner end of each pad protruding from the inner end of the corresponding solder end. the length of the outboard end;

根据每个焊盘的内侧端伸出印刷模板上对应开孔的内侧端的长度和每个开孔的外侧端伸出对应焊盘的外侧端的长度确定印刷模板上开孔的内侧端位置和外侧端位置；Determine the position of the inner end and the outer end of the opening on the printing template according to the length of the inner end of each pad protruding from the inner end of the corresponding opening on the printing template and the length of the outer end of each opening extending from the outer end of the corresponding pad. Location;

根据每两个相邻焊盘的中心间距确定印刷模板上开孔的上侧端位置与下侧端位置，并根据印刷模板上开孔的内侧端位置、外侧端位置、上侧端位置与下侧端位置确定印刷模板的开孔区域。Determine the position of the upper end and the lower end of the opening on the printing template according to the center distance between each two adjacent pads, and according to the inner end position, outer end position, upper end position and lower end position of the opening on the printing template The position of the side ends determines the opening area of the printing stencil.

优选的，通过下式确定每个焊盘的内侧端伸出对应焊端的内侧端的长度：Preferably, the length of the inner end of each pad protruding from the inner end of the corresponding solder end is determined by the following formula:

m＝(a-A)/2；m=(a-A)/2;

式中，m为每个焊盘的内侧端伸出对应焊端的内侧端的长度，A为每两个相对设置的焊盘之间的间距，a为每两个相对设置的焊端之间的间距，m＞0。In the formula, m is the length of the inner end of each pad protruding from the inner end of the corresponding welding end, A is the distance between every two oppositely arranged pads, and a is the distance between every two oppositely arranged welding ends , m>0.

优选的，通过下式确定每个焊盘的内侧端伸出印刷模板上对应开孔的内侧端的长度：Preferably, the length of the inner end of each pad protruding from the inner end of the corresponding opening on the printing template is determined by the following formula:

X＝m+Δt；X=m+Δt;

其中，0≤Δt＜0.1mm；Among them, 0≤Δt<0.1mm;

式中，X为每个焊盘的内侧端伸出印刷模板上对应开孔的内侧端的长度。In the formula, X is the length of the inner end of each pad protruding from the inner end of the corresponding opening on the printing template.

优选的，每个开孔的外侧端伸出对应焊盘的外侧端的长度满足下式：Preferably, the length of the outer end of each opening protruding from the outer end of the corresponding pad satisfies the following formula:

0≤X1≤X；0≤X1≤X;

式中，X1为每个开孔的外侧端伸出对应焊盘的外侧端的长度，X为每个焊盘的内侧端伸出印刷模板上对应开孔的内侧端的长度。In the formula, X1 is the length of the outer end of each opening protruding from the outer end of the corresponding pad, and X is the length of the inner end of each pad protruding from the inner end of the corresponding opening on the printing template.

优选的，获取QFN器件的每个焊端区域包括：通过QFN器件手册获取QFN器件的每个焊端区域。Preferably, obtaining each welding terminal region of the QFN device includes: obtaining each welding terminal region of the QFN device through a QFN device manual.

优选的，获取PCB的每个焊盘区域包括：通过PCB文件获取PCB的每个焊盘区域。Preferably, acquiring each pad area of the PCB includes: acquiring each pad area of the PCB through a PCB file.

优选的，所述开孔的形状与所述焊盘的形状相适配。Preferably, the shape of the opening matches the shape of the pad.

根据本发明的又一方面，提供了一种防锡珠印刷模板，所述印刷模板包括开孔，所述开孔采用上述任一所述方法获得。According to still another aspect of the present invention, there is provided an anti-tin ball printing template, the printing template includes openings, and the openings are obtained by any one of the methods described above.

优选的，所述印刷模板的厚度大于0.1mm。Preferably, the thickness of the printing template is greater than 0.1 mm.

