Patent ID: 12213254

DETAILED DESCRIPTION

The technical contents of this disclosure will become apparent with the detailed description of embodiments accompanied with the illustration of related drawings as follows. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.

Please refer toFIGS.1-4. The disclosure provides a multi-layer printed circuit board, which includes a base-layer metal10, multiple middle metal layers20and a top-layer metal30.

The base-layer metal10, each middle metal layer20and the top-layer metal30are made of, but not limited to, one of aluminum, steel, copper, and iron. In some embodiments, a metal layer made of aluminum, steel or iron may be further coated with copper foil to increase the conductive efficiency. A surface of the base-layer metal10and a surface of the top-layer metal30are respectively disposed with multiple metal pins11,31for facilitating plugging/unplugging of a connector (not shown in figures).

In the embodiment, the middle metal layers20are, but not limited to, four in number. However, the number of the middle metal layers20may also be two, six, eight or more than ten in other embodiments. In detail, the middle metal layers20in the embodiment include a first middle metal layer L1, a second middle metal layer L2, a third middle metal layer L3 and a fourth middle metal layer L4. The middle metal layer20are stacked on the base-layer metal from top to bottom in order. The top-layer metal30is disposed on the middle metal layers20. That is, the top-layer metal30and the base-layer metal10are located on the top side and the bottom side of the middle metal layers20, respectively.

The base-layer metal10, each middle metal layers20and the top-layer metal30are respectively formed with multiple through holes12,22,32to generate signal isolation to reduce the crosstalk interference between high-frequency signals. In the embodiment, at least two adjacent middle metal layers20are formed with multiple hole groups21. That is, the middle metal layers20, which are partially connected, are respectively formed with multiple hole groups21corresponding to the through holes22, but not limited to this. Please refer to the second embodiment shown inFIG.5, each hole group21may also be disposed on all of the middle metal layers20. Please refer back toFIGS.1-4, two of rest of the middle metal layers20in the embodiment are separately formed with a refuge hole23defined on the through holes22of the two middle metal layers20. Also, the two middle metal layers20with the refuge holes23are separately adjacent to the base-layer metal10and the top-layer metal30. In detail, each hole group21in the embodiment is disposed the second middle metal layer L2 and the third middle metal layer L3, and each refuge hole23is separately disposed on the first middle metal layer L1 and the fourth middle metal layer L4, but not limited to this.

Each hole group21includes multiple passing holes211. The passing holes211jointly surround a corresponding one of the through holes22and multiple connecting channels212are disposed between the passing holes211. In the embodiment, the passing holes211of each hole group21jointly surround a corresponding one of the through holes22to be arranged annularly, but not limited to this. The passing holes211may decrease the conductive area around the through holes22to reduce the cooling speed to avoid an excessively low temperature of a pad and to be advantageous to the subsequent soldering process. In the first embodiment of the disclosure, each passing hole211is of, but not limited, a substantially meniscoid shape. For example, each passing hole211may be of a substantially rectangular, triangular, oval, fan, or irregular shape. Each passing hole211with a rectangular shape is shown inFIG.9. The triangular, oval, fan or irregular shape may be deduced accordingly and the figures are omitted here for brevity.

Furthermore, the number of the connecting channels212depends upon the number of the passing holes211. Please refer toFIG.6, in each hole group21of the embodiment, the passing holes211are four in number and the connecting channels212are four in number, too, but not limited to this. Please refer toFIG.7, which shows the third embodiment of the disclosure. The passing holes211in each hole group21are two in number and the connecting channels212are two in number, too. Please refer toFIG.8, which shows the fourth embodiment of the disclosure. The passing holes211in each hole group21are three in number and the connecting channels212are three in number, too. Therefore, a designer may adjust the numbers of the passing holes211and the connecting channels212of the hole group21depending on a required cooling speed so as to increase or decrease the cooling speed around the through holes12,22,32.

Please refer toFIGS.3and4, the multi-layer printed circuit board of the disclosure further includes a substrate40and multiple conductive copper pillars50. In the embodiment, the substrate40is made of plastic or other insulative materials by injection molding, but not limited to this. The substrate40covers the middle metal layers20, and is connected with the base-layer metal10and the top-layer metal30and separates the base-layer metal10, each middle metal layer20and the top-layer metal30to prevent each metal layer from forming electric connection. Each conductive copper pillar50is disposed in each though hole12,22,32and covered by the substrate40, and each conductive copper pillar50separately forms electric connection with the base-layer metal10, the top-layer metal30and the middle metal layers20with the hole groups21so as to make each metal pin11,31of both the base-layer metal10and the top-layer metal30and the copper foil in the multi-player printed circuit board form electric conduction.

While this disclosure has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of this disclosure set forth in the claims.