KR101128146B1 - Printed Circuit Board - Google Patents

Abstract

In a printed circuit board according to an embodiment of the present invention, a plurality of pattern portions are provided in a predetermined region of the printed circuit board, and the pattern portion includes a plurality of electrode patterns and a plurality of through vias having the same center as the electrode pattern. The electrode patterns and the through vias corresponding to the electrode patterns each constitute one pattern symbol, and the plurality of pattern symbols constituting the pattern part evaluate the wettability evaluation region and lead filling resistance to evaluate wettability among soldering properties. It is characterized by consisting of a lead filling assessment area for.

According to the present invention as described above, it is possible to more quantitatively determine the soldering process state and the soldering characteristics of the insert-mount soldering process, and to determine the partial process anxiety factors such as flux coating, preheating, and soldering in the conventional soldering process, and the process anxiety. There is an advantage in that the degree to which the factor depends on the position on the printed circuit board can be confirmed.

Description

Printed Circuit Board

1 is a perspective view of a printed circuit board according to an embodiment of the present invention.

FIG. 2 is a front view of a pattern portion of the printed circuit board shown in FIG. 1.

3A and 3B are front and cross-sectional views of a pattern portion of a printed circuit board according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: printed circuit board 110, 210: pattern portion

112, 212: electrode patterns 114, 214: through vias

116, 216: pattern symbol 120, 220: wettability evaluation area

130, 230: lead filling evaluation area

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board, and more particularly, to a printed circuit board having a pattern portion for inspecting soldering characteristics of the printed circuit board.

A printed circuit board (PCB) refers to a thin plate on which electrical components such as integrated circuits, resistors, or switches are soldered, and various electrical components are mounted on both sides of the printed circuit board.

Here, the process of mounting the electrical components on the printed circuit board is divided into a surface mount and an insertion mount, wherein the insertion mount inserts and inserts the component for mounting mounting in the through-via of the printed circuit board, the component Flux is applied to the inserted printed circuit board, and then, after preheating of the wave equipment, the parts and the printed circuit board are joined by solder, and have electrical characteristics. It goes through the process.

Here, the soldering process is a process for electrically connecting the printed circuit board and the component, and has a great influence on the reliability of the printed circuit board on which the component is mounted.

The shape of the soldering portion formed by the soldering process is an important factor in determining the reliability of the electronic circuit as a whole, the inspection of the shape of the soldering portion plays a very important role in terms of improving the performance, reliability and quality of the product.

In addition, the reliability of the soldering characteristics of the solder in the soldering process can be determined by the solder filling and spreading (wetting), etc., the process conditions of the insertion mounting process by being able to quantitatively determine the filling and spreading of the solder The quality and reliability of printed circuit board products after optimization and soldering processes can be determined.

The filling of the solder is determined by the degree of solder filling in the through via, and the spreading of the solder is determined by the soldering degree of the electrode pattern through the through via.

In the conventional case, the solder used in the soldering process used a solder containing lead (Pb), and in the case of the solder containing lead, the soldering process such as the filling properties and spreadability of the solder was excellent in the soldering process, so that the process control was easy. .

However, due to the recent environmental regulations, lead-free solder has to be applied to the solder and lead-free solder has to be applied. There is a disadvantage that it requires continuous management afterwards.

In particular, the use of lead-free solder is a problem in the insertion and mounting process where lead filling and spreading are important.

In other words, the lead-free solder has a weak soldering property compared to the conventional solder, so that the various factors in the soldering process must be controlled very accurately, and the breakdown strength of the soldering site must be measured for the numerical evaluation. In addition to the disadvantages of expensive equipment, there are disadvantages in that the manufactured printed circuit board parts may be destroyed.

According to the present invention, a predetermined pattern portion for evaluating soldering characteristics is formed in an edge region of a printed circuit board, thereby evaluating riseability and spreadability of soldering characteristics in an insert mounting of a double-sided or multi-layered printed circuit board, thereby determining the appropriateness and soldering of an insert mounting process. It is an object of the present invention to provide a printed circuit board capable of determining characteristics.

In a printed circuit board according to an embodiment of the present invention, a plurality of pattern portions are provided in a predetermined region of the printed circuit board, and the pattern portion includes a plurality of electrode patterns and a plurality of through vias having the same center as the electrode patterns. It is characterized in that the configuration.

Here, the predetermined area is an edge area of the printed circuit board, and the electrode pattern and the through via corresponding to the electrode pattern each constitute one pattern symbol.