应用本发明的技术方案，根据焊盘与焊端的相对位置确定焊盘的实际焊接区域，再根据焊盘的实际焊接区域在印刷模板的对应区域上开孔，即通过改变印刷模板的开孔位置及形状尺寸，无需减薄印刷模板的厚度，可以在不减少焊锡量的情况下解决焊接后锡珠多余物的问题；同时，本发明根据各个QFN器件的焊盘位置进行针对性的开孔，不会造成整体缺失比例的增加。本发明的技术方案仅在二维平面上更改了开孔位置和形状，就达到了局部保持焊膏量、避免锡珠多余物的效果，与现有技术的三维阶梯印刷模板相比，设计更简单，更容易实现，而且成本更低。Applying the technical solution of the present invention, the actual welding area of the pad is determined according to the relative position of the pad and the welding end, and then holes are opened in the corresponding area of the printing template according to the actual welding area of the pad, that is, by changing the opening position of the printing template And the shape and size, without reducing the thickness of the printing template, can solve the problem of excess solder beads after soldering without reducing the amount of solder; at the same time, the present invention performs targeted openings according to the pad positions of each QFN device, It will not cause an increase in the overall missing ratio. The technical scheme of the present invention only changes the position and shape of the opening on the two-dimensional plane, and achieves the effect of locally maintaining the amount of solder paste and avoiding excess solder beads. Compared with the three-dimensional step printing template of the prior art, the design is more Simple, easier to implement, and less expensive.

附图说明Description of drawings

所包括的附图用来提供对本发明实施例的进一步的理解，其构成了说明书的一部分，用于例示本发明的实施例，并与文字描述一起来阐释本发明的原理。显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。The accompanying drawings are included to provide further understanding of the embodiments of the invention, and constitute a part of the specification, are used to illustrate the embodiments of the invention, and together with the description, explain the principle of the invention. Apparently, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings according to these drawings without creative efforts.

图1示出了根据本发明的一种实施例提供的防锡珠印刷模板开孔方法的流程图；Fig. 1 shows the flowchart of the method for opening holes in the anti-tin ball printing template provided according to an embodiment of the present invention;

图2示出了根据本发明的一种实施例提供的印刷模板的结构示意图；Fig. 2 shows a schematic structural view of a printing template provided according to an embodiment of the present invention;

图3示出了QFN器件的结构示意图；Fig. 3 shows the structural representation of QFN device;

图4示出了PCB的结构示意图；Figure 4 shows a schematic structural view of the PCB;

图5示出了QFN器件安装在PCB上的示意图；Fig. 5 shows the schematic diagram that QFN device is installed on PCB;

图6示出了根据本发明的一种实施例提供的印刷模板的开孔、QFN器件的焊端与PCB的焊盘重合后的示意图。Fig. 6 shows a schematic diagram of the holes of the printing template provided according to an embodiment of the present invention, the soldering end of the QFN device and the soldering pad of the PCB overlapped.

其中，上述附图包括以下附图标记：Wherein, the above-mentioned accompanying drawings include the following reference signs:

10、印刷模板；11、开孔；111、开孔的内侧端；112、开孔的外侧端；113、开孔的上侧端；114、开孔的下侧端；20、QFN器件；21、焊端；211、焊端的内侧端；212、焊端的上侧端；213、焊端的下侧端；30、PCB；31、焊盘；311、焊盘的内侧端；312、焊盘的外侧端。10, printing template; 11, opening; 111, inner side end of opening; 112, outer side end of opening; 113, upper side end of opening; 114, lower side end of opening; 20, QFN device; 21 , welding end; 211, inner side of welding end; 212, upper side of welding end; 213, lower side of welding end; 30, PCB; 31, welding pad; 311, inner side of welding pad; 312, outer side of welding pad end.

具体实施方式Detailed ways

需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本发明及其应用或使用的任何限制。基于本发明中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. The following description of at least one exemplary embodiment is merely illustrative in nature and in no way taken as limiting the invention, its application or uses. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

需要注意的是，这里所使用的术语仅是为了描述具体实施方式，而非意图限制根据本申请的示例性实施方式。如在这里所使用的，除非上下文另外明确指出，否则单数形式也意图包括复数形式，此外，还应当理解的是，当在本说明书中使用术语“包含”和/或“包括”时，其指明存在特征、步骤、操作、器件、组件和/或它们的组合。It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

