JPH0231800Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field In general, in electronic equipment such as computers, printed boards are often used as the core of equipment mounting configurations such as electronic circuit packages and back panels, and are used to connect signals between mounted components and to connect electronic circuit components. It has functions such as power supply. The present invention relates to a multilayer printed board used in such electronic equipment, and particularly to a structure of a power supply layer and a ground layer in a highly multilayer printed board consisting of a large number of signal layers, a power supply layer, and a ground layer.

Conventional technology Conventionally, printed boards used for the above-mentioned purposes are
As shown in Figure 1a, a print consisting of a signal wiring layer 1, a ground layer 2, and a power supply layer 3 is laminated in the required number of layers, taking into consideration the wiring capacity, power supply capacity, electrical characteristics of the signal wiring pattern, etc. Boards, such as 4- to 8-layer boards, were common. Here, earth layer 2 or power layer 3
has a copper foil pattern as shown in FIG. 1b,
When multiple layers were required for each layer, the same copper foil pattern was used. That is, although the figure shows an example of the power supply layer 3, there are through holes 4, into which the signal terminal 101 and the ground terminal 102 of the mounted component 100 are inserted and connected.
A copper foil relief 7 is provided around 5, and the through hole 6 into which the power supply terminal 103 is inserted and connected is designed to reduce heat dissipation to the wide copper foil pattern that forms the power supply circuit during soldering, and to ensure a good solder connection. This is a pattern in which a special connection land 8 is provided for the purpose of connection.

However, due to recent advances in LSI technology,
Electronic circuit components are becoming denser, have higher power, or have more terminals, and the printed boards on which these are mounted are required to have higher wiring capacity and power supply capacity, and the power supply layer and ground layer are each 3 to 5 times larger. having 10 layers
~Multi-layer printed boards with as many as 20 layers are coming into use. As a result, when connecting a multi-terminal component with a large number of power supply and ground terminals to a through hole by soldering, or when removing the component in the event of a failure, the through hole connected to the power supply layer and ground layer special connection land 8 mentioned above.
Even if it is provided, heat dissipation during soldering is too large and sufficient soldering characteristics cannot be obtained. On the other hand, in order to obtain sufficient soldering characteristics, it is necessary to apply excessive heat, which has the disadvantage of significantly impairing the reliability of not only the printed circuit board but also the mounted components.

DISCLOSURE OF THE INVENTION (Purpose) The present invention eliminates the drawbacks of the prior art described above, and provides a multilayer printed board that can provide the same soldering connectivity and component replaceability as the conventional one even if it is equipped with multiple power supply or ground layers. It's about doing.

(Structure) In order to achieve the above object, the multilayer printed board of the present invention has through-holes for soldering connection of multi-terminal components each having a plurality of power supply and ground terminals, and a plurality of power supply layers formed inside. and a ground layer, and is configured such that only one of the plurality of internal power supply or ground layers is connected to the through hole into which the power supply and ground terminals of the multi-terminal component are inserted and connected. .

(Effect) By using the above connection configuration, the earth layer and power layer can be connected through the through-hole wall during heating when soldering components and when heating for removing solder when replacing components after soldering. Heat conduction and dissipation can be kept to a minimum, and good solder connectivity and easy parts replacement can be obtained without excessive heating. As a result, it is possible to realize a highly multilayer printed board having good solderability without impairing the electrical characteristics that the printed board should have.

Preferred Embodiments of the Invention Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2a is a plan view showing an example of a terminal arrangement of a multi-terminal component 100 mounted on a multilayer printed board according to an embodiment of the present invention. Note that the multi-terminal component 100 has 4 terminals.
Book earth terminal 121, 122, 123, 124
This is an example of a component with 24 terminals having two power supply terminals 131 and 132. FIG. 2b is a partial sectional view of a multilayer printed board on which a plurality of the above components are mounted, specifically, a sectional view taken along line A-A' in FIG. 2a. This multilayer printed board consists of six signal layers 1 and three ground layers 21, 22, 23 and 3.
It is a 12-layer board consisting of power supply layers 31, 32, and 33. In the multi-terminal component 100, the terminals are inserted into through holes provided in the printed board corresponding to the terminal arrangement, and the terminals are connected by soldering.
Here, earth terminals 121, 122, 123, 12
The through holes to which the power supply terminals 131 and 132 are connected are connected only to the ground layer or the power supply layer, respectively. For example, the through hole 51 that connects the ground terminal 121 is connected only to the ground layer 21, and the through hole 52 is connected only to the ground layer 21.
is connected to the ground layer 22, and the through hole 53 is connected only to the ground layer 23. The same applies to the power terminal through holes 61 and 62. With this configuration, heat conduction and heat dissipation from the through-hole wall to the ground layer and power layer can be minimized during heating for component soldering or solder removal.

Furthermore, in this multilayer printed board, all the ground layers 21 to 21 in the printed board are placed near the ground terminal or power terminal through hole of the mounted component.
23 or all the power layers 31 to 33 are connected through holes 9. This provides a solution to various problems that occur when the number of ground terminals and power supply terminals of a multi-terminal component is smaller than the ground layer and power supply layer of a printed circuit board, for example, when there are fewer power supply terminals as in this embodiment. Firstly, in terms of power supply performance, it is necessary to equalize the allocation of the ground layer and power layer to the components mounted on the printed board.
Second, if the mounted multi-terminal component is an ultra-high-speed element with an operating speed of sub-nanoseconds, the ground terminal and power supply terminal are connected only to the ground layer and power supply layer, which is the only layer. There are cases where the signal pattern layers are not adjacent to each other, resulting in a longer return path for the signal current, resulting in waveform distortion and increased transmission delay. , or by connecting all power layers, these problems can be solved all at once. Since this all-ground layer or all-power layer connection through hole 9 is not for inserting and connecting component terminals, the hole diameter may be made small, and it can be relatively easily installed near the component's ground terminal or power supply terminal. be. Further, it goes without saying that the connection with each ground layer and power layer does not have to be in the special land shape shown in FIG. 1b.

[Brief explanation of the drawing]

Fig. 1a is a partial sectional view showing the layer structure of a conventional multilayer printed board, Fig. 1b is a partially enlarged view showing the copper foil pattern of the power supply or ground layer in the conventional multilayer printed board, and Fig. 2a is a partial cross-sectional view showing the layer structure of a conventional multilayer printed board. FIG. 2b is a partial sectional view showing the layer structure of the multi-layer printed board according to an embodiment of the present invention. 1... Signal layer, 2, 21, 22, 23... Earth layer, 3, 31, 32, 33... Power layer, 4...
Signal through hole, 5, 51, 52, 53... Earth layer connection through hole, 6, 61, 62... Power layer connection through hole, 7... Through hole escape clearance, 8... Special connection land, 9... All earth layers or all power layers connection through holes, 10
0... Multi-terminal component, 101, 111... Signal terminal, 102, 121, 123, 124... Earth terminal, 103, 131, 132... Power terminal.

Claims (1)

[Claims for Utility Model Registration] (1) A product that has a through-hole for soldering connection of a multi-terminal component each having a plurality of power supply and ground terminals, and a plurality of power supply layers and ground layers provided inside. The multilayer printed board is characterized in that a through hole into which one power supply or ground terminal of the multi-terminal component is inserted and connected is connected only to one power supply layer or ground layer inside the multi-terminal component. (2) Utility model registration claim 1, characterized in that a through hole is provided in the vicinity of the through hole into which the power supply or ground is inserted and connected, through-connecting all the power supply layers or all the ground layers inside. The multilayer printed board described in section.