TW200425809A - Printed steel plate and process applied in SMT assembly of SMT electronic components - Google Patents

Abstract

There is provided a printed steel plate applied in SMT assembly of SMT electronic components, which is used to coat conductive adhesive layer on the solder pads on the surface of PCB. The solder pads correspond to the contact electrodes of the SMT electronic components. Plural hollowed trapezoid openings are formed on the printed steel plate, which are exactly corresponding to the solder pads, so that conductive adhesive layer is coated on the solder pads via the trapezoid openings. Because the conductive adhesive layer coated on the solder pads also have trapezoid shapes, only a slight extension to two sides incurs even through they are squeezed by the contact electrodes, thereby avoiding the defects such as the generation of bridge short circuit or void soldering.

Description

200425809 V. Description of the invention (1) The technical field to which the invention belongs: The present invention relates to a surface mounting technology (SMT) of electronic parts, and particularly relates to a printing method for surface adhesive assembly of electronic parts Steel plates and related processes. Previous technology: With the advancement of integrated circuit manufacturing technology, the design and production of electronic components continue to trend toward miniaturization, and because of its larger-scale, high-integration electronic circuits, its product functions have also become more complete. In this case, the filled hole insert type component (Through Hole Technology; TjiT) will occupy a large amount of space on the printed circuit board because the size cannot be further reduced. Coupled with the "plug-in type" assembly method, it is necessary for each pin: place: 'Same ::: The pin of the piece will actually occupy the workshop on both sides of the printed circuit board, and the solder joint at the u joint Also relatively large

Technology; SMT) ^ V Λ V "# The electronic components are assembled on the printed circuit board. Use surface mount packaged parts on the same side of the printed circuit board as this to provide each pin insertion. In other words, the space utilization of the circuit board can be achieved on both sides of the printed circuit board at the same time. In addition, it is smaller and denser than printed circuit board parts compared to traditional perforation. “Since its pins are soldered on and the parts do not need to drill holes in the printed circuit board,” after using surface adhesion technology, , Will be electronic components, and greatly increase the surface-attached parts (SMT) volume plug-in parts (THT), using SMT technology a lot. Plus the manufacturing of SMT package parts

200425809 V. Description of the invention (2) I: also 2 t will be two because Λ has jumped to become the main part of the assembly process of today's printed circuit boards. The volume of electronic parts has continued to shrink, and it has also encountered considerable problems in SMT technology. Difficulties. The most basic and necessary component of the M Ganyan 1 product is the resistor, which is used as an example. The voltage and current in the electronic circuit are adjusted by Guang U. Therefore, for example, electric time system σσ such as computers, computers and peripheral equipment, Televisions, mobile phones, and instruments all require heavy use of resistors. In particular, due to the needs of resistors, it tends to have small specifications, high power, high quality stability, high accuracy, and complexity. It is the exclusion of wafers used in surface adhesion technology because of the precision and complexity of products. It is widely used in high value-added industries such as computers, communications, space military, and technology, and has become the mainstream of market development. However, with the size specification of the new generation of thick film resistors, the size has been reduced from 0 6 0 3 (1.6x0.8x0.45 mm) to 0402 size (1X 0.5x 0.35 coffee,). The volume of the 0 2 row group is more than 50% smaller than that of the 0 6 0 3 package row. Therefore, when the SMT technology is used to assemble on a printed circuit board, the adjacent pads are often densely arranged and the size is small. As a result, defects such as empty soldering or short-circuiting occur in the printed coated conductive adhesive after the reflow process. f Please refer to the first figure, which shows a typical 0 40 2 size bank structure 10. As shown in the figure, the bank structure 10 includes an alumina substrate 2 and a thick film resistor layer 14 formed on the surface of the alumina ceramic substrate 12. In thick film