除非另外具体说明，否则在这些实施例中阐述的部件和步骤的相对布置、数字表达式和数值不限制本发明的范围。同时，应当明白，为了便于描述，附图中所示出的各个部分的尺寸并不是按照实际的比例关系绘制的。对于相关领域普通技术人员已知的技术、方法和设备可能不作详细讨论，但在适当情况下，所述技术、方法和设备应当被视为授权说明书的一部分。在这里示出和讨论的所有示例中，任何具体值应被解释为仅仅是示例性的，而不是作为限制。因此，示例性实施例的其它示例可以具有不同的值。应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步讨论。The relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. At the same time, it should be understood that, for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered part of the Authorized Specification. In all examples shown and discussed herein, any specific values should be construed as exemplary only, and not as limitations. Therefore, other examples of the exemplary embodiment may have different values. It should be noted that like numerals and letters denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

如图1所示，本发明提供了一种防锡珠印刷模板开孔方法，所述方法包括：As shown in Figure 1, the present invention provides a method for opening holes in an anti-tin ball printing template, the method comprising:

S10、获取QFN器件20的每个焊端21区域和PCB30的每个焊盘31区域，每个焊端21区域与每个焊盘31区域一一对应设置；S10, obtaining eachpad 21 area of theQFN device 20 and eachpad 31 area of thePCB 30, eachpad 21 area is set in a one-to-one correspondence with eachpad 31 area;

S20、根据QFN器件20的每个焊端21区域确定不在同一条边上的每两个相对设置的焊端21之间的间距；S20, according to the area of eachwelding terminal 21 of theQFN device 20, determine the spacing between every two oppositely arrangedwelding terminals 21 that are not on the same side;

S30、根据PCB30的每个焊盘31区域确定与每两个相对设置的焊端21相对应的两个焊盘31之间的间距；S30, according to the area of eachpad 31 of thePCB 30, determine the distance between the twopads 31 corresponding to each two oppositely arrangedpads 21;

S40、将QFN器件20放置在PCB30上，使每个焊端21区域与每个焊盘31区域一一对应，根据每两个相对设置的焊端21之间的间距和每两个相对设置的焊盘31之间的间距确定每个焊盘的内侧端311伸出对应焊端的内侧端211的长度；S40, placing theQFN device 20 on thePCB 30, so that eachwelding terminal 21 area corresponds to eachwelding pad 31 area one by one, according to the spacing between every two oppositely arrangedwelding terminals 21 and every two oppositely arranged The spacing between thepads 31 determines the length by which theinner end 311 of each pad protrudes from theinner end 211 of the corresponding solder end;

S50、根据每个焊盘的内侧端311伸出对应焊端的内侧端211的长度确定每个焊盘的内侧端311伸出印刷模板10上对应开孔的内侧端111的长度和每个开孔的外侧端112伸出对应焊盘的外侧端312的长度；S50, according to the length of theinner end 311 of each pad protruding from theinner end 211 of the corresponding welding end, determine the length of theinner end 311 of each pad extending from theinner end 111 of the corresponding opening on theprinting template 10 and each opening Theouter end 112 of the corresponding pad extends out the length of theouter end 312;

S60、根据每个焊盘的内侧端311伸出印刷模板10上对应开孔的内侧端111的长度和每个开孔的外侧端112伸出对应焊盘的外侧端312的长度确定印刷模板10上开孔的内侧端111位置和外侧端位置；S60. Determine theprinting template 10 according to the length of theinner end 311 of each pad protruding from theinner end 111 of the corresponding opening on theprinting template 10 and the length of theouter end 112 of each opening extending from theouter end 312 of the corresponding pad. The position of theinner end 111 and the outer end of the upper opening;

S70、根据每两个相邻焊盘31的中心间距D确定印刷模板10上开孔的上侧端113位置与下侧端114位置，并根据印刷模板上开孔的内侧端位置、外侧端位置、上侧端位置与下侧端位置确定印刷模板10的开孔11区域。S70. Determine the position of theupper end 113 and thelower end 114 of the opening on theprinting template 10 according to the distance D between the centers of every twoadjacent pads 31, and according to the position of the inner end and the outer end of the opening on the printing template , the position of the upper side end and the position of the lower side end determine the area of theopening 11 of theprinting template 10 .

