JPH042139A - Solder supply plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a solder supply plate that supplies solder to connection terminals of electronic circuit boards or electronic components, and is applicable to places where it is difficult to form a solder layer. The present invention relates to a solder supply plate that can easily supply solder.

(Conventional technology) Electronic components such as surface mount components have traditionally been mounted on electronic circuit boards (
When mounting on a conductor circuit formed on a conductor circuit (hereinafter simply referred to as a board), a solder layer is formed on the connection terminals of at least one of the conductor circuit or the electronic component, and the connection terminals are brought into contact with each other. By heating and melting, electronic components and substrates are connected very easily.

There are two typical methods for forming the solder layer as described above.

The first method is to print solder paste on the connection terminals of a board or electronic component, and to connect by heating the printed solder paste. In this case,
Instead of using solder paste, a method of immersing the board or electronic component in molten solder, or a method of forming a solder film by sputtering, vapor deposition, etc. with a mask applied to areas other than the predetermined parts has also been adopted.

The second method is to use a plating lead that is electrically integrated with the conductor circuit on the substrate. In other words, in this method, a conductor circuit is plated with solder to form a solder layer at a predetermined location, but in order to do so, it is necessary to form a lead for plating to conduct electricity to a predetermined location of the conductor circuit. Must be. In other words, when forming conductive circuits on a substrate, it is necessary to design the circuit so that plating leads are connected to all conductive circuits on which solder layers are to be formed. Note that this plating lead is completely unnecessary for the final product.

Incidentally, in recent years, it has become necessary to increase the density of electronic circuit components, no matter what type they are. Therefore, the current situation is that the spacing between each conductor circuit is becoming smaller and smaller.

As a result, it has become difficult to mount electronic components, and when connecting circuit boards and electronic components, defects such as short-circuits and bridging between terminals after heat treatment are likely to occur, making it unavoidable to replace components. This is what is currently being done. And L.S.
Semiconductors such as I and ICs undergo burn-in tests to confirm their reliability.

In this way, the higher the density, the smaller the size of the terminals themselves, and the smaller the intervals between them. In this case, it becomes impossible to form the lead for plating as described above.

(Problems to be Solved by the Invention) Therefore, each of the above two methods includes problems that must be solved.

That is, the problem that arises in the first method is that it is difficult to accurately form a solder layer for a highly densified conductor circuit. In other words, the solder paste itself,
There is a limit to printing accuracy, and it is not possible to form a uniform amount of solder layer on minute parts. That is, when the solder becomes finer, the printing tends to fade and the amount of solder decreases.If you try to force the amount of solder to increase, bleeding occurs and the connecting terminals come into contact with each other when melted. Furthermore, even in the method of dipping into molten solder, if the gaps are too small, they will come into contact with each other in the same way as described above.

The problem that arises with the second method is that the plating lead must be formed and the terminal and the plating lead must be connected with a conductive pattern, which severely limits the formation of conductor circuits. Is Rukoto. That is, when trying to adopt the second method, it becomes difficult to achieve a sufficiently high density of conductor circuits.

Furthermore, when the electronic component is removed from the board and remounted in order to replace the electronic component, the following problem occurs.

That is, when the electronic component is removed from the board, the solder layer formed on the board is taken up by the electronic component, resulting in a decrease in the amount of solder.

Naturally, at the stage of re-mounting electronic components, the connection strength decreases, connection reliability decreases, and failures may occur due to disconnection.

To solve this problem, all parts must be removed and solder must be supplied by printing paste again.

Moreover, as soon as solder is supplied to the electronic component side, soldering is performed on the board side using filamentous solder, making the work extremely uncertain and complicated.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide highly accurate terminal connections to minute connection terminals of extremely densely wired circuit boards or electronic components. To provide a solder supply plate capable of supplying solder without causing a short circuit, and capable of quickly and accurately replenishing solder in case of solder shortage that occurs when some electronic components are removed. be.

(Means for Solving the Problems and Their Effects) The means taken by the present invention to solve the above problems are described with the reference numerals shown in the drawings. Solder (3) to the connection terminal (21) such as (20).
A solder supply plate (lO) for supplying solder 0), which is provided with a terminal (11) for solder supply in a portion corresponding to the connection terminal (21), and the solder adhesion of this terminal (11) is adjusted to match the connection terminal (11). This is a solder supply plate (10) J characterized in that the solder adhesion is lower than that of the terminal (21).

In other words, what is most noteworthy about the present invention is that the solder supply plate (10) is connected to the connection terminal (21) of the board (20) or electronic component (20) that receives the solder (30).
), the adhesion of the solder (30) is worsened. That is, as shown in Figure 1 (a) to ()\),
If the solder (30) comes into contact with the connection terminal (21) of the electronic component (20) or the board (20) to which the solder (30) has a high adhesion, the solder (30)
) is melted to form a substrate (20) or electronic component (20).
Apply the solder (
30) and remove the solder supply plate (10) while it is still melted, the board (20) or electronic component (2
Solder (30) is supplied to the connection terminal (21) of 0).