Page 5 200425809 V. Description of the invention (3) On the surface of the resist layer 14 and the alumina ceramic substrate 丨 2, it means that the number of electrodes 18 on the bottom surface of the bank structure 10 is connected to all of them. Mentioned thick film resistor layer 丨 4. In other words, according to the two electrodes 18 distributed on the alumina ceramic substrate 12 sides, the terminal electrodes 18a at the four corners and the electrodes 18b on the side of the substrate can be distinguished. As shown in the figure, the terminal electrode 18a is a line-shaped electrode 18b along the line of the line "t". In this way, when the rod =, f is slightly larger than the length: more: by welding these electrodes 18 to the printed electrical and adhesive technology, the purpose of group 1 is to fix the parts. In the surface bonding process, Dashi will first apply conductive adhesive to the pads of the printed circuit board. The method of $ :: brushing is described as an example. The chip array is fabricated on the second printed circuit. [The second figure, there are eight above, arranged in two rows, and each f = rectangular solder pad 20 total 1 8 . When conducting the conductive adhesive coating, the electrode circuit board on the substrate 10 is formed. This steel plate 22 has eight rectangular openings 2 and 4 opposite 2 covering the printed rectangular pads 20 described above, so that the openings 24 are exposed at the coating process 2 respectively, and the conductive adhesive is applied to the rectangular pads 2] = Those of these moments j After removing the steel plate 22, each of the rectangular soldering pads I * So-come 'the electric adhesive layer. Then you can move. The 402 row structure has a 10c-shaped guide, and is assembled and fixed by a subsequent reflow process. The electrodes 18 of the pads 2 and the pads 20 are electrically connected. Make the row structure 1 inch advance. However, it is worth noting that the specifications of the row group are changed from the original 0603 feet. Impressive appearance. The group question is based on the question, and the sticky and equivalence question list lacks its brilliance: the upper part is empty to zero or the inner needle Lu Mingdian short hair is connected 200425809 V. Description of the invention (4), Enter 0 4 0 2 size Later, because the distance between adjacent conductive adhesives is reduced to about 8m i 1, and when the row structure 10 is placed, it is squeezed by the electrodes 18, and the rectangular conductive adhesive layer often faces two Side edge spread, so it is easy to cause welding mistakes in subsequent reflow procedures. Especially when the conductive adhesive layer is melted by heat, the adjacent conductive adhesive may flow and bridge, which may cause short-circuit effect, or may be pulled by the surface tension of the solder ball, causing some electrodes to be soldered. In this way, in addition to reducing the assembly yield of related parts, it also requires more labor costs to perform repair and inspection work. In addition, in order to further reduce the size of various electronic components to improve the integration degree and related performance of printed circuit boards, the new chip array group has been reduced from 0 4 0 2 size to 0 2 0 1 size specification. It is foreseeable that under the 0 2 0 1 size specification, the distance between the rectangular conductive adhesives will be further reduced, and the above short-circuit or air-soldering problems will become more severe. In order to achieve the above purpose, the present invention provides a surface adhesion electron Parts printed steel plate design. This printed steel plate is used to apply conductive adhesive layer to printed circuits

Page 7 200425809 V. Description of the invention (5),. On the pads on the surface of the board, these pads correspond to the contact electrodes of the electronic parts on the surface. The printed steel plate has a plurality of trapezoidal openings, which correspond to these pads, so that a trapezoidal conductive adhesive layer is coated on the pads through the trapezoidal openings. In one embodiment, the openings on the surface of the printed steel sheet and the electronic parts can be arranged in two rows parallel to each other. According to the positions of the openings in each row, they can be divided into a first trapezoidal opening and Second trapezoidal opening. The first trapezoidal openings are located at both ends of each row of openings. Each first trapezoidal opening has a first short side and a first long side that are parallel to each other. The first long side is closer to the opening of the other row, and the first short side is farther from the opening of the other row. The second trapezoidal opening is located between the left and right first trapezoidal openings. Each second trapezoidal opening also has a second short side and a second long side that are parallel to each other. The second short side is closer to the other row of openings. The side is farther away from the other row of openings. By coating the printed steel plate on the printed circuit board, a conductive adhesive layer can be coated on the surface of each pad. The first conductive adhesive layer coated by the first trapezoidal opening also has a first short side and a first long side that are parallel to each other. The first long side is on the outside of the pad, and the first short side is on the inside of the pad. As for the second conductive adhesive layer applied through the second trapezoidal opening, it also has a second short side and a second long side that are parallel to each other. The second short side is on the inside of the pad, and the second long side is on the outside of the pad. After the printed steel plate is removed, the surface can be placed with printed electronic parts

