JPH0815200B2 - Conductor pins for semiconductor mounting boards - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is inserted into a through hole or the like of a semiconductor mounting board on which various semiconductor elements, chip elements, etc. are mounted, and output terminals or inputs of the semiconductor mounting board. The present invention relates to a conductor pin used as a terminal and a manufacturing method thereof.

(Prior Art) Generally, as a semiconductor mounting substrate having various semiconductor elements, chip elements, etc. and conductor pins used as output terminals or input terminals, a pin grid array as shown in FIG. 9 is used. Type semiconductor mounting board (3
0) is being developed.

This type of semiconductor mounting board (30) is used for mounting a semiconductor element by mounting a semiconductor element on its mounting part and connecting it to another board called a mother board.

This type of pin grid array type semiconductor mounting substrate (30) includes a conductor portion (33) wire-bonded to a semiconductor element and a plurality of through holes (32) electrically connected to the conductor portion (33). And through holes (32)
The conductor pins are fitted to all or part of the. As a result, this pin grid array type semiconductor mounting board (3
When mounted on another substrate such as a mother board, the semiconductor element is passed through the semiconductor element through a wire for wire bonding, a conductor portion (33), a through hole (32) and a conductor pin fitted to the mother board. It is electrically connected to a conductor circuit or an electronic part formed on the same.

Therefore, the conductor pins of this type of semiconductor mounting board (30) require high reliability when mounted as an external output terminal, and are sufficient for the through holes (32) of the semiconductor mounting board (30). Bonding strength is required, and the fitting portion between the through hole (32) and the conductor pin must be securely bonded electrically. In addition, this type of conductor pin and the through hole (32) may be joined by the solder (34), and in this case, the solder (34) is located inside the joint between the conductor pin and the through hole (32). It is necessary to penetrate sufficiently.

Then, even after the heat treatment step of the sealing packaging process after mounting the semiconductor element, the conductor pin needs to be well connected to the mounting component hole of the motherboard.

Due to this need, as shown in FIGS. 14 and 15,
A head portion (41) fitted in the through hole (32) formed in the substrate (31), and a collar having an outer diameter that is close to the head portion (41) and is larger than the inner diameter of the through hole (32). A semiconductor mounting substrate (30) is provided which includes a conductor pin (40) formed of a portion (42) and which is formed by immersing the conductor pin (40) fitted in the through hole (32) into molten solder and soldering the same. Known from the past.

However, in the semiconductor mounting board (30) shown in FIGS. 14 and 15, the conductor pins (40) are formed on the semiconductor mounting board (30) by the substantially circular collar portion (42). In some cases, the through hole (32) on the side of the conductor pin (40) was close to being hermetically sealed. Therefore, in such a case, when the semiconductor mounting board (30) is immersed in the molten solder from the conductor pin (40) side, the flux applied to the conductor pin (40) side before the solder immersion. The solvent inside is gasified to form a gas pool, which prevents the solder (34) from fully penetrating into the through hole (32), resulting in an electrical connection between the conductor pin (40) and the through hole (32). It became difficult to complete the mechanical joining, and there was also a problem in terms of joining strength. In order to solve this, it is conceivable to lengthen the dipping time in the molten solder. However, if the dipping time is increased in this way, not only will the semiconductor mounting board (30) itself be damaged, but the dipping time will also increase. Although it is long, the penetration of molten solder is not sufficient.

When the penetration time is lengthened, the thickness of the solder on the surface of the conductor pin tends to be thin, and in particular, the fillet-like solder is coated on the side of the flange of the conductor pin facing the molten solder, which is located at the tip of the fillet. The solder tends to be extremely thin in the portion, and when the immersion time is long and the molten solder temperature is set high, the solder becomes thin enough to expose the base of the conductor pin.

This hinders the solder wettability of the conductor pin surface by heat treatment when mounting a semiconductor element on this semiconductor mounting substrate and performing sealing packaging, and makes it impossible to mount this sealed package on the motherboard. .

Furthermore, in this pin grid array type package, unexpected deformation of the conductor pins easily occurs during handling before mounting on the motherboard. The parts where deformation occurs are concentrated in the lower part of the flange, especially at the root of the flange in the process until soldering of the conductor pin, and in the process after soldering, the fillet of the conductor pin that does not have a normal fillet shape. Occurrence was observed in the deformed portion, and work required to correct this deformation. This work is a manual work, and the labor and occasional breakage of the conductor pin are major problems of the prior art.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned circumstances, and the problem to be solved is that solder penetration in a joint portion of a conductor pin of this type with a semiconductor mounting substrate is permeated. It is difficult to solve the problem, it is difficult to solve the problem, the solder wettability of the conductor pin is obstructed, and the reliability of the semiconductor mounting substrate itself is accompanied by it. In addition, the conductor pins are easily deformed and the conductor pins are sometimes broken at the time of correction.

