JPS62240161A - Soldering device for electronic component lead - Google Patents

Abstract

PURPOSE:To prevent the generation of a defective soldering due to an oxide by reflowing the creamy solder of low viscosity coated on the lead of an electronic component with the latent heat of evaporation of the inert vapor phase formed inside a vapor tank. CONSTITUTION:A flux 32 is coated on an IC lead 12 in a flux coating device 21 and the low viscosity creamy solder 42 of a room temp. is coated on the IC lead 12 in a solder coating device 22. In case of the IC 11 passing through the upper side of a preheater 23, the activation of the lead base metal progresses by the activating force of the flux and the IC 11 enters in a vapor tank 24 in that state. In the inner part of the vapor tank 24, the creamy solder 42 reflows by the latent heat of evaporation of high temp. owned by an inert vapor phase 63 and the solder is melted equally on the whole surface of the lead 12, which is subjected to a solder plating.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention relates to an electronic component for soldering the leads (legs) of an electronic component such as an integrated circuit (hereinafter referred to as tC). This invention relates to a lead soldering device.

(Prior art) Conventionally, when performing solder plating on leads of ICs, etc., a large number of ICs were mounted on a jig as shown in Japanese Patent Publication No. 58-57269 @ gazette, and this jig was used on an automatic soldering line. The leads of this IC can be made by transporting the IC in a track consisting of several guide members installed along an automatic soldering line, as shown in Japanese Patent Application Laid-Open No. 59-202163. I am trying to do some soldering.

In this case, the automatic soldering line includes a flux applicator that applies flux to the leads, a preheater that preheats the leads, and a high temperature (approximately 250 degrees Celsius) that applies flux to the leads along the IC transport line. It is constructed by sequentially arranging a jet-type solder bath that jets molten solder.

(Problem to be Solved by the Invention) In this way, conventionally, the solder melted at high temperature in a jet soldering bath is applied directly to the leads, so that the solder in the soldering bath is Oxidation is significant and the oxide often adheres to the solder plating area, which is a major cause of solder plating defects.

An object of the present invention is to eliminate soldering defects caused by oxides when soldering leads of electronic components.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a soldering apparatus that performs solder plating on the leads 12 of an electronic component 11.
a flux coating device 21 for coating the leads, a solder coating device 22 for coating the leads with room temperature, low viscosity cream solder 42a, and a preheater 2 for preheating the leads 12.
3, and a steam tank 24 for reflowing the cream solder 42a applied to the leads using the latent heat of vaporization of the inert steam phase 63.
are arranged in sequence.

(Function) The present invention applies a low viscosity cream solder 42a at room temperature to the fluxed lead 12, preheats the lead 12, and then puts it into a steam tank 24. The cream solder 42a is reflowed by the latent heat of vaporization of the lead 12, melting the solder over the entire surface of the lead 12, and applying solder plating to the entire surface of the lead.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

11 is an IC as an electronic component, and a number of boards 12 are provided protruding from the side surface of this IC 11.

The IC 11 is transported by the jig-type or rack-type transport line 13.

Along the transport line 13, there is a flux coating device 21 for coating the IC lead 12 with flux, and a flux coating device 21 for coating the IC lead 12 with flux;
A solder coating device 22 applies low viscosity cream solder at room temperature to the C leads 12; a preheater 23 preheats the IC leads 12; and a solder coating device 22 that applies low viscosity cream solder to the C leads 12; The steam tanks 24 to be reflowed are arranged in sequence.

The flux applicator 21 is configured such that flux 32 stored in a flux tank 31 is circulated through a pump 33 and jetted from a nozzle 34, and the IC lead 12 is immersed in the jetted flux 32a.

Further, the solder applicator m22 jets the low-viscosity cream solder 42 at room temperature stored in the solder bath 41 from the nozzle 44 using the pump blade 43, and immerses the IC lead 12 in the jet cream solder 42a. It is something. Further, the preheater 23 has an electric heater [7152] disposed inside the heater main body 51 having an opening on the top surface,
The heat generated from this heating wire 52 when energized causes the TCll to
It is used to heat.

Further, the steam tank 24 stores an inert liquid (for example, fluorine-based inert solvent, trade name: 70 Linate) 61 in the lower part, and heats the inert liquid 61 with a heater 62 to evaporate it. An inert vapor phase 63 is formed inside 24. An inlet port 64 and an outlet port 65 are provided in the upper part of the steam tank 24 , and leakage of the vapor phase 63 to the outside from each port 64 , 65 is prevented by the condensing action of the cooling coil 66 .

Then, the IC lead 1 is coated with the flux coating device 21.
2 is coated with flux, and the solder coating device 22 coats the IC lead 12 with room-temperature, low-viscosity cream solder.Furthermore, when the IC 11 passes above the preheater 23, the activation force of the flux activates the lead base material. TCll enters the steam tank 24 in this state.

Inside this steam tank 24, the cream solder reflows due to the latent heat of vaporization of the inert vapor phase 63 at a high temperature (215° C. in the case of Fluorinert), and the IC lead 1
The solder melts evenly over the entire surface of the lead 12, and the entire surface of the lead 12 is plated with solder. When the cream solder is reflowed in this manner, the atmosphere is an inert vapor phase 63 at a temperature above the melting point of the solder, so that generation of oxides is suppressed.

The IC 11 that has been reflow soldered in the steam bath 24 is sent to a cleaning process to wash away residual flux.

Note that the lvl coating device 22 is not limited to the jet type solder bath of this embodiment. For example, low viscosity cream solder at room temperature is stored in a static bath, and either this static bath or an IC is used. By moving one side up and down, the IC
The leads 12 may be immersed in the cream solder, or the cream solder may be individually supplied and applied to each lead 12 by a dispenser V. According to this dispenser supply method, The supply amount can be controlled accurately.

〔Effect of the invention〕

According to the present invention, the low viscosity cream solder at room temperature applied to the leads of electronic components is reflowed by the latent heat of vaporization of the inactive bamboo vapor phase formed in the steam tank. The generation of oxides in the solder-plated portions of the leads can be greatly suppressed.

[Brief explanation of drawings]

The figure is a sectional view showing an embodiment of the electronic component lead soldering apparatus of the present invention. 11...IC as an electronic component, 12...Lead, 13
・・Transport line, 21・・Flux coating device, 22・
- Solder applicator, 23... Preheater, 24... Steam tank, 32a... Flux, 42a... Low viscosity cream solder at room temperature, 63... Inert vapor phase.

Claims (1)

[Claims] (1) A soldering device that performs solder plating on the leads of electronic components includes a flux application device that applies flux to the leads along the transport line of the electronic components, and a flux application device that applies room temperature, low-viscosity cream solder to the leads. A solder applicator for electronic component leads, a preheater for preheating the leads, and a steam tank for reflowing cream solder applied to the leads using latent heat of vaporization in an inert vapor phase, which are arranged in sequence. Soldering equipment.