Page 8 200425809 V. Description of the invention (6), on a circuit board ', each electrode touches the corresponding conductive adhesive layer. Next, a reflow process is performed to fix the surface-adhesive electronic components to the printed circuit board. According to the present invention, by changing the shape of the opening on the printed steel plate to a trapezoid, the amount of conductive adhesive coating on the inner end of the opening can be reduced, avoiding The above defects occurred in the subsequent reflow procedure. Implementation mode: The board 30 provided by one embodiment of the invention is used for surface-mounting ce mounting device; several electric-bonding electronic parts are connected together. On the printed steel plate 3 [The steel plate 30 covers the pads on the printed circuit board. The adhesive (such as conductive adhesive) is arranged on the 32 series to be parallel to each other, which can be divided into the first trapezoidal opening. Please refer to the third figure, which shows 30 from this printed steel sheet. As mentioned above, the surface adhesion process of this printed steel sub-component (such as surface adhesion component, surfa SMD), in order to connect the surface poles to several pads on the printed circuit board, creates a plurality of openings 3 2. When printed on, these openings will just be exposed on the conductive pads through the steel plate printing method. The printed steel plates 30 have opening rows, and according to the positions of the openings 3 2 a and the second trapezoidal openings 3 2 b in each row. As shown in the third figure, the first trapezoidal openings 3 2 a are located at the left and right ends of each row of openings, and the four adjacent edges of each of the first trapezoidal openings 3 2 a are first short parallel to each other. Side and the first long side (that is, the top and bottom sides),

Page 9 200425809 V. Description of the Invention (7), and the first hypotenuse and the first straight (ie, the left and right sides). As for the second trapezoidal openings 3 2 b are located between the left and right first trapezoidal openings 3 2 a, and the four adjacent sides of each second trapezoidal opening 3 2 b are second short sides parallel to each other and The second long side (the top and bottom bottom edges), and the two second hypotenuse (the left and right side edges).

It is worth noting that, for the first trapezoidal opening 3 2 a and the second trapezoidal opening 32 b located in the same row, the first long side of the first trapezoidal opening 32 a is located inside the opening, and is closer to the opening of the other row. 32. As for the first short side, because it is located outside the first trapezoidal opening 3 2 a, it will be farther away from the other row of openings 32. As for the second trapezoidal opening 32b, since the second short side is located inside the second trapezoidal opening 32b, it will be closer to the other row of openings 32. As for the second long side, it is located here The second trapezoidal opening 3 2 b is outside the second trapezoidal opening 3 2 b and is therefore further away from the other row of openings 3 2. In addition, for the first trapezoidal opening 3 2 a, the first oblique side is located outside the opening, and the first straight side is located inside the opening. As shown in the third figure, the first straight edge is closer to the second trapezoidal opening 32b in the same row, and the first hypotenuse is farther away from the second trapezoidal opening 32b in the same row.

