JPH04179259A - Solder plating apparatus for leads - Google Patents

Abstract

PURPOSE:To prevent the growth of flash when plating each lead and the development of a bridge among leads, as well as a failure in solder plating by the provision of an interposing member which is to be interposed between a cathode and the base of each lead and which is composed of a pressure anisotropic conductive material which establishes an electric conduction in the direction in which each lead is pressed. CONSTITUTION:With a pressure anisotropic conductive rubber 10 interposed between a cathode 2 and the base of a lead 1b, application of pressure to the lead 1b through the rubber leads to a squashed rubber 10 causes a part 10a of the rubber to be extruded onto a space between the leads 1b. Since the space between the leads 1b is sealed with a portion 10a of the extruded rubber, a plating liquid will not penetrate into the space between the leads 1b. This prevents the development of a bridge between the leads 1b and the growth of flash, as well. Moreover, an electric conduction is established only at the area of the pressure anisotropic conductive rubber 10 which is sandwiched between the cathode 2 and the lead 1, whereby the leads 1b, different from one another in height, are aligned and a failure in supplying power is prevented.

Description

[Detailed Description of the Invention] 1. Field of Industrial Application" This invention is directed to the 'I'-field of the 'I' field which is applied to the 'I' field (end T-) of a semiconductor device such as an IC (semiconductor integrated circuit). Regarding the HE knob device.

[Conventional technology-1] Conventionally, various semiconductor devices H, including a watt flat package (Q) type semiconductor device as shown in FIG.
';Single entry to the board] A. In order to improve the efficiency of 1 entry work,
A solder layer is formed on each lead in advance (for example,
3-67261).

FIG. 4 is a front cross-sectional view showing a schematic structure of a lead solder plating apparatus which is an improved technology which acquires the prior art described above and forms half-eleven layers by electroplating. In this figure, 2
is a cathode made of titanium material, which has a substantially rectangular parallelepiped shape, part of which is covered with a cover 3 made of insulated wire, and a concave portion corresponding to the main body portion 1a of the semiconductor device 1 is formed in the F portion. All the titanium materials around this recess are arranged on the four sides of the main body 1a - F'lb, l
b so that it comes into contact with the base of b. 4 is +
1) It is a lower holder made of insulated wire such as E E K U,
By removing the central part of the upper part, lead 1.
Plate-shaped ff1s4 that comes into contact with each legal part of b, l b, ·
a, 4a, are formed.

Further, the lower pedestal 4 is tapered at the side so that its cross-sectional area becomes smaller toward the bottom.

Reference numeral 5 denotes a holding member, which is formed with a forest-like recessed portion that comes into contact with the tapered portion of the lower pedestal 4. Further, an anode 6 is installed around the holding member 5 at a position facing the cathode 2.

Solder plating using this half [1] plating apparatus is performed as follows. The semiconductor device 1 on which lead forming has been completed is placed on the lower pedestal 4, and the bases of the leads on the four sides of the main body 1a]b, Ib are formed on the plate-like portion 4a,
It is supported from below by 4a,. Next, the cathode 2 is placed on the top of the semiconductor device 1, and the leads Ib, lb, . is caught. Sora-
Then, the pedestal 4 on which the semiconductor device 1 and the cathode 2 are mounted is housed in the slotted part of the holding member 4, and the lead l b
, Ib, and the anode 6 is determined depending on the plating conditions (current value, plating solution temperature, stirring strength, plating solution components, concentration, etc.), and is an appropriate value from several mm to several tens of mm. The holding member 5 is appropriately clamped so that In this way, the mounting of the semiconductor device 1 is completed, and the solder plating apparatus is immersed in half the plating solution, and a current is applied to the cathode 2 and the anode 6.

[Problem to be solved by the invention] By the way, in the conventional two-way solder plating device!
;11, Semiconductor device 1 glue-F' l b, l b
, When solder plating is applied to each lead I b,
] b. Growth of firmness may occur during the 5th period.
As shown in the figure, there was a problem in that the semi-1-B plating 7 adhered to the cathode 2, and this caused a gap between the leads Ib and lb. In addition, as shown in Fig. 5, there are variations in the height of each glue -1.
, I b, is not supplied with power, or all nodes -1.jb, l b.

There was also the problem that power was not being supplied to the parts, resulting in plating defects.

This invention has been made in view of the above-mentioned circumstances, and is a lead solder plating apparatus that prevents the growth of plating on each lead of a semiconductor device, prevents the formation of brittle between leads, and does not cause plating defects. is intended to provide.

