JPH1187907A - Soldering mounting method for mounting component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soldering mounting method of a mounting component for efficiently balancing the mounted components on a board surface, suppressing the enlargement of the board, preventing the generation of position deviation of surface mount components at the time of soldering and preventing defective soldering by the gas of a through-hole part. SOLUTION: On a board 1, an insertion mount component 5 and the surface mount component 2 to be fused by a solder ball, such as CSP and BGA, etc., are mounted together. The respective mount components are arranged on both sides of the board 1, and flow solder is supplied to the side of a copper foil pattern surface fs. A through-hole (h) is provided on the board 1, a solder ball 21 of the surface mount component 2 to be fused by the solder ball is fused by the heat of the flow solder wetted and raised inside the through-hole (h), and soldering is performed. The diameter of the through-hole (h) is set so as to make the solder ball 21 enter 1/3-2/3, and the through-hole (h) is provided with a hole for gas discharge. By this method, the insertion mount component and the surface mount component are efficiently arranged on both sides of the board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for soldering a mounted component, and more particularly to a method for soldering a mounted component applicable to an entire device manufactured using a substrate mounting technique.

[0002]

2. Description of the Related Art As a conventional technique, an example of a method of soldering a mounted component will be described with reference to FIGS.
FIG. 4 is a schematic configuration diagram for explaining an example of a conventional method of soldering mounting components. In the drawing, 1 is a substrate, 3 is a surface mounting component for drawing out an outer peripheral terminal, 4 is a surface mounting component for a leadless terminal, 5 is an insertion mounting component, fs is a copper foil pattern surface (soldering surface), and fi is a component insertion surface. FIG. 5 is a diagram showing a CSP or BGA as an example of a surface mount component to be melted by a solder ball. FIG. 5 (A) shows a schematic side view, and FIG. 5 (B) shows a schematic bottom view. is there. In the drawing, reference numeral 2 denotes a surface-mounted component to be melted by a solder ball, 21 denotes a solder ball, 22 denotes a base material, and 23 denotes a wafer chip. FIG. 6 is a schematic configuration diagram for explaining another example of a conventional soldering mounting method of a mounted component, and illustrates an example of a substrate on which a CSP or BGA which is a surface mounted component melted by a solder ball is mounted. FIG. 6A is an enlarged view of a main part of FIG. 6A, and FIG. 6, reference numeral 11 denotes a wiring pattern, and other portions having the same functions as those in FIGS. 4 and 5 are denoted by the same reference numerals as those in FIGS.

For example, in a current board such as a VTR, an insertion mounting component and a surface mounting component are mixedly mounted. When mounting these components by soldering, in mounting the insertion component 5 shown in FIG.
Using a method in which the lead wire attached to the bonding electrode is inserted into the through hole from the component insertion surface fi side of the substrate 1 and soldered to the copper foil pattern provided on the opposite copper foil pattern surface fs, On the other hand, in the mounting of the peripheral terminal lead-out surface mounting component 3 such as QFP and the leadless terminal surface mounting component 4, the lead wire of the bonding electrode does not pass through the through hole of the substrate 1,
A method is used in which the lead electrodes of the respective mounted components are temporarily fixed to the copper foil pattern surface fs to be joined with a bond or the like, and then the lead electrodes and the copper foil pattern are joined by soldering. As shown in FIG. 4, in a board on which an insertion mounting component and a surface mounting component are to be mixed and bonded, a technique of performing a flow solder bonding of these mounting components at once is used. In the mounting of the CSP and BGA melted by the solder balls shown in FIG. 5, the CSP and BGA are arranged on the wiring patterns 11 provided at the same pitch on the substrate 1 as shown in FIG.
A method of applying heat in a reflow furnace to melt the solder balls 21 and connect the solder balls 21 to the wiring pattern 11 is used.

[0004]

In the case of components mounted on a board, the number of surface mounted components such as peripheral terminal lead-out surface mounted components tends to increase, and the number of insertion mounted components tends to decrease. The occupied area is unbalanced. For example, one board uses 4 to 5 surface mount components such as outer peripheral terminal lead-out surface mount components, the number of components such as chips increases, the area occupied by the surface mount components increases, and the size of the substrate itself increases. Is progressing. In addition, when the surface-mounted components are temporarily fixed by a bond and soldered, there is a problem that the precision of the temporary fixing causes a deviation or dropout of the surface-mounted components. In addition, during soldering, a gas such as air may accumulate inside or outside the through-hole in the conventional through-hole, resulting in incomplete soldering and a problem of insufficient solder strength.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and by arranging a CSP or the like, which has been increasing recently, on a component insertion surface so that the CSP and the like can be efficiently joined to each other. Solder mounting of mounting components that efficiently balances and suppresses the size of the board, prevents surface mounting components from shifting during soldering, and prevents bonding failure due to gas in through holes Providing a method is an issue to be solved.