本发明根据焊盘31与焊端21的相对位置确定焊盘31的实际焊接区域，再根据焊盘31的实际焊接区域在印刷模板10的对应区域上开孔11，即通过改变印刷模板10的开孔11位置及形状尺寸，无需减薄印刷模板10的厚度，可以在不减少焊锡量的情况下解决焊接后锡珠多余物的问题；同时，本发明根据各个QFN器件20的焊盘31位置进行针对性的开孔11，不会造成整体缺失比例的增加。本发明的技术方案仅在二维平面上更改了开孔11位置和形状，就达到了局部保持焊膏量、避免锡珠多余物的效果，与现有技术的三维阶梯印刷模板10相比，设计更简单，更容易实现，而且成本更低。The present invention determines the actual welding area of thepad 31 according to the relative position of thepad 31 and thewelding end 21, and then opens ahole 11 in the corresponding area of theprinting template 10 according to the actual welding area of thepad 31, that is, by changing the position of theprinting template 10 The position and size of theopening 11 do not need to thin the thickness of theprinting template 10, and can solve the problem of excess tin balls after welding without reducing the amount of solder; meanwhile, the present invention according to the positions of thepads 31 of eachQFN device 20 Targetedopening 11 will not cause an increase in the overall missing ratio. The technical solution of the present invention only changes the position and shape of theopening 11 on the two-dimensional plane, and achieves the effect of locally maintaining the amount of solder paste and avoiding excess solder beads. Compared with the three-dimensionalstep printing template 10 of the prior art, The design is simpler, easier to implement, and less expensive.

在本实施中，开孔11的形状与焊盘31的形状相适配。具体地，开孔11的形状与焊盘31的形状相同，但开孔11的位置、尺寸与焊盘31的位置、尺寸均不同，如图2和图3所示。In this embodiment, the shape of theopening 11 matches the shape of thepad 31 . Specifically, the shape of thehole 11 is the same as that of thepad 31 , but the position and size of thehole 11 are different from those of thepad 31 , as shown in FIG. 2 and FIG. 3 .

在本实施例中，QFN器件20的每条边上设置5个焊端21，如图3所示；对应的，PCB30的每一侧设置5个与焊端21一一对应的焊盘31，如图4所示；对应的，印刷模板10的每一侧设置5个与焊盘31一一对应的开孔11，如图2所示。In this embodiment, fivewelding terminals 21 are arranged on each side of theQFN device 20, as shown in FIG. As shown in FIG. 4 ; correspondingly, fiveopenings 11 corresponding to thepads 31 are provided on each side of theprinting template 10 , as shown in FIG. 2 .

根据本发明的一种实施例，在本发明的S10中，获取QFN器件20的每个焊端21区域包括：通过QFN器件手册获取QFN器件20的每个焊端21区域。获取PCB30的每个焊盘31区域包括：通过PCB文件获取PCB30的每个焊盘31区域。According to an embodiment of the present invention, in S10 of the present invention, obtaining eachpad 21 area of theQFN device 20 includes: obtaining eachpad 21 area of theQFN device 20 through the QFN device manual. Obtaining eachpad 31 area of thePCB 30 includes: acquiring eachpad 31 area of thePCB 30 through a PCB file.

如图5所示，根据本发明的一种实施例，在本发明的S40中，通过下式确定每个焊盘的内侧端311伸出对应焊端的内侧端211的长度：As shown in FIG. 5, according to an embodiment of the present invention, in S40 of the present invention, the length of theinner end 311 of each pad protruding from theinner end 211 of the corresponding welding end is determined by the following formula:

m＝(a-A)/2；m=(a-A)/2;

如图6所示，根据本发明的一种实施例，通过下式确定每个焊盘的内侧端311伸出印刷模板10上对应开孔的内侧端111的长度：As shown in FIG. 6, according to an embodiment of the present invention, the length of theinner end 311 of each pad protruding from theinner end 111 of the corresponding opening on theprinting template 10 is determined by the following formula:

X＝m+Δt；X=m+Δt;

其中，0≤Δt＜0.1mm；Among them, 0≤Δt<0.1mm;

进一步地，在0＜Δt＜0.1mm的情况下，可以进一步避免锡珠多余物的产生。Furthermore, under the condition of 0<Δt<0.1 mm, the occurrence of redundant solder balls can be further avoided.

