JPH03123061A - Mounting of semiconductor device - Google Patents

Abstract

PURPOSE:To facilitate the mounting alignment of a semiconductor device and to improve a nut fastening operation and soldering operation in workability by a method wherein a positioning jig is used to tighten a nut fitted to a threaded stud provided to the semiconductor device. CONSTITUTION:A circuit board 1 is placed on the upside of the opening of an auxiliary heat dissipating case 4, a boss 4a is inserted into a through-hole 1b of the circuit board 1, and the four corners of the circuit board 1 are fixed by mounting screws 5. Then, a threaded stud 2c of a semiconductor device 2 is inserted into the through-hole 1b of the circuit board 1 and furthermore into a mounting hole 4a-1. Engaging grooves 3a of a positioning jig 3 are engaged with angular parts 2a-1 of the semiconductor device 2, and positioning pins 3b are inserted into positioning holes 1c respectively. At this point, leads 2b are automatically positioned to lands 1a. By this engagement, a nut 2d is tightened from below by a torque driver to bring the semiconductor device 2 into close contact with the boss 4a as the semiconductor device is stopped from rotating. In succession, the positioning jig 3 is drawn out, and then the leads 2b are soldered to the lands 1a.

Description

[Detailed Description of the Invention] [Summary] Regarding a mounting method for a semiconductor device having a threaded stud, the present invention aims to prevent the semiconductor device from co-rotating when tightening the NAND and eliminate any adverse effects on the solder joints and leads. , Insert the threaded stud of the rectangular semiconductor device to be mounted into the through hole of the circuit board, then use a positioning tool to fit the engagement groove of the positioning tool into the outer shape of the semiconductor device, and insert the locating pin of the positioning tool into the above-mentioned shape. After positioning the leads of the semiconductor device on the lands of the circuit board by fitting and securing them into the positioning holes of the circuit board and preventing the semiconductor device from rotating, the nuts are tightened, and finally the leads are soldered to the lands. Configure.

[Industrial application field]

The present invention relates to a method for mounting a semiconductor device having a threaded stud.

The threaded stud of a semiconductor device that has a threaded stud mounted on a circuit board serves as both a mounting means and a heat conduction means, and is suitable for circuit boards and heat sinks with good heat dissipation effects, such as ceramic substrates and auxiliary heat sinks. Although the solder joints are firmly fixed, there is a need to prevent the rotational force from being applied to the solder joints and leads when tightening the pads.

[Conventional technology]

Conventionally, as shown in the side sectional view of FIG. 3, the circuit board 11 has a semiconductor device 2 having a threaded stud on the land lla,
For example, the rectangular LSI board 2 shown in the perspective view of FIG.
After soldering and mounting, the boss 4a protruding from the bottom of the housing is placed on the top surface of the auxiliary heat dissipation housing 4 made of metal with good thermal conductivity, and the boss 4a protruding from the bottom of the housing is inserted into the through hole 11b of the circuit board 11, and the top surface of the boss 4a and the circuit are connected. flush with the mounting surface of the board 11), and attach the mounting screws 5 at the four corners.
It is identified by

The semiconductor device 2 is equipped with a threaded stud 2 for heat dissipation.
c is further inserted into the mounting hole 4a-1 of the boss 4a, the package 2a is brought into direct contact with the upper surface of the post 4a, and the screwdriver (not shown) is tightened from below using a torque driver (not shown) with a naso 1-26. It is fixed.

[Problem to be solved by the invention]

However, according to such a two-head mounting structure, the semiconductor device is tightened with nuts after the leads are soldered to the lands of the circuit board. There was a problem in that the added force caused stress and reduced reliability.

In view of the above-mentioned problems, an object of the present invention is to provide a method for mounting a semiconductor device that can prevent the semiconductor device from co-rotating during the initial tightening process and eliminate the adverse effects on the semi-ETI joint and the leads. shall be.

[Means to solve the problem]

In order to achieve the above object, in the semiconductor device mounting method of the present invention, the screws (-
Insert the J stud into the through hole of the circuit board, then use a positioning tool to fit the engagement groove of the positioning tool into the outer shape of the semiconductor device, and fit the locating pin of the locating tool into the locating hole of the circuit board. After aligning the leads of the semiconductor device to the lands of the circuit board and preventing the semiconductor device from rotating, NAND tightening is performed, and finally the leads are soldered to the lands.

[Effect]

The positioning tool can position the lead on the land by engaging the engagement groove with the external shape of the semiconductor device and the positioning pin with the positioning hole of the circuit board. This makes it possible to stop the semiconductor device from rotating and prevent co-rotation, and by finally soldering the leads, it is possible to eliminate any adverse effects on the solder joints and the leads.

〔Example〕

The gist of the present invention will be explained in detail below based on embodiments shown in the drawings. In order to make it easier to understand the explanation of the configuration and operation, the same parts are given the same reference numerals throughout all the figures, and repeated explanation thereof will be omitted.

As shown in the side sectional view of FIG. 1, the circuit board 1 has lands 18 to which leads 2b of the semiconductor device 2 shown in FIG. 4 are connected.
and a through hole 1b through which the boss 4a of the auxiliary heat dissipation housing 4 is inserted, and a hole diameter of approximately 0.9111 mm (to match the diameter of the other through hole (not shown)) on the outside of the land]a, that is, on the diagonal line of the package 2a. ) positioning hole 1c.

