JPH11214834A - Electronic circuit board - Google Patents

Abstract

(57) [Summary] [Purpose] When soldering a lead portion of a surface mount type electronic component to an electrode, a mounting land that can improve mounting accuracy while maintaining the solderability of the electronic component is formed. To obtain an electronic circuit board. The electronic circuit board 1 of the present invention includes four lands 3a, 3b, 3c, and 3d to which four lead portions 11a, 11b, 11c, and 11d of an electronic component 10 are soldered.
A pair of lands 3b and 3d are connected to a pair of lead portions 11b and 11
The peripheral portions of the rectangular electrodes 2a, 2c having a width equal to or slightly larger than the width of d are formed by coating with solder resist R, and the other pair of lands 3a, 3c has a pair of lead portions 11a at the tips. , 11c, only the electrodes 2a, 2c having a width equal to or slightly larger than the width D1 of the respective base ends.
Is formed by covering the peripheral portions of the electrodes 2a and 2c formed as wide as possible with respect to the width D2 of the distal end portion with a solder resist R, and has a diameter D3 at the center of each base end portion of the lead portion 11. It has a land pattern in which via holes 4a and 4c approximately equal to or greater than the width D1 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit board for a surface-mounted electronic component, and more particularly to an electronic circuit board having an electronic component connection land suitable for mounting a high-frequency electronic component.

[0002]

2. Description of the Related Art First, a conventional electronic circuit board will be described with reference to FIGS. In recent years, the microwave range on the order of GHz has been used mainly for communication with artificial satellites and transmission and reception of satellite broadcasts. The high-frequency circuit built in these electronic devices is called a hybrid integrated circuit or a hybrid integrated circuit, and various surface-mounted electronic devices are mounted on electrodes or metal wiring of a conductor pattern called a microstrip line on an electronic circuit board. In many cases, the terminals of components (hereinafter simply referred to as “electronic components”) are manufactured by being mounted by soldering.

However, in general, the higher the frequency of an electric signal to be handled, the shorter the wavelength becomes.
Variations in the mounting accuracy of electronic components mounted on an electronic circuit board often greatly affect the characteristics of electronic devices as products. For example, in a high-frequency circuit design including a high electron mobility transistor (HEMT) that operates at an ultra-high speed as an electronic component and has a low noise figure, an input matching pattern to the HEMT is reduced as much as possible by a general method. Although the design is performed so as to match the impedance that is hardly generated, when the mounting accuracy of the electronic component is reduced, the input matching impedance changes, and noise larger than the designed value is generated. Such a decrease in the mounting accuracy of the electronic component is caused by a displacement of the mounting of the terminal portion with respect to the electronic component connection land (hereinafter simply abbreviated as “land”) formed on the electronic circuit board.

In order to solve such a problem, various types of electronic circuit boards described below have been conventionally used. An electronic circuit board 1A, which is a first embodiment of the conventional electronic circuit boards, will be described with reference to FIGS. It is to be noted that, in the electronic circuit board shown below, only the relationship between one electrode and one land and only one terminal (lead) of the electronic component is shown.

First, the structure of a conventional electronic circuit board 1A will be described. Usually, the electronic circuit board 1A has an electronic circuit pattern (not shown) such as various conductive electrodes and wirings formed on one surface thereof, but the electronic circuit board 1A shown in FIG. Shows only a pattern of the electrode 2 on which the terminal portion 11 of one electronic component 10 (FIG. 7) is mounted as a part thereof. In the case shown, four rectangular electrodes 2 are formed in a cross shape and in a symmetric pattern. These electrodes 2 are designed to have a width slightly larger than the width of the terminal portion 11 of the electronic component 10, for example, the lead portion 11 in the case of the HEMT. As shown in FIG. 6, at least the peripheral portion of these electrodes 2 is coated with a solder resist R which is an insulating heat-resistant coating material so that solder paste does not adhere, and the solder resist R is not coated. The lead portion 11 of the electronic component is electrically connected to the central portion, that is, the conductor region of the opening (the above-mentioned “land”) 3. A solder paste is applied to these lands 3 and, as shown in FIG. 7, the lead portions 11 of the electronic components 10 are placed and flow soldering is performed in this state to utilize the surface tension of the molten solder. Then, a method of automatically positioning the lead portion 11 of the electronic component 10 in the land 3 to secure mounting accuracy of the electronic component 10 is adopted. Reference numeral 12 indicates a bent portion where each lead portion 11 is bent downward.