``Means for Solving the Problems-1 The present invention includes a cathode that comes into contact with a plurality of leads arranged around a semiconductor device, an anode that is spaced apart from each of the leads, and a solder plating group. In the lead solder plating apparatus that performs solder plating on each lead of the semiconductor device, a pressurizer is inserted between the cathode and the base of each lead and exhibits conductivity in the direction in which the leads are pressurized. It is characterized in that it includes an insertion member made of a pressure anisotropic conductive material.

1 Effect -1 According to the configuration described in -1-, the height of each lead is increased by inserting the insertion member made of a pressurized anisotropic conductive material between the cathode and the base of each lead of the semiconductor device. Since variations in power are absorbed, power supply failures do not occur. That is,
An intervening member made of a pressurized anisotropic conductive material has a lower limit value of the applied pressure that becomes conductive, and even if the height of each lead differs, the intervening member will respond to the difference. Because it deforms,
It works so that all the leads are suppressed with a pressure equal to or higher than the lower limit pressure 13. This focuses on the elastic deformation of the intervening member.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front sectional view showing a schematic configuration of the main parts of a lead solder plating apparatus according to an embodiment of the present invention. As shown in this figure, the cathode 2 and the lead l b of the semiconductor device 1,
The point that the pressurized anisotropic conductive rubber (pressurized anisotropic conductive material) 10 is inserted between the base of the I b, .
This is different from the conventional device shown in the figure. Note that the other parts other than the pressurized anisotropic conductive rubber 10 are common. This pressurized anisotropic conductive rubber 10 has a property of exhibiting conductivity only in the direction of pressurization, and is used between the cathode 2 and the base of the leads l b, I b, · of the semiconductor device 1. By applying pressure in the direction of pressing the leads lb, ++], and by the cathode 2 inserted between them, conductivity is exhibited in this pressure direction. In this case, as shown in FIG. 2, the portions of the metal particle buses 12, 12 of the pressurized anisotropic conductive gonograph 10 that are in contact with each other become electrically conductive.

Such a pressurized anisotropic conductive rubber 1o is inserted between the cathode 2 and the base of the semiconductor device 1 glue -1"lb, lb, -,
When pressure is applied to leads lb, Ib, · through this,
As shown in FIG. 2, the rubber 10 is crushed, and a part of it 10a, IOa, Kari-F' 1b, l I
It is pushed out between ll and . This extruded portion 10a, 1Oa, 1" 1b, I
b, Since each space is sealed, each -F l l),
The plating solution does not penetrate between lb and . As a result, no blycine is generated between each lead 11, ), l1), and no growth of paris occurs. In addition, since only the pressurized part that rises to the cathode 2 of the pressurized anisotropic conductive go A IO -J:' l b exhibits conductivity, each -F' l
It is possible to absorb variations in the heights of b, l b, and prevent power supply failures.

``Effects of the Invention'' As described in 1-1 above, according to the lead soldering device of the present invention, there is no electrical conductivity between the cathode and the base of each 1' of the semiconductor device in the direction of pressure action. Since we have provided an insert member made of pressurized anisotropic conductive rubber that exhibits conductivity, it exhibits conductivity only between the pressurized cathode on the insertion part side and the lead, so the height of each lead of the semiconductor device can be reduced. Variations in power are absorbed, and power supply failures do not occur.

Further, by applying pressure to each member -1 through this insertion member, the member is pushed out between each lead, thereby sealing between each lead. This prevents the plating solution from penetrating between the leads. In addition, since the plating solution does not penetrate, there is no growth of paris between the leads.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing a schematic configuration of the main parts of a lead solder plating apparatus according to an embodiment of the present invention, FIG. 2 is a partially enlarged view of the main parts, and FIG. FIG. 4 is a front sectional view showing the schematic structure of a conventional lead half plating device, and FIG. 5 is a partially enlarged view of the same device. 1114 conductor device, 2 cathode, l b, + 11.・Lead, 4] Pa holder, 6 Anode, 10 Insert member.

Claims (1)

[Scope of Claims] A cathode that comes into contact with a plurality of leads arranged around a semiconductor device, an anode that is spaced apart from each of the leads, and a solder plating solution, and each of the semiconductor devices In a lead solder plating apparatus that applies solder plating to the leads, the material is made of a pressure anisotropic conductive material that is interposed between the cathode and the base of each lead and exhibits conductivity in the direction in which each lead is pressed. A lead solder plating device characterized by comprising an insertion member.