The positioning tool 3 is made of metal, and as shown in the single perspective view of FIG. 2, has an engaging groove 3a into which the outer shape of the package 2a of the semiconductor device 2 shown in FIG. 4, that is, the opposing corner 2a-1 is fitted.
and a positioning hole 1c of the circuit board 1 on the center line on both outer sides thereof.
It is provided with a stepped positioning pin 3b that is fitted into the holder, and a ground screw 3c that connects a ground wire (not shown). In addition, as shown in FIG. 1, the depth of the engagement groove 3a is
When the engagement groove 3a is inserted into the corner 2a-1 of the package 2a and the positioning pin 3b is inserted into the positioning hole 1c, the lead 2b and the land 1a
Set the relative relationship so that it overlaps and matches.

When mounting the semiconductor device 2 on the circuit board 1 set in this way, it is performed as follows.

First, place the circuit board 1 on the opening top surface of the auxiliary heat dissipation housing 4,
Insert the boss 4a into the through hole 1b of the circuit board 1 and tighten the mounting screw 5.
Fix the four corners with. (The top surface of the post 4a and the mounting surface of the circuit board I are flush with each other.) Next, the semiconductor device 2 to be mounted is
After inserting the threaded stud 2c into the through hole 1b of the circuit board 1, it is further inserted into the mounting hole 4a-1 of the boss 4a.

Then, the engaging groove 3a of the positioning tool 3 is fitted into the corner 2a-1 of the semiconductor device 2, and the positioning pin 3b is fitted into the positioning hole 1c. At this time, lead 2b is connected to land la.
automatically positioned.

In addition, the ground wire 6 connected to the ground level (not shown)
The terminal 6a is connected to the ground screw 3c.

Then, by lightly pressing the positioning tool 3 from above with a finger or the like, the engagement groove 3a is engaged with the corner 2a-1 of the semiconductor device 2, and the positioning pin 3b is engaged with the positioning hole 1c. With the semiconductor device 2 prevented from rotating, tighten the nut 2d from below with a predetermined torque (approximately 5 to 6 kg/cm) using a torque driver (not shown) to fix the semiconductor device 2 to the boss 4a.
Fix it tightly.

Next, after removing the ground wire 6 and pulling out the positioning tool 3, soldering is performed between the lead 2b and the land 1a.

In this way, by using a positioning tool that serves both as a positioning jig and stopper to position the semiconductor device for mounting (overlapping the leads and lands) and to prevent the semiconductor device from rotating when tightening the NAND, the leads and lands can be automatically aligned. In this state, the nut can be safely tightened without the semiconductor device rotating together.

Since soldering is performed last after the semiconductor device is fixed with a NAND clamp, there is no adverse effect on the leads and solder joints as in the conventional method, and good electrical reliability can be maintained.

Note that the ground wire prevents electrostatic damage to internal elements of the semiconductor device.

In the semiconductor device described above, in order to improve heat dissipation efficiency, the circuit board is attached to an auxiliary heat dissipation case, and the semiconductor device is tightly fixed on the top surface of the boss. The ceramic substrate may be fastened with a nut to the ceramic substrate itself, or the ceramic substrate and the boss may be fastened together with a nut.

〔Effect of the invention〕

As described in detail above, according to the present invention, when tightening the nut of a semiconductor device having a threaded scud, the mounting position of the semiconductor device can be easily aligned by using a positioning tool, and the semiconductor device can be easily aligned while the semiconductor device is prevented from rotating. Since the NAND can be tightened, the workability of nut tightening and soldering is improved, and there is no stress on the leads or solder joints (it is possible to provide an electronic circuit unit with high electrical reliability). It exhibits extremely useful effects in industry.

Figure 3 is a side sectional view of the conventional technology; FIG. 4 is a perspective view of the semiconductor device of FIG. 3.

In the figure, l is the circuit board, 2d is the nut, 1a is the land,
3 is a positioning tool, 1b is a through hole,
3a is an engagement groove, 1c is a positioning hole, 3b is a positioning bottle, 2 is a semiconductor device, 4 is an auxiliary heat dissipation housing,
2b is a lead, 4a is a boss, 2C is a threaded stud, 4a-1 is a mounting hole 1°

[Brief explanation of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention, and FIG. 2 is a perspective view of the positioning tool shown in FIG. 1.

Claims (1)

[Claims] The threaded stud (2) of the rectangular semiconductor device (2) to be mounted
c) into the through hole (1b) of the circuit board (1), and then use the positioning tool (3) to insert the engagement groove (3) of the positioning tool (3).
a) into the outer shape of the semiconductor device (2), and the positioning pin (3b) of the positioning tool (3) is fitted into and engaged with the positioning hole (1c) of the circuit board (1). Connect the leads (2b) of the device (2) to the circuit board (
1) After positioning the semiconductor device (2) on the land (1a) and preventing it from rotating, the nut (2d) is tightened, and finally the lead (2b) is soldered to the land (1a). A method for mounting semiconductor devices.