根据本发明的一种实施例，每个开孔的外侧端112伸出对应焊盘的外侧端312的长度满足下式：According to an embodiment of the present invention, the length of theouter end 112 of each opening protruding from theouter end 312 of the corresponding pad satisfies the following formula:

0≤X1≤X；0≤X1≤X;

进一步地，在X1＝X的情况下，也就是说，焊盘31的长度与开孔11的长度相同的情况下，可以进一步确保焊膏量充足，避免因焊膏量不够而产生焊接缺陷。Further, in the case of X1=X, that is to say, the length of thepad 31 is the same as the length of theopening 11 , it is possible to further ensure sufficient amount of solder paste and avoid soldering defects due to insufficient amount of solder paste.

在本实施例中，若每两个相邻焊盘31的中心间距D为0.5mm，则印刷模板10上开孔的上侧端113位置与下侧端114位置之间的间距为0.23mm。具体地，可以根据现有焊接策略进行确定。In this embodiment, if the distance D between the centers of every twoadjacent pads 31 is 0.5 mm, the distance between theupper end 113 and thelower end 114 of the opening on theprinting template 10 is 0.23 mm. Specifically, it can be determined according to an existing welding strategy.

采用上述方法获得完成开孔11的印刷模板10后，将完成开孔11的印刷模板10覆盖在PCB30的对应位置上，以完成焊膏的印刷，然后进行焊接，以避免焊接后产生锡珠多余物。After the printedtemplate 10 with theholes 11 is obtained by the above method, cover the printedtemplate 10 with theholes 11 on the corresponding position of thePCB 30 to complete the printing of the solder paste, and then perform soldering to avoid unnecessary tin beads after soldering thing.

根据本发明的又一方面，提供了一种防锡珠印刷模板，所述印刷模板10包括开孔11，所述开孔11采用上述任一所述方法获得。According to still another aspect of the present invention, an anti-tin ball printing template is provided, theprinting template 10 includes anopening 11, and theopening 11 is obtained by any of the methods described above.

根据本发明的一种实施例，所述开孔11的形状与所述焊盘31的形状相适配。具体地，开孔11的形状与焊盘31的形状相同，但开孔11的位置、尺寸与焊盘31的位置、尺寸均不同，如图2和图3所示。According to an embodiment of the present invention, the shape of theopening 11 is adapted to the shape of thepad 31 . Specifically, the shape of thehole 11 is the same as that of thepad 31 , but the position and size of thehole 11 are different from those of thepad 31 , as shown in FIG. 2 and FIG. 3 .

根据本发明的一种实施例，所述印刷模板10的厚度大于0.1mm，以避免因焊膏量不够而产生焊接缺陷。According to an embodiment of the present invention, the thickness of theprinting template 10 is greater than 0.1 mm, so as to avoid welding defects due to insufficient amount of solder paste.

为了便于描述，在这里可以使用空间相对术语，如“在……之上”、“在……上方”、“在……上表面”、“上面的”等，用来描述如在图中所示的一个器件或特征与其他器件或特征的空间位置关系。应当理解的是，空间相对术语旨在包含除了器件在图中所描述的方位之外的在使用或操作中的不同方位。例如，如果附图中的器件被倒置，则描述为“在其他器件或构造上方”或“在其他器件或构造之上”的器件之后将被定位为“在其他器件或构造下方”或“在其他器件或构造之下”。因而，示例性术语“在……上方”可以包括“在……上方”和“在……下方”两种方位。该器件也可以其他不同方式定位(旋转90度或处于其他方位)，并且对这里所使用的空间相对描述作出相应解释。For the convenience of description, spatially relative terms may be used here, such as "on ...", "over ...", "on the surface of ...", "above", etc., to describe the The spatial positional relationship between one device or feature shown and other devices or features. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, devices described as "above" or "above" other devices or configurations would then be oriented "beneath" or "above" the other devices or configurations. under other devices or configurations”. Thus, the exemplary term "above" can encompass both an orientation of "above" and "beneath". The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

此外，需要说明的是，使用“第一”、“第二”等词语来限定零部件，仅仅是为了便于对相应零部件进行区别，如没有另行声明，上述词语并没有特殊含义，因此不能理解为对本发明保护范围的限制。In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing corresponding components. To limit the protection scope of the present invention.

以上所述仅为本发明的优选实施例而已，并不用于限制本发明，对于本领域的技术人员来说，本发明可以有各种更改和变化。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.