In addition, the electrode pattern is formed on the outer periphery of the corresponding through via, the center of the electrode pattern and the corresponding through via is the same, and a plurality of pattern symbols constituting the pattern portion wettability to evaluate the wettability of the soldering characteristics It is characterized by consisting of an evaluation area and a lead filling evaluation area for evaluating lead filling properties.

In addition, the electrode pattern constituting the pattern symbol of the wettability evaluation region is characterized in that at least two sizes or more, the through via corresponding to the electrode pattern is characterized in that the same size.

The through vias constituting the pattern symbol of the lead filling evaluation region may have at least two sizes, and an electrode pattern corresponding to the through vias may have a diameter larger than that of the through vias.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a perspective view of a printed circuit board according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the printed circuit board 100 according to the embodiment of the present invention is characterized in that a pattern portion 110 for evaluating soldering characteristics is formed in an edge region of the printed circuit board. In the case of FIG. 1, four 110 are illustrated, but the present disclosure is not limited thereto.

In general, the soldering process for printed circuit boards is difficult because the process such as flux application, preheating, soldering, etc. is difficult to maintain the process conditions on one printed circuit board due to equipment problems or other environmental problems. This will negatively affect the overall quality of the product.

In order to overcome the above problem, the present invention provides a pattern portion 110 as shown in the edge region of the printed circuit board 100, and the pattern portion 110 is formed in various regions of the printed circuit board 100. It is possible to determine the soldering process characteristics at each position by providing a plurality, it is possible to partially control the process to finally improve the quality of the printed circuit board.

That is, the present invention is for evaluating the soldering characteristics of the double-sided or multi-layer printed circuit board in the mounting of the mounting, in particular to evaluate the wettability and the filling properties. It is possible to determine the adequacy and soldering characteristics of the insertion-mounting process by further forming the pattern portion 110 for the evaluation of the soldering characteristics using the mass-produced printed circuit board 100 used in the general insertion-mounting process.

The pattern unit 110 includes a plurality of electrode patterns and a plurality of through vias having the same center as the electrode patterns.

A detailed configuration and operation of the pattern unit will be described with reference to FIGS. 2 and 3.

FIG. 2 is a front view of a pattern portion of the printed circuit board shown in FIG. 1.

As shown in FIG. 2, the pattern unit 110 is formed at an edge region of the printed circuit board and includes an electrode pattern 112 and a through via 114.

The electrode pattern 112 is formed to be larger than the through via 114 in a circular shape, and the through via 114 is formed to be smaller than the electrode pattern 112 in a circular shape, and each of the electrode patterns 112 and the through via ( 114 is identical in center.

Here, each of the electrode patterns 112 and corresponding through vias 114 is called a pattern symbol 116.

 In addition, the pattern unit 110 for evaluating the soldering characteristics is composed of a wettability evaluation region 120 for evaluating the wettability of the soldering properties and a lead filling evaluation region 130 for evaluating lead filling properties.

However, the electrode pattern 112 and the through via 114, that is, the pattern symbol 116 of the wettability evaluation region 120 and the lead filling evaluation region 130, are not separated.

The electrode pattern 112 of the wettability evaluation region 120 has at least two sizes to evaluate the wettability, whereas the through vias 114 corresponding to the electrode pattern 112 have the same size. do.

In addition, the through vias 114 of the lead filling evaluation region 130 have at least two through vias 114 formed in order to evaluate the lead filling properties, and the electrode patterns corresponding to the through vias 114. Silver 112 has a larger size than the through via 114.

Here, the diameter of the through via 114 in the lead filling evaluation region 130 is, for example, the smallest through via 114 is 0.1 mm, and if necessary, the diameter is 0.05 mm, or 0.1 mm units, with a maximum diameter of 0.5 mm. To configure at least two.

In addition, the size of the diameter of the electrode pattern 112 is 0.4 mm larger than the diameter of the largest through via 114 of the lead filling evaluation region 130 is configured on the outside of each through via 114.

The pattern portion 110 of the printed circuit board on which the lead filling evaluation region 130 is formed may be numerically determined according to the diameter of the lead via 114 in the soldering mounting process.

 In addition, the diameter of the through via 114 in the wettability evaluation region 120 is configured by at least two of the smallest through vias 114 having the same size as 0.1 mm or more, and the diameter size of the electrode pattern 112 is the through size. It is made at least 0.2 mm larger than the diameter of the via 114, and comprises at least 2 or more in 0.1 mm units.