The object of the present invention is not only to make the bonding strength to the semiconductor mounting board sufficient, but also to improve the solder permeability of the bonding section to the semiconductor mounting board with a simple configuration. The purpose of this is to provide a conductor pin that can be formed, and further to provide a pin shape in which the thickness of the solder on the surface of the conductor pin is uniformly coated in all areas, and the portion where this conductor pin is easily deformed or broken is structured. To provide a reinforced pin shape.

(Means for Solving Problems) Means adopted by the present invention for solving the above problems will be described with reference to the drawings corresponding to the embodiments. A head portion (11) fitted into the through hole (32) of the substrate (30), and a collar portion (12) located below the head portion (11) and having a larger shape than the through hole (32). A conductor pin (10) joined to the substrate (30) by soldering, the recess (21) is provided on the head side of the flange (12) and the lower side of the flange (12). A conductor pin (10) for a semiconductor mounting board (30), characterized in that it has a conical portion (14) in its.

(Operation of the Invention) Each of the above inventions has the following operations by adopting the above means.

First, in the conductor pin (10) according to the first invention,
After the head part (11) is fitted into the through hole (32) of the semiconductor mounting substrate (30), a solder coating film is formed on the surface of the head part (11), which is formed below the collar part (12). Due to the conical portion, a uniform solder coating film can be formed from the tip of the conductor pin (10) to the flange (12), and the reliability of solder wettability of the conductor pin (10) surface is deteriorated by heat treatment with time. There is no.

Further, by adopting the above-mentioned conical shape, the rigidity of the collar portion (12) itself is enhanced, and thereby, a recess can be easily formed in the upper side portion of the collar portion (12) without deforming the collar portion (12). It is a conductor pin for the board (30), and by fitting the head (11) of the conductor pin (10) into the through hole (32) of the semiconductor mounting board (30), the steps shown in FIGS.
Although joined as shown in the figure, in this case, the portion other than the concave portion (21) of the flange portion (12) is the substrate (31) of the semiconductor mounting substrate (30) or the conductor portion (33) formed on the substrate (31). Abut. Since the portion of the collar portion (12) that is in contact with the substrate (31) side has a sufficient size, it will never be deformed by the pressing force at the time of joining.

In addition, since the conductor pin (10) is most easily deformed and the lower side surface of the collar portion which leads to breakage has a conical shape having a stress dispersion effect, deformation and breakage during handling and correction are extremely reduced.

Further, in the conductor pin (10) according to the present invention, the portion other than the recess (21) of the collar portion (12) is the semiconductor mounting board (3).
0) substrate (31) or conductor part (3) formed on it.
As a result of the contact with 3), the concave portion (21) formed on the substrate (31) side of the flange portion (12) forms a gap (21a) as shown in FIGS. 7 and 8. Since the gap (21a) communicates the inside of the through hole (32) formed in the substrate (31) of the semiconductor mounting substrate (30) with the outside, the conductor pin (10) according to the first aspect of the present invention is fitted and fixed. If the molten solder is then immersed in the molten solder bath, the molten solder can sufficiently penetrate into the through hole (32) of the substrate (31) through the gap (21a).

Furthermore, in the conductor pin (10) according to the present invention, the recess (21) of the flange (12) and the recess (22) continuous with the recess (21) are formed in the head (11). Therefore, due to these recesses (21) and recesses (22), as shown in FIG. 7 and FIG.
a) will be formed, and the through hole (32) of the substrate (31) will be formed by these gaps (21a) and (22a).
The communication with the outside is reliable.

(Example) Hereinafter, the present invention will be described in detail according to an example shown in the drawings.

1 to 3, a conductor pin (1
A first embodiment of (0) is shown. This conductor pin (10)
Includes a head portion (11) inserted into a through hole (32) formed in the semiconductor mounting substrate (30) and a collar portion (12) located below the head portion (11). In particular, the lower side of the collar portion (12) has a conical shape and has a conical portion (14).

