JP2779853B2 - Manufacturing method of connection intermediate between inner lead and electronic component - Google Patents

Description

Description: TECHNICAL FIELD The present invention is used for electrically connecting an electronic component to an inner lead of a printed wiring board, and has a connection itself having a bump for electrical connection. The present invention relates to a method for producing an intermediate.

(Prior Art) There are various techniques for mounting electronic components on a printed wiring board. For example, when a flexible base material is used as a printed wiring board, a part of a conductor circuit is formed on the flexible base material. In this case, a method is employed in which the inner lead is made to protrude in a concentrated state in the device hole to form an inner lead, and the inner lead is connected to an external connection terminal of an electronic component by solder or the like. In such a method of connecting the inner lead and the connection terminal of the electronic component, generally, as shown in FIG. 6 or 7, a bump made of, for example, solder is formed on the inner lead side or the electronic component side. The bumps are once melted while being interposed between the inner lead and the connection terminal of the electronic component, so that the inner lead is connected to the electronic component.

By the way, in the conventional method as described above, the following inconvenience has been caused with the increase in the density of electronic components.

As the density of electronic components increases, the pitch between external connection terminals, and therefore the pitch between inner leads, also decreases.
It has become smaller than 80 μm. It is very difficult to form solder bumps independently on the inner leads and the connection terminals of electronic components at such small intervals.

Even if solder bumps are formed on each inner lead etc., if this is melted and connected, the molten solder may flow to other parts and cause a short circuit,
This becomes more remarkable as the pitch of the inner leads and the like becomes smaller.

In particular, when bumps are formed by solder on each of the inner leads with a small pitch interval, it is necessary to prevent the inner leads from being bent or bent, but the process for that must be very complicated. I can't get it. For example, in order to expose only the portions of each inner lead where solder bumps are to be formed, it is necessary to apply a solder resist to the printed wiring board, and remove the bumps after forming the bumps. This is because the inner lead must be protected.

Therefore, the present inventors have conducted various studies on how to reliably and easily connect particularly the fine inner lead and the connection terminal of the electronic component. The inventors have found that forming the bumps on a separate member has a good result, and have completed the present invention.

(Problems to be Solved by the Invention) The present invention has been made on the basis of the above-described background, and the problem to be solved is a reliable connection between a fine inner lead and a connection terminal of an electronic component. Connection.

An object of the present invention is to provide a method capable of reliably manufacturing a connection intermediate capable of reliably and easily connecting the fine inner lead and an external connection terminal of an electronic component. Is to do.

(Means and Actions for Solving the Problems) The connection intermediate (10) according to the present invention will be described with reference numerals used in the embodiments. The connection intermediate (10) is a connection terminal between the inner lead (30) and the electronic component (40). A connection intermediate (10) for electrically connecting them, the connection intermediate (10) comprising: a supporting base material (11) having an insulating property; It is composed of a support hole (12) formed in the material (11) and located between the inner lead (30) and the corresponding connection terminal, and a bump (13) supported in the support hole (12). ing.

That is, the inner lead (30) and the electronic component (40) are formed completely separately from each other, and the connection intermediate (10) itself connects the inner lead (30) and the electronic component (40). And has a bump (13) for use as follows. That is, as shown in FIG. 2, this connection intermediate (10)
0) and a connection terminal (not shown) of an electronic component (40) to be connected to the electronic component (40). The electrical connection between the inner lead (30) and the electronic component (40) is performed by melting each bump (13) in a state where the connection terminal of the corresponding electronic component (40) is in contact with the corresponding connection terminal. . As described above, this connection intermediate (10) arranges the inner lead (30) and the electronic component (40) at predetermined positions, and positions the inner lead (30) and the electronic component (40) between them to position the inner lead (30) as described above. ) And the electronic component (40), and of course, connect it to the inner lead (30) or the electronic component (40) before connecting other components. Sometimes used.

If the connection intermediate (10) is used as described above, it is not necessary to form bumps for connection on the inner lead (30) side or the electronic component (40) side. Therefore, it is possible to omit a step for forming a bump on the inner lead (30) or the electronic component (40) side. In particular, in comparison with the conventional method of forming a bump on the inner lead (30) side, when the connection intermediate (10) is used, a mask for forming a bump is formed on the inner lead (30). Since the peeling step is not required at all, the inner lead (30) can be sufficiently protected.