However, as shown in FIGS. 8 to 10,
The electronic circuit board 1B used in the high-frequency circuit further includes a via hole 4 having a diameter equal to or larger than the width of the lead portion 11 of the electronic component 10 in the land 3.
In many cases, good characteristics cannot be obtained unless ground (earth) is taken at a portion as close as possible to the ground surface of the lead portion 11 of the electronic component 10 to the land.
In this case, if the electrode 2 is narrowed to the base end where the via hole 4 is formed below the lead portion 11, solder is formed around the electrode 2 in the same manner as shown in FIG. When the lands 3 are formed by coating the resist R (FIG. 9), only the tip end of the lead portion 11 where the via holes 4 are not formed in these lands 3 has a bonding surface with the solder. Performance is reduced. For this reason, considering this solderability, it is better to make the width of the electrode 2 wider than the diameter of the via hole 4 as shown in FIG. 9, but as shown in FIG. When the leads 11 of the electronic component 10 are soldered to these lands 3, the positions of the leads 11 cannot be regulated with high accuracy because the lands 3 are wide. If the width of the electrode 2 is made larger than the diameter of the via hole 4 in consideration of the solderability as described above, it becomes a major factor that eventually deteriorates the mounting accuracy of the electronic component 10, and as described above, A problem arises that the electrical characteristics are greatly affected.

[0007]

As a means for solving this problem, as shown in FIG. 11, the electrodes 2 on the electronic circuit board 1B shown in FIG. A technique is employed in which the solder resist R is coated so that the land 3 is formed in a shape in which the tip of the portion 11 is soldered to a width substantially equal to the width of the lead portion 11. When this technology is used, as shown in FIG. 12, the mounting position of the lead portion 11 of the electronic component 10 is apparently regulated. However, since the coating of the solder resist R is usually performed by using a printing technique, the above-described technique determines whether the final mounting accuracy of the electronic component 10 depends on the printing accuracy of the solder resist R with respect to the pattern of the electrode 2. There is a problem that it is done.

An object of the present invention is to solve such problems, and to improve the mounting accuracy while maintaining the solderability of electronic components even when the width of the electrodes must be increased. It is an object of the present invention to obtain an electronic circuit board having lands formed thereon.

[0009]

Therefore, in the electronic circuit board according to the embodiment of the present invention, the terminal portion is electrically connected to the surface in order to surface-mount the surface-mounted electronic component from which the terminal portion is led out. In an electronic circuit board on which lands made of electrodes of a conductor pattern are formed, a part or a plurality of parts of the electrodes serving as the lands are formed to have a width substantially equal to the width of the terminal portion. Solved.

Therefore, according to the electronic circuit board of the embodiment of the present invention, the tip of the terminal portion of the electronic component is soldered to the land made of the electrode having a reduced width of a part or a plurality of parts. The component can be mounted at a predetermined position on the electronic circuit board with high precision.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an electronic circuit board according to a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial plan view of an electronic circuit board according to an embodiment of the present invention, FIG. 2 is a plan view showing a state where lands are formed on each electrode of the electronic circuit board shown in FIG. 1, and FIG. FIG. 4 is a plan view showing a dimensional relationship between a lead portion of the electronic component and a land in a state where one electronic component is mounted on a land of the electronic circuit board, and FIG. It is a top view of a partial conductor board for explaining a formation method.

First, the structure of an electronic circuit board according to the present invention will be described with reference to FIGS. Reference numeral 1 indicates an electronic circuit board according to an embodiment of the present invention. The electronic circuit board 1 has a plurality of, in the illustrated example, four lead portions 11a, 11b, 11 of the electronic component 10 at predetermined positions on one surface thereof.
Four electrodes 2a, 2b, 2c and 2d for soldering c and 11d (FIG. 3) are formed. Each of the pair of electrodes 2b and 2d is entirely formed as a rectangle having a width equal to or slightly larger than the width of the pair of leads 11b and 11d of the electronic component 10. Each of the other pair of electrodes 2a and 2c has a tip portion 2A having a pair of lead portions 11 of the electronic component 10.
The width D4 of the base 2B of each of the electrodes 2a, 2c is as wide as possible than the diameter D3 of the via hole formed in the land. (FIGS. 1 and 3), the entire structure is formed in a convex shape. The electronic component 10 has a diameter D3 at the center of the base 2B of each of the electrodes 2a and 2c.
Via holes 4a and 4c which are substantially equal to or larger than the width D1 of the lead portion 11 are formed.

Next, as described in the description of the prior art, the peripheral portions of these electrodes 2a, 2b, 2c and 2d are insulated so that the solder paste does not adhere as shown in FIG. The lead portions 11a, 11b, 11c and 11d of the electronic components are covered with a solder resist R, which is a heat-resistant and heat-resistant coating material, in the central area where the solder resist R is not covered, that is, in the conductor region of the opening. The parts to be electrically connected are formed as lands 3a, 3b, 3c and 3d. However, in the present invention, the electrodes 2a,
Note that both side surfaces of the tip 2A of 2c are not covered with the solder resist R.