On the surface of the flange (12) of the conductor pin (10) on the head (11) side, a recess (that extends from the center of the flange (12) to the outer periphery of the flange (12) ( 21) has been formed. The recess (21) is, so to speak, a groove formed in the collar portion (12), and if the structure is continuous from the central portion of the collar portion (12) toward the outer peripheral portion (circumferential portion), its shape is There is no particular limitation. The depth of the groove forming the recess (21) is not particularly limited as long as it is sufficient for the penetration of flux or solder, but a specific depth is 50
Most preferably, the thickness is about 100 μm. There are various conceivable numbers of the recesses (21),
Considering the ease of manufacturing and the supporting strength of the collar portion (12) itself, the two places shown in the drawing are the most suitable.

Since the conductor pin (10) has the recess (21) in the flange portion (12), the conductor pin (10) is provided with the through hole (32) of the substrate (31) constituting the semiconductor mounting substrate (30).
When fitted or inserted into and joined to, the flange portion (12) of the conductor pin (10) and the substrate (31) or the substrate (31) are formed as shown in FIGS. 7 and 8. Conductor (3
A gap (21a) is formed between it and 3). The solder (34) passes through the gap (21a) and the through hole (32).
It penetrates inside.

In addition, FIGS. 4 to 6 show conductor pins (1
A second embodiment of (0) is shown. The difference between this conductor pin (10) and the conductor pin (10) is that a recess (21) formed on the head (11) of the conductor pin (10) and continuous with the recess (21) formed on the flange (12) side ( 22) is further formed. This recess (22) is, so to speak, a groove formed in the head (11),
The recess (22) must be continuous from the flange (12) to the tip of the head (11).

This conductor pin (10) has a recess (21) in its flange (12), and a recess (22) continuous with this recess (21).
By having the conductor pin (10) in the head (11) thereof, the board (31) constituting the semiconductor mounting board (30).
When the conductor pin (1) is fitted or inserted into the through hole (32) and joined, as shown in FIGS. 7 and 8.
The recess (21) of the collar (12) of (0) and the recess (2) of the head (11).
2) allows a gap (21a) between the collar (12) and the substrate (31).
However, a gap (22a) continuous with the gap (21a) is formed in the through hole (32) into which the head (11) is inserted. The solder (34) penetrates into the through hole (32) through the gap (21a) and the gap (22a). The head portion (11) of the conductor pin (10) is formed into a flat shape as shown in FIGS.
You may implement by forming the protrusion part (11a) which makes the outer diameter of the said head part (11) larger than the inner diameter of 2). Each head (11)
The purpose of this is to securely insert and fix it in the through hole (32).

Next, a method for manufacturing the above-mentioned conductor pin (10) will be described with reference to FIGS. 10 to 13.

FIG. 10 shows that two continuous metal conductors, which are spaced apart by a predetermined distance, are sandwiched by two chucks, at least one of which has a protrusion extending in the radial direction of the metal conductor, and these two chucks are attached to the shaft of the metal conductor. By relatively moving in the core direction, the sandwiched part is pressed and deformed, and the collar part (12)
And a concave portion (21) is formed on the surface of the collar portion (12), and at the same time, a receiver having a conical concave portion for holding a part of the metal conductor wire at a position apart from the chuck by a predetermined distance. The step of forming a conical portion (14) on the opposite surface by moving the metal wire relatively in the axial direction is shown. In this step, two continuous metal conductors having a uniform diameter are chucked at predetermined intervals, and the metal conductors are deformed in a direction of compressing the predetermined intervals, whereby the collar portion ( 12) and one side of the flange (12) (the side opposite to the recess (21)) is formed into a conical shape.
In the case of this step, at the same time as forming the collar portion (12), a protrusion corresponding to the recessed portion (21) is provided in the mold of the surface that pushes one side of the collar portion (12), and this protrusion causes the collar portion (12) to be formed. Recesses (21)
Is formed.

In this way, the flange (12) of the conductor pin (10) has a recess (2
In the step of forming 1) and forming the conical portion (14) on the opposite surface of the collar portion (12), the concave portion (21)
Can be formed simultaneously with the formation of the collar portion (12) and the conical portion (14), so that the collar portion (12) forming step and the recessed portion (21) forming step need not be divided into two steps.

FIG. 11 shows a metal wire projecting on the side of the recess (21) of the collar (12) and a through hole (32) of the semiconductor mounting substrate (30).
It shows the step of forming the head (11) by cutting it into a length necessary to be inserted into the. That is, the metal conductor that becomes the head (11), which is the part that is inserted into the through hole (32) of the semiconductor mounting board (30), is cut to the length required for insertion into the through hole (32). The part (11) is formed. Then, in this step, the tip of the cut metal lead wire is tapped with a mold having a conical concave portion to form a taper on the formed head portion (11). The cut length of the head portion (11) is determined by the plate thickness of the substrate (31) into which it is inserted, and is preferably equal to or less than the plate thickness. The taper formed at the tip of the head (11) serves as a chamfer when the conductor pin (10) is inserted into the through hole (32) formed in the substrate (31). The tip diameter should be small and the taper should have a gentle slope.