Taking the 0 4 0 2 size group structure 10 as an example (refer to the first figure), there are eight electrodes 18 at the bottom of this group structure 10, which are arranged in two rows, and each row has four electrodes. 1 8. According to the distribution position of each electrode 18 in a row, it can be divided into terminal electrodes 18a located at the left and right ends of each row, and two terminal electrodes

Page 10 200425809 V. Description of the invention (8)

Line electrode 1 8 b between I pole 1 8 a. Therefore, as shown in the fourth figure, pads 4 corresponding to these electrodes 丨 8 will also be produced on the provided printed circuit board 40. These solder pads 42 have a total of eight, and all have a rectangular appearance. They are arranged in two rows, respectively, to correspond to the above-mentioned terminal electrodes 18a and along-line electrodes 18b, respectively, and provide the electrical connection required by the 0 402 row structure. Similarly, the fresh pads 4 2 can be divided into the first pads 4 2 a at the left and right ends of the row and the second pads 421 therebetween according to their positions in each row). 3 [Lu In the process of conducting conductive adhesive printing, 'the printed steel sheet 30 may be covered on the printed circuit board 40', and then the conductive adhesive layer may be coated on the printed steel sheet. By hollowing out the first trapezoidal opening 3 2 a and the second trapezoidal opening 3 2 b, a desired conductive adhesive layer can be formed on the upper surface of the bonding pad 42. As shown in the fourth figure, after the printed steel sheet 30 is removed, the first conductive adhesive layer 44a coated on the first pad 4 2 a will have the same trapezoidal appearance as the first trapezoidal opening 32 a, that is, Each first conductive adhesive layer 44a will also have a first short side and a first long side that are parallel to each other, and the first long side of the first conductive adhesive layer 44a will be closer to another row of pads 4 because it is located inside the first pads 42a. 2 ′, as the first short side is located outside the first welding pad 42 a, it is farther away from the other row of pads 42. Similarly, the second conductive adhesive layer 44b coated on the second pad 42b also has the same trapezoidal appearance as the second trapezoidal opening 3 2b. That is, each second conductive adhesive layer 4 4 b will have a second short side and a second long side that are parallel to each other, and the second short side will be compared because it is located inside the second pad 4 2 b. It is close to the other row of welding pads 4 2, and as the second long side is located outside the second pad 4 2 b, it is relatively far away from the other row of welding pads 4 2.

Page 11 200425809 V. Description of the invention (9) After removing the printed steel plate 30, the surface such as 0402 series can be adhered with electrical and sub-components' on the printed circuit board 4 and each The electrodes of the electronic component are pressed against the corresponding conductive adhesive layer 44. Among them, the terminal electrode 18a of the 042 array structure 10 will be pressed against the first conductive adhesive layer 44a, and the line electrode 8b will be pressed against the second conductive adhesive layer 44b. Next, by performing a reflow process, the surface-attached electronic components can be assembled and fixed on the printed circuit board 40, and the electrodes of the 0402 row group can be electrically connected to the pads 42 through solder. In a preferred embodiment, the rectangular solder pads 42 fabricated on the printed circuit board 40 have a length of about 20 mil and a width of 10 mU, and two :: mesh neighbors in the same row. The distance between the two is 8.8 mU, and when the distance between the upper and lower rows of pads is 1, the first short side of the first trapezoidal opening 3 can be controlled at about • ·, m 1 1, its first long side It is controlled in the range of 11. 5 to 16. 5 mi 1. The second short side is approximately 3.2 to 84 in the second short side of the trapezoidal opening 32b, and the first long side is approximately 8 to 14 mil. And, whether it is the first trapezoidal opening 32 & or the first brother The height of the shape-shaped opening 32b will be greater than the length of the rectangular pad M (20m 1 1). In other words, for the second trapezoidal opening 3 2 b, the height of the second trapezoidal opening 3 2 b is 2/5 ~ 3 / 5. Since the second short side of the second trapezoidal opening 321) is only 2/5 ~ 3/5 of its second long side, the second conductive adhesive layer coated through the opening 32b will also have The same trapezoidal shape. For two adjacent rows of pads, the second short side of the second conductive adhesive layer is located inside the second pad 42b,