[0006]

According to a first aspect of the present invention, there is provided a method for soldering and mounting a surface mounted component on a substrate by soldering, wherein the surface mounted component having an electrode solder ball as the surface mounted component is provided. Used, and a board having at least a through hole arranged according to the electrode solder ball as the board, and arranging the surface mount component on the board so that the through hole and the solder ball engage with each other; Characterized by supplying flow solder to the back side of the surface on which the surface mount component is arranged, melting the solder ball by the heat of the flow solder, and mounting the surface mount component, and developed for reflow soldering. In addition, the surface mount components that are melted by the solder balls used can be used by flow soldering, and the base By balancing the placement in the duplex is obtained as it is possible to effectively use the substrate.

According to a second aspect of the present invention, in the first aspect of the present invention, when the surface mount component is disposed on the board, the board is set so that 1/3 to 2/3 of the solder ball is inserted. The present invention is characterized in that a substrate having the through hole is used, and it is possible to prevent a displacement of a mounting position of a surface mount component that is melted into a solder ball.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a void generation preventing hole communicating with the through hole is provided as the substrate to prevent generation of a void when the flow solder is supplied. It is characterized in that a substrate is used, and it is possible to prevent a gas such as air from accumulating inside or outside of the through hole, resulting in incomplete soldering and preventing insufficient soldering strength.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a method of soldering mounting components according to the present invention, for example, a surface mounting component in which 0.6 mmφ electrode solder balls are arranged at a 1.0 mm pitch, and a solder ball pitch of the surface mounting component are set. 0.6 at the same pitch as
A substrate having a through-hole of about 0.7 mmφ is used (there is no technical problem since a through-hole of 0.3 mmφ is currently used in a glass epoxy substrate). Surface mount components such as CSP and BGA are placed on the through-hole, and flow solder is supplied to the copper plating part provided on the lower surface of the through-hole by the conventional flow soldering (flow soldering) method. The solder ball of the surface mount component is melted and connected by the heat of the flow solder wetted in the through hole. At this time, since a void is easily formed by entraining air, a substrate having a groove (void generation preventing hole) for venting is used on the solder ball side of the through hole.

An embodiment of the present invention will be specifically described below with reference to FIGS. In all the drawings for describing the embodiments, portions having similar functions are denoted by the same reference numerals, and are the same as the conventional example except for features of the present invention. FIG. 1 is a schematic configuration diagram for explaining an embodiment of a method of soldering and mounting a mounted component according to the present invention, wherein h is a through hole. FIG. 2 is an enlarged view of a main part around the through hole shown in FIG.
FIG. 2A is a plan view of the through hole, and FIG. In the figure, c is a copper plating, and p is a void generation prevention hole. FIG. 3 is a view showing an example of the arrangement of through holes in a board in the method for soldering mounting components according to the present invention.

In FIG. 1, a paper phenol laminate, a glass epoxy laminate, or the like is used for a substrate 1, and insert-mounted components, surface-mounted components, and the like are attached. The surface mount component 2 that is melted by the solder ball is a CSP, a BGA, or the like, and the outer peripheral terminal lead-out surface mount component 3 is an outer peripheral terminal lead-out surface mount component. The substrate 1 is provided with a through hole h, and as shown in FIG. 2, a wall around the through hole h is plated with copper. Further, the through hole h is provided with a void generation preventing hole p. Further, as shown in FIG. 3, the hole diameter of the through hole h is 1/3 or less of the solder ball 21 (ball diameter of about 0.6 mm) of the CSP or BGA which is the surface mount component 2 melted by the solder ball. 2
Approximately 0.6 to 0.7 so as to enter through hole h
mmφ, and the hole pitch of the through hole h is also C
The pitch is set to be the same as the solder ball pitch (approximately 1.0 mm pitch) of SP or BGA.

Hereinafter, an example of the mounting process will be described in detail.
The insertion mounting component 5 is inserted into the component insertion surface fi of the substrate 1, and the outer peripheral terminal lead-out surface mounting component 3 and the leadless terminal surface mounting component 4 are temporarily fixed to the soldering surface fs with a bond or the like. Then, the surface mount component 2 that is melted by the solder ball is placed on the through hole h of the component insertion surface fi.
The surface-mounted component 2 melted by the solder balls only needs to be placed on the through hole h of the component insertion surface fi, and does not require temporary fixing by bonding or the like on the soldering surface fs. Does not occur.

Further, since the hole diameter is set so that the solder ball 21 enters the through hole h about 1/3 to 2/3, there is a problem such as displacement of the surface mount component 2 melted by the solder ball. Does not occur, and even if they are slightly misaligned, the self-alignment effect works to ensure the mounting position accuracy.