FIG. 12 shows a step of forming a protrusion (11a) on the head (11) by pressing the head (11) formed as described above from the radial direction to flatten it. .

That is, in this step, the diameter of the large diameter portion of the head (11) of the conductor pin (10) is projected so as to be larger than the inner diameter of the through hole (32) of the board (31) into which the conductor pin (10) is inserted. This is the step of providing the part (11a). Further, in this step, by providing a protrusion corresponding to the above-mentioned recess (22) on a part of the mold, the recess (22) which is a groove continuous in the length direction of the head (11). ) Can be formed.

FIG. 13 shows a step of cutting the metal wire on the side opposite to the head (11) to a predetermined size. That is, in this process, the head (1
Cut the metal wire on the side opposite to 1). This cutting defines the length of the external connection terminal of the conductor pin (10). After that, the ends of the cut conductor pins (10) are barrel-polished to remove burrs at the cut portions and the like, thereby chamfering the ends.

The conductor pin (10) is completed by subjecting the conductor pin (10) to a series of workings, finishing the surface thereof, and optionally forming a metal plating on the surface.

FIGS. 7 and 8 show through holes (32) in which a conductor pin (10) according to the present invention is formed in a semiconductor mounting substrate (30).
After inserting the semiconductor mounting board (30) into the molten solder from the conductor pin (10) side to fill the solder into the through hole (32), FIG. 7 is a partially enlarged vertical sectional view showing a state in which the holes (32) are integrally joined. By the recess (21) formed in the conductor pin (10) or the recess (21) and the recess (22) formed in the conductor pin (10), the conductor pin (10) and the through hole (32) of the substrate (31) are formed. A fixed gap (21a) or a gap (21a) and a gap (22a) continuous with the gap (21a) can be provided between them, and the semiconductor mounting substrate (30) is melted from the conductor pin (10) side to the molten solder by these gaps. When soaked, the gas due to the gasification of the solvent in the flux can easily escape to the upper part of the through hole (32) in the direction of the arrow (↑) in Fig. 7 or 8, and the molten solder can also be easily uniformed. In addition, it is possible to obtain a uniform state of the solder film on the conical surface of the lower part of the tsuba because it is filled in the through hole (32).

FIG. 9 is a perspective view showing an embodiment of a semiconductor mounting substrate (30) having conductor pins (10) according to the present invention. In this semiconductor mounting board (30), the through hole (32) formed in the semiconductor mounting board (30) has the head (11) of the conductor pin (10) (this is a through hole in a part of the metal conductor wire). A protrusion (11a) having a diameter larger than the diameter of (32) is formed and fixed. This conductor pin (10)
The electrical connection between the through hole (32) and the through hole (32) is easily performed by immersing the semiconductor mounting substrate (30) in the molten solder layer from the conductor pin (10) side.

That is, in the conductor pin (10), on the surface of the flange portion (12) facing the substrate (31), a groove shape extending from the center of the flange portion (12) toward the circumference of the flange portion (12). The recess with the structure of (2
1) is formed, and the opposite side of this flange is a conical portion (14). Further, particularly when the conductor pin (10) according to the second embodiment is used, in addition to the recess (21) formed in the flange (12), a groove-like recess (22) corresponding to this recess (21) is formed. ) Is formed on the head (11). Therefore, when the semiconductor mounting substrate (30) is immersed in the molten solder bath from the conductor pin (10) side, the groove-shaped recess (21) or the conductor pin (10) formed in the flange portion (12) of the conductor pin (10). ) Collar (12)
The solder (34) penetrates into the through hole (32) through the groove-shaped recess (21) and the recess (22) formed on the surface of the head (11) and the solder (34). ) Is filled in.

In this way, in the semiconductor mounting board (30), the conductor pin (10) and the through hole (32) are electrically completely joined together, and all of the conductor pin surface is covered. Solder is evenly applied on the part. Further, since these operations are performed in a very short time, the semiconductor mounting board (30) is not damaged by the heat when the solder (34) is immersed, and the solder (34) is surely placed in the through hole (32). It has been filled in.