What is particularly important is that the bump (13) for connecting the inner lead (30) to the connection terminal of the electronic component (40) is completely independent of the inner lead (30) and the electronic component (40). Because the bumps (13) are retained in the support holes (12) by surface tension when they are melted, the bumps (13) are retained in the support holes (12) of the connection intermediate (10). It is difficult to flow to the outside. Therefore, even if the pitch between the inner leads (30) and between the connection terminals of the electronic component (40) becomes smaller,
Inner lead (30) adjacent to the molten bump (13)
And no connection terminal is contacted, and one connection terminal is not short-circuited to one inner lead (30). Therefore, by using this connection intermediate (10), the inner lead (30) and the electronic component (40)
This can sufficiently achieve the fine connection terminal.

In order to produce the connection intermediate (10) having the above-described effects, the means according to the first aspect of the present invention includes: a supporting base material (11) having insulating properties; A support hole (12) formed between the inner lead (30) and the corresponding connection terminal on the electronic component (40) side, and a bump (13) supported by the support hole (12). )
A method of manufacturing a connection intermediate (10) for electrically connecting an electronic component (40) to an inner lead (30) by the following steps.

(1) a step of forming a support hole (12) in the support substrate (11); (2) integrating the support substrate (11) having the support hole (12) formed on the conductive substrate (20) Step: (3) While energizing the conductive base material (20), electroplating is performed on the surface of the support base material (11) side, and each support hole (12)
(4) a step of removing the conductive substrate (20) from the supporting substrate (11) by peeling or dissolving.

That is, in this method, the supporting base material (11) which has insulation properties and is completely independent of the inner leads (30) and the electronic components (40) is applied to the supporting base material (11) of FIG. As shown by, it is necessary to form a plurality of support holes (12). Since these support holes (12) are formed with a pitch corresponding to the pitch between the fined inner leads (30), not only the diameter but also the pitch is very small. Therefore, the support base material (11) on which the support holes (12) are to be formed must be made of a material that can cope with the support base material (11). It is preferable to employ a material that can be formed, or a material that can form the support hole (12) by laser processing. In other words, the support holes (1
In 2), the photosensitive material is exposed, developed, or formed by laser processing.

As shown in FIG. 4B, the conductive base material (20) is integrated with one surface of the support base material (11) in which the plurality of support holes (12) are formed as described above. This conductive substrate (20)
FIG. 4 (c) shows that by applying a current to this, it can be electroplated.
As shown in the figure, the supporting base material (11)
The bumps (13) are formed by electroplating through the support holes (12). This bump (13)
The above-mentioned electroplating should be performed relatively satisfactorily, since it is easier for the protruding part to protrude from the surface of the supporting base material (11) to the inner lead (30) or the connection terminal of the electronic component (40). Further, as the material of the bump (13), a material different from the metal constituting the conductive base material (20) may be used. The reason is that the bumps (13) can be easily peeled off from the conductive base material (20) in a step described later, and the conductive base material (20) can be easily removed by a dissolving means such as etching. This is because an etchant for etching only (20) can be used.

In this manufacturing method, as shown in FIG. 4 (d), the conductive base material (20) that does not constitute the connection intermediate (10) is removed. There are roughly two removal methods. The first method is to simply peel the conductive substrate (20) from the supporting substrate (11). Each bump (13) is held in a very small support hole (12), so when peeling this conductive substrate (20), the bump (13) should be firmly held in the support hole (12). It is supported. Therefore, the conductive substrate (20) is
When peeled from 1), each bump (13) becomes conductive base material (2
The bumps (13) are not separated from the support base material (1).
1) When protruding upward, each bump (13) is in a state of being held on the supporting substrate (11) side. Conductive substrate (2
0) In the case of the second method of removing itself by dissolution such as etching, the support holes (1) of each bump (13) are removed.
It does not affect the mechanical support for 2), but in this case, as described above, it is necessary to select a material and an etchant that do not dissolve the bumps (13) together with the conductive substrate (20).

