RU2499374C2 - Printed circuit board - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: printed circuit board comprises a dielectric base (1) with contact sites (3) on the first side, connected by through metallised transition holes (5) with metallised sections (4) on the second side. At the same time each contact site (3) is connected with the specified transition holes (5) not more than with one metallised section, at the same time areas of the metallised sections (4) are in direct proportion to quantity of contact sites (3), with which they are accordingly connected electrically.

EFFECT: provision of even heat removal from contact sites of a printed circuit board with preservation of possibility of their electric connection.

8 cl, 3 dwg

Description

The field of technology.

The claimed invention relates to the fields of electrical engineering and radio engineering, and in particular to products of electronic equipment. The inventive printed circuit board is used to connect electronic components according to the electrical circuit in the nodes of electronic devices, mainly in LED lamps.

The prior art.

Among printed circuit boards, for example, a printed circuit board containing a base, on which both sides conductive patterns are made, is known. All required electrical connections of the two sides are connected mainly through metallized holes. (A. Medvedev "Printed Circuit Boards. Structures and Materials", Moscow: Technosphere, 2005, p. 23 [1]).

The disadvantage of this analogue [1] is that when the conductors of the conductive pattern are used not only to transmit electrical signals, but also for heat transfer, and if these conductors have a different area, but must dissipate the same amount of heat, an uneven heat sink from the conductors conductive drawing. This when using a printed circuit board leads to overheating of the conductors and the electronic components mounted on them, and reduces the reliability of both the printed circuit board itself and the product it is part of.

Also known is a printed circuit board containing a dielectric base, on the first and second sides of which conductors and contact pads are made. The contact pads on both sides are electrically connected by metallized holes (EV Pirogova “Design and technology of printed circuit boards”, Moscow: FORUM: INFRA-M, 2005, pp. 153-155 [2]).

The specified analogue [2] also has the disadvantage of the previous analogue [1]. The specified printed circuit board [2] is the set of essential features the closest device of the same purpose to the claimed invention. Therefore, it is adopted as a prototype of the claimed invention.

Disclosure of the invention.

The technical problem to which the invention is directed is to increase the reliability of the printed circuit board.

The technical result provided by the claimed invention is to ensure uniform heat removal from the contact pads of the printed circuit board while maintaining the possibility of their electrical connection.

The essence of the invention lies in the fact that the printed circuit board contains a dielectric base with contact pads on the first side, connected through metallized vias with metallized portions on the second side. Moreover, each contact pad is connected by said vias with no more than one metallized area, while the area of the plots is directly proportional to the number of contact pads connected to them.

The metallized sections preferably occupy the maximum possible area of the second side of the printed circuit board.

The dielectric base may be rigid. In this case, the dielectric base is preferably made of PCB.

The dielectric base can be made flexible.

Two metallized sections are electrically predominantly connected each to one contact pad, and the remaining metallized sections are each connected to two contact pads.

Two metallized sections can be electrically connected each to two contact pads, and the remaining metallized sections are each connected to four contact pads.

A soldering mask is preferably applied to the first and second surfaces of the board.

A brief description of the drawings.

Figure 1 shows a diagram of the first side of the printed circuit board, figure 2 is a diagram of the second side of the printed circuit board in example 3, figure 3 is a diagram of the second side of the printed circuit board in example 4.

The implementation of the invention.

The printed circuit board (Fig. 1, 2) is a dielectric base (1), on the first side of which there are printed conductors (2) and contact pads (3), and on the second side, metallized sections (4) are made.

The dielectric base (1) is a dielectric plate and is configured to perceive printing technology. The dielectric base (1) can be made rigid or flexible. The rigid dielectric base (1) is preferably made of PCB. The topology of printed conductors (2) and pads (3) on the first side of the base (1) and the topology of metallized sections (4) on the second side of the base (1) are printed drawings of the printed circuit board.

The printed conductors (2) are paths of conductive material deposited on the first side of the dielectric base (1) by known printed wiring methods. The electrically conductive material of the printed conductors (2) is preferably copper. The printed conductors (2) are designed to supply voltage to the electronic components, mainly LEDs mounted on the first side of the printed circuit board.

The contact pads (3) are made on the first side of the dielectric base (1) and are sections of printed conductors designed to connect the leads of electronic components, mainly LEDs. In this case, one contact pad (3) is designed to connect one output of the electronic component.

Through metallized vias (5) electrically connect the contact pads (3) on the first side of the base (1) to the metallized sections (4) on the second side of the base (1). In this case, the holes (5) are designed to transmit electrical signals and heat from the contact pads (3) to the metallized areas (4). One contact area (3) can be connected by said vias with no more than one metallized area (4). But one metallized area (4) can be connected to several contact pads (3).

Metallized sections (4) on the second side of the base (1) perform conductive and heat-removing functions. Each metallized area (4) is made in the form of an electrically closed area, mainly polygonal. Metallized sections (4) occupy as much of the surface of the second side of the dielectric base (1) as possible. It is preferable to perform metallized sections (4) so that they occupy the maximum possible area of the second side of the printed circuit board. The area of the plots (4) is directly proportional to the number of contact pads connected with them (3). Examples of implementation of the printed circuit board with the specified attribute are described below.