The pattern part 110 of the printed circuit board on which the wettability evaluation region 120 is formed may numerically determine the wettability characteristic of lead according to the size of the electrode pattern 112 in the soldering mounting process.

The wettability of the solder is determined by the solder spreading area on the electrode pattern 112 on the opposite side of the printed circuit board surface that is in direct contact with the solder, that is, the surface that is not in direct contact with the solder, after the soldering process of the insert mounting process. It is determined that the solder fills the through via 114.

 These soldering characteristics are influenced by materials, process conditions, etc., and materials include plating characteristics and shapes, fluxes and solder characteristics of printed circuit boards and components, and process conditions include flux coating method, preheating conditions, solder temperature, and solder spraying. It depends on several factors, including speed, actual contact time and angle with the solder.

Evaluation of the final soldering process includes the wettability and lead filling of the solder on the printed circuit board, and the amount of lead, the shape of the solder joint, and the presence of a bridge (electro-mechanical connection) to the out electrode.

 The present invention is to quantitatively determine the wetting and filling of solder, which greatly affects the reliability of a printed circuit board product after the soldering process, and to continuously control the quality of the soldering process. A plurality of pattern parts 110 for evaluating soldering characteristics are provided in the edge region of the printed circuit board.

However, in the case of the pattern unit illustrated in FIG. 2, four electrode patterns 112 and through vias 114 are provided therein, but are not limited thereto. The electrode pattern 112 and the through vias 114 are not limited thereto. Increasing the number of can also allow a more detailed assessment of the soldering properties.

3A and 3B are front and cross-sectional views of a pattern portion of a printed circuit board according to an embodiment of the present invention.

An operation of the pattern unit according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3A and 3B.

The wettability of the soldering characteristics is determined by the solder spreading area on the electrode pattern 212 on the opposite side of the printed circuit board surface that is in direct contact with the solder, that is, the surface that is not in direct contact with the solder, after the soldering process of the soldering process. Among the characteristics, the filling property is determined as the filling property of the solder according to the size of the through via 214.

To this end, in the present invention, as shown in the drawing, a pattern portion 210 for soldering property evaluation is additionally formed on an existing printed circuit board used in an insertion process.

The pattern part may include a wettability evaluation region 220 and a lead filling evaluation region 230. The diameter of the through-via 214 may be 200 μm in the wettability evaluation region 220 and the lead filling evaluation region 230. Three pieces each having a size of 300 µm and 400 µm are formed, and the diameters of the electrode patterns 212 are formed to 100 µm up to 400 µm to 700 µm.

 The wettability evaluation region 220 of the soldering process includes a pattern symbol 216 (a) (b) and a pattern symbol composed of a through via 214 and an electrode pattern 212 each having a different diameter as shown. (D) through e) and f) through pattern symbols (h) and (h).

The wettability of the solder is advantageous as the difference between the electrode pattern 212 and the through via 214, that is, the smaller the size of the electrode pattern 212 provided outside the through via 214.

The pattern symbol (a) has a diameter of 200 mu m of the through via and 600 mu m of the electrode pattern. The electrode pattern around the through via is 200 mu m. The pattern symbol (b) has a through via diameter of 200 mu m and an electrode pattern 500 mu m, and an electrode pattern around the through via is 150 mu m. The pattern symbol (C) has a through via diameter of 200 mu m and an electrode pattern of 400 mu m, and an electrode pattern around the through via is formed at 100 mu m.

If a reliable high quality soldering process is performed, the electrode pattern of 100 µm, 150 µm and 200 µm of the pattern symbol (a) is completely soldered with the solder at the pattern symbol (a).

Here, the wettability evaluation of the soldering process is evaluated in the order of pattern symbols (a), (b) and (c). If the solder is completely soldered to the electrode of the pattern symbol (a), the wettability in the soldering process may be determined to have a wetting characteristic of 200㎛, the solder is not completely soldered to the electrode of the pattern symbol (a), the pattern When the electrode of the symbol (b) is completely soldered, the wettability may be determined to have a wettability of 150 μm to 200 μm. If a highly reliable printed circuit board soldering process is required, the soldering process conditions for the electrode pattern of the pattern symbol (a) are completely soldered with solder should be set.

 As in the above description, the pattern symbols (D), (E) and (F) are used for the wettability evaluation, and the pattern symbols (G), (H) and (I) are also used for the wettability evaluation as described above. .

