JPS5849629Y2 - Container for semiconductor devices - Google Patents

Description

[Detailed description of the invention] This invention enables accurate wire punching of a container for semiconductor devices, which is equipped with a container body made of a stretchable insulating material and an inner lead formed on the surface of the container body. It is about the 6 good things to do.

FIG. 1 is a plan view of the main parts of a conventional container for semiconductor devices.

In FIG. 1, 1 is a semiconductor element bonded to this semiconductor device container, 2 is a plurality of electrodes formed on the entire surface of the semiconductor device 1, and 3 is elasticity of the semiconductor device container due to heat or processing. A container body made of a certain insulating material, 4 a plurality of inner leads made of a highly conductive metal and formed on the surface of the container body 3 to correspond to the electrodes 2, 5 a semiconductor element provided on the container body 3; 1 is an element fixing region to which it is fixed, and 6 is a thin metal wire made of gold Au, silver Ag, etc. and connecting the corresponding electrodes 2 and inner leads 4, respectively.

Note that the element fixing region 5 does not necessarily need to be on the same plane as the inner lead 4.

With the recent development of wire bonding technology, wire punching is becoming increasingly unmanned and automated.

In this case, basically, in most cases, the coordinates of the electrode 2 on the semiconductor element 1 are specified by the coordinates of the punching point on the inner lead 4 arranged on the container body 3, and the wire is connected under the control of a minicomputer or microcomputer. It performs bonding.

If the container body 3 has elasticity due to heat or pressure,
There are cases where the expansion/contraction ratios in the X direction (horizontal direction in FIG. 1) and the Y direction (vertical direction in FIG. 1) are not necessarily the same.

In particular, when the inner leads 4 are miniaturized or the number of inner leads 4 becomes extremely large, there may be cases where reliable wire bonding cannot be performed at a designated position.

This idea was made in view of the above points, and it is possible to measure the expansion/contraction rate of the container body in any direction parallel to the surface of the container body by providing at least three reference marks that are not on the same straight line on the container body. It is an object of the present invention to provide a container for a semiconductor device that allows accurate wire punching by making calculation possible.

This invention will be explained below based on examples.

FIG. 2 is a plan view of a main part of an embodiment of a semiconductor device container according to this invention.

In FIG. 2, the same reference numerals as in FIG. 1 represent the same components as shown in FIG.

3a is the container body of the semiconductor device container of the example, 7a, 7
b, 7C, and 7d are four reference marks formed on the surface of the container body and not on the same straight line.

By arranging the four reference marks 7a, 7b, 7C, and 7d so that they are not aligned on the same straight line, the container body 3a is
Even if they have different expansion/contraction rates in the direction (horizontal direction in Figure 2) and the Y direction (vertical direction in Figure 2), the distances between the four reference marks 7a, 7b, 7C, and 7d can be measured. , (that is, by measuring each coordinate) and comparing it with the values in the design drawing of this semiconductor device container, the expansion/contraction ratios in the X direction and the Y direction can be easily calculated.

Furthermore, in the case of the electrode 2 disposed on the semiconductor element 1, even after the semiconductor element 1 is fixed on the element fixing region 5, the mutual positional relationship between the semiconductor element 1 and the electrode 2 does not change. The mutual positional relationship between the virtual XY coordinate system of the device container and the xy coordinate system of the wire bonding device, that is, the amount of parallel movement and the rotation angle may be given.

When the container body 3a has anisotropic stretchability, the operation of providing the same amount of parallel movement and rotation angle as in the case of the semiconductor element 1 is not sufficient.

In order to perform accurate wire bonding to the inner lead 4 of the container body 3a, it is necessary to provide the expansion/contraction ratio of the container body 3 in each direction in addition to the above-mentioned translation amount and rotation angle.