According to the present invention, first, as a method for making a difference in the adhesion of the solder (30) between the terminals (11) and (21).

It is important to reduce the area of the terminals (11) of the solder supply plate (10). In other words, if the area of this terminal (11) is reduced, the solder (
30) Since the amount of solder is small, a large amount of solder (30) moves and adheres to the connection terminal (21) of the board (20) or electronic component (20), which has a larger area. This difference in area is based on the substrate (20) or the electronic component (
20) is preferably 80% or less with respect to the connection terminal (21). If it is more than 80%, the terminals of the solder supply plate (10) (
11) has a large amount of solder (30) to hold, and a sufficient amount of solder (30) can be applied to the board (20) or electronic component (2).
This is because it becomes difficult to supply to the connection terminal (21) of No. 0), and since there is not much difference in adhesion force, variations occur in the amount supplied.

In addition, as a method of making a difference in the adhesion of the solder (30) between the terminals (11) and (21), it is possible to A metal having a small contact angle with respect to molten solder (30) is used for the terminal (11) of the solder supply plate (1O). It is two. The metal materials used for this terminal (11) include copper,
Tin, lead, gold, silver, nickel, chromium, aluminum, palladium, platinum, iron, or composite metals thereof are used;
It is preferable to use a metal that has a smaller contact angle with the molten solder (30) than the metal used for the connection terminal (21) of the solder supply plate (10) for the terminal (11) of the solder supply plate (10). For example, the connection terminal (
If tin is used for 21), gold, copper, silver, or a tin-nickel alloy can be used for the terminal (11) of the solder supply plate (lO). On the other hand, the terminals (11) of the solder supply plate (10) are oxidized, etc.
It is also possible to reduce the contact angle by improving the surface or forming a small amount of organic or inorganic layer.

A third method for differentiating the adhesion of solder (30) between terminals (II) (21) is to use a solder supply plate (
10) A part of the terminal (11) is formed with a resin or resin composite (12) that does not get wet by the molten solder (30).

To explain this with reference to FIGS. 2 and 3, a resin (12) or a resin composite (12) is partially formed on the surface of the terminal (11) of the solder supply plate (1O). In the case of FIG. 2, the resin (12) or resin composite (12) is scattered or omnipresent, and in the case of FIG. 3, it is a dense film or porous. This resin (12) or resin composite (12) repels the molten solder (30), thereby causing the solder (3) on the terminal (11) of the solder supply plate (10) to
0) to the board (20) or the connection terminal (21) of the electronic component (20). Such materials include epoxy resin, polyimide resin, fluororesin,
Organic polymers such as polyethylene resin and acrylic resin are preferable, and these can be coated, dissolved in a solvent and immersed, and then the solvent removed, or after immersed in a solution in which particles or fibers of the organic polymer are dispersed. By removing the solvent, a resin (
12) Alternatively, there is a method of attaching particles of the resin composite (12).

On the other hand, solder (3) to the terminal (11) of the solder supply plate (lO)
0), general forming methods such as printing of solder paste, dipping into molten solder (30), vapor deposition, sputtering, electrolytic plating, or electroless plating can be used; however, the present invention For the purpose of forming extremely fine terminals (11)^, vapor deposition, sputtering, electrolytic plating, or electroless plating are more effective methods.

Note that the solder supply plate (10) and the board (20) or electronic component (20) are processed at high temperatures to melt the solder (30), so in order to supply solder with high precision, it is necessary to (10) and board (20) or electronic component (20)
It is preferable that the difference in thermal expansion between the two is as small as possible. For example, for supplying solder to things such as IC chips and silicon wafers, it is preferable to use a cordierite porous ceramic-epoxy resin composite substrate (20) with a low coefficient of thermal expansion or a low expansion glass substrate (20).

(Example) Next, examples and comparative examples of the present invention will be described.

Large 11 Soup 1 The electronic circuit board (20) for mounting components is a ceramic-resin composite board (2
0) and a copper connection terminal (21) with a diameter of 0.18 mm.
There are 184 pieces arranged in a square shape with a pitch of 0.3 mm. This board (20) 1000 pieces 1. On the other hand, a solder supply plate (10) having a copper terminal (11) with a diameter of 0.07 mm was manufactured so as to face the connection terminal (21). This solder supply plate (10) is a ceramic resin composite board (20) with a thermal expansion coefficient of 3.8 ppm/'C, which is made by filling the same cordierite sintered body (30% porosity) with epoxy resin as the board (20). It is.

Then, this solder supply terminal (11) has a thickness of 701 mm.
' m sφ140. czm solder (30) (S n
: Pb=63:37) was formed by electrolytic plating.

This solder supply plate (10) is brought into contact with the connection terminal (21) of the board (20), and the solder supply plate (10) is melted at 200°C.
10), the connecting terminal (2) of the board (20) was removed.
In 1), extremely uniform solder (30) with a height of 71 μm±12 μm could be formed.

Next, this substrate (20) has a diameter of 0.15 mm and a height of 0. 1
mm high melting point solder (30) (Sn: Pb=5:
When connected to a flip chip having a connection terminal (21) according to 95), not one connection failure occurred out of 1000.