In the electronic circuit board 1 according to the embodiment of the present invention, as described above, the lead portions 11a
The tip 2 of the electrode 2a, 2c to which the tip of 11c is connected
The lands 3a and 3c are formed by narrowing the width of A. Thus, the lands 3a and 3c are formed only by the conductors of the electrodes, so that the leads 11a and 11c can be pulled and the electronic component 10 can be formed with extremely high precision. Position can be regulated.

Next, referring to FIG. 3, the dimensions of a preferred example of the electronic circuit board 1 according to the embodiment of the present invention will be described.
0 in connection with the lead portions 11a and 11c.

[0016]

In this embodiment, the electronic component 10 is
A HEMT generally used for an RF circuit of a satellite broadcast receiving LNB converter will be exemplified, and a case where the present invention is applied to a source land thereof will be described. HEMTs are provided on the lands 3a, 3b, 3c, and 3d formed on the electronic circuit board 1.
Ten lead portions 11a, 11b, 11c, 11d are connected to each other. These lead portions 11a, 11
b, 11c, and 11d are a source, a drain,
It corresponds to a source and a gate. In the lands 3a and 3c corresponding to the source lands, via holes 4a having a diameter D3 of 0.80 mm are formed. Hereinafter, one source land 3a will be described as a representative. The via hole 4a is connected to the ground surface on the other surface (back surface) of the electronic circuit board 1. In the vicinity of the via hole 4a, the land 3a has a base end 2 of the electrode 2a formed at 1.20 mm.
B is narrower than the width D4, but is sufficiently wider than the diameter D3 of the via hole 4a, whereas the width D1 is 0.65.
The width D2 of the electrode 2a to which the tip of the lead portion 11a formed in mm is soldered and the tip 2A of the land 3a.
Is reduced to approximately 0.75 mm, which is approximately the width D1 of the lead portion 11a. The length of the narrow end of the land 3a was 0.4 mm with respect to the total length of the land 3a of 1.3 mm. HEMT 10 of each land 3a, 3b, 3c, 3d
The conductor region on the package side is a region that does not come into contact with each of the lead portions 11a, 11b, 11c, and 11d that bend downward and project. It should be noted that the dimensions of each part in FIG. 3 do not match the dimensions for the sake of easy understanding.

By configuring the pattern of the land 3a with the above-described structure, the tip of the land pattern having a narrow land pattern can be maintained while maintaining the solderability at a wide portion of the base end 2B near the via hole 4. The lead portion 11a is mounted at the mounting position, that is, the land 3a by the solder surface tension melted at 2A.
Can be drawn into the center of the pattern
The mounting position of 1a can be automatically controlled with high precision. In addition, the land 3c is formed in the other source land 3c in the same shape as the above-described dimensional relationship as shown in the figure, and the description thereof is omitted. The lands 3b, 2d in which the via holes 4a, 4c are not formed
In the same manner as in the prior art, the patterns of the lands 3b and 3d are formed to be slightly wider than the widths of the lead portions 11b and 11d. In this embodiment, the width of the lands 3b and 11d is reduced to 0.65 mm. 0.1 mm tolerance, 0.75
mm.

According to this embodiment, not only the leads 11b and 11d connected to the lands 3b and 3d, but also the leads 11a and 11c connected to the lands 3a and 3c in which the via holes 4a and 4c are formed. Land 3
a, 3c, the position can be regulated with high accuracy at the narrow end portion, so that the HEMT 10 can be mounted at a predetermined position with high mounting accuracy, and the noise figure due to the decrease in mounting accuracy. Variations in characteristics such as gain and gain can be prevented. In addition, since the solderability between the lead portions 11a and 11c can be ensured at the wide base ends of the lands 3a and 3c, the reliability of soldering is not reduced.

As described above, since the via holes 4a, 4c are present in the lands 3a, 3c, even if the width of the land pattern must be widened, the electrode 2
The electronic component 10 can be mounted at a predetermined position on the electronic circuit board 1 with high accuracy only by changing the shapes of the conductor patterns a and 2c. The same effect can be obtained.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical concept of the present invention. For example, in the above-described embodiment, the dimension values (D2, D4 and length) of the lands 3a and 3c are not limited thereto. The width D1 of the lead portions 11a, 11c, the via holes 4a, 4
It can be changed appropriately according to the diameter D3 of c and the like. Also, among the lands 3a and 3c, the lead portions 11a and 1
The width D2 of the tip corresponding to the tip of the lead 1c
a, 0.75 mm 0.10 mm wider than width D1 of 11c
However, if only the improvement of the mounting accuracy of the electronic component 10 is focused on, the smaller these differences are, generally, the better, the size is not limited to the size of the above embodiment.