In the embodiment shown in FIG. 4, a large supporting base material (11) is used to simultaneously form a large number of connection intermediates (10).
Therefore, as shown in FIG. 4 (e), this is processed into individual connecting intermediates (10). In the case of a bump (13) formed by plating, if the quantity is insufficient to melt and connect the inner lead (30) and the electronic component (40), the entire connection intermediate (10) is removed. As shown in FIG. 4 (f), solder may be further adhered to the surface of each bump (13) by a solder dip immersed in the molten solder tank.

Further, in order to manufacture the connection intermediate (10), the means adopted in the invention according to the second claim includes: a supporting base material (11) having an insulating property;
A support hole (12) formed between the inner lead (30) and the corresponding connection terminal on the electronic component (40) side, and a bump (13) supported by the support hole (12). ), Wherein a connection intermediate (10) for electronically connecting the electronic component (40) to the inner lead (30) is manufactured by the following steps.

(1) a step of forming a support hole (12) in the support base material (11); (2) an auxiliary plating (1) at least in the support hole (12).
(3) Applying solder plating to this auxiliary plating (14), or immersing the whole of the supporting substrate (11) in a molten solder tank to apply the auxiliary plating (14). A step of forming a bump (13) using solder as a core. However, the difference from the method of the first claim of the second claim is that the bump (13) is formed without using the conductive base material (20). Is to form.

That is, in the method of the second claim, as shown in FIG. 5 (a), up to the point where the necessary support holes (12) are formed in the support base material (11), it is the same as that of the first claim. However, the difference is that the auxiliary plating (14) is formed in the bump (13). That is, the auxiliary plating (14) in the bump (13) should be a core of the bump (13), like the conductive base material (20) in the first aspect of the invention. This auxiliary plating (14) is formed by a method similar to the case where so-called through-hole plating is performed.

As described above, the auxiliary plating (1
The supporting base material (11) on which 4) is formed is immersed in a chemical plating tank to form each auxiliary plating (14) as shown in (c) and (d) of FIG. A bump (13) centering on each of these auxiliary platings (14) is formed by performing chemical plating as a nucleus. This bump (13)
By adjusting the amount of chemical plating, (c) in FIG.
Can be made into a donut shape as shown in,
Alternatively, it can be a solid one as shown in FIG. 5 (d).

When each of the bumps (13) has a donut shape shown in (c) of FIG. 5, the bumps (13) are melted to connect the inner lead (30) to the electronic component (40). In addition, since the extra bumps (13) can be made to flow into the support holes (12) so that they do not flow outward, the connection between the fine inner leads (30) and the connection terminals of the electronic components (40) can be made. This is to make the connection more secure.

(Example) Next, the invention according to the first and second claims for producing the connection intermediate (10) will be described.

Embodiment 1 FIG. 4 shows the steps of the manufacturing method according to the first claim in order. In this manufacturing method, first, as shown in FIG. 4A, a support hole (12) is formed at a position where a bump (13) is to be formed on a support substrate (11). As the supporting base material (11), a connection intermediate (1
The larger one is used so that many 0) can be obtained. In order to form a support hole (12) by exposing and developing this support base material (11),
In this embodiment, a so-called dry film is used, but a material that can be laser-processed may be used. Further, in the case where the connecting intermediate (10) is a flat plate as shown in FIG. 1, it is not necessary to process the supporting base material (11) other than the supporting hole (12). When forming the connection intermediate (10) having the opening (15) at the center as shown in the figure, the opening (15) is formed in the support base material (11) in advance.

A conductive base material (20) is attached to the back surface of the support base material (11) having the necessary support holes (12) formed thereon as shown in FIG. 4 (b). Since the conductive substrate (20) needs to be electroplated on its surface, it has conductivity and is integral with itself. Then, using the conductive base material (20), as shown in FIG. 4C, the support holes (12) of the support base material (11) are provided above the conductive base material (20). Then, the necessary bumps (13) are formed by electroplating.

Next, as shown in FIG. 4D, the conductive base material (20) is removed from the support base material (11). The removal method includes a method of simply peeling the conductive substrate (20),
Alternatively, a method of dissolving the conductive substrate (20) by means such as etching or the like is adopted.

