JPS6220361A - Mounting method for heat sink fin - Google Patents

Abstract

PURPOSE:To improve the solderability by mechanically removing an oxide film of a portion to be soldered with a semiconductor element of the surface of a conductor layer formed by metallizing, and immediately soldering the cap of the element on the removed portion after removing. CONSTITUTION:The surface of an aluminum substrate 1 is roughed by sand- blasting, fine alumina powder is melted in a plasma arm to form a mounting pattern electrically independent from the substrate, the liquefied powder is injected to form an alumina insulating layer 3 only the prescribed range on the substrate. Copper fine powder is melted in a plasma, and injected to obtain a pattern 4 on a mounting pattern 2 and the layer 3. Then, a semiconductor element mount in the pattern 2 and a conductor pattern 4 are ground and removed at six portions over the depth of 50-100mum in diameter larger than the cap 10a of the element with a rotary abrasive formed with grinding surface on the cylindrical surface. Thus, soldering with high reliability can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for mounting a radiation fin on a heat generating component, and is particularly used for mounting a power supply element.

[Technical Background of Invention 1] Semiconductor elements that generate a lot of heat, such as rectifier elements, require appropriate heat radiation to maintain their performance, and for this reason, heat radiation fins are generally used.

These heat dissipation fins are also used in rectifier assembly products in which multiple rectifier elements are mounted simultaneously.

Figure 4, which is a cross-sectional view of B-8 in Figure 3, shows the configuration of the radiation fins used in such conventional rectifying assemblies. A first conductor pattern 2 for mounting the element 1 formed by thermal spraying: A second conductor pattern 2 for mounting the element formed by thermal spraying copper through an alumina (aluminum Mide) insulating layer 3. conductor pattern 1, copper sprayed lead-out pattern 5 for electrical connection from aluminum substrate 1
has been formed.

Copper pattern 1 pattern 2 and 4 formed in this way
4, a semiconductor element 10 such as a rectifying element is soldered (SF+) to its kissep part 10a.

[Problems with background technology]

However, in such a mounting structure, J3 is half)9
Since the conductor pattern made of copper or other material from which the body element is removed is formed by molten DI, it is subjected to plasma heat treatment.
), an oxide film is formed on the surface. For this reason, when attaching semiconductor elements, terminals, etc., the wettability of solder to the oxide film is very poor, and the reliability of solder I-1 is lacking.

A strong flux can be used to solve this problem, but requires sufficient cleaning and leads to double culm growth.

To prevent oxidation of the solder, use a solder corner surrounding the solder.
Although it is possible to apply 1- to 9-dimensionality, it is not sufficient, and both of these methods require strict visual inspection of the solder (jt 1'! and this visual inspection, 13 J: correction of defects determined by the external visual inspection of This will require a large amount of time.

In addition, the oxide film on the surface of the conductor pattern can be removed using acid, but since the molten m layer has a porous structure, harmful acids can easily penetrate inside, and the permeated acid cannot be removed. Because of this, there is a problem that oxidation occurs later or corrodes the aluminum substrate, impairing reliability.

[Purpose of the invention]

The present invention has been made to solve and overcome the above problem, and an object of the present invention is to provide a method for mounting a heat dissipation fin that improves solder immobility and has a single heat dissipation fin.

[Summary of the invention]

In order to achieve the above object, the present invention mechanically removes the oxide film on the surface of the conductor layer formed by thermal spraying, at least in the part where the semiconductor element is to be exposed, and immediately after the removal, the semiconductor element is placed on the removed part. The kissep part of the product is soldered, making highly reliable soldering possible.

[Embodiments of the invention]

An embodiment of the present invention will be described below.

FIG. 1 is a plan view showing the configuration of a heat dissipation fin used in the heat dissipation fin mounting method of the present invention, and is a plan view showing the structure of a heat dissipation fin used in the heat dissipation fin mounting method of the present invention.
Good heat dissipation as well/i First conductor pattern 2 for mounting the element formed by direct copper spraying on the aluminum substrate 1, copper spraying via the alumina insulating layer 3 formed by melting. A second conductor pattern 4 for the number of elements formed with 1 and a drawer 1 flange turn are formed on the copper spraying for electrical connection from the aluminum substrate 1.

Layer formation using such thermal spraying is performed as follows.

First, the surface of an aluminum substrate 1 having a thickness of 1.0 m, for example, is roughened by sandblasting or the like. This surface roughening can also be carried out using a blast mask that exposes the part () that will be thermally sprayed later and sprays the +1-.

= 4 - Next, in order to form a mounting pattern that is electrically independent from the board, fine alumina powder is melted in a plasma arc and the liquefied fine powder is injected onto the board surface.
．． Now deposit 2mm.