Further, the shape of the electrode pattern can be determined as follows. As shown in FIG. 4, for example, when an electrode is formed from a good electric conductor (hereinafter simply abbreviated as “conductor”) 20 such as a rectangular copper foil, for example, the conductor 20 is formed in an arbitrary size. It can be formed by selectively etching each of the plurality of regions (9 regions 1 to 9 in FIG. 4). That is, FIG.
In the case where the lead portion of the component is located in the region (4, 5, 6) and the via hole exists in the region (3, 6, 9), the region (1, 2, 7, 8) , 7)
Alternatively, one of the three sets of the regions (2, 8) is removed by etching. Via holes are in the area (2, 3,
5, 6, 8 and 9), the region (1, 7) may be etched to form a part of the electrode pattern with a width substantially equal to the width of the lead portion.

In addition, although it depends on the position of the via hole, the electrode pattern can be formed by etching a combination of the regions (1, 3, 7, 9) and (3, 9) in addition to the above. Such an electrode pattern shape is also conceivable. By appropriately changing the land pattern according to the position and size of the via hole and the shape of the lead portion, the land pattern for a surface-mount type electronic component having both good solderability and high-precision position control. Can be formed.

In the method described so far, a part of the conductor width itself in each region is made substantially the same as the electrode width by etching. However, based on the same idea, a slit is formed in the conductor. The same effect can be obtained. For example, the region (2, 3, 5, 6,
8) If via holes exist over 9),
An electrode having the same effect can be obtained by forming a narrow slit along each boundary line between the region (1, 4) and the region (4, 7) instead of etching the region (1, 7). You can get a pattern.

In the above embodiments, the HEMT used for a high-frequency circuit has been described as a surface-mounted electronic component. However, the present invention is not limited to this, and other surface-mounted electronic components requiring high mounting accuracy are also required. It should be added that it can be applied to parts.

[0025]

As is apparent from the above description, according to the electronic circuit board of the present invention, only a part or a plurality of parts of the electrode pattern are formed with a width substantially equal to the width of the lead part of the electronic component. Even when the width of the land pattern has to be widened, the position of the lead portion is regulated in a narrow land pattern width (a narrow electrode portion) while ensuring solderability in a wide land pattern portion. In addition, the mounting accuracy of the electronic component can be improved regardless of the ability of the mounting apparatus.

[Brief description of the drawings]

FIG. 1 is a partial plan view of an electronic circuit board according to an embodiment of the present invention.

FIG. 2 is a plan view showing a state where lands are formed on each electrode of the electronic circuit board shown in FIG.

FIG. 3 is a plan view showing a dimensional relationship between a lead portion and a land of the electronic component in a state where one electronic component is mounted on the electronic circuit board shown in FIG. 2;

FIG. 4 is a plan view of a partial conductor substrate for explaining one method of forming the electrode pattern shown in FIG. 1;

FIG. 5 is a partial plan view of a conventional electronic circuit board.

6 is a plan view showing a state where lands are formed on each electrode of the electronic circuit board shown in FIG.

FIG. 7 is a plan view showing a state where one electronic component is mounted on the electronic circuit board shown in FIG. 6;

FIG. 8 is a partial plan view of another conventional electronic circuit board.

9 is a plan view showing a state where lands are formed on each electrode of the electronic circuit board shown in FIG.

10 is a plan view showing a state in which one electronic component is mounted on the electronic circuit board shown in FIG.

11 is a plan view showing still another electronic circuit board of the prior art, in which different lands are formed on each electrode of the electronic circuit board shown in FIG.

FIG. 12 is a plan view showing a state where one electronic component is mounted on the electronic circuit board shown in FIG. 11;

[Explanation of symbols]

1. Electronic circuit board according to the embodiment of the present invention, 2a, 2b, 2
c, 2d electrode, 2A electrode tip, 2B electrode base, 3, 3a, 3b, 3c, 3d land, 4a, 4
c: Via hole, 10: (Surface mount type) electronic component, 1
1a, 11b, 11c, 11d: lead portion, 20: conductor, R: solder resist

Claims (4)

[Claims] An electronic component connection land comprising an electrode of a conductor pattern for electrically connecting the terminal portion is formed on the surface for surface mounting the surface mount type electronic component from which the terminal portion is derived. An electronic circuit board according to claim 1, wherein a part or a plurality of parts of said electrodes serving as said electronic component connection lands are formed with a width substantially equal to a width of said terminal part. 2. The shape of the land for connecting electronic parts is formed by cutting or slitting one or more rectangles having an area smaller than that of the base rectangle of the electrode. The electronic circuit board according to claim 1, wherein: 3. The electronic circuit board according to claim 1, wherein via holes for connecting layers of the electronic circuit board are formed in the electronic component connection lands. . 4. The electronic circuit board according to claim 1, wherein the surface-mounted electronic component is a high-frequency electronic component.