(Effects of the Invention) As described above, according to the conductor pin (10) of the first invention, as illustrated in the above embodiment, the conductor pin (10) is provided in the middle portion of the metal conductor wire. By forming the portion (12) and forming the conical portion (14) in the collar portion (12), a uniform solder coating film can be formed on the conductor pin surface,
The reliability of solder wettability of the conductor pin can be improved.

Further, by making the lower side of the collar portion, which was a weak point against the external force of the conductor pin (10), into a conical shape having the effect of dispersing the external force, it is possible to prevent the conductor pin from being deformed or broken during handling or correction.

Further, a recess (21) having a groove-like structure is formed on the surface of the collar portion (12) from the center of the collar portion (12) toward the circumference, thereby forming the conductor pin (10) on the substrate ( When it is inserted into the through hole (32) of (31) and joined, a gap (21a) can be formed between it and the substrate (31).
The penetration of the solder (34) into the through hole (32) can be further enhanced by 1a).

In the conductor pin (10) according to the second embodiment,
It is characterized in that a recess (21) is formed on the surface of the collar (12) and a groove-like recess (22) corresponding to the recess (21) is formed in the head (11). , This allows
The conductor pin (10) is connected to the through hole (32) of the substrate (31).
When it is inserted and bonded to the substrate (31), a gap (21
a) and the gap (22a) can be formed, and the penetration of the solder (34) into the through hole (32) can be further enhanced by these gap (21a) and the gap (22a).

The semiconductor mounting board (30) in which the conductor pin (10) having the above effects is fitted and fixed in the through hole (32) formed in the semiconductor mounting board (30) having the conductor portion (33).
In the above, each conductor pin (10) is firmly supported by the semiconductor mounting substrate (30) by the collar portion (12), and the conical portion (14) formed on the lower surface of the collar portion and the surface of the collar portion (12). When the semiconductor mounting substrate (30) is immersed in the molten solder bath from the conductor pin (10) (10) side due to the groove-shaped recess (21) formed, the solder easily passes through the hole (32).
Then, the molten solder is filled in the through hole (32) in a short time. This effect is particularly high in a semiconductor mounting substrate (30) using a conductor pin (10) having a recess (22) in addition to the recess (21).

Therefore, by using such a conductor pin (10), when the molten solder is dipped, the solder is lifted in the through hole (32) in a short time, and the damage due to the molten solder dipping of the semiconductor mounting substrate (30) is small. , A pin grid array type semiconductor mounting board that can have a uniform solder coating on the surface of the conductor pins and has high solder wettability (30)
It can be

[Brief description of drawings]

1 to 3 show a first embodiment of a conductor pin according to the present invention. FIG. 1 is a front perspective view thereof, FIG. 2 is a side view thereof, and FIG. 3 is a plan view thereof. is there. Moreover, FIGS.
FIG. 4 shows a second embodiment of the conductor pin according to the present invention. FIG. 4 is its front perspective view, FIG. 5 is its side view, and FIG.
The figure is a plan view of the same. 7 and 8 are partially enlarged vertical sectional views when the conductor pins are fitted to the substrate of the semiconductor mounting substrate, and FIG. 7 is a partially enlarged vertical sectional view in which the conductor pins are not cut, and FIG. Is a partially enlarged vertical sectional view showing a state in which the conductor pin is cut,
The figure is a perspective view of a semiconductor mounting substrate to which conductor pins according to the present invention are joined. Further, each of FIGS. 10 to 13 is a perspective view showing each step for explaining the method for manufacturing the conductor pin according to the present invention. Furthermore, FIG. 14 is a partially enlarged vertical sectional view of a conventional conductor pin,
FIG. 15 is a plan view thereof. Explanation of code 10 …… Conductor pin, 11 …… Head, 11a …… Projection, 12 ……
Collar part, 13 ... Support part, 14 ... Conical part, 21 ... Recess, 21a ... Gap, 22 ... Recess, 22a ... Gap, 30 ... Semiconductor mounting substrate, 31 ... Substrate, 32 …… through hole, 33
...... Conductor part, 34 ... Solder.

Claims (2)

[Claims] 1. A semiconductor mounting substrate having a head portion fitted into a through hole and a collar portion located below the head portion and having a shape larger than the through hole, and joined to the substrate by soldering. A conductor pin for a semiconductor mounting board, wherein the conductor pin has a concave portion on a head side of the collar portion and a conical portion on a lower side of the collar portion. 2. The conductor pin according to claim 1, wherein a head portion of the conductor pin has a recess that is continuous with the recess of the collar portion.