The above steps may be performed individually for one support base material (11). However, in this embodiment, since a large number of connection intermediates (10) are taken, As shown in FIG. 4 (e), the support base material (11) is cut and separated to obtain a connection intermediate (10) as shown in FIG. 1 or FIG. In the case where each of the bumps (13) is insufficient in quantity, each connection intermediate (10) is immersed in a molten solder tank, and is shown in FIG. 4 (f). So big bump (1
3) may be formed.

Embodiment 2 FIG. 5 shows a manufacturing method according to the second claim. In this manufacturing method, as shown in FIG. The auxiliary plating (14) formed in each support hole (12) is used in place of the conductive base material (20) employed in (1). Each of these auxiliary platings (14) is formed by a general means when performing through-hole plating, but it is preferable that the auxiliary plating (14) be of such an extent that it does not become a solid state.

Then, the support base material (11) as described above is immersed in a plating tank and subjected to chemical plating, or the support base material (11) is immersed in a molten solder tank to form the fifth base material.
As shown in (c) or (d) of the figure, a bump (13) having each auxiliary plating (14) as a nucleus is formed.

(Effects of the Invention) As described in detail above, according to the present invention, a connection intermediate that can reliably and easily perform connection between a fine inner lead and an external connection terminal of an electronic component is reliably and easily manufactured. This has the effect of being able to do so.

In other words, according to the connection intermediate (10), it is not necessary to form a bump on the connection terminal of the fine inner lead (30) or the electronic component (40), so that the inner lead (30) and the electronic component ( Processing for connection with 40) can be made very simple, and the structure of the connection intermediate (10) itself can be made very simple. The use of this connection intermediate (10) not only facilitates the connection between the inner lead (30) and the electronic component (40), but also allows the conventional inner lead (30) or electronic component (40) to be connected. Compared to the connection method using the bump formed on the side, it is possible to avoid the short circuit between them as much as possible. Furthermore, in the conventional method of forming a bump on the inner lead (30), the bump had to be formed on each electronic component (40) without bending it. The use of a wrench not only eliminates the need for such precautions, but also greatly reduces the risk of bending the inner lead (30).

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of a connection intermediate manufactured by the present invention, FIG. 2 is an enlarged sectional view showing a state in which an inner lead and an electronic component are connected using the connection intermediate, and FIG.
FIG. 4 is a perspective view of a connection intermediate according to another embodiment, FIG. 4 is a partially enlarged sectional view showing each step of the manufacturing method according to the first claim in order, and FIG. 5 is a second claim. FIGS. 6 and 7 are partially enlarged sectional views showing the manufacturing method, and FIGS. 6 and 7 are partially enlarged sectional views showing a conventional connection method. DESCRIPTION OF SYMBOLS 10 ... Connection intermediate, 11 ... Support base material, 12 ... Support hole, 13 ... Bump, 14 ... Auxiliary plating, 15 ... Opening, 20 ... Conductive base material, 30 ... Inner lead, 40 ... Electronic component.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-502511 (JP, A) JP-A-3-97237 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/60

Claims (2)

(57) [Claims] 1. A supporting base material having an insulating property, a supporting hole formed on the supporting base material and located between an inner lead and a corresponding connection terminal on an electronic component side, and a supporting hole supported by the supporting hole. A method of manufacturing a connection intermediate, which is constituted by the bumps and electrically connects the electronic component to the inner leads, by the following steps. (1) a step of forming the support hole in the support base; (2) a step of integrating the support base in which the support hole is formed on a conductive base; (3) energizing the conductive base. A step of forming the bumps in each of the support holes by electroplating the surface on the side of the support base while (4) removing the conductive base from the support base by peeling or dissolving. 2. A supporting base having an insulating property, a supporting hole formed in the supporting base and located between an inner lead and a corresponding connection terminal on an electronic component side, and a supporting hole supported by the supporting hole. A method of manufacturing a connection intermediate, which is constituted by the bumps and electrically connects the electronic component to the inner leads, by the following steps. (1) a step of forming the support hole in the support base material; (2) a step of applying an auxiliary plating at least in the support hole; (3) a step of applying a solder plating to the auxiliary plating;
Alternatively, a step of immersing the whole of the supporting base material in a molten solder bath to form the bumps with solder having the auxiliary plating as a core.