In order to protect the conductive patterns of the first and second sides of the printed circuit board, a solder mask is applied to both of its surfaces. The solder mask is an electrically insulating heat-resistant coating, such as an enamel coating or a dry film photoresist coating. In this case, the solder mask on the first side (from the side of the contact pads (3)) is white, as this increases the reflectivity of the printed circuit board.

Examples of specific performance.

Example 1. A printed circuit board contains six metallized sections (4), each of which is electrically connected to two contact pads (3) with two pairs of through metallized vias (5). In this case, the areas of metallized areas (4) are related to each other as 2: 2: 2: 2: 2: 2, that is, the areas of metallized areas (4) are equal to each other.

Example 2. The printed circuit board contains twelve metallized sections (4), each of which is electrically connected to four contact pads (3) with four pairs of through metallized vias (5). In this case, the areas of the metallized areas (4) are related to each other as 4: 4: ...: 4, that is, the areas of the metallized areas (4) are equal to each other.

Example 3. The printed circuit board contains twenty-four metallized area (4) (figure 2). Wherein:

- the first and twenty-fourth metallized sections (4) are each electrically connected to one contact pad (3) by a pair of through metallized vias (5);

- each of the metallized sections (4) from the second to the twenty third is electrically connected to two contact pads (3) with two pairs of through metallized vias (5).

In this case, the areas of metallized areas (4) are correlated as 1: 2: 2: ...: 2: 2: 1. I.e:

- the areas of the first and twenty-fourth metallized sections (4) are equal to each other;

- the areas of each of the metallized sections (4) from the second to the twenty third are equal to each other;

- the area of the second metallized area (4) is two times larger than the area of the first metallized area (4).

Example 4. The printed circuit board contains twelve metallized sections (4) (figure 3). Wherein:

- the first and twelfth metallized sections (4) are each electrically connected to two contact pads (3) with two pairs of through metallized vias (5);

- each of the metallized sections (4) from the second to the eleventh are electrically connected to four contact pads (3) with four pairs of through metallized vias (5).

In this case, the areas of metallized areas (4) are correlated as 2: 4: 4: ...: 4: 4: 2. I.e:

- the areas of the first and twelfth metallized sections (4) are equal to each other;

- the areas of each of the metallized sections (4) from the second to the eleventh are equal to each other;

- the area of the second metallized area (4) is two times larger than the area of the first metallized area (4).

The implementation of the structural elements of the claimed invention is not limited to the above examples. Work description.

The use of the inventive printed circuit board lies in the fact that the same type of electronic components are soldered to its contact pads (3), mainly LEDs. Then, the resulting printing unit is installed in the site of electronic equipment, mainly in the housing of the LED lamp. The installation of this printing unit is mainly carried out so that the metallized sections (4) mechanically come into contact with the elements of the electronic equipment node, designed to ensure heat removal from the printed circuit board.

During operation of the printing unit, heat from the legs of the electronic components is transferred to the contact pads (3). Then, through metallized through vias (5), heat is transferred to the metallized sections (4). Since sections (4) occupy most of the area of the second side of the base (1), heat removal from these sections (4) will go at maximum speed. Since the area of the plots (4) is directly proportional to the number of contact pads connected to it (3), and the electronic components are of the same type, the heat is removed from the metallized plots (4) uniformly. The maximum rate of heat dissipation in combination with the uniformity of this process ensures the efficiency of heat dissipation provided by the inventive printed circuit board.

Thus, from the foregoing, it follows that in the inventive printed circuit board the claimed technical result: "ensuring uniform heat removal from the contact pads of the printed circuit board while maintaining the possibility of their electrical connection" is achieved due to the fact that the printed circuit board contains a dielectric base with contact pads on the first side connected through metallized vias with metallized portions on the second side. Moreover, each contact pad is connected by the indicated vias to no more than one metallized area, while the areas of the metallized areas are related to each other as the number of contact areas with which they are respectively electrically connected.

Industrial applicability.

The inventors made a prototype of the claimed printed circuit board, tests of which confirmed the achievement of the technical result.

The inventive printed circuit board is implemented using industrially produced devices and materials, can be manufactured at an electrical enterprise and will find wide application in the electronics industry and instrument engineering.

Information sources

1. A. Medvedev “Printed circuit boards. Constructions and materials ”, Moscow: Technosphere, publ. 2005 year

2. E.V. Pirogov "Design and technology of printed circuit boards", Moscow: FORUM: INFRA-M, publ. 2005 year

Claims (8)

1. A printed circuit board containing a dielectric base with contact pads on the first side, connected through metallized vias with metallized portions on the second side, characterized in that each terminal is connected by said vias with no more than one metallized region, while the area plots directly proportional to the number of pads connected to them. 2. The circuit board according to claim 1, characterized in that the metallized sections occupy the maximum possible area of the second side of the printed circuit board. 3. The board according to claim 1, characterized in that the dielectric base is made rigid. 4. The board according to claim 3, characterized in that the dielectric base is made of textolite. 5. The circuit board according to claim 1, characterized in that the dielectric base is flexible. 6. The circuit board according to claim 1, characterized in that the two metallized sections are each electrically connected to one contact pad, and the remaining metallized sections are each connected to two contact pads. 7. The board according to claim 1, characterized in that the two metallized sections are each electrically connected to two contact pads, and the remaining metallized sections are each connected to four contact pads. 8. The board according to claim 1, characterized in that a solder mask is applied to its first and second surfaces.

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