Next, the substrate (20) to which the flip chip was connected was heated again to remove the flip chip.

Next, the terminal (11) of the solder supply plate (10) is coated with a thickness of 50 mm.
pm, φ1.20 (t m solder (30) (Sn:P
b: 63237) was formed by electrolytic plating, brought into contact again, melted at 200°C, and removed the solder supply plate (10).
It was possible to form extremely uniform solder (30) of 0 μm±9 μm, and when new flip chips were connected again, not one connection failure occurred out of 1000.

It is the same as Embodiment 1, but the terminals of the solder supply plate (10) (
11), φ0.18 mm tin-2 Nokel (35
%) alloy with a thickness of 30 μm and a diameter of 210 μm (
30) (Sn:Pb=63:37) was formed by electrolytic plating method, and the connecting terminal (
21), uniform solder with a height of 45 μm ± 15 μm (3
0) could be formed.

Next, in the same manner as described above, when free-tube chips were connected to this substrate (20), good results were obtained, although 2 disconnections occurred out of 1000 chips.

Next, the substrate (20) to which the fritted knob was connected was heated again and the fritted knob was removed. next time),
The terminal (11) of this solder supply plate (10) has a thickness of 30 μm.
1φ210μm solder (30) (Sn: Pb=6
3:37) by electrolytic plating method and brought into contact again.
When the solder supply plate (10) was melted at 200°C and removed, the connection terminal (21) of the board (20) had a height of 55 μm.
It was possible to form a uniform solder (30) of m±21 μm, and when a new flip chip was connected again, 10
Not even 1 out of 00 connection failures occurred.

On the Yugo 11 1C chip (20) side, 240 connecting terminals (21), which are tin terminals (21) with a diameter of 0.08n+m and are arranged in a double square shape with a pitch of 0.15mm, are formed. There is. The terminal (11) of the solder supply plate (10) is φ0.07
5 mm, and the surrounding area is covered with 10 μm thick epoxy resin (1
It is surrounded by 2). This terminal (11) is filled with epoxy resin (
12) Solder on top with a thickness of 65 μm and a diameter of 120 μm (30)
(Sn:Pb=63:37) was formed by electrolytic plating method, and when solder (30) was supplied to the connection terminal (21) of the IC chip (20), the height was 98 μm ± 12 μm1.
Solder (30) with a diameter of 118 μm±15 μm was supplied, and no short-circuit failure occurred between connection terminals (21) out of 1,000.

Next, when the connection terminals (21) of this IC chip (20) were connected to the substrate (20), no connection failures such as disconnections or shorts occurred in any of the 1000 chips.

The epoxy resin (12) surrounding the terminal (11) of the solder supply plate (10) of Example 3 was removed, and when the same solder supply as described above was performed, the solder ( 3
0) is height 78μm±28μm1φ106μm±32μ
28 out of 1000 short-circuit defects occurred.

Next, when the IC chip (20) was connected to the substrate (20), 3 out of 978 disconnections occurred.

(Effects of the Invention) As described in detail above, the solder supply plate according to the present invention is [a solder supply plate that supplies solder to connection terminals of an electronic circuit board or electronic component, etc., which corresponds to the connection terminals] In addition to providing a terminal for supplying solder to the connecting terminal, the solder adhesion of this terminal is lower than that of the connection terminal.''

Therefore, this solder supply plate can supply solder to any connection terminal of a board or electronic component with extremely high precision.
Moreover, it is possible to replenish solder stably even during replacement work, which is extremely effective in increasing the efficiency of the mounting process and improving the yield.

Furthermore, by using this solder supply plate, different types of solder can be supplied to one board, one electronic component, or one IC chip.

[Brief explanation of the drawing]

1(a) to (c) are partial cross-sectional views showing states in which solder is supplied to an electronic circuit board using the solder supply plate according to the present invention, and FIG. 2 is a partial sectional view of the solder supply plate according to the present invention. FIG. 3 is a partial sectional view showing one embodiment, and FIG. 3 is a partial sectional view showing another embodiment. Explanation of number 1 10...Solder supply plate, 11...Terminal, 12...Resin or resin composite, 21...Connection terminal, 20...Electronic circuit board or electronic component, 30...Solder . that's all

Claims (1)

[Scope of Claims] 1) A solder supply plate for supplying solder to connection terminals of an electronic circuit board or electronic components, comprising: a solder supply terminal provided in a portion corresponding to the connection terminal; A solder supply plate characterized in that the solder adhesion of the connecting terminal is lower than the solder adhesion of the connecting terminal. 2) The solder supply plate according to claim 1, wherein the area of the solder supply terminal is smaller than the area of the connection terminal. 3) The solder supply plate according to claim 1 or 2, wherein a contact angle of the solder supply terminal to the molten solder is smaller than a contact angle of the connection terminal to the molten solder. 4) The solder supply plate according to claim 1, wherein the solder supply terminal is partially formed with a resin or a resin composite that repels molten solder.