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200425809 V. Description of the invention (ίο) * As shown in the fourth figure, only a part of the conductive adhesive on the inner surface of the pad will be coated. In this way, when the 0 4 0 2 row structure is placed, even if it is squeezed by the electrode 18b along the line, the amount of conductive adhesive located inside the second pad 42b is small, so it is stretched to both sides. The situation will be mild. In the subsequent reflow process, the second conductive adhesive layer 4 4 b is also less likely to be short-circuited due to bridging with adjacent conductive adhesive layers. And because the molten solder does not cause bridging, the empty soldering caused by the surface tension of the molten solder in the traditional process can also be effectively prevented. In addition, in this embodiment, the first trapezoidal opening 3 2 a is shifted to the outside so as to have a larger distance from the second trapezoidal opening 3 2 b of the counterpart. Therefore, as shown in the fourth figure, the first straight edge of the inner side of the first conductive adhesive layer 44a will not completely cover the inner side of the first recording pad 42a, but will expose the inner side of the first pad 4 2a. Part of the border area. That is, when the distance between the first bonding pad 4 2 a and the second bonding pad 42 b is 8.8 mi 1, the first conductive adhesive layer 44 a will be shifted to the outside, so that it is in contact with the second conductive adhesive. The distance between the layers 44b is greater than 8.8 mi 1. In this way, by increasing the distance between the first conductive adhesive layer 44a and the second conductive adhesive layer 44b, the chance of a bridging effect occurring therebetween can be greatly reduced. Due to the effective prevention of short-circuit and air soldering problems, the overall surface adhesion and process yield can be greatly improved. In addition, because there is no need to consume a large amount of labor costs, the detection and debugging work can effectively reduce the related process cycle and achieve the purpose of increasing production capacity. Furthermore, due to the opening of the steel plate designed by the present invention, it has a smaller area and is coated with the conductive adhesive.

Page 13 200425809 V. Description of the invention (π) The amount of glue is also small, which achieves the effect of saving costs. Although the present invention is explained as above with a preferred example, it is not intended to limit the spirit and the inventive substance of the present invention, but only to the above embodiments. For those familiar with this technology, it is easy to understand and use other components or methods to produce the same effect. Therefore, all modifications made without departing from the spirit and scope of the present invention should be included in the scope of patent application described below.

Page 14 200425809 Simple illustration of the diagram, simple explanation of the diagram: Through the following detailed description combined with the attached diagram, the above content and many advantages of the invention can be easily understood, of which: The first picture shows 0 4 0 Structure diagram of 2 exclusion components; the second diagram shows the opening design of the printed steel plate applied to the surface-attached electronic parts in the conventional technology; the third diagram shows the opening design of the printed steel plate applied to the surface-attached electronic parts in one embodiment of the present invention; The fourth figure shows a conductive adhesive layer coated on a printed circuit board using a printed steel plate according to an embodiment of the present invention. Drawing number comparison table: 0 4 0 2 size row structure 1 0 thick film resistance layer 1 4 electrode 18 line electrode 1 8 b steel plate 2 2 printed steel plate 3 0 first trapezoidal opening 3 2 a printed circuit board 4 0 first fresh塾 4 2 a First conductive adhesive layer 44a Conductive adhesive layer 44 Oxide ceramic substrate 1 2 Protective layer 16 Terminal electrode 1 8 a Rectangular pad 2 0 Rectangular opening 2 4 Opening 3 2 Second trapezoidal opening 3 2 b Fresh塾 4 2 Second pad 42b Second conductive adhesive layer 44b

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Claims (1)

