JPS63227097A - Method of thick film through-hole land - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [1 Summary] The present invention relates to the shape of a land for through-hole connection in a thick film hybrid integrated circuit using a ceramic substrate, and the shape is proportional to the position of the through-hole from the dimensional reference point of the substrate. This method eliminates the problem of aligning the printed land with a mask to the misalignment of the through hole caused by firing the ceramic. This can improve the efficiency of mask fitting work.

[Industrial application field]

The present invention relates to a thick film hybrid integrated circuit using a ceramic substrate, and relates to a method for forming a thick film through-hole land that eliminates misalignment between a through-hole connecting land and a through-hole.

To create through holes in thick film hybrid integrated circuits using ceramic substrates, first drill through holes at predetermined positions on the ceramic substrate before firing, then bake them.Next, ink is applied to the surface of this substrate. A commonly used method is to print a paste onto a circuit pattern using a mask, spread it over the large surface of the through hole, and then bake it to form a thick film conductor.

Here, the dimensions of the through holes shrink due to firing of the ceramic, and in particular, large deviations in positional relationship occur.

Also, the amount of this deviation varies depending on the lot.

This hole position shift of the through hole affects the pattern formation of the connection land in the subsequent process, and how to deal with this problem with less adverse effects has become a big problem in terms of cost.

[Conventional technology]

The hole position tolerance of through holes that occurs in thick film hybrid integrated circuits using ceramic substrates increases in proportion to the distance from the substrate's dimensional reference point, and in one conventional example, including loft variations, it is approximately ±1. %, and there was no direction.

On the other hand, the dimensional tolerance of the mask for producing a thick IS body is about one loss less than the above tolerance.

Therefore, as it is, the larger the board size, the more the through-hole and the connection land are formed, and in the worst case, the hole protrudes from the connection land.

For this reason, as an example of the conventional method, several types of masks are prepared for the same circuit pattern, with the vertical and horizontal dimensions uniformly changed within the hole position tolerance, and the mask is adjusted to match the hole position deviation according to the board. By selecting a mask and then printing,
It had been resolved.

[Problem that the invention seeks to solve]

For this reason, (1) it was necessary to create and prepare several types of masks with slightly expanded and contracted dimensions for the same circuit pattern;

(2) Also, in printing work, first align the mask with the substrate,
The printing process had to be carried out after selecting the optimal mask that would prevent the holes and patterns from protruding.

There were problems such as.

The present invention aims to solve the above-mentioned problems and provides a new method for solving the problem of misalignment of through-holes with efficient work without waste.

[Means for solving problems]

As shown in the principle diagram of the present invention in FIG. 1, in forming a through hole land 3 for connecting through holes 2 in a thick film hybrid integrated circuit using a ceramic substrate 1, the through hole is This problem is solved by the method of forming a thick film through-hole land of the present invention, in which the shape of the through-hole land 3 is expanded in proportion to the position up to 2.

[For production]

In other words, the deviation in hole position increases in proportion to the position from the dimensional reference point of the board to the through-hole hole, so if the shape of the through-hole land is expanded accordingly, the hole becomes a land. It no longer sticks out and is resolved.

As shown in Figure 1, A on the straight line passing through the dimension reference point A of the substrate l.
When providing through-holes 2 (hole diameter d, land diameter D) at point B, point B (distance Lb from A-B), and point 0 (distance Lc from A-C), through-hole land 3 can be formed with high accuracy using a mask. However, if the hole of through hole 2 is reduced by firing the ceramic and varies within ±α% with respect to the designed position, the hole misalignment at each point is δb = ±α・Lb・・・・・・Point B δC=±α・L
c ・・・・・・0 point Here, at point B, the hole is inscribed in the land, and at point 0, it protrudes outside the land, D=d+2δb,°b=(D-d)/2αD
<d+2δc, °c>(D-d)/2α Therefore,
If the distance from the reference point A is L≦(D-d)/2α, the hole will not protrude outside the land.