At this time, the alumina insulating layer 3 is formed only in a predetermined area.
: Place a mask on the sea urchin substrate 1 and perform plasma spraying.

Next, a mask is placed on the substrate 1 in the same manner, and fine copper powder is melted in plasma and sprayed onto the substrate.
．． A mounting pattern 2 formed directly on the alumina insulating layer 3 with a thickness of 15 mm and a pattern 4 with a thickness of about 0.15 mm formed on the alumina insulating layer 3 are 1q.

Next, 4 parts of the semiconductor elements in the conductor pattern 2 and the conductor pattern 4 are polished to a diameter of 50 to 100 μm larger than the sharpened part 10a of the semiconductor element using a rotary grindstone with an abrasive surface formed on the lower surface of the cylinder. A total of six locations are ground and removed over a depth of, for example, 80μ.

After this grinding, before the oxide film is re-formed on the surface of the ground part, the solder preform containing pine resin and the rectifying element for bonding, etc. are placed on the ground part, and the temperature is 270'C.
7. In the furnace, from IJii Rikukoto IJ, the riff [1-(read I・1(I)(').J, the rectifying element 10 is 1,=7 Solid idea 7\rel, 24
'lXX mj @I! 16゜(-) 4I: The mounting method removes the conductor pattern surface i'rij of the LL semiconductor (jl 1.J).
1ti is removed before the oxide film 711 is formed (, - is Δ.

(Do N+, 1, -) i4 2 and do l, 2v)
, Nitome 11's high good A1 is Δ, and D1 is possible. % to 0.3-・(L7%) 1! (2 J- is possible, no six-1)
Weak 1-)'s (・0-1 minutes), :me cleaning IT culm)'l! t'l is abbreviated or Iζ- is 4 so that 1g can be omitted.
L-')

In the above embodiment, copper is used in each of the nine layers, and
A conductor layer is formed on the contact electrode through the alumina insulating film, but this is limited to the conductor layer made of an alloy of 41<, other metals A), etc. (using, 1 41: Separate the power supply system into two sets of membranes () 41: 1) Good 1) with only the Knoin I- (1) to form a conductor layer
, and when using an insulating layer, in the embodiment, j-Ui=,
In addition to aluminum oxide, oxidized drying zone etc. have good heat conductivity.
, furthermore, the first layer is ``,′>(, the second fin-1 layer of the embodiment
A part of the fin is formed on the entire surface of the fin. be exposed.

The removal range of the oxidized 9R is as shown in Example 1. It is also possible to remove -C from the entire surface of the conductor layer by using plane 1i11 abrasion. Also, soldering is done using a furnace, but various known methods such as a soldering iron, hot plate, hot air, vapor, etc. can be used. .

Furthermore, the target object of /υday is not limited to semiconductor devices, but can be applied to various active elements and passive components.

〔Effect of the invention〕

Based on the above embodiments, according to the present invention, the surface oxide film of the molten conductor layer formed on the heat dissipation fins 1 to 1 is mechanically removed, and the oxide film is re-formed. Soldering the heating element etc. beforehand (+t) makes it possible to use highly reliable soldering (1), and there is no need to use processing liquids such as strong flux, so cleaning, etc. You can improve your work efficiency without having to stutter.

[Brief explanation of the drawing]

Figure 1 shows the configuration of the radiation fin used in the present invention.
17 side view, Fig. 2 is a △-△ cross-sectional view of [my], showing the state in which the parts are installed, Fig. 3 is a -Jri side view showing the configuration of a conventional heat dissipation fin, and Fig. 4 is its [ 3, -, B sectional view. DESCRIPTION OF SYMBOLS 1... Substrate, 2, 4...) υ body layer, 3... Insulating layer, 55... Lead-out part, 6... rdT Ti11 part,
7... Solder, 10... Rectifying element, 10a... Kitotsubu. Applicant's Representative Buddha Fuji -kjlFigure 1Figure 3Figure 2Figure 4

Claims (1)

[Claims] 1. A process of forming a conductor layer by metal spraying on a heat dissipation fin made of a metal substrate with good heat dissipation properties, and surface oxidation of at least a portion of the surface of the sprayed conductor layer to which a heat generating component is soldered. A method for mounting a heat dissipation fin, comprising: mechanically removing a film; and after removing the surface oxide film and before re-forming the oxide film, soldering the heat generating component to the portion from which the surface oxide film has been removed. 2. The method of mounting a heat dissipation fin according to claim 1, wherein the mechanical removal of the surface oxide film is performed by grinding. 3. The method of mounting a heat dissipation fin according to claim 2, wherein the heat dissipation fin is an aluminum plate and the thermally sprayed conductor is copper. 4. The method for mounting a heat dissipating fin according to claim 1, wherein the metal spraying is performed by plasma spraying.