200425809 VI. Application patent scope 1 * 1. A printed steel plate applied to the surface adhesion process of surface-adhesive electronic parts, wherein the printed steel plate is used to coat a conductive adhesive layer on a pad on the surface of a printed circuit board. The pad corresponds to a contact electrode on which electronic components are adhered on the surface, and the printed steel plate has: at least one trapezoidal opening, and corresponding to the solder pads, a conductive adhesive can be coated on the solder pad through the trapezoidal opening. 2. For example, the printed steel sheet of the scope of patent application, wherein the trapezoidal openings are arranged in two rows, and each of the trapezoidal openings has a short side and a long side parallel to each other, and at least one of the trapezoidal openings has The short side is closer to another row_the trapezoidal opening, and the long side is farther from the other row of the trapezoidal opening. 3. For example, the printed steel sheet in the scope of the patent application, wherein the short side of the trapezoidal opening is about 3.2 ~ 8.4 mil, and the long side is about 8 ~ 14 mil. 4. For the printed steel sheet in the scope of patent application item 2, the length of the short side of the trapezoidal opening is about 2/5 ~ 3/5 of the length of the long side. 5. For example, the printed steel sheet in the scope of patent application No. 2, wherein in each row of the trapezoidal openings, each trapezoidal opening is closer to the spring spacing of the other part of the trapezoidal opening, which is larger than each trapezoidal opening and farther away from the other row. The pitch of the trapezoidal opening. 6. If the printed steel sheet in the scope of patent application No. 2, each row of the ladder Page 16 200425809 VI. Application scope-· Shaped openings are divided into first trapezoidal openings, located at both ends of each row of trapezoidal openings, and the long sides of the first trapezoidal openings are adjacent to another row of trapezoidal openings, the first trapezoidal opening The short side of the opening is far away from another row of the trapezoidal openings, and the second trapezoidal opening is located between the first trapezoidal openings, and the short side of the second trapezoidal opening is adjacent to the other row of the trapezoidal openings and the second trapezoidal opening The long side is far away from the trapezoidal opening in another row. 7. For the printed steel plate of the scope of application for patent No. 6, wherein the first trapezoidal opening has a straight side and a hypotenuse that are not parallel to each other, the hypotenuse is farther away from the second trapezoidal opening in the same row, The straight edge is closer to the second trapezoidal opening in the same row, and the extending direction of the straight edge is perpendicular to the arrangement direction of the trapezoidal opening in the row. 8. A printed steel plate, which is used in the surface adhesion process of surface-adhesive electronic parts, in which there are several pads on a printed circuit board for connecting with several electrodes of the non-extended leg electronic parts. The printed steel plate There are several openings. When the printed steel plate is covered on the printed circuit board, the surfaces of the pads are just exposed, so that conductive adhesive is coated on the pads. The openings on the printed steel plate are Arranged into two rows parallel to each other, each row of which is divided into first trapezoidal openings, located at both ends of each row of openings, each of the first trapezoidal openings having a first short side and a first parallel to each other Long side, the first long side is adjacent to another row of openings, and the first short side is away from the other row Page 17 200425809 6. The scope of patent application, the opening and the second trapezoidal opening are located between the first trapezoidal openings, each of which has a second short side and a second long side parallel to each other, the The second short side is adjacent to the other row of openings, and the second long side is away from the other row of openings. 9. As for the printed steel sheet in the scope of patent application item 8, wherein the first short side of the first trapezoidal opening is about 7 · 5 ~ 1 2. 5 mi 1, and the first long side is about 11.5 ~ 16.5 mi 1 ° 10. For example, the printed steel sheet of item 8 of the patent application scope, wherein the length of the second short side of the second trapezoidal opening is approximately 2/5 ~ 3/5 of the length of the second long side. 11. If the patent is applied for The printed steel sheet of the range item 8, wherein the second short side of the second trapezoidal opening is approximately 3.2 to 8. 