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Printed circuit board for mounting a quad flat package IC

A printed circuit board, flat packaging technology, applied in the direction of assembling printed circuits with electrical components, printed circuits connected with non-printed electrical components, printed circuits, etc., can solve problems such as short circuits, reduce tin bridges, increase manual labor Correction of work, effect of preventing solder short circuit

Active Publication Date: 2009-10-21
MITSUBISHI ELECTRIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the solderability of lead-free solder is worse than that of lead-containing eutectic solder that has been used in the past. For this reason, solder failure occurs between pin terminals such as 4-pin flat package ICs. resulting short circuit

Method used

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  • Printed circuit board for mounting a quad flat package IC
  • Printed circuit board for mounting a quad flat package IC
  • Printed circuit board for mounting a quad flat package IC

Examples

Experimental program
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Embodiment Construction

[0030] Embodiment 1

[0031] below, through Figure 1 to Figure 4 A 4-direction pin flat package IC mounted printed wiring board according to Embodiment 1 of the present invention will be described. it's here, figure 1 The plan view of the figure shows the schematic configuration of the 4-direction pin flat package IC mounting printed wiring board according to Embodiment 1 of the present invention viewed from the back, figure 2 is a plan view showing a 4-direction pin flat package IC according to Embodiment 1 of the present invention, image 3 The enlarged plan view of the main part of the first embodiment of the present invention shows the relationship between the front land group and the rear land group of the printed wiring board of the 4-direction flat package IC mounting printed wiring board according to Embodiment 1 of the present invention, Figure 4 The enlarged plan view of the main part of the first embodiment of the present invention shows the relationship betw...

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Abstract

Where a quad-directional-lead flat-package IC (3) is soldered using a flow-soldering bath, particularly, for example, when the inter-lead pitch is narrow, there has been a problem in that solder bridges are generated. In the present invention, a printed circuit board (1) is configured so that a quad-directional-lead flat-package IC (3) is mounted thereon, and attached by soldering using a flow-soldering bath; forward soldering land groups (5) are angled with respect to the soldering advance direction so that with respect to the flow soldering direction a corner of the quad-directional-lead flat-package IC will be at the head end and a diagonally opposing corner will be at the tail end; a solder-drawing land (7,9) having a lattice form is provided in either one of the spaces between each forward soldering land group (5) and its adjacent rearward soldering land group (6), and / or in the tail-endmost portion of the rearward soldering land groups; and an eyelet (8) is provided in the other one of the spaces. <IMAGE>

Description

[0001] This application is a divisional case of the invention patent application filed by Mitsubishi Electric Corporation on December 10, 2004 with the application number 200410100702.3 and the title of the invention "IC assembly printed circuit board and its welding method and air conditioner equipped with it" Apply. technical field [0002] The present invention relates to mounting a printed wiring board of a 4-direction pin flat package IC by soldering using a jet soldering bath. Background technique [0003] Generally speaking, printed circuit boards are increasingly required to be finer in the mounting density of components, so board assembly of narrow-pitch 4-direction pin flat package ICs and the like has become indispensable. On the other hand, the practical use of lead-free solders in consideration of environmental issues has also become an urgent task. However, the solderability of lead-free solder is worse than that of lead-containing eutectic solder that has bee...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H05K1/18H05K1/02H05K3/34H05K1/11H05K3/42
CPCH05K2201/09681H05K2203/046H05K3/42H05K3/3468H05K2201/094H05K2201/09781H05K2201/10689H05K1/111Y02P70/50
Inventor 三浦刚福岛宽信森秀树
Owner MITSUBISHI ELECTRIC CORP
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