 In addition, the lead filling evaluation region 5 of the soldering step includes pattern symbols (a), (d), (g), pattern symbols (b) (e) (h), and pattern symbols (c) (f) ( Tea).

In the pattern symbols (a), (d), and (g), the conditions of the soldering process are determined by checking lead filling properties in the through vias of the pattern symbols (a), (d) and (d).

When lead is completely filled in the through via of the pattern symbol (a), it can be said to have a lead filling characteristic of Φ200㎛. The pattern symbol (a) is not completely filled in lead and lead is formed in the through via of the pattern symbol (d). When fully loaded, the lead filling properties can be said to have a level of Φ 200 μm to Φ 300 μm.

 In the same manner as described above, the lead-carrying characteristics are evaluated by using the pattern symbols b) e) and the pattern symbols c) f).

 The wettability of lead is not independent because the wettability and the lead filling properties of the solder are not independent since lead is sufficiently filled through the through-via and then wetting begins with the electrode pattern.

The lead fillability is generally advantageous when the size of the through via is large. Therefore, in the pattern symbols (a), (b) and (c), where lead filling is most difficult, wetting of the solder is less likely to occur than the pattern symbols (a), (a) and (c).

If the lead filling degree satisfies the pattern symbol (B) but does not satisfy the pattern symbol (D) having a larger through-via size than the pattern symbol (B), it may be determined that there is a problem in the flux coating process.

Therefore, the soldering process can be improved by adjusting the flux coating process.

In addition, the wettability characteristics are evaluated in the order of pattern symbols (a), (b), (d), (c), (e), (4), (f), (h), and (c). If wetting is required, the wettability and the filling of the solder must fully satisfy the pattern symbol. If the pattern symbol is not satisfied, serious reliability problems may occur.

In addition, the wettability may be different between the pattern symbol D and the pattern symbol A having the same electrode pattern size. This is due to the lead filling ability since the through via size is 200 μm in the case of the pattern symbol A, which is smaller than 300 μm of the pattern symbol D.

This characteristic also occurs in the pattern symbol (b) and the pattern symbol (e), and also in the pattern symbol (c) and the pattern symbol (bar). However, if the wettability characteristic of the pattern symbol (a) is better than the wettability characteristic of the pattern symbol (d), the pattern symbol (a) is continuously affected by the application state of the flux and foreign matter on the electrode pattern or the effect of the preheating phenomenon. If the) (b) (c) group has better wettability than the pattern symbol (d) (d) (e) group, it is possible to improve the soldering process by checking the flux coating process, preheating section, soldering temperature and time.

  As described above, the evaluation of the characteristics of the soldering process can continuously manage the soldering process by determining the reliability level of the soldering process of the final printed circuit board product and determining whether the desired pattern symbol satisfies the wettability and lead filling resistance.

In addition, when the through via size is provided in a unit of 50 μm, the lead filling property may be further subdivided to quantitatively evaluate.

According to the present invention as described above, it is possible to more quantitatively determine the soldering process state and the soldering characteristics of the insert-mount soldering process, and to determine the partial process anxiety factors such as flux coating, preheating, and soldering in the conventional soldering process, and the process anxiety. There is an advantage in that the degree to which the factor depends on the position on the printed circuit board can be confirmed.

Claims (7)

A plurality of pattern parts are provided in a predetermined area of the printed circuit board, The pattern portion includes a plurality of electrode patterns and a plurality of through vias having the same center as the electrode pattern. Each of the electrode pattern and the through via corresponding to the electrode pattern constitutes one pattern symbol, A plurality of pattern symbols constituting the pattern portion is composed of a wetness evaluation region for evaluating the wettability of the soldering properties and a lead charge evaluation region for evaluating the lead filling properties, The electrode pattern constituting the pattern symbol of the wettability evaluation region is formed of at least two sizes, the through vias corresponding to the electrode pattern are configured of the same size, The through via constituting the pattern symbol of the lead filling evaluation region is formed of at least two sizes, and the electrode pattern corresponding to the through via has a larger diameter size than the through via. The method of claim 1, The predetermined area is a printed circuit board, characterized in that the edge area of the printed circuit board. delete The method of claim 1, The electrode pattern is formed on the outer periphery of the through via corresponding to the electrode pattern, the printed circuit board, characterized in that the center of the electrode pattern and the corresponding through via is the same. delete delete delete

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