4 mi 1 and the second long side is approximately 8 to 1 4 mil. 12. For the printed steel sheet of the scope of application for patent No. 8, wherein the first trapezoidal opening has a first straight edge and a first hypotenuse, the first hypotenuse is farther from the second trapezoidal opening in the same row, the The first straight edge is closer to the second trapezoidal opening in the same row, and the extending direction of the first straight edge is parallel to the arrangement direction of the trapezoidal opening in the row. Page 18, 200425809 VI. Scope of patent application, 1 3. —A method for assembling surface-attached electronic parts on a printed circuit board by surface adhesion technology (SMT), wherein the bottom of the surface-attached electronic parts is arranged in two A plurality of electrodes in a row, the electrodes including a first electrode located at both ends of each row and a second electrode located between the two end electrodes, the method includes at least the following steps: providing a printed circuit board, The circuit board has a plurality of pads, each corresponding to the plurality of electrodes with electronic components adhered to the surface, and the plurality of pads are also arranged in two rows, including the first pads at the ends of each row, and A second bonding pad between two of the first bonding pads; coating a conductive adhesive layer on each of the bonding pads, wherein the first conductive adhesive layer coated on the first solder pad has a trapezoidal appearance, and Each of the first conductive adhesive layers has a first short side and a first long side that are parallel to each other, the first long side is adjacent to another row of the bonding pads, and the first short side is far from the A row of pads, wherein the second conductive adhesive layer applied on the second pad has a trapezoidal appearance, and each of the second conductive adhesive layers has a second short side and a second long side that are parallel to each other. Two short sides are adjacent to the other row of pads, and the second long side is away from the other row of pads; and the surface-attached electronic parts are placed on the printed circuit board, and each of the electrodes touches correspondingly The conductive adhesive layer. 14. The method according to item 13 of the scope of patent application, further comprising: performing a reflow process to fix the surface-attached electronic parts on the printed circuit board. Page 19, 200425809 6. Scope of patent application ^ 1 5. The method according to item 13 of the scope of patent application, wherein before applying the conductive adhesive layer on the fresh pad, it further includes: covering a printed steel plate on the printed circuit On the board, the printed steel plate has several openings, and the surfaces of the pads are exposed. The number of 16 is divided into the first long opening and the second short opening. For the method of item 13 of the patent application, the openings of the printed steel plate are arranged in two rows parallel to each other. Each row of the opening is a trapezoidal opening, which is located at both ends of each row of openings. Each trapezoidal opening has a first short side and a first long side parallel to each other, the first adjacent to the other row of openings, and the first One short side is far from the other two trapezoidal openings, and is located between the first trapezoidal openings. Each trapezoidal opening has a second short side and a second long side that are parallel to each other, and the second side is adjacent to the other row of openings. The second long side is far from the other line. 17. The method according to item 13 of the scope of patent application, wherein the length of the second short side of the trapezoidal opening of the second conductive adhesive layer is approximately the second long side. The length is 2/5 ~ 3/5 〇1. The method according to item 13 of the scope of patent application, wherein the first conductive adhesive layer will expose a part of the edge area inside the first pad. Page 20 200425809 6. Application for patent scope f 1 9. The method according to item 15 of the patent scope, wherein the distance between the first conductive adhesive layer and the second conductive adhesive layer will be larger than the first pad. And the second pad. 20. A printed circuit board comprising: a plurality of solder pads arranged in two rows; a surface with electronic parts adhered thereto having a plurality of electrodes arranged in two rows, and the positions of each of the electrodes corresponding to the solder pads And a plurality of solder layers arranged in two rows to connect the pads and the electrodes, respectively, wherein in each row of the solder layer, each solder layer is closer to another _ row of the solder layer portion The distance between the solder layers is larger than the distance between each solder layer and the portion of the solder layer farther away from the other row. 2 1. The printed circuit board according to Item 20 of the scope of patent application, wherein the solder layer of each row can be divided into a first conductive adhesive layer, which is located at both ends of the solder layer of each row, and each of the first The width of the portion of the conductive adhesive layer closer to the other conductive adhesive layer is greater than the width of the portion further away from the other conductive adhesive layer. The second conductive adhesive layer is located between the first solder layers. The width of a portion of each second conductive adhesive layer that is closer to the other conductive adhesive layer is smaller than the width of a portion that is relatively far from the other conductive adhesive layer. Page 21