The board 1 on which the components are arranged is soldered by flow soldering, and the outer peripheral terminal lead-out surface mount component 3, the leadless terminal surface mount component 4, and the insert mount component 5 are soldered in the same manner as in the prior art. You. In the surface-mounted component 2 that is melted by the solder ball, flow solder is supplied to the copper plating portion on the lower surface of the through hole, and the through hole h is formed by a capillary phenomenon.
The solder ball 2 is heated by the heat of the flow solder
1 is melted and joined to the substrate 1 to be electrically connected to the wiring pattern. Therefore, in the present invention, the solder bridges frequently generated during the conventional reflow soldering do not occur in the present invention.

At this time, if the through-hole is the same as the conventional one, voids are generated due to accumulation of gas such as air. However, in the present invention, as shown in FIG. It is provided, and a gas such as air accumulates inside or outside of the through hole h, resulting in incomplete soldering and no problem of insufficient soldering strength.

Note that the CSP can secure a pin count of about 100 pins which is equal to or greater than the number of pins of the surface mounting component for drawing out the outer peripheral terminals in a 10 to 12 mm square. Does not occur. Also, in pattern routing from the through hole of the board,
If it is a fine pattern of about 0.25 mm, it can be pulled out without any problem.

As described above, according to the present invention, it is possible to use a surface mount component which is developed and used for reflow soldering and which is melted by a solder ball, by flow soldering. According to the method of the present invention, there is no need to temporarily fix the surface-mounted component to the soldering surface with a bond, but only to place the component on the through-hole of the component insertion surface. Also, 1/3 to 2 /
Since 3 enters the through-hole, problems such as shift displacement of the surface mount component do not occur. Further, even if a deviation occurs in the initial stage, the position where the self-alignment effect works is corrected, and the problem that the position accuracy is deteriorated does not occur. Further, bonding stability can be obtained by the void generation preventing holes.

[0018]

【The invention's effect】

Effect of Claim 1: Surface mount components that are melted by solder balls developed and used for reflow soldering can be used by flow soldering, and the placement of insert mounting components and surface mount components on both sides of the board is improved. Balancing allows for efficient use of the substrate. Effect of Claim 2: In addition to the effect of Claim 1, displacement of the mounting position of the surface mount component melted by the solder ball can be prevented. Effect of Claim 3: In addition to the effect of Claim 1 or 2, it is possible to prevent a gas such as air from accumulating inside or outside the through hole, resulting in incomplete soldering and preventing insufficient soldering strength.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment of a method for soldering a mounted component according to the present invention.

FIG. 2 is an enlarged view of a main part around a through hole shown in FIG. 1;
FIG. 2A is an enlarged cross-sectional view around the through hole, and FIG. 2B is a plan view of the through hole.

FIG. 3 is a diagram showing an example of a through-hole arrangement of a board in a method for soldering mounting components according to the present invention.

FIG. 4 is a schematic configuration diagram for explaining an example of a conventional soldering mounting method of a mounted component.

FIG. 5 is a view showing a CSP or BGA as an example of a surface mount component to be melted by a solder ball. FIG. 5 (A) is a schematic side view, and FIG. 5 (B) is a schematic bottom view. is there.

FIG. 6 is a schematic configuration diagram for explaining another example of a conventional mounting method of mounting components by soldering.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Board, 2 ... Surface mounting component, 3 ... Outer peripheral terminal lead-out surface mounting component, 4 ... Leadless terminal surface mounting component, 5 ... Insertion mounting component, 11 ... Wiring pattern, 21 ... Solder ball, 22
... Base material, 23 ... Wafer chip, c ... Copper plating, f
i: component insertion surface, fs: copper foil pattern surface (soldering surface), h: through hole, p: void prevention hole.

Claims (3)

[Claims] 1. A method for soldering a mounted component, wherein the surface mounted component is mounted on a substrate by soldering, wherein the surface mounted component having an electrode solder ball is used as the surface mounted component, and at least a through hole is formed as the substrate. Using a substrate arranged in accordance with the electrode solder balls, disposing the surface mount components on the substrate so that the through holes and the solder balls are engaged, and a back side of the surface of the substrate on which the surface mount components are arranged. Wherein the solder balls are melted by the heat of the flow solder to mount the surface-mounted component. 2. The method according to claim 1, wherein when the surface mount component is disposed on the substrate, the substrate is one third to two thirds of the solder ball.
2. The method according to claim 1, further comprising using a substrate having the through hole set so as to insert a third hole. 3. The substrate according to claim 1, wherein said substrate is provided with a void generation preventing hole communicating with said through hole to prevent generation of a void when said flow solder is supplied. Soldering mounting method of mounting parts.