However, by changing the land radius in proportion to the distance, D≧a
+2α·L That is, if the long axis D=Do+2α·L and the short axis Do (Do is D at point A) are used as the oval land 31, the land will not protrude and the minimum thickness of (Do-d) will be achieved.

FIG. 1 is a diagram showing the principle, and only the deviation in the -axis direction has been explained, but the same can be done for the plane of two orthogonal wheels by combining each axis component.

(Then, the shape of the through-hole land is expanded in proportion to the position from the dimension reference point, and only one type of mask is created for the circuit pattern, and this mask is adjusted to the dimensions of the board. Printing can be done simply by aligning with the reference point, which solves the problem.

〔Example〕

The present invention will be specifically described below with reference to embodiments shown in the drawings.

The same reference numerals indicate the same objects throughout the figures.

FIG. 2 shows an embodiment of the present invention.

A through hole 21゜2 in a rectangular ceramic substrate 1)
2...29 are provided, and a land 31 is provided corresponding to each land.
32...39 are provided, and the arrangement is as shown in FIG. 2, with the circuit pattern portion omitted.

The dimension reference point A is the corner of the substrate 1), and the -side X is the reference line.

Each through-hole 21, 22. ...29 is the distance Lyl parallel to the X side, Ly2. Three rows of Ly3 and Lxl, Lx2, which are parallel to the Y side orthogonal to this. It is provided at the intersection of three columns of Lx3.

The hole diameter of all the through holes is d, and the through hole 21 closest to point A is circular with a land diameter Do.

The reduction rate of this substrate 1) by firing is non-directional and uniformly ±α
%.

Therefore, the deviations δX and δy of the hole positions of the through holes at positions X and Y from the reference point A are: δX=α・X δy=α・Y If this is replaced with the through hole 21 as the reference, δxO
=δX−δxl=α(X−Lxl)δyo”δy−
δyi=α(Y-Lyl), and if this deviation is added to the land diameter Do and the land is expanded proportionally, it will no longer protrude.

That is, its shape is an ellipse centered on the point (X, Y) and inscribed in the rectangle Dx, Dy, Dx = Do + 2δxo = Do + 2 cx (X
-Lxl)Dy=Do+26yo=Do+2
cx (Y −Lyl ), as shown in the figure.

Here, shrinkage rate due to firing is ±1%, 100 x 100 dragon ceramic substrate 1), through hole hole diameter d = 0.5
Kinho, through hole Lxl, Lx2, Lx3 =10.50.9On+, L
yl, Ly2, Ly3 = 10.

For 50 and 90 mm, D of each through hole 21...
x and Dy have the values shown in the table below. (Unit 1
Therefore, for each through-hole 21..., a circuit pattern is designed by changing the shape of the through-hole land 31... as shown in the table above, only one type of mask is prepared, and the substrate after firing is If you align the mask with the dimension reference point A and the side 0.3 am) is obtained.

〔Effect of the invention〕

In this way, the shape of the through-hole land is expanded in proportion to the position from the dimensional reference point, and only one type of mask is created for the circuit pattern, and this mask is set at the dimensional reference point of the board. Printing work can be done just by aligning the parts, eliminating waste and increasing work efficiency, which is highly effective.

[Brief explanation of drawings]

Figure 1 is a diagram of the principle of the present invention. FIG. 2 shows an embodiment of the present invention. In the figure, 1, 1) is the board, 2, 21...29 are through holes, 3, 31...39 are through-hole lands.

Claims (1)

[Claims] A thick film hybrid integrated circuit using a ceramic substrate (1),
Through-hole (2) Through-hole land (3) for connection
), from the dimensional reference point A of the substrate (1) to the through hole (2).
A method for forming a thick film through-hole land, characterized in that the shape of the through-hole land (3) is expanded in proportion to the position of the through-hole land.