As an example, the four reference marks 7a, 7b, 7C, 7d and each inner lead 4 are on the same virtual -XY coordinate system, and the straight line connecting the reference marks 7a and 7b is the reference mark 7b.
An example is a case where the straight line connecting the reference mark 7C and the reference mark 7C, the straight line connecting the reference mark 7C and the reference mark 7d, and the straight line connecting the reference mark 7d and the reference mark 7a are arranged so as to be perpendicular to the X-axis or the Y-axis. , four reference marks 7 a , 7 b , 7 C,
The role of 7d will be explained in detail.

The numerical values stored in the minicomputer or microcomputer are the coordinates A (XO, YO) of multiple bonding points and four reference marks 7 a , 7 on a virtual XY coordinate system.
Each coordinate B (Xm.

Ym), and the distance specified on the design drawing between these reference marks [for example, the distance between reference mark 7a and reference mark 7b is Ll, and the distance between reference mark 7b and reference mark 7C is L2.
, the distance between the reference mark 7C and the reference mark 7d is L3. The distance between the reference mark 7d and the reference mark 7a is L4].

Next, calculation of the expansion/contraction rate of the container body 3a, which is a problem, and the relationship between the container body 3a fixed on the punching device and the virtual
It is necessary to calculate the amount of translation and rotation angle with respect to the Y coordinate system.

The amount of parallel movement and the rotation angle can be determined by converting the coordinate values in the virtual XY coordinate system to the real coordinate system A (Xo, yo) of the bonding apparatus using two fixed points on the container body 3a.

However, if the container main body 3a has anisotropy in its elasticity, it is impossible to perform bonding at an accurate position by only correcting the amount of translation and the angle of rotation.

The expansion/contraction ratio in each direction is determined by actually measuring the coordinates of four reference neighbors 7a, 7b, 7C, and 7d on the container body 3a.
The distances 11, 12, 13, and 14 (corresponding to Ll, L2, L3, and L4, respectively) between these reference marks can be calculated.

Therefore, the expansion/contraction ratio in each direction is 1=11/L1. to 2
-12/L2゜k 1=l 3/L3. k2=
It can be expressed in the form l4/L4.

In this way, the container body 3a has anisotropy in elasticity.
The coordinates of the bonding point of the inner lead 4 placed above are determined by converting the stored virtual coordinates A (Xo, Yo) to the actual coordinates A (xo, yo) of the bonding device based on actual measurements at two fixed points.
It can be seen that it is sufficient to perform wire bonding after converting to 200 and correcting the anisotropic expansion/contraction ratio A (klXo, 2yo) by actually measuring the four reference marks.

Although the above embodiment describes the case where there are four reference marks, it is sufficient to have at least three reference marks that are not on the same straight line.

Note that the material, shape, and size of the reference marks, and the distance between the reference marks are not particularly specified.

As detailed above, in the container for semiconductor devices according to this invention, at least three reference marks that are not on the same straight line are provided on the elastic container body, so that by measuring the coordinates of these reference marks, The expansion/contraction rate in any direction parallel to the surface of the container body can be calculated, and the anisotropy of the expansion/contraction rate can be determined.

Therefore, the accurate position of the bonding point of the inner lead can be calculated, and accurate wire bonding can be performed.

[Brief explanation of the drawing]

Figure 1 is a plan view of the main parts of a conventional container for semiconductor devices;
The figure is a plan view of essential parts of an embodiment of the semiconductor device container according to this invention. In the figure, 1 is a semiconductor element, 2 is an electrode of the semiconductor element 1, 3 and 3a are the container body, 4 is an inner lead, 5 is an element fixing area, 6 is a thin metal wire, and 7a, 7b, 7C, and 7d are reference marks. be. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] In a container body made of an insulating material that is stretchable when subjected to heat or pressure, and an inner lead formed on the surface of the container body, at least three coordinates that are not on the same straight line on the container body. By providing a reference mark exclusively for measurement and measuring the coordinates of the reference mark, it is possible to calculate the expansion and contraction rate of the container body due to heat or pressure in any direction parallel to the surface of the container body. A container for a semiconductor device, characterized in that: